Factors that affect the thermal stability of whey protein emulsification system.

Li Xiangyu Yu Daozheng Xiaomin Wang Zhiming Li Boling Jia Biyou Bioengineering (Wuhan) Co., Ltd./Hubei Province Nutritional Chemical Biosynthetic Engineering Technology Research Center .Wang Feng Hubei Province Nutritional Chemicals Biosynthetic Engineering Technology Research CenterWhey protein is a by-product of whey produced during the production process of cheese, after a special process to concentrate refined a class of proteins. In recent years, more and more milk powder enterprises use whey protein as raw material. Not only is it natural and non-toxic, it also provides the necessary protein for the human body, and whey protein has a faint milky aroma and strong emulsification. Whey protein can be well distributed on the surface of unsaturated fatty acids, delaying the oxidation of unsaturated fatty acids. However, because whey protein is a thermal protein, the solubility in water after thermal denaturation decreased significantly, directly affecting its functional characteristics, so that its use range is limited. Because the thermal stability of whey protein has an important influence on its physiological activity and product characteristics, the study of its stability has become a link that can not be ignored in the production process of milk powder.in the process of preparation emulsification system, whey protein will be adsorbed to the surface of the grease, reduce the free energy of the surface of the grease, and maintain the stability of the emulsification system. During the heating process, the structure of whey protein will change, in the initial heating phase, whey protein began to expand, with the degree of heating, whey protein molecular structure open, at this time whey protein emulsification capacity is optimal. Add other wall materials for shearing, wait for the wall material to fully dissolve and then add oil phase together to cut 10min, homogeneity after the formation of o/w type emulsion. In the process of preparation of whey protein emulsion, the factors affecting the thermal stability of whey protein emulsion are heating conditions, salts (e.g. hydrogen phosphate ddi potassium), homogeneous pressure, different fillers in the wall material, etc., they will denature whey protein, thus destroying the whole whey protein emulsification system. This paper mainly studies the effect of these factors on whey protein emulsification system, and discusses how to produce a satisfactory whey protein emulsification system by controlling and utilizing these factors during the preparation of emulsion.Materials and MethodsExperimental MaterialsPeanut tetryrene oil (Kabiyu Bioengineering (Wuhan) Co., Ltd.), Whey Protein (Hilmar), Maltodextin DE value of 20 (Cargill), a water crystalline glucose (Cargill), hydrophosphate d potassium phosphate (national medicine).test instrumentsshear emulsification machine (Shanghai Sovi Electrical and Mechanical Equipment Co., Ltd.), high-pressure homogeneity machine (Shanghai Donghua high-pressure homogeneity plant), Malvern viscosity meter (Malvern Instrument Co., Ltd.).Experimental MethodFirst dissolves the wall material in pure water, emulsifying machine 12000r/min shearing 10min, adding peanut tyrenate oil to continue cutting 10min, using high-pressure homogenizer 30MPa homogenous pressure cycle homogenous 80s, to obtain a whey protein emulsion.the viscosity of the emulsified liquidthe viscosity of the homogenous material is measured with a Bohlin Visco 88 viscosity meter to obtain the viscosity curve under different temperature conditions.parameter setting of the viscosity meter: rouser C30; Shear Value: 600; Delay Time: 5s; Integration Time: 5s; Wait Time: 2s; Number of Samples: 30; Total test time: 360s.factors that affect the thermal stability of whey protein emulsionthe effect of heating conditions and the effect of heating treatment temperature and time on whey protein emulsification system. The structure of whey protein solution will change during the heating process, at the beginning of heating, the molecular structure of whey protein gradually opened, with the increase of heating degree, when the temperature is greater than 70 degrees C, whey protein gradually denatured.whey protein emulsion: 5% whey protein, 32% peanut tetrene oil, 25% maltodext, 1% hydrophosphate potassium. After even shearing, the homogeneity is matched to emulsion. Divide the preparation of the lotion into 2 small cups, 30g each, and keep warm in hot water at 80C and 70C respectively.1, the higher the temperature, the faster the protein emulsion denatures, resulting in a surge in the viscosity of the solution.effects of phosphate (e.g. hydrophosphate)the addition of salts (e.g. hydrophosphate) has an effect on the whey protein emulsification system. Preparation of whey protein emulsion, formula 1: 5% whey protein, 32% peanut tetrenate oil, 30% maltodext, 5% hydrophosphate potassium; The materials in the above two formulations are called well, cut homogenously and then formulated into emulsion. Divide the preparation lotion into 2 small cups, 30g each, and keep warm in 70C hot water.as can be seen from Figure 2, hydrophosphate ddi potassium phosphate has a great influence on whey protein emulsion degeneration, with the increase of hydrophosphate d potassium hydroxide addition, whey protein emulsion denaturation time significantly earlier, the solution viscosity significantly increased.of homogeneity pressure according to the formula called to take the corresponding materials, cut, respectively, 30, 35, 40, 45MPa cycle homogenization 10s.3, as homogeneity increases, the more easily the protein emulsion denatures, and the greater the viscosity.of different fillers in the walldifferent fillers in the wall material have an effect on whey protein emulsion. According to the following formula preparation emulsion, formula 1: 5% whey protein, 32% peanut tetrene acid oil, 30% maltodext, 1% hydrophosphate potassium ddi potassium; According to the above two formulations called good material, cut homogeneity and then added to the emulsion, put in 72 degrees C hot water insulation.As can be seen from Figure 4, formula two has a better insulation effect, mainly because formula two of the first water crystalline glucose and whey protein merade reaction, so that hydrophobic groups in the water-oil interface denaturation, dissolved in oil droplets, hydrophobic polysaccharide part dissolved in water, thereby improving emulsification stability.conclusionwhey protein degeneration is a complex process, and there are many factors that affect protein denaturation. This paper mainly studies the effects of heating conditions, salts, homogeneity pressure, different fillers and other factors on the whey protein emulsification system.The effect of heating conditions on whey protein emulsification system: at the beginning of heating, the molecular structure of whey protein gradually opened, with the increase of heating, heat treatment destroys the hydrogen bond of whey protein molecules, so that the whey protein molecular chain unfolds, through co-priced bonds such as sulfur bonds to promote protein polymerization, forming an orderly three-dimensional mesh structure. When the temperature is greater than 70 degrees C, the protein molecules gradually form a three-dimensional mesh structure over time, resulting in more and more whey protein denaturation, and denatured whey protein irreversible, which in turn destroys the entire whey protein system. Therefore, when making whey protein emulsion, the whole system should be controlled to a reasonable temperature range.Effects of salts (e.g. hydrogen phosphate dikalasium) on whey protein emulsification systems: The solubility of whey protein in aqueous solutions is determined by the degree to which hydrophobic groups and water around the protein form hydration membranes and the charge on protein molecules. When hydrophosphate di potassium phosphate is added to the whey protein emulsion, the affinity of hydrophosphate di potassium di potassium phosphate to the water molecule is greater than that of whey protein, which causes the hydration film layer around the protein molecule to weaken or even disappear. At the same time, hydrogen phosphate d potassium oxide into the whey protein, due to changes in ion strength, the protein surface charge is largely moderated, resulting in a decrease in the solubility of whey protein, so that protein molecules gather and precipitate. With the addition of hydrophosphate d potassium phosphate, the more severe whey protein denaturation, emulsification system damage is greater, so the preparation of whey protein du potassium phosphate to control the addition of hydrophosphate.homogeneity pressure on the whey protein emulsification system: homogeneity pressure mainly acts on the whey protein molecules between the two sulfur bonds, so that the whey protein molecules after homogenization through the non-co-priced bond crosslinking, destroying the protein's two-dimensional results, resulting in protein denaturation. However, since this degeneration is reversible, reasonable homogeneous pressure should be controlled when preparation of whey protein lotions.effects of different fillers in the wall material on whey protein emulsions: by adding a water glucose to the preparation of whey protein emulsions, a water glucose and whey protein are subjected to a merad reaction under heating conditions, thereby improving the solubility of whey proteins.by studying the effects of these factors on whey protein degeneration, we can help us to suppress and utilize the adverse effects of thermal protein and establish a more rational whey protein emulsification system.
.