JPH0463663B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for preserving emulsified foods. [Prior Art] Conventionally, a method of preserving emulsified foods at temperatures above 0° C. has been adopted, but the storage period is short. If the temperature is lower than 0°C in an attempt to extend the storage period, there are problems such as ice formation, destruction of the emulsification system, and coalescence/aggregation of oil droplets and syneresis. The emulsified food mentioned in this specification is a food whose main characteristic is that it is an emulsion formed from water and oil, and specific examples thereof include whipped cream (including whipped products). , coffee whitener, fresh cream, mayonnaise, dressing, milk, butter, margarine, sauces, etc. For example, if whipped cream is refrigerated before whipping, UHT sterilization is required for preservation.
The flavor of fresh cream deteriorates due to sterilization, and the shelf life of pasteurization, which has relatively little flavor deterioration, is 3 to 4 days. In addition, during the distribution process of chilled products, freezing sometimes occurs, which causes coalescence and aggregation of oil droplets, resulting in oil separation and creaming, and melted polymers such as proteins undergo freezing denaturation, causing aggregation. As a result, syneresis and a decrease in whipping properties may occur. On the other hand, if whipped cream is refrigerated after whipping, spoilage will occur within 3 to 7 days even at temperatures below 7 to 8 degrees Celsius. Also, if it freezes, the whipped product becomes hard and has a bad texture, causes syneresis, cracks, and other tissue damage, and the emulsion is destroyed, so the oil will separate at 15-20℃. Because of this, thawing at high temperatures of 20 to 30 degrees Celsius is not possible. Furthermore, thawing at a temperature of 0 to 15°C takes time and is accompanied by deterioration, so thawing is difficult. [Problems to be solved by the invention] The present invention solves the problem that the storage period of emulsified foods is short, and if the temperature is lowered to extend the storage period, ice will form and the emulsification system will be destroyed, resulting in coalescence and aggregation of oil droplets. This is an attempt to solve problems such as syneresis. [Means for Solving the Problems] The present invention provides that 100 parts of water (parts by weight,
Store the emulsified food containing 0.03 to 10 parts of protein (hereinafter referred to as MP) modified with an amino acid ester esterified with an aliphatic alcohol having 4 to 13 carbon atoms at 0 to -10°C. The present invention relates to a method for preserving emulsified foods characterized by: [Example] As the protein used in the present invention, for example, casein, gelatin, albumin, lactalbumin, soybean protein, fish protein, etc. can be suitably used, but the protein is not limited thereto. When these proteins are poorly soluble in water, such as casein, they may be acylated or succinylated to increase their water solubility. In the present invention, the protein is modified with an amino acid ester esterified with an aliphatic alcohol having 4 to 13 carbon atoms using oxygen or by a conventional chemical method to produce MP used as an emulsified food preservative. Ru. As the amino acid constituting the amino acid ester, hydrophobic amino acids such as leucine, norleucine, and alanine are preferably used, but the amino acid is not limited thereto. As the number of carbon atoms in the aliphatic alcohol constituting the amino acid ester decreases, the foaming power of the produced MP tends to increase, and as the number of carbon atoms increases, the emulsifying power tends to increase. Specific examples of MP in the present invention include succinylcasein leucine dodecyl ester, gelatin leucine decyl ester, gelatin leucine dodecyl ester, etc., and have a molecular weight of 2,000 to 40,000 daltons. When enzymes are used to modify proteins with amino acid esters, thiol proteases such as papain, bromelain, and ficin are preferably used. Specific examples of modifying proteins with amino acid esters using enzymes include Watanabe et al.
As described in J. Food Sci, 46 1467-1469 (1981), it can be obtained by reacting a protein and an amino acid ester with oxygen in an aqueous solvent. The aqueous solvent used in this case is, for example, water-acetone or water-ethanol, and a thiol protecting agent such as 2-mercaptoethanol or cysteine is used to make the reaction system homogeneous and to prevent the enzyme reaction. This is preferable from the viewpoint of efficient progress. This method is easy to perform, so
It is possible to produce large quantities on an industrial scale. Reaction conditions may be selected appropriately depending on the type of protein, enzyme type, amino acid ester, etc., but usually the reaction system is adjusted to pH 7-10, and pH 5-50.
The reaction may be carried out at ℃ for 0.25 to 24 hours. A specific example of producing MP by a chemical method is a method in which a mixture of a protein and an amino acid ester is covalently bonded to a protein by ultrasonication, but the method is limited to this method. It's not a thing. The obtained MP may be used as it is, or may be used after being dried by a method such as freeze-drying. The amount of MP added is 100% water in emulsified foods.
0.03 to 10 parts, preferably 0.03 to 5 parts. If the amount is less than 0.03 parts, no antifreeze effect will occur. On the other hand, even if the amount of MP used exceeds 10 parts, it is difficult to freeze the emulsified food at a temperature below about -10°C. As a method of adding MP to emulsified foods, it is preferable to add MP to water when producing emulsified foods because it can be mixed easily and uniformly, but it is not limited to such a method.
Any method may be used as long as the emulsified food and MP are not denatured. As mentioned above, when emulsified foods contain MP, a supercooling phenomenon occurs even when the emulsified foods are heated to freezing temperatures, allowing them to be stored for long periods of time without freezing. and substances that have a freezing point lowering effect, such as salts such as table salt, sugars such as sucrose, glucose, and fructose, sorbitol,
When used in combination with sugar alcohols such as maltitol, the supercooling phenomenon can be further stabilized than when MP is used alone, and the supercooling phenomenon can also be caused at lower temperatures. It goes without saying that when salts, sugars, etc. are added to emulsified foods, there is no need to add salts, sugars, etc. Furthermore, even if emulsified foods containing MP are frozen, the flavor and properties of thawed emulsified foods are closer to those of unfrozen emulsified foods than those of emulsified foods.
Less freezing damage. The reason for this is not clearly elucidated, but it is thought that it is because ice crystals do not grow large when MP is used, making it difficult to destroy the structure of emulsified foods. Next, the preservation method of the present invention will be explained based on examples. Production example 1 1M carbonate buffer (PH9) containing 10mM cysteine and 20% (wt%) ethanol
Add commercially available gelatin to a concentration of 33%, and add L-leucine dodecyl ester to the gelatin.
0.1M was added to 100g, and 1g of papain was added to 100g of gelatin. Thereafter, the reaction was carried out at 37°C for 15 minutes, and then 1N hydrochloric acid was added to lower the pH to 1 to stop the enzyme reaction, and the non-dialyzable fraction was collected by running water dialysis. The lyophilized non-dialyzable fraction was washed with dichloromethane and acetone to obtain purified enzyme-modified gelatin (hereinafter referred to as EMG-12) with an average molecular weight of 7300 daltons.
) was obtained. Example 1 and Comparative Example 1 Water was added so as to have the following composition, heated to 40°C, and stirred while adding whole milk powder, sucrose fatty acid ester, sodium polyphosphate, xanthan gum, casein soda, flavoring agent, and Production Example 1 was produced
After dissolving EMG-12, the temperature was raised to 60°C, stirring was stopped, and the mixture was allowed to stand still for degassing. Separately, hydrogenated palm oil and refined coconut oil were mixed and stirred at 60°C to have the following composition.
Propylene glycol fatty acid ester and sorbitan fatty acid ester were dissolved, this oil solution was added to the previously prepared aqueous solution, and the mixture was mixed and stirred using a stirrer at 60° C. to pre-emulsify.

【table】

[Table] Next, the pre-emulsified liquid was homogenized using a homogenizer by applying a homogeneous pressure of 30 kg/cm ² G, then 80 kg/cm ² G, cooled to 10°C, transferred to a 500 ml plastic container, and It was left overnight in the refrigerator at ℃. After that, this material was heated to -5℃, -10℃, -15℃,
Store at each temperature of -20℃ for 20 days, and after thawing (20℃,
(Left for 24 hours) The properties shown in Table 1 were investigated. (Oil separation) Evaluated by whether or not there is oil separated on the surface. −: None +: Slightly present ++: Present (agglomeration) Evaluated based on the presence or absence of aggregates. -: None ±: Slightly present +: Present ++: A large amount (syneresis) Evaluate based on the presence or absence of syneresis. -: Not present +: Slightly present ++: Present (flavor) Evaluated by 5 panelists. △: Fair ○: Good (whipability) Evaluated by overrun after whipping. (Fluidity before thawing) Evaluate the fluidity before thawing. -: No liquidity +: Slightly illiquid ++: Slightly illiquid

[Table] On the other hand, after leaving the liquid in the refrigerator at 5℃ and whipping it to an overrun of 130 to 150, -5
The samples were stored at temperatures of -10°C, -15°C and -20°C for 20 days, and after thawing, the properties shown in Table 2 were evaluated by the following methods. (Cracks) −: None +: Slightly present ++: Present (melt in the mouth) Sensory evaluation was performed by five panelists. (Physical properties before thawing) Check to see if a spoon can fit in.

〔Effect of the invention〕

According to the method of the present invention, emulsified foods can be
Since it can be stored at a low temperature of °C without freezing, it can be stored for a long period of time without destroying the emulsion system, and without causing oil droplets to coalesce or aggregate or syneresis. Even if it is frozen, the flavor and properties of the thawed product will be affected by MP
It is similar to an unfrozen emulsified food and has fewer freezing problems than those without the addition of .

Claims (1)

[Claims] 1. An emulsified food containing 0.03 to 10 parts by weight of a protein modified with an amino acid ester esterified with an aliphatic alcohol having 4 to 13 carbon atoms per 100 parts by weight of water in the emulsified food at 0 to -10°C. A method for preserving emulsion-based foods characterized by preserving them.