WO2019063811A1

WO2019063811A1 - Pork skin derived emulsion for use in palatability-enhancers

Info

Publication number: WO2019063811A1
Application number: PCT/EP2018/076506
Authority: WO
Inventors: Kathleen MAY; Bernard LE BRETON; Caroline LACOTTE
Original assignee: Specialites Pet Food
Priority date: 2017-09-28
Filing date: 2018-09-28
Publication date: 2019-04-04
Also published as: CN111372465A; EP3687303A1

Abstract

The present invention concerns a pet food palatability-enhancer comprising a pork skin derived emulsion having a moisture content greater than about 70%, a protein content inferior than about 15 % and a fat content ranging from 5 to 20%. The present invention also relates to a method for preparing this pet food palatability-enhancer.

Description

PORK SKIN DERIVED EMULSION FOR USE IN PALATABILITY-ENHANCERS

The present invention generally relates to the field of pet food.

More precisely, the present invention concerns a pet food palatability-enhancer comprising a pork skin derived emulsion having a moisture content greater than about 70%, a protein content inferior than about 15 % and a fat content ranging from 5 to 20%.

BACKGROUND OF THE INVENTION

Pets are well taken care of by their owners which provide them a proper selection of foods. Those foods include not only pets' usual nutritionally-balanced diet, but also supplements, treats, and toys. Pets, like humans, are attracted to and eat more regularly and easily foods which they find palatable.

Palatability-enhancers contribute to improve the stimulation of taste and/or olfactory system. To stimulate the nose and tongue sensorial sensors of cats and dogs, volatile and soluble compounds must be present in palatability-enhancers. Hence, many processes used to prepare these palatability-enhancers are based on transformation of raw materials like animal by- products for instance, via treatments such as enzymatic hydrolysis.

The enzymatic hydrolysis releases "simple" products coming from the raw material like proteins (not volatile and/or sapid). These "simple" products can further react to each other if a thermal treatment is applied (e.g. Maillard reaction). Flavour compounds are generated thereby and their nature, origin and chemical formulas bring to the final enhancers specificities. Consequently, a modification of the raw material used to produce the palatability- enhancers may directly impact the generation of final flavours.

Among the generally used animal by-products, pets are particularly attracted by liver. Beef, pork and chicken livers are the more common animal by-products used in pet foods. According to U.S Department of Agriculture nutrient databases, pork liver composition is rather different from other pork organs essentially due to its high protein content, which is a real asset for pet food palatability. Furthermore, many flavour compounds have been identified in both raw and cooked liver which reinforce its attractiveness for pets. Livers are now considered as an essential component of pet food palatability-enhancers. However, problems of supply, high costs and of exportations are often encountered with animal by-products.

Moreover, livers (as well as other edible offals) are highly perishable because of the high content of readily available nutrients for microbial growth. There is therefore a need for new raw materials which could efficiently replace, at least partially, animal by-products (such as viscera, and more particularly livers) in palatability- enhancers.

An object of the invention is thus to provide a palatability-enhancer in which animal byproducts are at least partially replaced without negatively impacting, or even increasing, palatability to pets.

DEFINITIONS

Percentages are expressed herein by weight of a product reference. However, percentages of ingredients in a palatability-enhancer are expressed by weight of the total amount of starting ingredients (or raw materials). In the present disclosure, ranges are stated in shorthand, so as to avoid having to set out at length and describe each and every value within the range. Any appropriate value within the range can be selected, where appropriate, as the upper value, lower value, or the terminus of the range. For example, a range of 0.1-1.0 (from 0.1 to 1) represents the terminal values of 0.1 and 1.0, as well as the intermediate values of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and all intermediate ranges encompassed within 0.1-1.0, such as 0.2-0.5, 0.2-0.8, 0.7-1.0, etc. Moreover, the terms "at least", "less than" or "more than" encompass the hereafter cited value. For example, "at least 5%" has to be understood as also encompassing "5%".

In the present disclosure, all of the possible ranges have not been explicitly mentioned so as to avoid having to set out at length and describe each and every value within the range. However, the ranges and ratio limits recited herein are combinable. For example, if ranges of 1-20 and 5-15 are recited for a technical feature, it is understood that ranges of 1-5, 1-15, 5-20 or 15-20 are also contemplated and encompassed thereby. This also applies on values illustrating lower and upper limits. A value illustrating a lower limit is thus combinable with a value illustrating an upper limit so as to form a ratio. For example, if a particular embodiment relates to the ratio X being superior to 2 and another particular embodiment relates to the ratio X being inferior to 5, it is understood that range of 2-5 is also contemplated and encompassed thereby.

As used throughout, the singular form of a word includes the plural, and vice versa, unless the context clearly dictates otherwise. Thus, the references "a", "an", and "the" are generally inclusive of the plurals of the respective terms. For example, reference to "a method" or "a food" includes a plurality of such "methods" or "foods". Similarly, the words "comprise", "comprises", and "comprising" are to be interpreted inclusively. Likewise the terms "include", "including" and "or" should all be construed to be inclusive. All these terms however have to be considered as encompassing exclusive embodiments that may also be referred to using words such as "consist of.

The methods and products and other embodiments exemplified here are not limited to the particular methodologies, protocols, and reagents that are described herein because, as the skilled artisan will appreciate, they may vary.

Unless defined otherwise, all technical and scientific terms, terms of art, and acronyms used herein have the meanings commonly understood by the skilled artisan in the field(s) of the invention, or in the field(s) where the term is used. Although any products, methods, or other means or materials similar or equivalent to those described herein can be used in the practice of the present invention, the preferred products, methods, or other means or materials are described herein. The term "about" as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±10%, more preferably ±5%, even more preferably ±2% from the specified value, as such variations are appropriate to reproduce the disclosed methods and products.

"Pet" refers to any domesticated animal including, without limitation, cats, dogs, rabbits, guinea pigs, ferrets, hamsters, mice, gerbils, birds, horses, cows, goats, sheep, donkeys, pigs, some fish species, and the like. In the context of the present invention, pets such as dogs and cats are preferred. However, although the present disclosure is focused on dogs and cats, the invention can be adapted for use with other classes of companion animals. If desired, the invention can be tested to evaluate its suitability for use with different classes of animals that may be considered as companion animals. As used herein, the term "food" means a product or composition that is eaten by a pet and provides at least one nutrient to the pet. The term "food" includes any food, feed, snack, food supplement, treat, toy (chewable and/or consumable toys), edible meal substitute, or edible meal replacement. Drinks and beverages of any type are encompassed within the term "food". The term "pet food" or "pet food product" means a composition intended for consumption by a pet. For instance, a "dog food" or a "dog food product" means a composition intended for consumption by a dog. As another example, a "cat food" or a "cat food product" means a composition intended for consumption by a cat.Nutritionally-balanced pet foods are widely known and used in the art. A "nutritionally-complete", "nutritionally-balanced" or "complete and nutritionally-balanced food" is one that contains all known required nutrients for the intended recipient or consumer of the food, in appropriate amounts and proportions based, for example, on recommendations of recognized or competent authorities in the field of companion animal nutrition. Such foods are therefore capable of serving as a sole source of dietary intake to maintain life, without the addition of supplemental nutritional sources. There are three main categories or classes of nutritionally-balanced pet foods depending on their moisture content, which is either low or medium or high:

- dry or low moisture-containing products (having less than about 14% moisture), such as dry kibbles;

- canned or wet or high moisture-containing products (having more than about 50% moisture), such as loaf (terrines, pates, mousses, and the like), chunk-in-"X" products (chunks in a "X" preparation, such as chunk-in-jelly products, chunk-in-gravy products, and the like;

- semi-moist or semi-dry or soft dry or soft moist or intermediate or medium moisture- containing products (having from about 14 to about 50% moisture).

Drinks and beverages are not encompassed within the terms "nutritionally-balanced pet foods".

The term "food supplement" or "dietary supplement" or "supplement" means a product that is intended to be eaten in addition to the normal animal diet. Drinks and beverages are encompassed. Dietary supplements may be in any edible form, e.g., solid, liquid, gel, paste, tablets, capsules, powder, and the like. Palatability-enhancers can be used to improve palatability of dietary supplements in the same manner as they are used to improve palatability of nutritionally-balanced foods.

The term "treat" (or "biscuit") means any food item that is designed to be fed to a pet, preferably at non-meal time, by the owner to help, promote or sustain a bonding process between a pet and its owner. Treats often contain palatability-enhancers in a manner comparable to nutritionally-balanced foods.

"Toys" include, for example chewable toys. Toys further include partially consumable toys (e.g., comprising plastic components) or fully consumable toys (e.g., rawhides).

As used herein, the term "palatability" refers to the overall willingness of a pet to eat a certain pet food. Whenever a pet shows a preference, for example, for one of two or more pet foods, the preferred pet food is more "palatable", and has "enhanced palatability". Such preference can arise from any of the pet's senses, but typically is related to, inter alia, taste, aroma, flavour, texture, smell and/or mouth feel.

Different methods exist to assess palatability. Examples of such methods involve exposure of pets to pet foods either simultaneously (for example, in side-by-side, free-choice comparisons, e.g., by measuring relative consumption of at least two different pet foods in a so- called "two-bowl" test), or sequentially (e.g., using single bowl testing methodologies). Advantageously, at least two different methods may be used to consolidate the thus obtained results on palatability of a given pet food. Advantageously, expert panels of pets are used in order to guarantee repeatable and fine measurement of palatability performance for pet food products.

A pet food that is stated herein to have "enhanced palatability" is one for which a pet exhibits preference relative to a control composition.

The term "pork skin derived emulsion" or "pork skin derived oil-in-water emulsion" refers to an oil-in-water emulsion as described hereafter, which originates from pork skin. The pork skin is typically the one used for gelatine production process, and it can sometimes include pork bones, but preferably not. This emulsion possesses the technical features described hereafter. The terms "pork skin derived emulsion" and "pork skin derived oil-in-water emulsion" as used hereafter are equivalent, both refer to a "pork skin derived oil-in-water emulsion". As well known by the skilled person, an oil-in- water emulsion is an emulsion where oil (or fats or the fatty phase) is the dispersed phase and water (or aqueous phase) is the dispersion medium.

The term "animal-by-product" is clear for the skilled artisan. Typically, animal-by- products can be selected from as lungs, spleen, kidneys, brain, livers, blood, bone, stomachs and intestines (freed of their contents), excluding skin.

The term "animal digest" means herein material which results from chemical and/or enzymatic hydrolysis of clean, undecomposed animal tissue. In some embodiments, an animal digest as used herein is fully consistent with the definition promulgated by the Association Of American Feed Control Officials, Inc. (AAFCO). Animal digest is preferably derived from animal meat or from animal meat by-products, such as lungs, spleen, kidneys, brain, livers, blood, bone, stomachs and intestines (freed of their contents). An animal digest may be dried or not. Typical examples of animal digests are digests from poultry, pork, beef, sheep, lamb, fish, etc. The term "yeast" herein refers to any yeast, preferably inactive, as well as to yeast byproducts that are compatible with compositions for animal consumption. Yeasts are well known in the art as being protein-rich. Yeasts include, without limitation, brewer's yeast, baker's yeast, torula yeast, molasses yeast, and the like. Yeast by-products include, without limitation, yeast extracts, yeast hydrolysates, cream yeasts, etc. Sugars include monosaccharides, disaccharides or oligosaccharides (including hydrolysis products of disaccharides and/or of oligosaccharides), and more particularly reducing sugars that can provide a free or available carbonyl group. These reducing sugars can take part in Maillard reaction with amino acids. Examples of reducing sugars include xylose, arabinose, ribose, glucose, fructose, mannose, galactose, rhamnose, lactose, maltose, raffinose. The term "amino acid" means a molecule containing both an amino group and a carboxyl group. In some embodiments, the amino acids are α-, β-, γ- or δ-amino acids, including their stereoisomers and racemates. Amino acids can be free amino acids, i.e. exogenous (or extrinsic) amino acids that are individually provided as unbound ingredients in a composition.

As used herein, a "pet food ingredient" is any compound, composition or material that is suitable for pet consumption and that is comprised into a pet food. Non-limiting examples of pet food ingredients are palatability-enhancers, proteins, peptides, amino acids, grains, carbohydrates, fats or lipids, flavours, additives etc.

The terms "palatability enhancers" (PEs), "palatants", "palatability agents", "appetizing factors", "appetizing agents", "palatability-enhancing compositions (PECs)", "palatability- enhancer ingredient", and any other similar terms mean any material that enhances palatability of a food product to an animal. A PE may be a single material or a blend of materials, and it may be natural, processed or unprocessed, synthetic, or part of natural and part of synthetic materials. Typically, a PE for animal food is a liquid or dry edible composition that provides a taste, aftertaste, smell, mouth feel, texture, and/or organoleptic sensation that is pleasant to the target animal. For pets, a PE may contribute to attractiveness (also called "initial food appeal") by its smell and/or to continued consumption by its smell but also by its taste and/or its aftertaste, and/or its mouth feel, and/or its texture. "Attractiveness" is an aspect of palatability that induces an animal to initially taste or try a food product, and that can be measured by the criteria "first choice" or "first food consumed". "Continued consumption" is an aspect of palatability that induces an animal to continue consuming a food product that has been initially only tasted or tried.

As used herein, "palatability enhancers" (PEs), "palatants", "palatability agents", "appetizing factors", "appetizing agents", "palatability-enhancing compositions (PECs)", "palatability-enhancer ingredient", and any other similar terms is any compound, composition or material that is suitable for pet consumption. Non-limiting examples of palatability-enhancer ingredients are inorganic phosphate compounds, animal digests, water, fats, vegetable hydrolysates, vitamins, amino acids (in particular free amino acids), yeasts, sugars, and/or carbohydrates, carriers, additives, flavors, etc. Ingredients may be comprised as such in the palatability-enhancer, or they can be contacted into the composition and react in situ for producing transformed materials that are also encompassed by the term "palatability-enhancer". Examples of ingredients that react together in the composition are, without limitation, fats, peptides, amino acids, and carbohydrates, so as to obtain transformed materials such as Maillard reaction products, and the like.

"Proteins" include all conventional protein sources that are compatible for animal consumption, especially plant or vegetable proteins, animal proteins (such as casein or albumin or animal digests), and microbial proteins (e.g., yeasts).

Examples of carbohydrates include polysaccharides, fibers, starches, and the like. Examples of grains are corn, milo, alfalfa, wheat, barley, rice, soy, and the like.

Examples of fats include tallow, oils, from any origin such as animal, plant (including vegetable), or marine oils. Plant oils which are available in large quantities are typically canola oil, soybean oil, corn oil, olive oil, sunflower oil, linseed oil, palm oil, safflower oil, and the like, as well as by-products thereof. Typical animal fats are tallow, lard, poultry fat, and the like, as well as by-products thereof. Marine oils are typically tuna oil, sardine oil, salmon oil, anchovy oil, fish oil, and the like, as well as by-products thereof. Also are encompassed herein the fats that are derived from animal, plant, marine sources, or that are produced by animals and plants. Additives include, without limitation, nutrients, anti-oxidants, preservatives, surfactants, texturing agents, colouring agents.

The term "carrier" refers to a "carrier for drying", encompassing conventional compounds that are well-known in the art to perform a drying step in a given method. Examples of "carriers for drying" are microbial proteins (e.g., yeasts), maltodextrin or cyclodextrin. The term "processed" means that the product of reference has been either hydrolyzed or cooked.

The term "cooked" means that the product of reference has been cooked through a thermal treatment, without any hydrolysis.

The term "hydrolysis" or "hydrolyzed" means that the product of reference has been enzymatically hydrolyzed, for example by a protease or by a lipase. Typically, an hydrolysis comprises a step of contacting the product with an enzyme in an appropriate amount, allowing said enzyme to hydrolyze said product for a suitable period of time, and then a step of thermally treating the thus obtained product to inactivate said enzyme. Hydrolysis also includes autolysis, with or without thermal treatment. The term "proteolysis" or "proteolyzed" means that the product of reference has been enzymatically hydrolyzed by a protease.

The term "protease" means any proteolytic enzyme that catalyzes the cleavage of internal bonds in a peptide or a protein. A protease can be acidic, alkaline or neutral depending on the pH which provides an optimal hydro lyzing activity. Typically, an acidic protease is active at a pH inferior to about 6; a neutral protease is active at a pH from about 6 to 8; and an alkaline protease is active at a pH greater than 8.

The term "lipolysis" or "lipolyzed" means that the product of reference has been enzymatically hydrolyzed by a lipase. The term "lipase" means any lipolytic enzyme that breaks down fats into fatty acids and glycerol.

"Coating", as used herein, refers to the topical deposition of the palatability-enhancer onto the surface of the food composition, such as by spraying, dusting, and the like.

"Inclusion" as used herein, refers to the addition of the palatability-enhancer internally to the food composition, by mixing it with other pet food ingredients, before further steps for obtaining the final pet food product (including thermal treatment and/or extrusion and/or retorting, etc.).

The term "single package" means that the components of a kit are physically associated in or with one or more containers and considered a unit for manufacture, distribution, sale, or use. Containers include, but are not limited to, bags, boxes, cartons, bottles, packages of any type or design or material, over-wrap, shrink-wrap, stapled or otherwise affixed components, or combinations thereof. A single package may be containers of individual components physically associated such that they are considered a unit for manufacture, distribution, sale, or use. As used herein, "means for communicating information or instructions" is a kit component under any form suitable for providing information, instructions, recommendations, and/or warranties, etc. Such a means can comprise a document, digital storage media, optical storage media, audio presentation, visual display containing information. The means of communication can be a displayed web site, brochure, product label, package insert, advertisement, visual display, etc.

DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

Palatability-enhancers for pets commonly comprise animal digests, such as liver hydro lysates. The present inventors surprisingly observed that compositions comprising a specific pork skin derived emulsion efficiently enhance palatability of foods to pets. The use of an emulsion according to the invention advantageously enhances palatability of foods to pets, in particular compared to foods which do not comprise it. This can substitute (at least partially) for animal materials, such as digests, in particular liver hydrolysates, without negatively impacting palatability of foods to pets. Pet food palatability-enhancer

The present invention thus concerns a pet food palatability-enhancer comprising a pork skin derived emulsion having a moisture content greater than about 70%, a protein content inferior than about 15 % and a fat content ranging from 5 to 20%.

The pork skin derived emulsion according to the invention is a liquid oil-in-water emulsion. When the terms "pork skin derived emulsion" are used hereafter without any other indication, it is intended to refer to this liquid pork skin derived emulsion. This particular emulsion has a higher fat content than some animal by-products, such as pork liver. Thus, the use of this pork skin derived emulsion in palatability-enhancers can increase their final fat content compared to the use of some animal digests. The moisture content of the pork skin derived emulsion can range from 70 to 90%, preferably from 70% to 85%, more preferably from 70% to 80% by weight. Pork skin derived emulsions having these moisture content can be more easily transformed (for example processed and/or dried) than those having higher moisture content.

The protein content of the pork skin derived emulsion can range from 5 to 15%, preferably from 5% to 10% by weight.

The fat content of the pork skin derived emulsion ranges from 5% to 20%, preferably from 5% to 15%, more preferably from 7% to 12% by weight.

Advantageously, the pork skin derived emulsion according to the invention has a ratio of protein/fats comprised from 0.4 to 1.2, more preferably from 0.5 to 1.0. The palatability-enhancer can comprise from 0.1% to 100% of the pork skin derived emulsion.

In a particular embodiment, the palatability-enhancer consists of the pork skin derived emulsion. Indeed, it has been demonstrated that palatability of foods to pets can be increased when foods comprise a pork skin derived emulsion according to the invention. In another particular embodiment, the palatability-enhancer comprises more than 0.1%, or more than 0.5%, or more than 1.0%, or more than 1.5%, or more than 2.0% of the pork skin derived emulsion. The palatability-enhancer can comprise less than 97%, or less than 95%, or less than 90%, or less than 80%, or less than 70%, or less than 60% or less than 50%, or less than 40%, or less than 30%, or less than 20%, or less than 10% of the pork skin derived emulsion. In a typical embodiment, the palatability-enhancer comprises 4 to 10 % of the pork skin derived emulsion.

In a particular embodiment, the fat content of the palatability-enhancer is inferior to 50%, more preferably inferior to 45%, more preferably inferior to 40%, more preferably from 1% to 45%, more preferably from 2% to 45%. For this particular embodiment, the palatability- enhancer preferably comprises less than 15%, or less than 12%, or less than 10% of the pork skin derived emulsion, in order to keep a relatively low fat content. The palatability-enhancer can typically comprise more than 1% of the pork skin derived emulsion, or more than 2% of the pork skin derived emulsion of the pork skin derived emulsion. It has been demonstrated that these percentages of addition provide palatability-enhancers highly appreciated by pets.

The pet food palatability-enhancer can also comprise at least one additional ingredient, such as at least one palatability-enhancer ingredient as above defined. Preferably, said at least one palatability-enhancer ingredient further enhances palatability and is for example selected from amino acids, sugars, vitamins, inorganic phosphate salts, animal digests, fats, vegetable hydro lysates, yeasts and combinations thereof.

In a particular embodiment, the pet food palatability-enhancer comprises less than 97%, or less than 95%, or less than 90%, or less than 80%, or less than 70%, or less than 60%, or less than 50% of additional animal material different from the pork skin derived emulsion. For example, the pet food palatability-enhancer comprises from 5% to 50% of animal digests, such as liver hydrolysate.

In an advantageous particular embodiment, the pork skin derived emulsion of the invention has a specific amino acid composition, typically different from the one of gelatin and/or pork livers. Preferably, the pork skin derived emulsion comprises from 5% to 20% of total amino acids, more preferably from 5% to 15%, more preferably from 5% to 10% (% based on total weight of pork skin derived emulsion). In some embodiments, the pork skin derived emulsion comprises more than 5% of glycine, preferably more than 6%, preferably more than less than 7%, preferably more than less than 8%, preferably more than less than 9%, preferably more than 10% of glycine (% based on weight of total amino acids). The pork skin derived emulsion typically comprises less than 15% of glycine (% based on weight of total amino acids).

In some embodiments, the pork skin derived emulsion comprises less than 9%, preferably from 2% to 8%, more preferably from 2% to 6% of hydroxyproline (% based on weight of total amino acids).

In some embodiments, the pork skin derived emulsion comprises less than 9%, preferably from 2% to 8%, more preferably from 3% to 8% of alanine (% based on weight of total amino acids).

In some embodiments, the pork skin derived emulsion comprises more than 10%, preferably from 10% to 16%, more preferably from 11% to 15% of glutamic acid (% based on weight of total amino acids). In some embodiments, the pork skin derived emulsion comprises more than 1%, preferably from 1% to 5%, more preferably from 2% to 5% of tyrosine (% based on weight of total amino acids).

A pork skin derived emulsion according to the invention has typically an acid pH. In a particular embodiment, the pork skin derived emulsion has a pH ranging from 3 to 6, preferably from 4 to 6.

Another aspect of the present invention concerns products obtained from the pork skin derived emulsion. In particular, the pork skin derived emulsion can be processed and/or dried.

For example, the pork skin derived emulsion is processed through a thermal treatment, thus providing a cooked pork skin derived emulsion. In another example, the pork skin derived emulsion is processed through hydrolysis, thus providing an hydrolyzed pork skin derived emulsion. For example, if the enzyme used is a lipase, the product obtained is a lipolyzed pork skin derived emulsion. Yet for example, if the enzyme used is a protease, the product obtained is a proteolyzed pork skin derived emulsion. In a particular embodiment, the pork skin derived emulsion, the cooked pork skin derived emulsion or the hydrolyzed pork skin derived emulsion is dried, for example when the pet food palatability-enhancer to be obtained is a dry palatability-enhancer.

Method for preparing a pet food palatability-enhancer

Another aspect of the present invention concerns a method for preparing a pet food palatability-enhancer comprising:

a) providing a pork skin derived emulsion as above described;

b) optionally, adding at least one additional ingredient as described herein;

c) obtaining said pet food palatability-enhancer. The pork skin derived oil-in-water emulsion can be prepared by any appropriate method known by the skilled person (before step a). In a particular embodiment, the pork skin derived emulsion is a co-product obtained during a standard process of preparation of pork gelatin. Preferably, the pork skin derived emulsion is prepared by a method comprising at least the steps of: i) providing pork skin,

ii) separating the solid phase and the fatty aqueous phase of said pork skin of step i), thereby recovering a fatty aqueous phase,

iii) at least partially removing fats from the thus obtained fatty aqueous phase, thereby obtaining a mixture,

iv) concentrating the thus obtained mixture so as to obtain the pork skin derived emulsion.

In a particular embodiment, the pork skin used in step i) is an acid pork skin obtained from a standard gelatin production process. Typically, a standard gelatin production process provides Type A gelatin. Step ii) of separating the solid phase and the fatty aqueous phase of pork skin can be conducted by decantation, centrifugation or any other well-known method for separating two physical phases, and more particularly here a solid phase and a liquid phase. Typically, step ii) is performed by decantation.

Intermediate steps can be performed after step ii) and before step iii), for example steps of clarification and/or acidification and/or thermal treatment. Step iii) of at least partially removing fats from the thus obtained fatty aqueous phase can also be conducted by decantation, centrifugation or any other well-known method for separating two physical phases, and more particularly here two liquid phases. Typically, step iii) is performed by centrifugation. Step iv) of concentrating the thus obtained mixture can be conducted by filtration or any other well-known method. When filtration is used, the retentate obtained forms the pork derived emulsion of interest in the context of the invention.

The product obtained after having performed steps i) to iv) is a pork skin derived oil-in- water emulsion as above described. This pork skin derived emulsion can be further transformed and the method according to the present invention can thus comprise one or more additional step after step iv) above. Depending on the desired product (in particular dry or liquid, processed or not), the person skilled in the art will be able to select, adapt if need be, and sequence appropriate steps, given that some steps may be performed concomitantly according to usual practice in the art. For example, the method for preparing a pet food palatability-enhancer can comprise one or more steps of processing the pork skin derived emulsion of the invention. In an example, the method for preparing a pet food palatability-enhancer comprises one step of processing the pork skin derived emulsion of the invention. In another example, the method for preparing a pet food palatability-enhancer comprises two steps of processing the pork skin derived emulsion of the invention. In an example, the method for preparing a pet food palatability- enhancer comprises three steps of processing the pork skin derived emulsion of the invention. Steps of processing can be performed simultaneously or sequentially. If more than one step of processing is performed, processing steps can be the same or they can be different from one to another. In particular, one processing step can be a cooking step, another one an hydrolysis step, and reciprocally. The method for preparing a pet food palatability-enhancer can thus comprise one hydrolysis, such as a proteolysis or a lipolysis, or one thermal treatment, or it can comprise at least two hydrolysis (at least two proteolysis, or at least two lipolysis, or at least one proteolysis and one lipolysis) or at least one hydrolysis and at least one thermal treatment, or at least two thermal treatments. Typical processing can be performed at a temperature ranging from 30°C to 300°C and for a period ranging from 10 sec to 48 hours. In some embodiments, processing is performed at a temperature ranging from about 30°C to about 200°C for a period of time ranging from about 10 sec to about 10 hours. More particularly, said temperature can range from about 30°C to about 180°C, preferably from about 30°C to about 160°C, yet preferably from about 30°C to about 150°C, yet preferably from about 35°C to 150°C. More particularly, said period of time can range from about 15 sec to about 8 hours, preferably from about 1 min to about 6 hours, yet preferably from about 10 min to about 6 hours, even yet preferably from about 15 min to about 5 hours.

In a first embodiment, the method according to the invention comprises at least one step of proteolysis. The product obtained is thus a proteolyzed pork skin derived emulsion. Proteolysis is typically performed with at least one protease. The skilled person will be able to select the protease according to the desired proteolyzed pork skin derived emulsion to be obtained. For example, a protease can be an exopeptidase or an endopeptidase. A protease can be an alkaline or acid or neutral protease.

Said step of proteolysis is preferably performed at a temperature which is the optimal temperature value or within the optimal temperature range according to the enzyme manufacturer's recommendations. This belongs to the normal skills in the art. Typically, the temperature is from about 45 to about 80°C, preferably from about 50 to about 75°C, yet preferably from about 50 to about 70°C. Said step of proteolysis is typically performed during a period of time from about 0.25 to about 5.0 hours, preferably from about 0.5 to about 3.0 hours. The period of time taken into account typically starts from the addition of enzyme and ends when the temperature of inactivation of said enzyme is reached.

In a second embodiment, the method according to the invention comprises at least one step of lipolysis. The product obtained is thus a lipolyzed pork skin derived emulsion. Lipolysis is typically performed with at least one lipase. The skilled person will be able to select the lipase according to the desired lipolyzed pork skin derived emulsion to be obtained.

Said step of lipolysis is preferably performed at a temperature which is the optimal temperature value or within the optimal temperature range according to the enzyme manufacturer's recommendations. This belongs to the normal skills in the art. Typically, the temperature is from about 30 to 75°C, preferably from about 30 to about 75°C, yet preferably from about 30 to about 65°C, yet preferably from about 35 to about 60°C. Said step of lipolysis is typically performed during a period of time from about 1.0 to about 8.0 hours, preferably from about 2.0 to about 6.0 hours. The period of time taken into account typically starts from the addition of enzyme and ends when the temperature of inactivation of said enzyme is reached.

For these first and second embodiments of hydrolysis, a further step of inactivation of the (at least one) enzyme can be performed, typically by thermally treating it, preferably at a temperature from about 80 to about 140°C, during a period of time from about 5 to about 120 minutes.

In a third embodiment, the method according to the invention comprises at least one step of thermal treatment. In other terms, this third embodiment does not make use of hydrolysis. The product obtained is thus a cooked pork skin derived emulsion.

Said step of thermal treatment is typically performed at a temperature from about 45 to 130°C, preferably from 50 to 130°C, more preferably from 50 to 110°C during a period of time from about 0.25 to about 5.0 hours, preferably from about 0.25 to about 3.0 hours.

The method according to the present invention can comprise one or more steps of adjusting the pH of the pork skin derived emulsion. The pH can in particular be adjusted when a step of hydrolysis is performed, as above mentioned. Said adjusted pH value will thus typically depends on the enzyme (for example protease or lipase or both) used in the method of the invention. It is chosen in order to favor, or even optimize, the hydrolyzing activity of the enzyme. Preferably, said step of adjusting the pH of the pork skin derived emulsion is performed so as to adjust the pH to a pH value which is the optimal pH value or pH range according to the enzyme manufacturer's recommendations. That will be readily apparent to those skilled in the art. The pH can be adjusted by any appropriate compound that is acceptable for use in pet food, such as phosphoric acid, caustic soda, other conventional and appropriate acidity or basicity regulators, and combinations thereof. Advantageously, the method according to the present invention comprises the step b) of adding at least one additional ingredient, preferably at least one palatability-enhancer ingredient as above defined, for example at least one palatability-enhancer ingredient that further enhances palatability, such as one selected from amino acids, sugars, vitamins, inorganic phosphate salts, animal digests, fats, vegetable hydrolysates, yeasts and combinations thereof.

For example, at least one additional ingredient can be added before, during and/or after a step of processing, as mentioned above. The method according to the present invention can comprise one or more steps of drying.

For example, an additional step of drying the pork skin emulsion of step a) (optionally processed) can be performed. The product obtained is thus a dry pork skin derived emulsion. Drying step is routine for the skilled artisan. In particular, the resulting water content is less than or equal to about 10%, preferably from about 2 to about 8%, by weight of the pork skin derived emulsion. For example, a dry pork skin derived emulsion is obtained by combining the pork skin derived emulsion (processed or not) with carriers as defined above in appropriate proportions, and by blending the components. The mixture is then dried, for example by roller drying or by spray drying, preferably by roller drying.

An additional step of drying the palatability-enhancer of step c) can also be performed. As previously mentioned, drying step is routine for the skilled artisan. In particular, the resulting water content of the palatability-enhancer is less than or equal to about 15%, preferably about 10%, yet preferably from about 1 to about 8%, by weight of the thus obtained dry product. The skilled person will be able to select the operational conditions to apply in the method of preparation according to the invention depending on the final desired product.

In a first particular embodiment, the palatability-enhancer comprises a pork skin derived emulsion, optionally mixed with at least one additional ingredient. The method for preparing a pet food palatability-enhancer can thus comprise the following steps:

1) providing a pork skin derived emulsion as above described,

2) optionally, drying said pork skin derived emulsion;

3) obtaining said pet food palatability-enhancer.

For this first particular embodiment, one or more steps of adding at least one additional ingredient can be performed, for example during or after step 1) or 2). Alternatively, the palatability-enhancer consists of the pork skin derived emulsion and the method for preparing a pet food palatability-enhancer thus consists of steps 1 to 3).

In a second particular embodiment, the palatability-enhancer comprises a cooked pork skin derived emulsion, optionally mixed with at least one additional ingredient. The method for preparing a pet food palatability-enhancer can thus comprise the following steps:

1) providing a pork skin derived emulsion as above described, 2) thermally treating the pork skin derived emulsion;

3) optionally, drying the thus obtained cooked pork skin derived emulsion;

4) obtaining said pet food palatability-enhancer.

For this second particular embodiment, one or more steps of adding at least one additional ingredient can be performed, for example during or after step 1), 2) or 3). Alternatively, the palatability-enhancer consists of the cooked pork skin derived emulsion and the method for preparing a pet food palatability-enhancer thus consists of steps 1 to 4).

In a third particular embodiment, the palatability-enhancer comprises a hydrolyzed pork skin derived emulsion, optionally mixed with at least one additional ingredient. The method for preparing a pet food palatability-enhancer can thus comprise the following steps:

1) providing a pork skin derived emulsion as above described,

2) optionally adjusting the pH;

3) hydrolyzing the pork skin derived emulsion and if any, the at least one additional ingredient;

4) optionally, drying the thus obtained hydrolyzed pork skin derived emulsion;

5) obtaining said pet food palatability-enhancer.

Preferably, step 3) is performed and the pH value is adjusted from 3 to 9, more preferably from 4 to 8.5.

For this third particular embodiment, one or more steps of adding at least one additional ingredient can be performed, for example during or after step 1), 2), 3) or 4). Alternatively, the palatability-enhancer consists of the hydrolyzed pork skin derived emulsion and the method for preparing a pet food palatability-enhancer thus consists of steps 1 to 5).

The method for preparing a pet food palatability-enhancer can also combine these particular embodiments. For example, more than one step of processing can be performed and the second and the third embodiments can thus be combined.

For all of these particular embodiments, additional ingredient is preferably a palatability-enhancer ingredient, and even more preferably a palatability-enhancer ingredient that further enhances palatability, such as Maillard ingredients, including amino acids and/or reducing sugars. An object of the present invention relates to a pet food palatability-enhancer obtained by one of the method as above described.

Pet food comprising the pet food palatability-enhancer

Another aspect of the invention consists of a pet food comprising the pet food palatability-enhancer as above described.

In all aspects of the present invention, said pet food is preferably a nutritionally complete food. The pet food can be a dry pet food, a semi-moist pet food or a wet pet food. In particular, said pet food can be in the form of dry kibbles, chunk-in-"X" products, and loafs. In a particular embodiment, the pet food is a dry pet food, in particular a dry kibble. Preferably for this particular embodiment, the pet food palatability-enhancer is coated on the dry pet food. In another particular embodiment, the pet food is a wet pet food, in particular a chunk-in-"X" product or loaf.

In an embodiment, the palatability-enhancer as above described is coated on the pet food. In another embodiment, the palatability-enhancer as above described is included in the pet food.

In an embodiment, the pet food is a cat food. In another embodiment, the pet food is a dog food.

The pet food can comprise pet food ingredients such as other palatability-enhancers, animal digests, proteins, peptides, amino acids, grains, carbohydrates, fats or lipids, flavours, additives. The food balance, including the relative proportions of vitamins, minerals, lipids, proteins and carbohydrates, is determined according to the known dietary standards in the veterinary field, for example by following recommendations of the National Research council (NRC), or the guidelines of the American Association of Feed Control Officials (AAFCO).

Preferably, said pet food comprises at least 0.5 %, at least 1%, at least 2%, at least 3%, at least 4%, at least 5% by weight of said palatability-enhancer, based on the total weight of said pet food.

Said pet food can comprise from 0.5% to 50%, preferably from 0.5% to 40%, more preferably from 0.5% to 30%, more preferably from 0.5% to 20%, more preferably from 0.5% to 10%, more preferably from 0.5% to 7.5%, more preferably from 0.5 to 5%, more preferably from 0.5% to 4%, more preferably from 0.5% to 3%, more preferably from 0.5% to 2%, more preferably from 0.5% to 1% of said pet food palatability-enhancer (% based on the total weight of said pet food).

Said pet food can comprise from 0.0005% to 50%, preferably from 0.001% to 40%, more preferably from 0.005% to 30%, more preferably from 0.01% to 20%, more preferably from 0.02% to 10%, more preferably from 0.02% to 7.5%, more preferably from 0.023% to 6% of said pork skin derived oil-in-water emulsion (% based on the total weight of said pet food).

Method for producing a pet food having enhanced palatability

Another aspect of the present invention concerns a method for producing a pet food having enhanced palatability comprising:

a) adding to a pet food a pet food palatability-enhancer as above described; and, b) obtaining a pet food having enhanced palatability.

Dry pet food, such as dry kibbles, wet pet foods and semi-moist pet foods can commonly be prepared by different methods known by the skilled person.

Step a) can be performed by adding the palatability-enhancer to a pet food either by coating or by inclusion. In an embodiment, step a) is performed by adding the palatability- enhancer to a pet food by coating. In another embodiment, step a) is performed by adding the palatability-enhancer to a pet food by inclusion.

In a particular embodiment, the pet food is a dry pet food, such as a dry kibble, and the pet food palatability-enhancer is added by coating. For example, uncoated kibbles can be placed in a container such a tub or a coating drum for mixing. The palatability-enhancer may then be applied, as either a liquid or a powder. A fat can be previously sprayed onto dry kibbles. Alternatively, a fat and the palatability-enhancer can be mixed and applied concurrently.

Alternatively, the palatability-enhancer can be incorporated or included into a dry pet food according to the following illustrative method. The palatability-enhancer is typically contacted with the raw ingredients of the pet food preparation prior to processing. For example, the palatability-enhancer is combined to proteins, fibers, carbohydrates and/or starch, etc., of the pet food preparation and is processed with those materials in the cooker-extruder.

Inclusion into moist pet foods can be achieved as follows. The palatability-enhancer can be applied in a gravy- or jelly-type matrix during the blending process in addition to the other pet food ingredients. The palatability-enhancer can also be applied into a meat-by mixtures for chunks or loaf preparation. In this case, it can be added to raw materials before or after the grinding process. The meat-by mixture may be cooked in a steam or grilling oven in the case of chunks manufacturing, or directly sealed in cans in the case of loaf manufacturing.

Method and uses for enhancing the palatability of a pet food

Yet another aspect of the present invention is related to a method for enhancing the palatability of a pet food, wherein said method comprises:

a) adding to a pet food, a palatability-enhancer as above described; and

b) obtaining a pet food having enhanced palatability.

Yet another aspect of the present invention is related to a method for increasing pet food intake of a pet, wherein said method comprises:

a) adding to a pet food, a palatability-enhancer as above described;

b) obtaining a pet food having enhanced palatability; and

c) feeding said pet food having enhanced palatability to a pet thereby increasing its pet food intake.

The above-mentioned technical features recited for the method for producing a pet food having enhanced palatability can also apply to the method for enhancing the palatability of a pet food or the method for increasing pet food intake of a pet.

Yet another aspect of the present invention is related to the use of a pork skin derived emulsion as above described for enhancing the palatability of a pet food.

It is also referred herein to the use of a pork skin derived emulsion as above described for increasing pet food intake of a pet.

The present invention also relates to the use of a pork skin derived emulsion as above described as a palatability-enhancer.

The present invention also relates to the use of a pork skin derived emulsion as above described as a pet food palatability-enhancer ingredient.

Indeed, it has been observed for the first time that pets are particularly attracted by foods comprising a pork skin derived emulsion or a palatability-enhancer according to the invention to pets, in particular compared to another pet food which does not comprise a composition according to the invention. Moreover, the pet food intake is at least equivalent to the pet food intake comprising animal digests instead of the emulsion according to the invention.

Method for feeding pets

Another aspect of the present invention concerns a method for feeding a pet comprising at least:

a) providing a pet food having enhanced palatability as above described; and

b) feeding said pet food to the pet.

Kit for enhancing palatability of a pet food

Another aspect of the present invention concerns a kit for enhancing palatability of a pet food comprising at least the following components, in one or more containers in a single package:

a) at least one palatability-enhancer as above described; and

b) optionally, at least one pet food ingredient.

Particular kits according to the present invention further comprise a means for communicating information or instructions, to help using the kits' elements.

EXAMPLES

1. MATERIAL AND METHODS

1.1. Preparation of pork skin derived emulsion

Pork skins marcs were extracted from the production process of Type A gelatin. A step of decantation was performed in order to separate the solid phase (wet cracklings) and a fatty aqueous phase (water phase comprising fats). The fatty aqueous phase was clarified and the thus obtained fatty phase was further acidified at a pH of about 3 and heated at a temperature of about 100°C for an appropriate period of time. A step of centrifugation was then performed in order to separate fats and a liquid fatty gelatinous phase. This latter phase was concentrated by using micro-filtration, so as to provide the pork skin derived emulsion.

1.2. Preparation of dry pork skin derived emulsion

A pork skin derived emulsion was prepared as described in paragraph 1.1.

This pork skin derived emulsion was then dried by roller-drying with drying carriers. The dry pork skin derived emulsion thus obtained comprises 45% of pork skin derived emulsion, and 55% of carrier. 1.3. Preparation of proteolyzed pork skin derived emulsion

A pork skin derived emulsion was prepared as described in paragraph 1.1.

A proteolyzed pork skin derived emulsion was then prepared as follows: a step of proteolysis was performed by adding an protease into the mixture and hydrolyzing during about 2 hours at about 60°C, followed by a step of enzyme inactivation.

1.4. Preparation of lipolyzed pork skin derived emulsion

A pork skin derived emulsion was prepared as described in paragraph 1.1.

A lipolyzed pork skin derived emulsion LI was also prepared as follows: a step of lipolysis was performed by adding a lipase into the mixture and hydrolyzing at about 50°C during about 3 hours, followed by a step of lipase inactivation.

A lipolyzed pork skin derived emulsion L2 was then prepared as follows: A step of lipolysis was performed by adding a lipase into the mixture and hydrolyzing at about 50°C during about 3 hours. Amino acids and reducing sugars (both being Maillard ingredients) were then added to the pork skin derived emulsion and a step of lipase inactivation was performed.

l.S.Preparation of pet food comprising palatability-enhancer

Control and experimental diets were prepared by using nutritionally-complete foods that contained all known required nutrients for the animal, in appropriate amounts and proportions based, for example, on recommendations of recognized or competent authorities in the field of companion animal nutrition.

Palatability-enhancers were prepared by using pork skin derived emulsion as prepared in paragraph 1.1, 1.2, 1.3. or 1.4, optionally in mixture with liquid and/or dry ingredients.

1.5.1. Preparation of kibbles (dry pet food)

When the pet food to be tested was kibbles (dry pet food), the palatability-enhancer was applied topically on the kibbles (i.e., by coating).

1.5.2. Preparation of loaf (wet pet food)

When the pet food to be tested was a loaf (wet pet food), the palatability-enhancer was incorporated with other meat tissues and ingredients (i.e., by inclusion), before sterilization.

1.6. Determination of palatability with a two-bowl test

1.6.1. Principle of the two-bowl test: The test is based on the postulate whereby the more food consumed, the more palatable it is. Individual versus (Two bowls) appetence tests, based on the comparison between two foods, were carried out. Tests are performed either on panel of 36 dogs or on panel of 40 cats, depending on the test's objectives.

1.6.2. Operating method of the test:

- Identical amounts of food product A and food product B were weighed out and placed in identical bowls. The amount present in each ration enables the daily requirements to be met.

- Distribution of the bowls:

Dog test: the bowls were placed in an individual feed trough accessible to dogs.

Cat test: The bowls were presented at the same time to each cat in an individual loose box and their positions were switched at each meal to avoid a choice led by handedness.

- Duration of the test:

* Cat test for dry food: from about 15 minutes to about 20 hours (if one of the two bowls was entirely eaten before the end of the test, the two bowls were removed, and the test was stopped);

* Dog test for dry food: from about 15 minutes to about 30 minutes (if one of the two bowls was entirely eaten before the end of the test, the two bowls were removed, and the test was stopped).

- Calculated parameters:

Individual consumption ratio in % (CR)

CRA = consumption of A (g) x 100/(consumption of A+B) (g)

CRB = consumption of B (g) x 100/(consumption of A+B) (g)

Average consumption ratio (ACR) = average of all individual ratios (an equal importance is given to each animal, regardless of its size and of its corresponding consumption).

If animals have higher or lower consumption compared to predetermined values (which are function of, e.g., the animal weight and/or metabolism), they are not taken into account into statistical treatment.

Statistical analysis: Statistical analysis was used to determine if there was a significant difference between the 2 ratios. A Student's t-test with 3 error thresholds, namely 5%, 1% and 0.1%, was performed.

A Chi-square test was used to determine if there was a significant difference between the number of pets with Food A as first food eaten and the number of pets with Food B as first food eaten.

Significance levels are noted as below:

NS not significant (p > 0.05)

* significant (p < 0.05)

** highly significant (p < 0.01)

*** very highly significant (p < 0.001)

2. RESULTS

2.1.Characterization of pork skin derived emulsion according to the invention

Different products were analyzed: a liquid pork skin derived emulsion prepared according to paragraph 1.1, a dry pork skin derived emulsion prepared according to paragraph 1.2., a proteolyzed pork skin derived emulsion prepared according to paragraph 1.3., and lipolyzed LI and L2 pork skin derived emulsions prepared according to paragraph 1.4.

In comparison, analyses of a pork liver and Type A pork gelatin were done.

Table 1 - Characterization of different products

As shown in Table 1, a pork skin derived emulsion has higher fat content and moisture content than pork liver and pork gelatin, whereas it has a lower protein content. As a consequence, the ratio protein/fats of the pork skin derived emulsion is of 0.7 while the one of pork liver is of 5 and the one of pork gelatin is 0.

Amino acid composition of the (liquid) pork skin derived emulsion was further analyzed and compared to Type A pork gelatin, as shown in Table 2:

Table 2 - Amino acid characterization of different products

As shown in Table 2, a pork skin derived emulsion according to the invention has acid composition different from the one of type A pork gelatin.

2.2.Example 1 - Effect of dry pork skin derived emulsion on palatability of dry pet foods to cats

Dry pet foods were prepared as described in paragraph 1.5.1. coated with 6% of poultry fat and with 1% of dry palatability-enhancer.

The palatability-enhancer of control diet 1 was an hydrolyzate of 15.3% of pork liver, 15% of poultry liver, yeasts and pyrophosphate.

The palatability-enhancer of experimental diet 1 was exactly the same hydrolyzate as the one of control diet 1, except that it comprised 13% of pork liver and 2.3% of dry pork skin derived emulsion prepared according to paragraph 1.2 instead of 15.3% of pork liver.

The palatability-enhancer of experimental diet 2 was exactly the same hydrolyzate as the one of control diet 1, except that it comprised 10% of pork liver and 5.3% of dry pork skin derived emulsion prepared according to paragraph 1.2 instead of 15.3% of pork liver.

The palatability-enhancer of experimental diet 3 was exactly the same hydrolyzate as the one of control diet 1, except that it comprised 7.65% of pork liver and 7.65% of dry pork skin derived emulsion prepared according to paragraph 1.2 instead of 15.3% of pork liver. Versus tests were performed to compare palatability to cats of the control diet 1 and of experimental diets. The results are presented in Table 3.

Table 3

The partial substitution of pork liver by these emulsions according to the invention in dry form and in different amounts allows obtaining parity of palatability for dry cat foods. Compositions comprising a specific pork skin derived emulsion can thus be used to efficiently enhance palatability of dry foods to cats.

2.3.Example 2 - Effect of pork skin derived emulsion on palatability of dry pet foods to cats

Dry pet foods were prepared as described in paragraph 1.5.1. coated with 6% of poultry fat and with 2% of liquid palatability-enhancer.

The palatability-enhancer of control diet 2 comprised 56% of pork liver hydrolyzate, and also amino acids, sugars and pyrophosphate.

The palatability-enhancer of experimental diet 4 was exactly the same as the one of control diet 2, except that it comprised 50% of pork liver hydrolyzate and 6% of pork skin derived emulsion prepared according to paragraph 1.1 instead of 56% of pork liver hydrolyzate.

The palatability-enhancer of experimental diet 5 was exactly the same as the one of control diet 2, except that it comprised 44% of pork liver hydrolyzate and 12% of pork skin derived emulsion prepared according to paragraph 1.1 instead of 56% of pork liver hydrolyzate.

Versus tests were performed to compare palatability to cats of the control diet 2 and of the experimental diets. The results are presented in Table 4.

Table 4

The partial substitution of pork liver by these emulsions according to the invention in liquid form and in different amounts allows obtaining parity of palatability for dry cat foods. Compositions comprising a specific pork skin derived emulsion can thus be used to efficiently enhance palatability of dry foods to cats.

2.4.Example 3 - Effect of pork skin derived emulsion and proteolyzed pork skin derived emulsion on palatability of wet pet foods to cats

A control diet 3 was prepared according to 1.5.2. The loaf comprised 53% of poultry and pork tissues, water, wheat flour, texturing agents and vitamins & minerals. The control diet 1 did not comprise any palatability-enhancer.

The experimental diet 6 was exactly the same as the one of control diet 1, except that it comprised 47% of poultry and pork tissues and 6% of a palatability-enhancer consisting of pork skin derived emulsion prepared according to paragraph 1.1 instead of 53% of poultry and pork tissues.

The experimental diet 7 was exactly the same as the one of control diet 1, except that it comprised 45% of poultry and pork tissues, 5% of a palatability-enhancer consisting of proteolyzed pork skin derived emulsion prepared according to paragraph 1.3 and 3% of water instead of 53% of poultry and pork tissues.

The experimental diet 8 was exactly the same as the one of control diet 1, except that it comprised 45% of poultry and pork tissues, 5% of a palatability-enhancer consisting of pork skin derived emulsion prepared according to paragraph 1.1 and 3% of water instead of 53% of poultry and pork tissues.

Versus tests were performed to compare palatability to cats of the control diet 3 and of the experimental diets. The results are presented in Table 5.

Table 5

The partial substitution of poultry and pork tissues by a pork skin derived emulsion according to the invention, proteolyzed or not, enhanced palatability of loaf to cats. Compositions comprising a specific pork skin derived emulsion can thus be used to efficiently enhance palatability of wet foods to cats.

Versus tests were also performed to compare palatability to cats of the experimental diets 7 and 8. The results are presented in Table 6.

Table 6

As shown in Table 6, the use of a proteolyzed pork skin derived emulsion enables to enhance palatability to cats higher than a non-proteolyzed pork skin derived emulsion.

2.5.Example 4 - Effect of pork skin derived emulsion on palatability of dry pet foods to dogs

a) Substitution of poultry viscera

Dry pet foods were prepared as described in paragraph 1.5.1. coated with 6% of poultry fat and with 2% of palatability-enhancer.

The palatability-enhancer of control diet 4 consisted of a poultry viscera hydro lyzate.

The palatability-enhancer of experimental diet 9 consisted of pork skin derived emulsion prepared according to paragraph 1.1 instead of poultry viscera hydrolyzate and further heated at 90°C during 30 min.

Versus tests were performed to compare palatability to dogs of the control diet 4 and of the experimental diet 9. The results are presented in Table 7. Table 7

The total substitution of poultry viscera hydrolyzate by an emulsion according to the invention allows obtaining parity of palatability for dry dog foods. Compositions comprising a specific pork skin derived emulsion can thus be used to efficiently enhance palatability of dry foods to dogs.

b) Substitution of pork liver

Dry pet foods were prepared as described in paragraph 1.5.1. coated with 6% of poultry fat and with 3% of palatability-enhancer.

The palatability-enhancer of control diet 5 was an hydrolyzate of 58.4% of pork liver and also amino acids, sugars.

The palatability-enhancer of experimental diet 10 was exactly the same hydrolyzate as the one of control diet 5, except that it comprised 52.4% of pork liver and 6% of dry pork skin derived emulsion prepared according to paragraph 1.1 instead of 58.4% of pork liver.

The palatability-enhancer of experimental diet 11 was exactly the same as the one of control diet 5, except that it comprised 46.4% of pork liver and 12% of dry pork skin derived emulsion prepared according to paragraph 1.1 instead of 58.4% of pork liver.

Versus tests were performed to compare palatability to dogs of the control diet 5 and of the experimental diets 10 and 11. The results are presented in Table 8.

Table 8

The partial substitution of pork liver by an emulsion according to the invention enhanced palatability of dry food to dogs. Compositions comprising a specific pork skin derived emulsion can thus be used to efficiently enhance palatability of dry foods to dogs.

2.6.Example 5 - Effect of lipolyzed pork skin derived emulsion on palatability of dry pet foods to dogs

The palatability-enhancer of control diet 6 was a commercial pork-based palatability- enhancer.

The palatability-enhancer of experimental diet 12 comprised 93% of the dry pork skin derived emulsion LI prepared according to paragraph 1.4 and additives, such as phosphoric acid.

The palatability-enhancer of experimental diet 13 comprised 88% of the dry pork skin derived emulsion L2 prepared according to paragraph 1.4, free amino acids, sugars and additives, such as phosphoric acid.

Versus tests were performed to compare palatability to dogs of the control diet 6 and of the experimental diets 12 and 13. The results are presented in Table 9.

Table 9

The use of lipolyzed pork skin derived emulsion (with or without Maillard ingredients) enhances palatability of dry food to dogs as efficiently as a commercial palatability-enhancer and it can thus be used to enhance palatability of dry foods to dogs.

Claims

1. Use of a pork skin derived oil-in- water emulsion having a moisture content greater than about 70%, a protein content inferior than about 15 % and a fat content ranging from 5 to 20% for enhancing the palatability of a pet food, and wherein said pet food is selected from a dry, a semi-moist and a wet pet food.

2. The use according to claim 1, wherein said pork skin derived oil-in-water emulsion comprises less than 15% of glycine (% based on weight of total amino acids).

3. The use according to claim 1 or 2, wherein said pork skin derived oil-in-water emulsion comprises less than 9% of hydroxyproline (% based on weight of total amino acids).

4. The use according to any one of claims 1 to 3, wherein said pork skin derived oil-in- water emulsion comprises less than 9% of alanine (% based on weight of total amino acids).

5. The use according to any one of claims 1 to 4, wherein said pork skin derived oil-in- water emulsion comprises more than 10% of glutamic acid (% based on weight of total amino acids).

6. The use according to any one of claims 1 to 5, wherein said pork skin derived oil-in- water emulsion comprises more than 1% of tyrosine (% based on weight of total amino acids).

7. The use according to any one of claims 1 to 6, wherein said pork skin derived oil-in- water emulsion has a pH ranging from 3 to 6, preferably from 4 to 6.

8. The use according to any one of claims 1 to 7, wherein said pork skin derived oil-in- water emulsion is combined to at least one additional palatability-enhancer ingredient, preferably selected from amino acids, sugars, vitamins, inorganic phosphate salts, animal digests, fats, vegetable hydrolysates, yeasts, carriers and combinations thereof.

9. Use of a pork skin derived oil-in-water emulsion as defined in any one of claims 1 to 7 as a palatability-enhancer.

10. Use of a palatability-enhancer comprising a pork skin derived oil-in-water emulsion as defined in any one of claims 1 to 7 and at least one additional palatability-enhancer ingredient notably as defined in claim 8 for enhancing the palatability of a pet food, wherein said pet food is selected from a dry, a semi-moist and a wet pet food.

11. A method for preparing a pet food palatability-enhancer comprising: a) providing a pork skin derived oil-in- water emulsion as defined in any one of claims 1 to 7;

b) adding at least one additional ingredient, preferably as defined in claim 8; c) obtaining said pet food palatability-enhancer.

12. The method according to claim 11 comprising an additional step of:

processing said pork skin derived oil-in-water emulsion.

13. A method for preparing a pet food palatability-enhancer comprising:

a) providing a pork skin derived oil-in-water emulsion as defined in any one of claims 1 to 7;

b) processing said pork skin derived oil-in-water emulsion;

c) obtaining said pet food palatability-enhancer.

14. The method according to claim 12 or 13 wherein said processing of pork skin derived oil-in-water emulsion is chosen from cooking, hydrolysis, proteolysis, lipo lysis, thermal treatment, pH adjustment, drying, or a combination of those.

15. A method for producing a pet food having enhanced palatability comprising:

a) adding to a pet food a pet food palatability-enhancer as defined in claim 9 or 10, b) Obtaining a pet food having enhanced palatability.

16. The method according to claim 15 wherein said pet food palatability enhancer is added either by coating or by inclusion.

17. The method according to claim 15 or 16 wherein said pet food comprises from 0.5% to

50%, preferably from 0.5% to 10%, and even more preferably from 0.5% to 1% of said pet food palatability-enhancer, based on the total weight of said pet food.

18. The method according to any one of claims 15 to 17 wherein said pet food comprises from 0.0005% to 50%, preferably from 0.01% to 20%, more preferably from 0.02% to 10%, more preferably from 0.023% to 6% of said pork skin derived oil-in-water emulsion, based on the total weight of said pet food.

19. The method according to any of claims 15 to 18 wherein said pet food is selected from a dry, a semi-moist and a wet pet food.