Casein enzymatic

Dietary treatment Intact casein Enzymatic hydrolysate Amino acid mixture... 

Total riboflavin Casein Enzymatic hydrolysis with Precolumn ODS... 

Fig. 2A. Changes in dopamine levels upon transfer of P. bracteatum cultures to hormone-free media. (A) P. bracteatum callus culture was transferred from Murashige and Skoog s revised to tobacco medium (MSRT) supplemented with 0.1 mgl 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg 6-benzylaminopurine (BA) (dark-grown) to suspension medium without hormones (dark grown). Aliquots (3 ml) were removed every 3-4 days and analyzed for growth and dopamine content (see Fig. 1). Values represent the average from three separate flasks analyzed in duplicate. (B) P. somniferum caUus was maintained in the dark on MSRT without glycine and supplemented with 0-1% casein enzymatic hydrolysate and 0.2 mg naphthaleneacetic acid. After transfer to hormone-free suspension culture, aliquots were removed at 4-6 day intervals and analyzed as in A. Values represent the average of two separate experiments assayed in duplicate...

The enzymatic hydrolysates of milk casein and soy protein sometimes have a strong bitter taste. The bitter taste is frequently developed by pepsin [9001 -75-6] chymotrypsin [9004-07-3] and some neutral proteases and accounted for by the existence of peptides that have a hydrophobic amino acid in the carboxyhc terminal (226). The relation between bitter taste and amino acid constitution has been discussed (227). 

When assaying tissue, growth stimulation by unknown factors is always a drawback. In the assay of rat liver with L. pJantarum such stimulation was noted the drift was overcome by the addition of enzymatically hydrolyzed casein (FI). When assaying human liver, we also noted growth enhancement for O. danica by unknown factors the 1 2 dilution, as described above, obviated any drift. Biotin recoveries ranged from 96 to 103%. 

Salt-free hydrochloric acid hydrolyzate of casein, Baltimore Biological Laboratory Inc., Baltimore, Maryland. These casein hydrolyzates can be substituted by Casamino acid (Difco), enzymatically hydrolyzed casein or acid-hydrolyzed casein. 

Table IV). Huff et al (11) extended these observations to include enzymatic hydrolysates of the native proteins and amino acid mixtures equivalent to soy or casein. In this experiment amino acid contents were identical among the diets fed as the three forms of each protein but the structure was different (Table V). 

The Daily Industiy. The first step in cheese manufacture is the coagulation of milk. Coagulation can be divided into two distinct phases, enzymatic and the non-enzymatic. In the primary enzymatic phase a proteol ic enzyme such as chymosin (rennet), or less effectively, pepsin, carries out an extremely specific and limited proteolysis, cleaving a phenylalanine-methionine bond of /c-casein, making the casein micelle metastabie. In the second, non-enzymatic phase, the... 

For the purpose of synthesizing flavor peptides or proteins in large scale, we developed "protein recombination method" and "enzymatic synthesis using chemically modified enzyme". "Protein recombination method" was applied to the synthesis of C-terminal portion of p-casein and its analog. Chymotrypsin was chemically modified by Z-DSP in aqueous solution. It was stable for organic solvents. Using this modified enzyme, we succeeded in the synfiiesis of Inverted-Aspartame-Type Sweetener "Ac-Phe-Lys-OH" in one step. 

Soy protein is a low-cost food protein with good nutritional value, but its uses in foods are limited because of inferior functional properties as compared to those of commonly used animal proteins such as casein and albumin (1.2). Therefore, modifications are often required to make soy protein more suitable for food use. Improved functional properties, particularly in the pH range of 3 to 7 where most food systems belong, have been achieved by non-enzymatic methods, including succinylation (3-5), deamidation (6.7), and phosphorylation (8.9). 

The weak physical forces that hold together self-assembled nanoparticles are, of course, susceptible to disruption under the influence of thermodynamic and/or mechanical stresses. Hence some workers have investigated ways to reinforce nanoscale structures via covalent bonding. For instance, improved stability of protein nanoparticles, in particular, casein micelles, can be achieved by enzymatic cross-linking with the enzyme transglutaminase, which forms bonds between protein-bound glutamine and lysine residues. By this means native casein micelles can be converted from semi-reversible association colloids into permanent nanogel particles (Huppertz and de Kruif, 2008). 

There is currently little understanding of the influence of interfacial composition and (nano)structure on the kinetics of enzymatic hydrolysis of biopolymers and lipids. However, a few preliminary studies are beginning to emerge (McClements et al., 2008 Dickinson, 2008). Thus, for example, Jourdain et al. (2009) have shown recently that, in a mixed5 sodium caseinate + dextran sulfate system, the measured interfacial viscosity increased from qs = 220 mN s m 1 without enzyme to qs = 950 mN s m 1 with trypsin present. At the same time, the interfacial elasticity was initially slightly reduced from (7S = 1.6 mN m 1 to (h = 0.7 mN m, although it later returned to close to its original value. Conversely, in the... 

It is essential to consider the physico-chemical properties of each WPC and casein product in order to effectively evaluate their emulsification properties. Otherwise, results merely indicate the previous processing conditions rather than the inherent functional properties for these various products. Those processing treatments that promote protein denaturatlon, protein-protein Interaction via disulfide interchange, enzymatic modification and other basic alterations in the physico-chemical properties of the proteins will often result in protein products with unsatisfactory emulsification properties, since they would lack the ability to unfold at the emulsion interface and thus would be unable to function. It is recommended that those factors normally considered for production of protein products to be used in foam formation and foam stabilization be considered also, since both phenomena possess similar physico-chemical and functionality requirements (30,31). 

Any factor that accelerates the crystallization of lactose shortens the storage life of the product. At very low temperatures (below — 23°C), neither lactose crystallization nor casein flocculation occurs, even after long periods. Enzymatic hydrolysis of lactose by /S-galactosidase before freezing retards or prevents lactose crystallization and casein precipitation in proportion to the extent of the hydrolysis (Figure 2.14). 

Enzymatic coagulation of milk. The enzymatic coagulation of milk involves modification of the casein micelles via limited proteolysis by selected proteinases, called rennets, followed by calcium-induced aggregation of the rennet-altered micelles ... 

Payens, T. A. J. 1978. On different modes of casein clotting the kinetics of enzymatic and non-enzymatic coagulation compared. Neth. Milk Dairy J. 32, 170-183. 

Ekstrand, B., Larsson-Raznikiewicz, M. and Perlman, C. 1980. Casein micelle size and composition related to the enzymatic coagulation process. Biochim. Biophys. Acta 630, 361-366. 

The physical and chemical characteristics of cheese curd depend on the method used to form the curd matrix. The curd is formed in basically one of two ways acid or enzymatic coagulation. In acid curd cheeses (cottage, baker s, cream), the curd is formed by direct addition of acid to the milk or by lactic acid produced by the fermentation of lactose. As the pH of the milk approaches the isoelectric point of casein (pH... 

---