Whey proteins enzymatic

Wijers, M.C., Pouliot, Y., Gauthier, S.F., Pouliot, M., and Nadeau, L. 1998. Use of nanofiltration membranes for the desalting of peptide fractions from whey protein enzymatic hydrolysates. Le Lait 78, 621-632. 

Nakamura, T., (1993). Production of low antigenic whey protein hydrolysates by enzymatic hydrolysis and denaturation with high pressure, Milchwiss., 48, 141-147. 

Figure 8. Effect of enzymatic hydrolysis on specific volume of foam obtained by whipping a heated whey protein sol (4% w/w, 85°C, 6 min whipping) (43)...

A cheese-like spread, which is similar to processed cheese spread, is prepared by combining hydrolyzed Swiss-or Cheddar-whey protein and cultured cream. The whey protein is precipitated by heat and acid. The granular, chalky precipitate then acquires a smooth texture by enzymatic hydrolysis with Rhozyme P-11 at 39.5 to 40.5 °C for 30 min. The product is heated to 85 °C for 15 min to inactivate the enzymes then it is homogenized and blended with an equal quantity of 45° cream culture containing Lactobacillus casei (Webb and Whittier 1970). 

Faergemand, M., Otte, J., Qvist, K.B. 1998. Cross-linking of whey proteins by enzymatic oxidation. J Agric Food Chem 46 1326-1333. 

Enzymatic gelation of partially heat-denatured whey proteins by trypsin, papain, pronase, pepsin, and a preparation of Streptomyces griseus has been studied (Sato et al., 1995). Only peptic hydrolysate did not form a gel. The strength of the gel depended on the enzyme used and increased with increasing DH. Hydrolysis of whey protein concentrate with a glutamic acid specific protease from Bacillus licheniformis at pH 8 and 8% protein concentration has been shown to produce plastein aggregates (Budtz and Nielsen, 1992). The viscosity of the solution increased dramatically during hydrolysis and reached a maximum at 6% DH. Incubation of sodium caseinate with pepsin or papain resulted in a 55-77% reduction in the apparent viscosity (Hooker et al., 1982). 

Chobert, J.-M., Bertrand-Harb, C., and Nicolas, M.-G. 1988b. Solubility and emulsifying properties of caseins and whey proteins modified enzymatically by trypsin. J. Agric. Food Chem. 36, 883 —892. 

Although whey protein concentrates possess excellent nutritional and organoleptic properties, they often exhibit only partial solubility and do not function as well as the caseinates for stabilizing aqueous foams and emulsions (19). A number of compositional and processing factors are involved which alter the ability of whey protein concentrates to function in such food formulations. These include pH, redox potential, Ca concentration, heat denaturation, enzymatic modification, residual polyphosphate or other polyvalent ion precipitating agents, residual milk lipids/phospholipids and chemical emulsifiers (22). 

Tolkach, A. and Kulozik, U., Fractionation of whey proteins and caseinomacropeptide by means of enzymatic cressbnking and membrane separation techniques, J. Food Eng., 67, 13, 2005. 

Eissa, A., and Khan, S. A. (2005). Acid-induced gelation of enzymatically modified, preheated whey proteins. ]. Agric. Food Chem. 53, 5010-5017. 

A membrane cell recycle reactor with continuous ethanol extraction by dibutyl phthalate increased the productivity fourfold with increased conversion of glucose from 45 to 91%.249 The ethanol was then removed from the dibutyl phthalate with water. It would be better to do this second step with a membrane. In another process, microencapsulated yeast converted glucose to ethanol, which was removed by an oleic acid phase containing a lipase that formed ethyl oleate.250 This could be used as biodiesel fuel. Continuous ultrafiltration has been used to separate the propionic acid produced from glycerol by a Propionibacterium.251 Whey proteins have been hydrolyzed enzymatically and continuously in an ultrafiltration reactor, with improved yields, productivity, and elimination of peptide coproducts.252 Continuous hydrolysis of a starch slurry has been carried out with a-amylase immobilized in a hollow fiber reactor.253 Oils have been hydrolyzed by a lipase immobilized on an aromatic polyamide ultrafiltration membrane with continuous separation of one product through the membrane to shift the equilibrium toward the desired products.254 Such a process could supplant the current energy-intensive industrial one that takes 3-24 h at 150-260X. Lipases have also been used to prepare esters. A lipase-surfactant complex in hexane was used to prepare a wax ester found in whale oil, by the esterification of 1 hexadecanol with palmitic acid in a membrane reactor.255 After 1 h, the yield was 96%. The current industrial process runs at 250°C for up to 20 h. 

One of the current approaches to the improvement of the functional properties of proteins is enzymatic hydrolysis [148], The emulsifying ability of soy protein isolate can be increased by treatment with neutral fungal protease however, this treatment decreases emulsion stability [163], Partial hydrolysis of fish protein concentrate improves both emulsification and stability [164]. On the other hand, treatment of whey protein concentrate with pepsin, pronase, and pro-lase leads to a decrease in emulsification ability, suggesting that there... 

Ultrafiltration treatment of enzymatic hydrolysates can further reduce the immunoreactivity of whey protein in vitro [179]. Nakamura and coworkers [176,177] stated that combinations of hydrolysis and membrane treatment (microfiltration or ultrafiltration) result in a desirable hypoallergenic peptide. The antigenicity of the fractions decreased with the decreasing of the pore size of the ultrafiltration membrane. 

RP-HPLC CHARACTERIZATION OF ENZYMATIC HYDROLYSIS OF WHEY PROTEINS... 

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