Emulsifying capacity and stability

Emulsifying capacity and stability were measured by Ogungbenle (2003), Oshodi et al. (1999), and Ogungbenle et al. (2009) they found an emulsifying capacity of 104% with a stability of 45% (according to the methods... 

A.N. Gurov, M.A. Mukhin, N.A. Larichev, N.V. Lozinskaya and V.B. Tolstoguzov, Emulsifying properties of proteins and polysaccharides, I, Methods of determination of emulsifying capacity and emulsion stability, Colloids Surfaces 6 (1983) 35-42. 

The emulsifying properties of proteins have been a subject of concern for those dealing with functional properties of proteins. The studies so far have been restricted to two main approaches emulsifying capacity and emulsion stability measurements. The former measures the maximum oil addition until inversion or phase separation of the emulsion occurs, whereas the latter measures the ability of the emulsion to remain unchanged. 

Emulsion Capacity and Stability. The emulsion capacities of the three protein preparations are shown in Table IV. and again both the unheated and microwave treated samples were significantly superior to that of the hot water process. Although it is difficult to relate these data to those of other workers, since a wide variety of conditions are employed for measuring this property, it has generally been found that emulsifying properties are related to the aqueous solubility of proteins (7.) which further bears on the capacity of proteins to lower interfacial tension between hydrophobic and hydrophilic components. 

Grant (58), single-cell protein concentrates by McElwain et al. (59), and fish protein by Groninger and Miller (60) and Chen et al. (61). Succinylated fish myofibrillar protein had rapid rehydration and good dispersion characteristics at neutral pH (60). Succinylation of fish protein concentrate improved its emulsifying capacity and emulsion stability (61). 

Emulsifying capacity and emulsion stability —sausages, mayonnaise, soups, breads... 

Sherman, P. (1995) A critique of some methods proposed for evaluating the emulsifying capacity and emulsion stabilizing performance of vegetable proteins. /. Food Sci., 1,3. 

The presence of a thermodynamically incompatible polysaccharide in the aqueous phase can enhance the effective protein emulsifying capacity. The greater surface activity of the protein in the mixed biopolymer system facilitates the creation of smaller emulsion droplets, i.e., an increase in total surface area of the freshly prepared emulsion stabilized by the mixture of thermodynamically incompatible biopolymers (see Figure 3.4) (Dickinson and Semenova, 1992 Semenova el al., 1999a Tsapkina et al., 1992 Makri et al., 2005). It should be noted, however, that some hydrocolloids do cause a reduction in the protein emulsifying capacity by reducing the protein adsorption efficiency as a result of viscosity effects. 

Tornberg and Ediriweera, 1987). Phase inversion temperature (Shinoda and Saito, 1969) and emulsifying capacity (Swift et al., 1961) have been used to evaluate the effects of low molecular weight and protein emulsifiers, respectively. Unfortunately, it is not possible to measure the size of the large droplets present in unhomogenized water-in-oil emulsions because the droplets coalesce very quickly. The phase inversion temperature is not a relevant test, as it may not be related directly to the stability to inversion at the emulsification temperature. Furthermore, it has been stated (Matsumoto and Sherman, 1970) that water-in-oil emulsions do not exhibit a true phase inversion temperature, unlike oil-in-water emulsions. 

Emulsion Capacity. Enzymatic digestion of proteins beyond 10 min, except the trypsin-treated sample for 30 min, destroyed emulsifying capacity of the flour (Figure 13). Apparently, hydrolysis substantially altered protein surface activity strengths and the ability of the protein to stabilize oil-in-water emulsions. This assumption agrees with earlier work showing decreased emulsion capacity of peanut flour fermented with fungi (27). 

Succinyl- ation Increased solubility at acidic pH, increased tolerance to Ca +, good foam capacity, stability, emulsifying activity and emulsion stability. More resistance to aggregation. Lowered viscosity (12)... 

Succinylation increased the emulsifying activity and emulsion stability of soy and cottonseed proteins (12,38). The pH emulsifying capacity profiles of succinylated protein paralleled those of the solubility curves and in all cases the succinylated protein had about double the emulsifying capacity of the unmodified... 

Kazmi SJA, Mitchell AG. Preservation of solubilized and emulsified systems II theoretical development of capacity and its role in antimicrobial activity of chlorocresol in cetomacrogol-stabilized systems. J Pharm Sci 1978 67 1266-1271. 

Stearyl alcohol is used in cosmetics and topical pharmaceutical creams and ointments as a stiffening agent. By increasing the viscosity of an emulsion, stearyl alcohol increases its stability. Stearyl alcohol also has some emollient and weak emulsifying properties and is used to increase the water-holding capacity of ointments, e.g. petrolatum. In addition, stearyl alcohol has been used in controlled-release tablets, " suppositories, and microspheres. It has also been investigated for use as a transdermal penetration enhancer. ... 

Euston et al. (2001) found that whey protein concentrates with low degree of hydrolysis (4—10%) impaired the emulsifying capacity of whey protein concentrate but increasing the degree of hydrolysis to 10-27% improved emulsifying capacity. However, further increases in the degree of hydrolysis reduced emulsion stability and heat stability of emulsions. 

Spinelli et al. (14) determined the emulsion stability and emulsion capacity of polypeptides recovered from hydrolysates of fish myofibrillar protein using hexametaphosphate. In general the emulsion capacity and emulsion stability increased through 30 min of proteolysis but then declined. Even the unhydrolyzed protein-phosphate complex yielded better emulsion stability and capacity values compared with sodium caseinate. The effect of the residual hexametaphosphate in the hydrolysate conceivably could have a beneficial effect on emulsifying characteristics of the modified fish myofibrillar proteins. 

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