Soybeans emulsifying properties

Soybean lecithins can be chemically altered to modify their emulsifying properties and improve their dispersibihty in aqueous systems. Phospholipids may be hydrolyzed by acid, base, or enzyme to achieve better hydrophilic and emulsification properties. Hydroxylation of lecithin improves its oil-in-water emulsification property and water dispersibihty. Acetylation creates improved fluidity and emulsification, water dispersion properties, and heat stability (200). 

As cottonseed lecithin contains only trace amounts of fatty acids with more than two double bonds (linolenic acid), it is more stable to oxidation and rancidity than soybean lecithin. Cottonseed phospholipids are relatively high in phosphatidylcholine, which could provide good emulsifying properties in foods (32, 37). 

Cyclic adenosine monophosphate-dependent protein kinase is useful for phosphorylation of a.a. residues in mild conditions. The modification makes the soybean proteins soluble in media rich in calcium and improves their emulsifying properties (Seguro and Motoki, 1990). 

Smiles, A., Kakuda, Y. and MacDonald, B.E. (1989) Effect of degumming reagents on the composition and emulsifying properties of canola, soybean and sunflower acetone insolubles. J. Am. Oil Chem. 

Definition End prod, of controlled hydrogenation of soybean monoglycerides Properties Nonionic Uses Emulsifier, emollient, stabilizer, dispersant, opacifier for cosmetics, foods, pharmaceuticals lubricating greases synthetic waxes textile lubricants antistat, lubricant, processing aid in plastics, nonwoven fibers dispersant for color cones. defoamer in food-contact paper/paperboard in food-contact textiles... 

Although emulsifying properties of sunflower lecithin are not considered to be worse than those of soybean lecithin, users are reluctant to apply it because its consistency is even more paste-like than that of natural soybean lecithin, so it is difficult to handle. Reviewing the technical literature, it was obvious that some modification can solve this problem. 

The present study was conducted to obtain additional information on changes in soy protein subunits during limited proteolysis. Enzymatic soy protein deamidation that occurred, in addition to limited proteolysis, during germination of soybean seeds was investigated. The effects of proteolysis and deamidation on solubility and emulsifying activity were compared. Phosphorylation of soy protein with a commercially available protein kinase and its effects on subsequent changes in functional properties of the protein were also studied. 

Reversibly insolubilized soybean protein products possess various functional properties, such as binding, emulsification effect, etc. These functionalities may appear when the native protein molecules are unfolded during heating in food processing. Therefore these products, such as soybean protein isolate, are useful as binders or emulsifiers for sausage, hams, etc. 

Lin et al. (15) showed that sunflower meal was superior to soybean and sunflower concentrates or isolates In emulsion capacity. McWatters and Cherry (9) compared select functional properties of defatted soybean, peanut, field pea, and pecan flours and showed that major seed storage proteins were important in emulsifying and foaming properties. Protein solubility was related to the quality of the emulsions and foams. Behavioral characteristics contributed by nonprotein components that occur naturally In the seeds, especially carbohydrates, were Implicated. 

The most common modifications of lecithin and the intended physical/functional alterations are shown in Table 20 (31). The range of physical/functional properties available in commercial lecithins is listed in Table 21 (31). These changes in lecithin allow for the basic lecithin obtained from soybean oil to be converted to various emulsifier products having a wide variety of food, feed, and industrial applications. Reviews describing chemical reactions for phospholipid modifications intended to obtain specific functionalities include those of Eichberg (89), Hawthorn and Kemp (90), Kuksis (91), Pryde (86), Snyder (92), Strickland (87), and Van Dee-nen and DeHaas (93). 

Lecithin has some catalytic or cocatalytic effects in multiphase systems because of its surface-active properties. Lecithin is reported to be useful as an emulsifier in the curing of aqueous dispersions of unsaturated polyesters (337). The products are more easily removed from their molds and have improved mechanical properties when lecithin is used. In a fermentation application, 1.5% soybean lecithin acts as an inducer in the preparation of cholesterol esterase using a strain of Pseudomonas bacteria (338). Aside from its role as a catalyst, initiator, or modifier, lecithin may have ancillary uses in catalyst systems as part of a protective coating (339). 

K. Taiwo, H. Karbstein, and H. Schubert [/. Food Process Eng., 20, 1-16 (1997)] studied the influence of temperature on the kinetics of adsorption of a variety of food emulsifiers at oil-water interfaces. They used interfacial tension measurements to monitor the rate at which egg yolk present at 10 times its critical micelle concentration was transferred to a water-soybean oil interface. The rates of these processes are important in assessing the potential stability of oil-in-water emulsions of the type found in salad dressings and mayonnaise. The interfacial tension can be viewed as a property that reflects the contributions of the various species present at the interface, being an additive function of these contributions. Each individual contribution is proportional to the quantity of the material in question located at the interface between the oil and the water. The reaction of interest can be regarded as... 

Definition PEG deriv. of sterols found in soybean oil with avg. 25 moles EO Properties HLB 17.0 nonionic Uses Emulsifier, solubilizer, emollient, pigment... 

Definition PEG deriv. of sterols obtained from soybean oil with avg. 30 moles EO Properties Nonionic Uses Emulsifier in cosmetics PEG-40 soy sterol... 

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