IES970259A2 - Improvements in reduced-fat food products - Google Patents

Abstract

A preformed gel block made from whey protein concentrate (WPC) is prepared by reconstituting a high gelling WPC having a protein concentration in the range of 30 to 50% and being capable of forming a gel strength of at least 100g/(math) for an 11% w/v solution, heating the resulting solution to between 25 degrees celcius and 100 degrees celcius for 5 to 120 minutes and cooling the solution to less than 20 degrees celcius until the solution solidifies. The so-formed gel can be utilised as a fat replacer in foods including sausage and fermented meat product to yield reduced fat or low fat products. Organoleptically acceptable sausage with a fat content of less than 3% may be prepared using the gel as a fat replacer. <Figure 1>

Description

. APPLICATION’ IMPROVEMENTS IN REDUCED-FAT FOOD PRODUCTS The present invention relates to reduced-fat food products and in particular to the preparation of a thermally induced preformed gel block for use in low-fat meat applications A major functional property of dairy whey proteins is their ability to form a three dimensional network on thermal processing, producing gels capable of immobilising water and solute particles. Use of gelled whey proteins and especially β-lactoglobulin in food products can significantly alter the texture and water holding capacity of the food products (de Wit, 1984).

A gel network may be defined as ‘a continuous network of macroscopic dimensions immersed in a liquid medium and exhibiting no steady state flow’ (Zeigler and Foegeding, 1990).

Much information has been published on the topic of whey protein functionality and the influence of thermal processing (Mulvihill and Donovan, 1987; Morr and Ha, 1995). salts, especially divalent cations such as NaCL and CaCh (Foegeding et al.,1992; Sherwin and Foegeding, 1997) and pH changes (Harwalker and Kalab, 1985 a, b, c; Mulvihill and Kinsella 1987) on final whey protein gelation/ Foods such as cheese and comminuted meat products including frankfurters, sausages, etc may be considered multi-component gels and their textural properties are determined by the gel matrix and other constituents of the food such as fat or filler particles (Tolstoguzov and Braudo, 1983).

Whey proteins have been utilised in processed meat manufacture both as filler/texturising agents (US Patent No 5,232,732) and as microparticulate gels (International Patent Application No. WO 93/00832 ) o ο ... J c -2Comminuted meat products such as pork sausages generally contain between 30% and 40% fat, a level which in health terms is considered to be high. A major obstacle in the acceptance by consumers of a low-fat ground meat product is that of palatability. Consumers have certain expectations with regard to the organoleptic properties of such products and these are difficult to meet with less fat present. The term “low-fat” fresh pork sausages refers to sausages which have a fat content less than 10%, and the term “reducedfat” sausages refer to a product with a fat content in the range of 10 to 20%. There are several approaches which may be taken with respect to the reduction of fat in meat products, for example, including removal of the fat, without adjustment of the other ingredients; addition of protein as a texturiser; incorporation of added water to replace fat; and addition of various hydrocolloids, (gums starches etc).

Each of these options can create a number of problems. Removing fat significantly lowers sensory scores for tenderness and juiciness in ground pork made with 20% fat when compared with those made with greater than 20% (Reitmeier and Prusa, 1987). Decker et al. (1987) reported that using leaner meats to reduce the fat content from 30% to 15% in all-meat frankfurters containing less than 10% AW resulted in the products becoming tougher in texture. Replacement of 20% or more of the meat with hydrated isolated soya protein in the 15% fat products reversed the negative effects of using leaner meats.

However, high levels of hydrated soy protein result in a more pronounced soy flavour.

The present invention seeks to overcome the problems associated with known fat replacement methods in the preparation of comminuted meat products and to provide an organoleptically acceptable low-fat or reduced-fat product such as a sausage.

Accordingly, the present invention provides a process for preparing a proteinaceous gel for use as a fat replacer in the manufacture of a low-fat or reduced-fat comminuted meat product comprising the steps of:30 (a) reconstituting a high gelling whey protein concentrate (WTC) powder in aqueous medium, the WTC having a protein concentration in the range of 30 to 50% and -3 being capable of forming a gel having a gel strength of at least 100 g/cm2 for an 11 % w/v solution; (b) heating the resulting solution at a temperature between 25°C and 100°C for between 5 and 120 minutes; and (c) cooling the solution to less than 20°C for a period of time sufficient to allow the solution to form a solid gel.

After the reconstitution step, the protein solution is preferably filled into a liner, such as a polythene liner, and sealed prior to the heat treatment. Most preferably, the heat treatment is conducted at between 70°C and 90°C for between 30 and 120 minutes. It is conveniently achieved by immersing the sealed liner in a hot water bath or in a steam cabinet.

The protein powder is preferably reconstituted in a food grade medium solvent to yield a solution having a protein concentration in the range of 80 to 150 g/litre.

Other texturising or additive ingredients may be incorporated into the solution prior to the heating step. For example, polysaccharides including carrageenan and/or starch (including tapioca starch) may be used.

The invention also provides a solid gel prepared as described above for use as a fat replacer in foods, including comminuted meat products.

The present invention refers to a process for the manufacture of a whey protein concentrate preformed gel block which can be utilised directly as a 100% replacement for added fat (25 - 35%) in fine or coarsely ground comminuted meat products, especially fresh pork sausages, as well as fermented meat products, to give a final product with a low-fat content. Fat content of less than 3% may be achieved.

The protein ingredient used in this invention is a physically modified whey protein concentrate with enhanced gelation properties. The protein concentration of the high gelling whey protein concentrate is in the range of 30 to 50% protein and more preferably -434 to 45% protein. Gels prepared from the high gelling material typically have a gel strength of at least 100g/cm2 for an 11% w/v solution. Such high gelling protein products are available under the Trade Mark GAELAC from Dairygold Co-Operative Society Limited.

Adjustment in the character of the final meat product may also be obtained by the addition of polysaccharides especially carrageenans as well as salts flavourings and colorants added to the protein solution prior to gelation. The polysaccharide may be present in an amount of up to 3%.

The steps involved in the process are depicted in the accompanying Figure 1.

In step (a) modified high gelling whey protein concentrate powder is reconstituted (hydrated) in water to give a protein concentration in the range of 10 - 150g/L true protein.

In step (b) the hydrated protein solution is filled into polythene liners, sealed and subjected to a heat treatment in the range of 25 - I00°C for 5 - 120mins. but more preferably 70 90°C for 30 - 120mins by either submersion into a hot water bath under controlled conditions or heating in a steam cabinet, and/or any other suitable heating process. In step (c) after heat treatment, the protein solution is next cooled at ambient temperatures or below. During this period of time a solid gel is formed. In optional step (d) the solid gel block is diced into 2 - 5cm cubes in preparation for sausage manufacture.

Batch trials with whey protein concentrates of different percentages w-ere undertaken and prepared as follows. Lots of 5 litres of protein solution with protein concentrations of 8 25 10% w/w were prepared. The high gelling powdered whey protein concentrates used contained protein concentrations of 34, 35, 38 40 and 45% true protein. Powders were reconstituted and held at temperatures of 80 - 90°C for periods of time of 60 - 120mins. After thermal processing, protein solutions were held at 4° for 12 - 16 hours. A whey protein concentration of 35% used at a 10% w/w protein concentration thermally processed at 80°C for 120mins was found to give the most acceptable gel composition for use as a fat replacer. in ti. iii -5In the process of the invention, both chopped and emulsified fat typically present in sausage are replaced by preformed whey protein gel and/or protein/carbohydrate gel blends to produce a final meat product with a fat content which can be less than 3% fat. A typical sausage product according to the invention is a low-fat sausage containing <3% fat, may be made according to the following formulation.

Composition % w/w Pork (98 visual lean) 25-40 10 Porkbackfat 0 Preformed whey protein gel 20-25 Ice 25 - 38 Rusk 10-15 Soya 0-4 15 Seasoning 1.5-2.0 Rind 0-2 Carrageenan (in preformed WPC gel) 0-3 Tapioca starch 0-6 Total 100 The sausage mix containing whey protein preformed gel product can be processed into traditional Irish breakfast sausage using known technology to give a product with the appearance, texture and organoleptic acceptability of the full fat meat product The invention will now be described more particularly with reference to the following non25 limiting examples. -6Comparative Example A Preparation of low-fat fresh pork breakfast sausage.

Irish fresh pork breakfast sausage traditionally contains lean meat and fat coarsely 5 comminuted and distributed in a uniform meat and fat emulsion with a typical total fat content of 20 - 30%. This example outlines the composition of a typical sausage product.

Commerical product Sausage Formulation Composition Pork (60-70 visual lean) Pork backfat Ice Rusk Soya protein isolate (Soya 500-E. Supro T, Protein International) Seasoning Total % w/w 100 EXAMPLE 1 Manufacture of low-fat fresh pork breakfast sausage using high gelling 35% WPC preformed gel as a 100°% fat replacer for added pork back fat Preparation of preformed gel block 10L of a 10% w/w protein solution was prepared using a 35% high gelling whey protein concentrate powder reconstituted in water. The whey protein concentrate product used was GAELAC 535, available from Dairygold Co-Operative Society Limited. The protein solution was heated to 80°C x 120min in a temperature controlled water bath. Thermally -Ί , processed protein solution was subsequently cooled by placing in a chill at 4°C x 12 hours. The chilled preformed gel was finally cut into 4cm cubes in preparation for use in sausage manufacture.

Low-fat pork breakfast Sausage manufacture The following is an outline of the sausage recipe used for the manufacture of the low-fat sausage Low-fat Sausage Formulation Composition % Kg Pork (98 v/1) 33 4.95 Pork backfat 0 0 Preformed whey protein gel 20 3.0 (GAELEC 535) 15 Water 10 1.5 Ice 25 3.75 Rusk 10 1.5 Seasoning 2 0.3 Total 100 15.0 Method The pork was chilled to 5°C and minced separately through a 5mm plate using a monica mincer.

Soya and water were added to the bowl chopper (Monica) and chopped at low speed for 60 25 seconds.

Lean pork (98v/l), seasonings and ice were then added to the bowl and chopped at high speed for 60 seconds -8Pre-diced whey protein gel was then added to the bowl in place of backfat and chopped at high speed for 60 seconds.

Rusk was finally added to the bowl and chopped at low speed for 30 seconds.

The low-fat sausage batter was finally stuffed into edible collagen casing and linked using a Vemag vacuum stuffer/Iinker Final low-fat fresh pork sausages were stored at 4°C x 16 hours prior to evaluation Sausage Composition Compositional analysis of AOAC (1984) were used to determine the fat (petroleum ether 10 extractable method), moisture (oven drying method) and protein (Kjeltech total nitrogen determination, N x 6.25) of final fresh pork sausages.

Component % Protein 22.5 15 Fat 2.5 Moisture 72.5 Textural Analysis Textural analysis was carried out using an Instron Universal Testing Machine in 20 compressive mode at 20°C with a cross head velocity of lOOmm/min and a load cell of 5Kg. The Instron was fitted with either a Warner Bratzler Shear Cell or a Kramer Shear cell unit. Cooked pork sausages were cored and samples sheared, all values reported are the mean of three determinations Sample Kramer Shear Values Warner Bratzler Shear Cell Control 250 280 Low-fat 249 277 EXAMPLE 2 Manufacture of low-fat fresh pork breakfast sausage using Tapioca starch (dry addition) 10 and high gelling 35% WPC preformed gel as a 100% fat replacer for added pork back fat Preformed gel preparation As outlined in Example 1 Low-fat Sausage Formulation Composition % Kg Pork (95-98 v/1) 40 6.0 Preformed whey protein gel (GAELAC 535) 20 3.0 Ice 25 3.75 Rusk 10 1.5 Tapioca starch 3 0.45 Seasoning 2 0.3 Total 100 15.0 - 10Method As previously outlined in Example 1 Compositional analysis Compositional analysis carried out according to methods outlined in Example 1 Component % Protein 20. Fat 2.0 Moisture 74.5 Textural Analysis Sample Kramer Shear Values Warner Bratzler Shear Cell Control 250 280 Low-fat 248 275 EXAMPLE 3 Manufacture of low-fat fresh pork breakfast sausage using high gelling 35% WPC /carrageenan preformed gel blend as a 100°% fat replacer for added pork back fat Preformed gel preparation 10L of an 8% w/w protein solution was prepared using a 35% high gelling whey protein concentrate powder (GAELAC 535, Dairygold) reconstituted in water. A 3% w/w addition of carrageenan to the protein solution was also carried out. The protein/polysaccharide solution was heated to 80°C x 120min in a temperature controlled water bath. On heating, -lithe protein/carbohydrate blend was subsequently cooled by placing it in a chill at 4°C x 12 hours. The chilled preformed gel was finally cut into 4cm cubes in preparation for use in sausage manufacture.

Sausage Formulation Composition % Kg Pork (95-98 v/1) 40 6.0 Preformed whey protein/carrageenan gel 20 3.0 Ice 28 4.2 Rusk 10 1.5 Tapioca Starch 0 0 Seasoning 2 0.3 Total 100 15.0 Method As outlined in Example 1 Compositional analysis Compositional analysis carried out according to methods outlined in Example 1 Component % Protein 22. Fat 2.2 Moisture 73.2 - 12Textural analysis Sample Kramer Shear Values Warner Bratzler Shear Cell Control 250 280 Low-fat 246 267 EXAMPLE 4 Manufacture of low-fat fresh pork breakfast sausage using Tapioca starch (dry addition) IO and high gelling 35% WPC /carrageenan preformed gel blend as a 100°% fat replacer for added pork back fat Preformed gel preparation 1OL of an 8% w/w protein solution was prepared using a 35% high gelling whey protein 15 concentrate powder (GAELEC 535, Dairygold) reconstituted in water. A 3% w/w addition of carrageenan to the protein solution was also carried out. The protein/polysaccharide solution was heated to 80°C x 120min in a temperature controlled water bath. On heating, the protein/carbohydrate blend was subsequently cooled by placing it in a chill at 4°C x 12 hours. The chilled preformed gel was finally cut into 4cm cubes in preparation for use in sausage manufacture.

Sausage Formulation Composition % Kg Pork (60 - 70 v/1) 60 9.0 Preformed whey protein/carrageenan gel 20 0.0 ice 25 3.75 Rusk 10 1.5 - 13Tapioca starch Seasoning Total 0.45 0.3 100 15.0 Method As outlined in Example 1 Compositional analysis Compositional analysis carried out according to methods outlined in Example 1 Component % Protein 22. Fat 2.2 Moisture 73.2 Textural Analysis It IB Sample Kramer Shear Values Warner Bratzler Shear Cell Control 250 280 Low-fat 244 281 Although described particularly in relation to sausage manufacture, it will be appreciated that the process of the invention may be used in the manufacture of other low-fat or reduced-fat comminuted meat products.

The references referred to herein are set out in the attached Schedule. SCHEDULE Bisson, J P , Des Baisants, S.J., Beauvais, PoilIot,G., L’Isle.Adam, G P Process for improving the texture of meat with whey proteins. Patent No. 5,232,723 De Wit, JN 1984. Functional properties of whey proteins in food systems Neth. Milk Dairy J. 39 71-39 Foegeding, E.A., Kuhn, PR. and Hardin, C.C. 1992. Specific divalent cation changes during gelation of #-lactoglobulin. J. Agri. And Food Chem. 40 2092-2097.

Harwalkar, V.R. and Kalab, M. 1985a. Thermal denaturation and aggregation of cQlactoglobulin at pH 2 5. Effect of ionic strength and protein concentration. Milchwissenschaft 40 31 Harwalkar, V.R. and Kalab, M. 1985b. Thermal denaturation and aggregation of tQlactoglobulin in solution. Electron Microscopy study. Milchwissenschafi 40 65 Harwalkar, V.R. and Kalab, M 1985c. Microstructure of isoelectric precipitates from $-lactoglobulin solutions heated at various pH values. Milchwissenschafi 40 665.

Mulvihill, DM. and Kinsella, J.E. and 1987. Gelation of -lactoglobulin.· Effects of sodium chloride and calcium chloride on the rheological structure properties of gels. J.

Food Sci. 53 231-236 Morr, C.V. and Ha, E.Y.W. 1995. CRC Crit. Rev. Food Sci. Nutri. 33 431-476.

Mulvihill, DM and Donovan, M. 1987 Whey proteins and their thermal denaturation-a review Irish J. Food Sci. andTechnol. 11 43-75 Sherwin, C.P. and Foegeding, E.A. 1997. The effects of CaCLon aggregation of whey proteins. Milchwissenschafi 52 93-96.

Pearce, R.J. and Dunkeriey, J A. Gelled food products containing microparticulate suspensions. Patent No WO 93/00832 Tolstoguzov, V.B. and Braudo, E.E. 1983. Fabricated foodstuffs as multicomponent gels. 14 183-212.

Zeigler, G.R. and Foegeding, A.E 1990 Gelation of proteins CRC Adv. In Food Nutri.

Res. 34 204-298 Decker, C.D.; Conley C.C.; Richert, S.H.; 198/ Use of isolated soy protein in the development of frankfurters with reduced levels of fat, calories and cholesterol European meeting of meat research workers 7:1. - 15 It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the appended claims.

Claims (5)

CLAIMS:

1. A process for preparing a proteinaceous gel for use as a fat replacer in the manufacture of a low-fat or reduced-fat comminuted meat product comprising the steps 5 of:(a) reconstituting a high gelling whey protein concentrate (WPC) powder in aqueous medium, the WPC having a protein concentration in the range of 30 to 50% and being capable of forming a gel having a gel strength of at least 100 g/cm 2 for an 11% 10 w/v solution; (b) heating the resulting solution at a temperature between 25°C and 100°C for between 5 and 120 minutes; and (c) cooling the solution to less than 20°C for a period of time sufficient to allow the solution to form a solid gel.

2. A process according to claim 1, in which after the reconstitution step, the protein solution is filled into a liner, such as a polythene liner, and sealed prior to the heat treatment, optionally in which the heat treatment is conducted at between 70°C and 90°C for between 30 and 120 minutes, and optionally in which the heat treatment involves 20 immersing the sealed liner in a hot water bath or in a steam cabinet.

3. A process according to claim 1 or claim 2, in which the protein powder is reconstituted in a food grade medium solvent to yield a solution having a protein concentration in the range of 80 to 150 g/litre, and optionally in which texturising or 25 additive ingredients are incorporated into the solution prior to the heating step.

4. A solid gel prepared by a process according to any of claims 1 to 3, for use as a fat replacer in foods, including comminuted meat products. - 17

5. A process according to claim 1 or a solid gel according to claim 4, substantially as herein described with reference to the accompanying drawing.