Sodium Caseinate and Skim Milk Gels Formed by Incubation with Microbial Transglutaminase

Abstract

Several suspensions and emulsions containing commercial sodium caseinate or skim milk were gelatinized by Ca*+-independent microbial transglutaminase treatment. The characteristics of the gels were largely affected by the enzyme concentrations employed. For caseinate gels generally the higher enzyme concentration gave steep decreases in breaking strength, strain and cohesiveness of the gels. The creep tests on emulsified gels prepared to two different enzyme concentrations showed that the gel made with a higher enzyme concentration was the more viscoelastic. For skim milk gels, the enzyme treatment in higher concentration caused substantial increase of the breaking and hardness while the strain and cohesiveness had little or no changes.

Influence of transglutaminase treatment on properties of micellar casein and products made therefrom

“…It was further suggested that this repulsive layer had to be neutralised (through acidification) before gelation became evident. In contrast, Nonaka et al [28] showed that skim milk suspensions could be turned into self-supporting gels by using appropriate concentrations of transglutaminase and that the breaking strength and hardness of the gels were remarkably enhanced by employing higher enzyme concentrations. However, these authors used 150 g protein·kg -1 (430 g solids·kg -1 ) in their suspensions giving closely packed casein micelles, which would undoubtedly have lead to greater opportunities for intermicellar cross-linking compared to the protein concentration (~33 g·kg -1 ) of unconcentrated milk.…”

Enhancement of microbial transglutaminase production from

“…MTGase from Streptoverticillium sp. used for several food applications such as producing polymers of casein and soybean proteins and gelatinizing sodium caseinate and skim milk gels [12,13].…”

Effects of Microbial Transglutaminase for Gelation of Soy Protein Isolate during Cold Storage

“…TGase, derived from a microorganism, has been found and mass produced (Ando et al, 1989). Enzymological properties and various basic effects on physical properties of food proteins have been reported Nonaka et al, 1992;Nonaka et al, 1994;Nonaka et al, 1996).…”

“…TGase, derived from a microorganism, has been found and mass produced (Ando et al, 1989). Enzymological properties and various basic effects on physical properties of food proteins have been reported Nonaka et al, 1992;Nonaka et al, 1994;Nonaka et al, 1996).The principal mechanism of gelation of soy protein isolate (abbreviated SPI) is due to the formation of disulfide bonds, reported by Wolf and Smith (1961), Circle et al (1964), Aoki and Sakurai (1969), Saio et al (1971) on heat-induced gel, and by Watanabe et al (1963), andHashizume et al (1974) on freezeinduced gel. On the other hand, as described in previous reports (Soeda, 1994a;1994b;1995a;Soeda & Baba, 1999), the gel (abbreviated Cold-gel) was obtained by keeping it in cold storage.…”