WO2018122463A1

WO2018122463A1 - Defoamer, its use and methods of controlling, preventing or reducing foam

Info

Publication number: WO2018122463A1
Application number: PCT/FI2017/050952
Authority: WO
Inventors: Danny Nguyen
Original assignee: Kemira Oyj
Priority date: 2016-12-31
Filing date: 2017-12-29
Publication date: 2018-07-05

Abstract

This invention relates to defoaming compositions suitable for direct food contact and methods of controlling, preventing or reducing foam using the said composition. The defoaming compositions comprises vegetable oil, preferably rapeseed oil or canola oil or both; polyalkylene glycol, preferably polypropylene glycol; one or more nonionic surfactants, preferably polysorbates and polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and polyethylene glycol dioleate and optionally hydrophobic silica.

Description

DEFOAMER, ITS USE AND METHODS OF CONTROLLING, PREVENTING OR REDUCING FOAM

Field of the Invention

[001] This invention relates to defoaming composition, especially suitable for direct food contact, and methods of controlling, preventing or reducing foam using the composition.

Background of the Invention

[002] In industrial processing of vegetables or plant parts, specifically sugar or starch containing vegetables or plants, foaming may be a major issue. An example of processes where foam is commonly formed is sugar extraction process from sugar beets. Foam may also be formed in washing or processing starch or sugar containing vegetables or plant parts for other than sugar extraction purposes, such as washing or processing potatoes for various purposes. Examples of washing and processing plant is washing or processing sugar cane plants. Foams formed during vegetable or plant processing steps can cause problems, such as decreased production efficiency and quality. Currently commercially available defoamers have certain flaws: for example many of them are unsuitable for food contact, they may not be FDA non- compliant, many times they are non-biodegradable, some of them have low efficiency or they do not have a continuous defoaming effect, and/or they are expensive.

[003] Thus there is a clear need for cost effective defoamers suitable for food contact.

Summary of the Invention

[004] One objective of the present invention is to provide solutions to or minimize the problems encountered in the prior art. [005] In particular, one objective of the present invention is to provide biodegradable, FDA compliant, cost effective defoaming compositions suitable for direct food contact. [006] Typical defoamer according to the invention comprises vegetable oil, polyalkylene glycol, and one or more nonionic surfactant(s). [007] In a typical method according to the invention of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming, the method comprises a step of treating the liquid with a defoamer according to the invention. [008] Typical use according to the invention of a defoamer according to the invention is for controlling or preventing or reducing foam in a processing of vegetables, preferably starch containing vegetables.

[009] Now it has been surprisingly found that a defoamer comprising vegetable oil, polyalkylene glycol and at least one nonionic surfactant are able to provide sufficient, even good or excellent, defoaming effect, while being suitable for food contact. This provides a defoamer which can be used in food processing, especially for processing of starch or sugar containing vegetable, where defoaming is a common problem. [010] Certain embodiments are related to defoaming compositions comprising vegetable oil; polyalkylene glycol, preferably polypropylene glycol; and one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate. Vegetable oil is preferably rapeseed or canola oil, but it may as well be corn oil, soybean oil, sunflower oil, other vegetable oil or combination thereof. Certain other embodiments are related to defoaming compositions further comprising hydrophobic silica.

[01 1] Certain embodiments are related to methods of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming: comprising a step of treating the liquid with a defoamer comprising vegetable oil, polyalkylene glycol preferably polypropylene glycol, one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate and optionally hydrophobic silica. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, soybean oil, peanut oil, flax oil, sunflower oil, other vegetable oil or combination thereof.

[012] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, wherein a defoamer comprising vegetable oil, polyalkylene glycol preferably polypropylene glycol, one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate and optionally hydrophobic silica, is added to a washing liquid. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, peanut oil, soybean oil, flax oil, sunflower oil, other vegetable oil or combination thereof.

[013] The compositions provided are suitable for use as defoamers in washing and processing vegetables, plants and plant parts, especially sugar or starch containing vegetables, plants or plant parts. Processing preferably is processing of the vegetables, plants or plant parts for food production and it may include sugar extraction.

[014] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. Brief Description of the Drawings [015] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of the specification embodiments presented herein.

[016] Figure 1 shows experimental set up for Foam and Entrained Air Test (FEAT).

[017] Figure 2A shows the kinetic of a base formulation X2628 which is a non-FDA- compliant lab control, a competing benchmark product, and three experimental formulations A, E and J.

[018] Figure 2B shows the kinetics of base formulation X2628, competing benchmark, and formulation K. Detailed Description of the Invention

[019] The present invention provides biodegradable, FDA compliant, economic, and cost effective defoaming composition and method of using the same in vegetable processing industry. [020] The defoaming compositions of this disclosure are useful in industrial scale washing and processing of sugar or starch containing vegetables, plants and plant parts, especially for food processing purposes. The processing may include sugar extraction, such as extracting sugar from sugar beets or sugar cane, but the processing may be any industrial process where foam is formed when the sugar or starch containing vegetables, plants or plant parts, are washed or processed. Examples of processing are peeling, cutting or slicing of starch containing vegetables. Examples of starch or sugar containing vegetables are sugar cane, sugar beet, corn, potatoes and sweet potatoes. [021] The defoamer comprises vegetable oil. Vegetable oil may be selected from rapeseed oil, canola oil, corn oil, soybean oil, sunflower oil, or any other suitable vegetable oil or any combination thereof. Preferably vegetable oil is rapeseed oil or canola oil. The defoamer may comprise 50-80 weight-%, preferably 60-70 weight-%, of vegetable oil, calculated from the total weight of the defoamer composition. [022] According to one embodiment of the invention vegetable oil comprises >50%, preferably >80%, sometimes even >85%, of unsaturated fatty acids, preferably oleic, linoleic and linolenic acids, calculated from the total weight of vegetable oil.

[023] The defoamer further comprises polyalkylene glycol. Polyalkylene glycol may be selected polyethylene glycol, polypropropyle glycol, polybutylene glycol and any of their combinations. Preferably polyalkylene glycol is polypropylene glycol. The molecular weight of polypropylene glycol is preferably over 1200 g/mol. According to one embodiment of the invention defoamer comprises 10-30 weight-%, preferably 15- 25 weight-%, of polyalkylene glycol, calculated from the total weight of the defoamer composition. According to one preferable embodiment polypropylene glycol concentration in defoamer may be 10-30 weight-%, preferably 15-25 weight-%.

[024] The defoamer comprises also one or more nonionic surfactant(s). The nonionic surfactant may be selected from polysorbates, polyethylene glycol esters, and any combinations thereof. According one preferable embodiment the nonionic surfactant may be polyoxyethylene sorbitan monolaurate, polysorbate sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate or any of their combinations, preferably polyoxyethylene sorbitan monooleate, polyethylene glycol dioleate or any of their combinations. According to one embodiment polyethylene glycol ester is polyethylene glycol dioleate and/or polysorbate is polyoxyethylene sorbitan monooleate. The defoamer may comprise, in total, 1 -20 weight-%, preferably 5-20 weight-%, more preferably 10-20 weight-%, of nonionic surfactant, calculated from the total weight of the defoamer composition. [025] The defoamer may comprise, in total, 1 -20 weight-%, preferably 5-20 weight- %, more preferably 10-20 weight-%, of nonionic surfactant, calculated from the total weight of the defoamer composition. According to one embodiment of the invention polyethylene glycol dioleate concentration in the defoamer may be 5-10 weight-% and/or polyoxyethylene sorbitan monooleate concentration may be 1 -10 weight-%. [026] Certain embodiments are related to defoaming compositions comprising vegetable oil; polyalkylene glycols, preferably polypropylene glycol; and one or more nonionic surfactant(s), preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, peanut oil, soybean oil, flax oil, sunflower oil, other vegetable oil or combination thereof. In certain embodiments vegetable oil concentration is 50%-80%. In certain embodiments polyalkylene glycol concentration is 10%-30%. In certain embodiments nonionic surfactant concentration is 1 %-20%. [027] The defoamer may further comprise hydrophobic silica. The concentration of hydrophobic silica in the defoamer may be 0.1 -1 .5 weight-% preferably 0.75-1.25 weight-%, calculated from the total weight of the defoamer. According to another embodiment, the defoamer is essentially free from hydrophobic silica. Low amount, or absence, of hydrophobic silica makes the defoamer suitable for processes where the use of silica might otherwise create problems.

[028] Certain embodiments are related to defoaming compositions comprising vegetable oil; polyalkylene glycols, preferably polypropylene glycol; hydrophobic silica; and one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, soybean oil, sunflower oil, other vegetable oil or combination thereof. In certain embodiments vegetable oil concentration is 50%-80%. In certain embodiments polyalkylene glycol concentration is 10%-30%. In certain embodiments nonionic surfactant concentration is 6%-20%. In certain embodiments hydrophobic silica concentration is 0.1 % to 1.5% [029] Certain embodiments are related to defoaming compositions comprising 50%- 80% of rapeseed oil, 5%-10% of polyethylene glycol dioleate, 10%-30% of polypropylene glycol and 1 %-10% of polyoxyethylene sorbitan monooleate.

[030] Certain embodiments are related to defoaming compositions comprising 50%- 80% of canola oil, 5%-10% of polyethylene glycol dioleate, 10%-30% of polypropylene glycol and 1 %-10% of polyoxyethylene sorbitan monooleate. [031] Certain embodiments are related to defoaming compositions comprising 50%- 80% of rapeseed oil, 5%-10% of polyethylene glycol dioleate, 10%-30 % of polypropylene glycol, 0.1 %-1 .5% of hydrophobic silica, and 1 %-10% of polyoxyethylene sorbitan monooleate. [032] Certain embodiments are related to defoaming compositions comprising 50%- 80% of canola oil, 5%-10% of polyethylene glycol dioleate, 10%-30% of polypropylene glycol, 0.1 %-1.5% hydrophobic silica and 1 %-10% polyoxyethylene sorbitan monooleate. [033] According to one embodiment the defoamer may comprise one or more diluting agent(s). Diluting agents may be selected from water, compatible chemicals, compatible chemical mixtures or premixtures, compatible liquids, compatible solids or combinations thereof. Preferably diluting agent is water. Compatible are those that do not result in separation between the components of defoamer, and/or precipitation reactions, and maintain the microemulsion state of the defoamer while and/or after adding and/or mixing those to the defoamer. Examples of compatible liquids are various alcohols, and sometimes hydrocarbons.

[034] According one embodiment of the invention the defoamer is essentially free of mineral oils and/or mineral waxes. In the present context, mineral oils and mineral waxes are understood as hydrocarbon compounds of mineral origin, obtained e.g. from petroleum processing. Defoamer according to the present invention is preferably free of mineral oils and/or mineral waxes, making it thus especially suitable for use in food processing. [035] According to one embodiment of the invention the defoamer is essentially free from block copolymers, e.g. block copolymers of ethylene oxide and propylene oxide, i.e. EO/PO block copolymers. This improves the suitability of the defoamer for food processing purposes. [036] Certain embodiments are related to methods of controlling or preventing or reducing foam in foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming, where the method comprises a step of treating the liquid with a defoamer comprising vegetable oil; polyalkylene glycols, preferably polypropylene glycol; and one or more nonionic surfactants, preferably polyethylene glycol ester and polysorbates, more preferably polyethylene glycol dioleate and polyoxyethylene sorbitan monooleate. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, soybean oil, sunflower oil, other vegetable oil or combination thereof. In certain embodiment vegetable oil concentration is 50%-80%. In certain embodiments polyalkylene glycol concentration is 10%-30%. In certain embodiments nonionic surfactant concentration is 1 %-20%.

[037] Certain embodiments are related to methods of controlling or preventing or reducing foam in a foam containing aqueous liquid or a aqueous liquid which is susceptible to foaming, where the method comprises a step of treating the liquid with a defoamer comprising vegetable oil; polyalkylene glycols, preferably polypropylene glycol; hydrophobic silica; and one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, soybean oil, sunflower oil, other vegetable oil or combination thereof. In certain embodiment vegetable oil concentration is 50%-80%. In certain embodiments polyalkylene glycol concentration is 10%-30%. In certain embodiments nonionic surfactant is 1 %-20%. In certain embodiments hydrophobic silica concentration is 0.1 % to 1.5%. Certain embodiments are related to methods of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming comprising a step of treating the liquid with a defoamer comprising 50%-80% rapeseed oil, 5%-10% polyethylene glycol dioleate, 10%-30 % polypropylene glycol, and 1 %-10% polyoxyethylene sorbitan monooleate.

[038] Certain embodiments are related to methods of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming, comprising a step of treating the liquid with a defoamer comprising 50%-80% canola oil, 5%-10% polyethylene glycol dioleate, 10%-30 % polypropylene glycol and 1 %-10% polyoxyethylene sorbitan monooleate. [039] Certain embodiments are related to methods of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming comprising a step of treating the liquid with a defoamer comprising 50%-80% rapeseed oil, 5%-10% polyethylene glycol dioleate, 10%-30% polypropylene glycol, 0.1 %-1.5% hydrophobic silica and 1 %-10% polyoxyethylene sorbitan monooleate.

[040] Certain embodiments are related to methods of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming comprising a step of treating the liquid with a defoamer comprising 50%-80% canola oil, 5%-10% polyethylene glycol dioleate, 10%-30% polypropylene glycol, 0.1 %-1.5% hydrophobic silica and 1 %-10% polyoxyethylene sorbitan monooleate

[041] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, especially of vegetables, wherein a defoamer comprising vegetable oil; polyalkylene glycol, preferably polypropylene glycol; and one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate, is added to a washing liquid, preferably before it comes into contact with the vegetables to be washed. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, soybean oil, sunflower oil, other vegetable oil or combination thereof. In certain embodiment vegetable oil concentration is 50%-80%. In certain embodiments polyalkylene glycol concentration is 10%-30%. In certain embodiments nonionic surfactant concentration is 1 %-20%. [042] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, especially of the vegetables, wherein a defoamer comprising vegetable oil, polyalkylene glycols preferably polypropylene glycol, hydrophobic silica and one or more nonionic surfactants, preferably polysorbates and/or polyethylene glycol ester, more preferably polyoxyethylene sorbitan monooleate and/or polyethylene glycol dioleate, is added to a washing liquid, preferably before it comes into contact with the vegetables to be washed. Vegetable oil is preferably rapeseed oil or canola oil, but it may as well be corn oil, soybean oil, sunflower oil, other vegetable oil or combination thereof. In certain embodiment vegetable oil concentration is 50%-80%. In certain embodiments polyalkylene glycol concentration is 10%-30%. In certain embodiments nonionic surfactant concentration is 1 %-20%. In certain embodiments hydrophobic silica concentration is 0.1 % to 1.5%.

[043] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, wherein a defoamer comprising 50%-80% rapeseed oil, 5%-10% polyethylene glycol dioleate, 10%-30 % polypropylene glycol and 1 %-10% polyoxyethylene sorbitan monooleate, is added to a washing liquid.

[044] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, wherein a defoamer comprising 50%-80% canola oil, 5%-10% polyethylene glycol dioleate, 10%-30 % polypropylene glycol and 1 %-10% polyoxyethylene sorbitan monooleate, is added to a washing liquid. [045] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, wherein a defoamer comprising 50%-80% rapeseed oil, 5%-10% polyethylene glycol dioleate, 10%-30 % polypropylene glycol, 0.1 %-1 .5% hydrophobic silica and 1 % - 10% polyoxyethylene sorbitan monooleate, is added to a washing liquid.

[046] Certain embodiments are related to a method to processing vegetables, said method comprising a step of washing, wherein a defoamer comprising 50%-80% canola oil, 5%-10% polyethylene glycol dioleate, 10%-30 % polypropylene glycol, 0.1 %-1 .5% hydrophobic silica and 1 %-10% polyoxyethylene sorbitan monooleate, is added to a washing liquid.

[047] Other embodiments of the invention are discussed throughout this application. Any embodiment discussed with respect to one aspect of the invention applies to other aspects of the invention as well and vice versa. Each embodiment described herein is understood to be embodiments of the invention that are applicable to all aspects of the invention. It is contemplated that any embodiment discussed herein can be implemented with respect to any method or composition of the invention, and vice versa. Furthermore, compositions and kits of the invention can be used to achieve methods of the invention.

Definitions

[048] The use of the word "a" or "an" when used in conjunction with the term "comprising" in the claims and/or the specification may mean "one," but it is also consistent with the meaning of "one or more," "at least one," and "one or more than one."

[049] Throughout this document, the term "about" is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value. [050] The use of the term "or" in the claims is used to mean "and/or" unless explicitly indicated to refer to alternatives only, or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and "and/or."

[051] As used in this disclosure, the words "comprising" (and any form of comprising, such as "comprise" and "comprises"), "having" (and any form of having, such as "have" and "has"), "including" (and any form of including, such as "includes" and "include") or "containing" (and any form of containing, such as "contains" and "contain") are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[052] Percentages of components in compositions described throughout this application are weight percentages of the components in the compositions or defoamers, calculated from total weight of the defoamer composition or defoamer. Weight percentages are calculated with the assumption that the components contain no impurities. [053] Vegetable oils are triglycerides, glycerin esters, of fatty acids. Fatty acids are 4 to 28, preferably 6 to 22, carbon atom containing carboxylic acids with saturated or unsaturated aliphatic chains. Examples of fatty acids found in vegetable oils, include but are not limited to, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, erucic acid. Non-limiting examples of vegetable oils are rapeseed oil, canola oil, soy bean oil, peanut oil, sunflower oil, flax oil, corn oil and any combination thereof.

[054] For the purpose of the current invention the term "defoaming" means, prevention of foaming, control of foaming and/or reduction of foaming. Defoamers or defoaming compositions of the present invention prevent, control and/or reduce foaming. Terms 'defoamer' and 'defoaming composition' are equivalent, fully synonymous, and are interchangeably used in this disclosure. Prevention of foaming is not letting the foam being formed, i.e. inhibition of occurrence of foam. Control of foaming is limiting amount of foam to certain extent or amount depending on the process. Reduction of foaming is decrease of amount of foam, or complete elimination of foam after it was formed. Defoamers of the current invention are to be used to treat aqueous liquids susceptible to foaming and/or foam containing aqueous liquids. Treating the liquids with the defoamers is achieved by adding the defoamer to the liquids or vice versa. To control, reduce, or prevent foaming, defoamer can be added to the liquids continuously and/or at certain intervals, either intermittently or at regular predetermined intervals. Amounts of defoamer added, time interval, time duration of addition depends on, factors including but not limited to, amount of liquid to be treated, properties and components of the liquid, type of vegetables treated, amount of foam, foaming susceptibility of the liquid and on the process itself. [055] Components of the defoaming compositions of the current invention shows interactive behavior, thus the defoaming efficiency of the composition is much higher than that of the individual components.

[056] Surfactant as referred in this disclosure contain hydrophilic head group and hydrophobic tail group. Nonionic surfactants are surfactants with an uncharged hydrophilic head and do not dissociate into ions in aqueous solutions. Nonionic surfactants include ethoxylates, especially fatty alcohol ethoxylates, alkoxylates, cocamides, polysorbates. Surfactant useful for the current invention makes the components of the claimed compositions miscible with each other, keeps them well dispersed and forms microemulsion.

[057] Polysorbates are amphipathic, nonionic surfactants composed of fatty acid esters of polyoxyethylene sorbitan. Examples of polysorbates, which are suitable for use in the present invention are polyoxyethylene sorbitan monolaurate, polysorbate sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, preferably polyoxyethylene sorbitan monooleate. [058] Polyalkylene glycols are alkyl oxide polymers with one or more types of alkyl oxy repeat units, the most common repeat units are ethylene oxy [CH₂CH₂O] and propylene oxy [CH₂CH(CH₃)0].

[059] Polyethylene glycols ester (PEG ester) are surfactants manufactured by reacting polyethylene glycol with a fatty acid, with polyethylene glycol comprises of the hydrophilic part of the surfactant, and the fatty acid the lipophilic Depending on the molecular weight, PEG ester surfactant covering a wide range of HLB that ranging from water soluble to water insoluble. PEG 400 DO as an example can be used as an emulsifier for defoamer formulation.

[060] Polypropylene glycols are polymers of propylene oxide. Molecular weight of commercially available polypropylene glycols varies from 200 g/mol to 4000 g/mol. Polypropylene glycols with molecular weight above 1200 g/mol are suitable to food contact.

Examples

[061] The following examples as well as the figures are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples or figures represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute some of the preferred modes for its practice.

However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

[062] Foam and Entrained Air Test (FEAT) was performed to test defoaming efficiency of compositions A, E, J and K, having compositions as given in Table 1 . The experimental FEAT set up comprises a water bath, a foam column, a micro pump, a density meter, a computer, and acquisition software, as schematically shown in Fig. 1. Parallel experiments were run to compare defoaming efficiency of A, E, J and K. Compositions A and E were reference compositions. Potatoes extract water was used as foam generating medium. The medium was heated to 65 ^°C, and was circulated with the micro pump. As the medium was circulated, the density dropped over time due to formation of entrained air (bubbles within medium) and foam (bubbles on top of the medium). As soon as the density read-out was stable (e.g. no significant changes within 5 to 10 seconds) the defoamer was added. Density of the medium increased after compositions A, E, J, K, X2628 or benchmark composition were added to the medium. Change of density of the medium was recorded.

[063] Figure 2A shows that X2628 and composition A had fast knock down rate (conventionally, knock down rate is associated with how fast the foam dissipates and with the ability of the defoamer to destroy excising foam) and the density of the medium reached value 1 within 30 seconds. Benchmark compound had fast knock down rate but the density level remained low. Compositions E and J had slow knock down rate and for composition E the density never reached value 1. Thus, composition A and lab control composition X2628 are efficient defoamers, however neither of them is FDA compliant and thus not suitable for use in food industry. These compounds are mineral oil based. Block copolymer OE/PO 10100 used in composition A is not FDA compliant; moreover of weight percentage of PEG ester in composition A is over the FDA recommended level suitable for direct food contact. FDA recommended level for PEG ester in a composition is 10% or less. Compositions E and J are slower in their knockdown rates and composition E contains mineral oil in excess of recommended levels for FDA compliancy.

[064] Fig. 2B shows knock down kinetics of benchmark composition, lab control composition X2628 and composition K. Composition K is FDA compliant and does not contain block copolymer OE/PO like the benchmark composition, and amount of PEG ester in composition K is within FDA recommended level. Also composition K is not mineral oil based as is the lab control. Composition K is FDA compliant and also a very efficient defoamer.

Table 1 Compositions A, E, J and K used in the experiments.

Example 1 : Preparation of composition A (reference)

In a glass beaker, add 21.5 grams of vegetable oil, 1 grams hydrophobic silica, 10 grams white mineral oil, 2.5 grams crystalline wax. Heat the contents to 80^°C. Mix the melted contents for 1.5 hours. Start cooling to room temperature. When the temperature reaches below 35^°C, add 7.5 grams block copolymer and 7.5 grams polyethylene glycol ester. Mix for another 30 minutes or until ambient temperature is reached.

Example 2: Preparation of composition E (reference) In a glass beaker, add 32.5 grams of vegetable oil, 10 grams white mineral oil, 2.5 grams crystalline wax. Heat the contents to 80^°C. Mix the melted contents for 1.5 hours. Start cooling to room temperature. When the temperature reaches below 35^°C, add 5 grams polyethylene glycol ester. Mix for another 30 minutes or until ambient temperature is reached.

Example 3: Preparation of composition J

In a glass beaker, add 34.75 grams of vegetable oil, 0.25 grams hydrophobic silica. Heat the contents to 80^°C. Mix the melted contents for 1 .5 hours. Start cooling to room temperature. When the temperature reaches below 35^°C, add 10 grams polypropylene glycol, and 5.0 grams polyethylene glycol ester. Mix for another 30 minutes or until ambient temperature is reached.

Example 4: Preparation of composition K

In a glass beaker, add 32.5 grams of vegetable oil, 0.5 grams hydrophobic silica. Heat the contents to 80^°C. Mix the melted contents for 1 .5 hours. Start cooling to room temperature. When the temperature reaches below 35^°C, add 10 grams polypropylene glycol, 2 grams polysorbate, and 5.0 grams polyethylene glycol ester. Mix for another 30 minutes or until ambient temperature is reached.

Example 5

In a glass beaker, add 45 grams of vegetable oil, 0.5 grams hydrophobic silica. Heat the contents to 80^°C. Mix the melted contents for 1.5 hours. Start cooling to room temperature. When the temperature reaches below 35^°C, add 2 grams block copolymer, 2.5 grams polyethylene glycol ester. Mix for another 30 minutes or until ambient temperature is reached.

Example 6

In a glass beaker, add 47 grams of vegetable oil, 0.5 grams hydrophobic silica. Heat the contents to 80^°C. Mix the melted contents for 1.5 hours. Start cooling to room temperature. When the temperature reaches below 35^°C, add 2.5 grams polyethylene glycol ester. Mix for another 30 minutes or until ambient temperature is reached.

Claims

1. A defoamer comprising vegetable oil, polyalkylene glycol, and one or more nonionic surfactant(s).

2. The defoamer of claim 1 , wherein it comprises 50-80 weight-% of vegetable oil, 10- 30 weight-% of polyalkylene glycol, and/or 5 -20 weight-% of one or more surfactant(s).

3. The defoamer of claim 1 or 2, wherein the defoamer further comprises hydrophobic silica, preferably 0.1 -1.5 weight-% hydrophobic silica.

4. The defoamer of claim 1 , 2 or 3, wherein the vegetable oil concentration is 50-80 weight-%, preferably 60-70 weight-%.

5. The defoamer of any of claims 1 -4, wherein the vegetable oil is rapeseed oil or canola oil or any combination thereof.

6. The defoamer of any of claims 1 -5, wherein one or more nonionic surfactant(s) is/are selected from the group consisting of polyethylene glycol esters, polysorbates and any combination thereof.

7. The defoamer of claim 6, wherein polyethylene glycol ester is polyethylene glycol dioleate and/or polysorbate is polyoxyethylene sorbitan monooleate.

8. The defoamer of claim 7, wherein polyethylene glycol dioleate concentration is 5- 10 weight-% and polyoxyethylene sorbitan monooleate concentration is 1 -10 weight- %.

9. The defoamer of any of claims 1 -8, wherein polyalkylene glycol is polypropylene glycol.

10. The defoamer of claim 9, wherein molecular weight of polypropylene glycol is over 1200 g/mol.

1 1. The defoamer of claim 9 or 10 wherein polypropylene glycol concentration is 10- 30 weight-%.

12. The defoamer of claim 1 , wherein the defoamer comprises 50-80 weight-% vegetable oil, 10-30 weight-% polyalkylene glycol, 1-10 weight-% polysorbates, 5-10 weight-% polyethylene glycol esters, and 0.1 -1 -5% hydrophobic silica.

13. The defoamer of claim 12, wherein polyalkylene glycol is polypropylene glycol, polyethylene glycol ester is polyethylene dioleate, and polysorbate is polyoxyethylene sorbitan monooleate.

14. The defoamer of any one of claim 1 -13 wherein the defoamer comprises one or more diluting agents.

15. The defoamer of claim 14, wherein the diluting agent is selected from a group consisting of water, compatible chemicals, compatible solids, compatible liquids or a combination thereof.

16. The defoamer of any one of claims 1 -15, wherein the defoamer is free of mineral oils and/or mineral waxes.

17. Use of a defoamer according to any of claims 1 -16 for controlling or preventing or reducing foam in a processing of vegetables, preferably starch containing vegetables.

18. A method of controlling or preventing or reducing foam in a foam containing aqueous liquid or an aqueous liquid which is susceptible to foaming, wherein the method comprises a step of treating the liquid with a defoamer of any one of claims 1 - 16.

19. The method of claim 18, wherein the aqueous liquid is used and/or generated during processing vegetables, preferably starch containing vegetables.

20. The method of claim 18 or 19, wherein the aqueous liquid is used and/or generated during washing vegetables, preferably starch containing vegetables.

21. A method of any one of claim 18-20, wherein said method comprises a step of washing, wherein the defoamer is added to a washing liquid.

22. The method of any one of claim 18-21 , wherein the sugar or starch containing vegetables are processed for extraction of sugar and wherein the method further comprises an extraction step wherein the defoamer is added.