A HEAT-STABLE EMULSION

BACKGROUND

Description of the Related Art

Diet and health concerns have increasingly redirected consumption of traditional meat products to their lower-fat versions. While leaner meat products are healthier, they often have different textures and are less palatable on account of a reduced level of fat and a higher content of protein. For instance, compared to its high-fat counterpart, leaner meat is stiffer {e.g., leaner cuts of beef) or flakier {e.g., white poultry meat). The changes in texture often lead to difficulties in processing the meat, particularly for producing shelf-stable meat products such as jerky.

BRIEF SUMMARY

Disclosed herein are protein-based food products incorporating a heat-stable emulsion. The heat-stable emulsion imparts cohesiveness to a protein-based food source {e.g., animal meat or plant-based protein) and enhances the texture thereof. The heat-stable emulsion is capable of withstanding the pasteurization process {e.g., heating) of the protein-based food source.

Thus, provided herein is a protein-based food product comprising: a protein-based food source; and a heat-stable emulsion having, based on the total weight of the heat-stable emulsion: (1 ) at least 15% of water; (2) at least 40% of an oil, and (3) 0.1 -10% of an emulsifier, and wherein the heat-stable emulsion is about 0.5-20% of the weight of the protein-based food source.

In various embodiments, the emulsifier is enzyme-modified egg yolk, Quillaja extract, or a combination thereof.

In further embodiments, the emulsifier comprises a monoglyceride or diglyceride, and one or more polysorbate. In other embodiments, the emulsifier has a hydrophilic-lipophilic balance (HLB) value between 4-10.

In various embodiments, the weight ratio of the emulsifier and the oil is in the range of 0.01 -0.25.

Another embodiment provides a method of preparing a protein- based food product comprising: providing a protein-based food source;

providing a heat-stable emulsion comprising: (1 ) at least 15% of water; (2) at least 40% of an oil, and (3) 0.1 -10% of an emulsifier; and combining the heat- stable emulsion with a protein-based food source at a weight percentage of about 0.1 -20%.

A further embodiment provides a method of preparing a protein- based food product including providing a protein-based food source, incorporating a heat-stable emulsion into the protein-based food source, wherein the heat-stable emulsion is about 0.1 -20% of the protein-based food source, and drying and pasteurizing the protein-based food source incorporated with the heat-stable emulsion.

Yet a further embodiment provides a method of preparing a protein-based food product including providing a protein-based food source in a ground form, combining a heat-stable emulsion with the protein-based food source to form a batter, wherein the heat-stable emulsion is about 0.1 -20% of the protein-based food source; forming the batter into segments; and encasing the segments.

DETAILED DESCRIPTION

Disclosed herein are various embodiments directed to protein- based food products incorporating a heat-stable emulsion. In particular, the heat-stable emulsion is incorporated directly into a protein-based food source {e.g., meat) to provide enhanced texture and/or cohesiveness. The resulting protein-based food product may be further pasteurized, processed, shaped, or cooked according to known methods in the art. Protein-Based Food Source

As used herein, a protein-based food source may be derived from animals (including muscles, milk and eggs) or plants. The protein-based food source typically comprises, based on its total weight, at least 10% protein or more, and preferably at least 20% protein by weight. Typically, a predominant component of the protein-based food source is water. The protein-based food source may further comprise 0-25% fat by weight. Preferably, the protein- based food source is less than 15% fat by weight, or less than 10% fat by weight, and more preferably is less than 5% by weight of fat. The protein- based food source may be fresh or raw (unseasoned), or may contain minor amounts of additives such as spices, sugar, salt, nitrite, yeast, antioxidants, and the like.

In preferred embodiments, the protein-based food source is derived from animal muscle tissues {e.g., meat). Examples include, without limitation, pork, beef, lamb, veal, poultry (chicken or turkey), fish or game {e.g., venison). The protein-based food source may be in any form suitable for consumption, including, for example, whole muscle, ground or restructured muscle tissue. It may be in cuts low in fats and in collagen, for example tenderloin, loin, kernel of pork or veal, blade-bone of beef, breast of chicken or turkey. It may also be in cuts containing more fat and collagen, for example neck of beef, veal, lamb or mutton, chopped kernel of pork, knuckle of beef, drumstick or thigh of chicken or turkey.

In other embodiments, the protein-based food source is derived from plants, including grains, beans, legumes, and the like. In one

embodiment, the protein-based food source is a soy-based protein, such as textured vegetable protein and tofu. In another embodiment, the protein-based food source is based on wheat gluten.

In further embodiments, the protein-based food source is derived from fresh water or marine algae {e.g., cyanobaceteria). For instance, dried Spirulina contains about 51-71 % protein, most commonly 60% protein. It is a complete protein containing all essential amino acids. In certain embodiments, the protein-based food source is a blend of two or more animal and plant-based proteins. As used herein, it should be understood that "meat" may refer to both animal-based protein food sources and plant-based protein food sources (i.e., "imitation meat"). Heat-Stable Emulsion

An emulsion refers to a kinetically stable mixture of two immiscible liquids with one of the liquids dispersed as small droplets in the other liquid, which is in a continuous phase. A typical oil-in-water emulsion comprises miniscule oil droplets dispersed in a continuous water phase. While kinetically stable and having the appearance of homogeneity, emulsions are generally thermodynamically unstable due to tension at the interface of the immiscible oil and water. As a result, phase separation typically occurs at elevated

temperatures. The heat-stable emulsion according to the present disclosure, on the other hand, is capable of withstanding temperatures (>60°C) necessary to pasteurize the protein-based food source without phase separation.

By judicious selections of appropriate emulsifiers and respective ratios of the dispersed phase (oil), continuous phase (water) and the emulsifier, the heat-stable emulsions can be incorporated into the protein-based food source and do not undergo phase separation even when heated up to 71 °C.

In various embodiments, the heat-stable emulsion comprises, by percentage of the total weight of the emulsion:

(1 ) at least 15% of water;

(2) at least 40% of an oil, and

(3) 0.1 -10% of an emulsifier

.Water forms the continuous phase of the heat-stable emulsion.

At least 15% of the water is needed. The water content may be as high as 30%, and may be about 20-24%, or more typically 22-26%, or more typically 24-28%.

Oil forms the dispersed phase. Through high shear mixing, the oil phase breaks into small droplets and is dispersed in the water to form an oil-in- water emulsion. The oil typically comprises at least 40% of the total weight of the heat-stable emulsion, and more typically comprises at least 60% of the total weight. There is no limitation to the types of the oil, although plant-based oil is preferred. Examples of suitable oils include sunflower oil, olive oil, canola oil, sesame oil, cocoa butter, soybean oil, and the like.

The presence of the emulsifier stabilizes the oil-in-water emulsion. Emulsifiers are typically amphiphilic compounds, i.e., compounds that have both hydrophilic and lipophilic components, making them compatible with both oil and water. The presence of the emulsifier thus reduces the interfacial tension between the oil and water phases. As used herein, "an emulsifier" may refer to one or more amphiphilic compounds.

The suitability of the emulsifier may be evaluated by its hydrophilic-lipophilic balance (HLB), which is a measure of the relative hydrophilicity and lipophilicity. Typically, the higher the HLB value, the more hydrophilic the emulsifier is. As used herein, suitable emulsifiers have an HLB value in the range of 4-10, or more preferably in the range of 5-9. In certain embodiments, two or more emulsifiers may be used for a combined HLB value of 4-10 (inclusive of 4 and 10).

In preferred embodiments, the emulsifier is a lecithin or an enzyme-modified lecithin. Lecithin represents a class of amphiphilic

compounds sharing the characteristics of having two lipid tails and a charged or polar head. The lipid tails may be saturate or unsaturated fatty acids. The charged or polar head may be choline, phosphoric acid, phosphatidylcholine, phosphatidylethanolamine, or phosphatidylinositol. Sources for food-grade lecithin include soybean or egg yolks, from which lecithin may be extracted chemically or mechanically.

While naturally-occurring lecithin is suitable (HLB=4), it is particularly suitable to employ an enzyme-modified lecithin, which has one of the lipid tails enzymatically cleaved. An enzyme-modified lecithin provides better water dispersibility due to one fewer lipid tail and a higher HLB value (about 8). In a preferred embodiment the enzyme-modified lecithin is derived from egg yolks, and may also be referred to as "enzyme-modified egg yolk," which is commercially available. In another embodiment, the enzyme-modified lecithin is soy-based and is commercially available under the trade name of SOLEC™ K-EML (Solae, a subsidiary of DuPont). Lecithin from other sources such as sunflower seeds may also be used. A skilled person in the art would recognize that steps may need to be taken to remove allergens {e.g., egg allergens) from the lecithin source.

As alternatives to lecithin, alpha-cyclodextrins, as well as Nu-Rice (a hypoallergenic rice bran extract), or Quillaja extract (supplied by, e.g., Desert King International) may also be used as the emulsifier.

In other embodiments, the emulsifier may be a monoglyceride, diglyceride or a combination thereof. Monoglyceride has a single lipid chain coupled to a glycerol, whereas diglyceride has two lipid chains coupled to a glycerol. Monoglycerides and diglycerides as emulsifiers distinguish from fat molecules, which are triglycerides. Optionally, polysorbate may be combined with monoglyceride and/or diglyceride to enhance the stabilizing effect.

Polysorbate 60 or polysorbate 80 are suitable food-grade emulsifiers.

The emulsifier is typically in an amount of about 0.1 -10% of the total weight of the heat-stable emulsion. More typically, the amount of the emulsifier is at least about 1 % of the total weight of the emulsion. In various embodiments, the emulsifier is about 4% or about 6% of the total weight of the emulsion.

The ratio of the emulsifier and the oil can also be an important parameter to control or adjust for the stability of the emulsion. In various embodiments, the ratio is typically in the range of 0.01 -0.25, and more typically in the range of 0.05-0.2, or more typically in the range of 0.05-0.1 .

In certain embodiments, the heat-stable emulsion may further comprise a thickener. A thickener increases the viscosity of the emulsion, and may enhance the stabilizing effect of the emulsifier, especially an emulsifier that has an HLB value at the lower end of the range. Typical thickeners include polysaccharide-based additives, such as gum and starch. Gums are natural or synthetic polysaccharide-based food additives. They often serve as thickeners, viscosity modifiers, emulsifiers or binders {e.g., for holding water). Suitable gums include, for example, gum Arabic, gum tragacanth, gum carrageenan, Xanthan, alginate {e.g., propylene glycol alginate), guar, agar-agar, cellulose, gellan, hydroxypropyl cellulose, Konjac gum, locust bean gum, and pectin.

Starch is also a common polysaccharide-based food additive. Starch generally has less thickening power than gum.

The heat-stable emulsion may further comprise an antioxidant, which serves as a preservative to prevent lipid oxidation. Examples of antioxidants include, but are not limited to, vitamin E, C0Q10, tocopherols, lipid soluble derivatives of more polar antioxidants such as ascobyl fatty acid esters {e.g., ascobyl palmitate), plant extracts {e.g., rosemary, sage, green tea extracts and oregano oils), algal extracts, as well as synthetic antioxidants, e.g., butylated hydroxytoluene (BHT), tertiary butylhydroquinone (TBHQ),

ethoxyquin, alkyl gallates, hydroquinones, and tocotrienols.

The heat-stable emulsion may further comprise a chelating agent, which serves as a preservative and binds to metal ions {e.g., iron and copper) in meat in order to prevent the metals from oxidizing and causing spoilage. Suitable chelating agents include, for example, EDTA, gluconic acid, citric acid, ascorbic acid (vitamin C), lactic acid, phosphate, mannitol, and Vitamins D, E, or K.

The heat-stable emulsion is prepared by first mixing all the weighted components except for the oil in a high shear mixer. Typically, multiple blades spinning at high velocity are used to break the oil particle size down to small globules. Any high-speed mixer in food processing may be used, for example, a Silverson Mixer, Breddo Liquefier, or a bowl chopper.

Equipment designed specifically for creating emulsions, such as a mayonnaise, are preferred.

After the other components are fully mixed and incorporated, with the mixer running, oil is then added at a certain rate. The rate of addition is typically in the range of 3 Ib/min to 8 Ib/min, and preferably at about 5 Ib/min. If the oil is added too fast, the emulsion may break and lose stability. If the oil is added too slowly, the existing emulsion may be over-mixed and may start leaching oil.

In a preferred embodiment, in a the protein-based food product, the protein-based food source is poultry meat, the heat-stable emulsion comprises sunflower oil, water, Quillaja extract, and a blend of rosemary and green tea extracts.

The heat-stable emulsion, unless used within hours, should be stored at refrigerated temperatures {e.g., 35-41 °F) for extended shelf life as well as tempering for meat application in order to inhibit meat spoilage. The emulsion is ready to use at refrigerated temperatures.

Incorporating the Heat-Stable Emulsion

In various embodiments, the heat-stable emulsion is incorporated into a protein-based food source at about 0.5-20% or about 0.5-10% by weight of the protein-based food source. Typically, the protein-based food source is raw and no special treatment is necessary prior to incorporation of the emulsion. The meat is generally maintained at an ambient temperature of below 50°F to prevent spoilage.

Thus, one embodiment provides a method of preparing a protein- based food product comprising: providing a protein-based food source;

providing a heat-stable emulsion comprising: (1 ) at least 15% of water; (2) at least 40% of an oil, and (3) 0.1 -10% of an emulsifier; and combining the heat- stable emulsion with protein-based food source at a ratio of about 0.1 -20%.

Depending on the types and applications of the protein-based food source, the heat-stable emulsion may be at about, by weight, 0.5-1 %, 1 - 5%, 2-6%, 3-7%, 4-8%, 5-9%, 6-10%, 7-15%, 10-15%, or 15-20% of the protein-based food source.

In certain embodiments, the heat-stable emulsion is used as a marinade, or more typically, a part of a marinade (e.g., brine), into which the protein-based food source (e.g., whole muscle meat) is immersed. The marinade may further comprise acidic ingredients (vinegar, lemon juice or wine), salt, enzyme, spices, or herbs. Soaking allows for a passive infiltration of the emulsion into the meat. Marination should take place at refrigerated temperature to inhibit bacteria growth, and may last for a period of time sufficient for a desired amount of marinade to be incorporated. The marinating period typically lasts anywhere from several hours to 24 hour, up to 72 hours.

In other embodiments, the heat-stable emulsion (alone or as a part of a marinade) is injected directly into the protein-based food source {e.g., whole muscle meat). A plurality of micro-needles may be used to provide uniform distribution of the emulsion. Similar to immersive marination, the injected emulsion may be allowed to remain or marinade for several hours to 24 hours, up to 72 hours.

In further embodiments, the heat-stable emulsion is mixed directly with the protein-based food source in a ground form {e.g., sausage batter). As in all manners of incorporating the emulsion in meat, the mixing is typically carried out at refrigerated temperature. The resulting mixture may be

immediately processed.

Processing the Protein-Based Food Product

As discussed herein, the protein-based food product comprises a protein-based food source incorporated with a heat-stable emulsion. The heat- stable emulsion enhances the texture of the protein-based food source {e.g., whole muscle meat) and imparts cohesiveness {e.g., batter). Once the emulsion is incorporated, the resulting protein-based food product may be processed based on the intended applications of the protein-based food source by known methods in the art.

For example, in a whole muscle application, e.g., jerky making, the meat {e.g., beef or chicken) may be tumbled (with or without vacuum), followed by marination with a marinade for 24 hours, the marinade comprising the heat-stable emulsion and a brine. The meat may be tumbled again briefly to break up the muscle tissue and redistribute the brine. The meat is then flattened and sliced to desired shape before being dried and pasteurized at about 65°C -71 °C. Advantageously, the presence of the heat-stable emulsion enhances the texture and palatability of jerky made from low-fat meat without adding a significant amount of fat. As a result, low-fat beef jerky becomes tender and poultry-base jerky becomes less flaky.

Thus, one embodiment provides a method of preparing a protein- based food product comprising: providing a protein-based food source, incorporating a heat-stable emulsion into the protein-based food source to provide a protein-based food product, wherein the heat-stable emulsion is about 0.1 -20% of the protein-based food source, and drying and pasteurizing the protein-based food product.

In further embodiments, the drying and pasteurizing are carried out at a temperature of about 65-71 °C.

For a batter application, the ground meat is directly mixed with the heat-stable emulsion. The mixture may be extruded directly into sausage casing and pasteurized. Advantageously, the presence of the heat-stable emulsion enhances the texture and extrudability of the ground meat, especially for a low-fat meat source.

Thus, one embodiment provides a method of preparing a protein- based food product comprising: providing a protein-based food source in a ground form, combining a heat-stable emulsion with the ground protein-based food source to provide batter, wherein the heat-stable emulsion is about 0.1 - 20% of the protein-based food source; forming the batter into segments; and encasing the segments.

The embodiments described herein are further illustrated in more detail by the following non-limiting examples. EXAMPLES

EXAMPLE 1

PREPARATION OF A HEAT-STABLE EMULSION

All ingredients are pre-weighed and portioned in separate containers. A high shear mixer {e.g., Silverson Mixer, Breddo Liquefier, or a bowl chopper ) is cleaned and prepped for use. Water (25%), enzyme modified egg yolk (6%), chelating agents and antioxidants (<0.5%) by weight are added to the clean mixer and the mixer is turned on. The ingredients are allowed to mix until fully incorporated. At this time the oil (68%) is slowly added to the mixer over time (5.04 Ibs/min) with the mixer speed on high. Once all the oil is incorporated, the mixer is shut off and the emulsion removed and stored at refrigerated temperature until needed.

EXAMPLE 2

A HEAT-STABLE EMULSION FOR A JERKY MARINADE 18% water, 6% enzyme modified egg yolk based lecithin and 76% canola oil by weight are mixed in a high shear mixer to provide a heat-stable emulsion. Optionally, a gum such as gum Arabic, gum tragacanth, gum carrageenan, Xanthan, propylene glycol alginate, or guar may be added to the emulsion.

The emulsion is incorporated into a lean cut beef {e.g., top round steak, flank steak or rump roast) in an amount of 0.5% to 1 .0% by weight.

From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. § 1 19(e) to U.S. Provisional Application 61/759,212 filed January 31 , 2013, which application is incorporated by reference herein in its entirety.