Property modification of caseinate responsible to transglutaminase-induced glycosylation and crosslinking in the presence of a degraded chitosan

Abstract

Transglutaminase at a concentration of 10 kU/kg of protein and degraded chitosan were used for glycosylation and crosslinking of caseinate at a fixed molar ratio of the acyl acceptor to the acyl donor of 3:1, a protein concentration of 50 g/L, a pH 7.5 at 37 o C, and a reaction time of 4 h. Electrophoretic and chemical analyses showed glycosylation and crosslinking of caseinate. Glycosylated and crosslinked caseinate (GC-caseinate) contained glucosamine at 12.77 g/kg of protein, and the protein fraction had fewer reactable amino groups than original caseinate (0.58 vs. 0.64 mol/kg of protein). GC-caseinate exhibited an enhanced surface hydrophobicity, in vitro digestibility, water-binding capacity, and rheological properties, with poor protein dispensability and emulsification activity, but a similar oilbinding capacity and emulsion stability, compared with original caseinate. GC-caseinate also exhibited better properties than transglutaminase-crosslinked caseinate. Glycosylation and crosslinking was effective for better water-binding and rheological properties of caseinate.

Pre‐deamidation of soy protein isolate exerts impacts on transglutaminase‐induced glucosamine glycation and cross‐linking as well as properties of the products

“…That is, TGase‐induced glucosamine glycation occurred during sample preparation. The present FTIR result was consistent with the results reported in two previous studies, which also verified TGase‐induced glycation of the target proteins. It is well known that soy protein is composed of many globulins, and thus has an ordered secondary structure.…”

Modified properties of a glycated and cross‐linked soy protein isolate by transglutaminase and an oligochitosan of 5 kDa

“…Oligochitosan amount conjugated into GC‐SPI was evaluated using the reversed phase HPLC method, and expressed as the amount of glucosamine (g) per 1 kg of protein fraction. Amount of reactable &bond;NH 2 of these protein samples was assayed using the o ‐phthaldialdehyde (OPA) method, and reported as the amount of &bond;NH 2 (in moles) per 1 kg of protein.…”

Structure and Property Changes of Transglutaminase-Induced Modification of Sodium Caseinate in the Presence of Oligochitosan of 5 kDa

“…[18] Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the samples as well as protein and saccharide staining were performed as per the study. [11] Oligochitosan amount conjugated into the two GC-caseinates was evaluated using the reversed phase-HPLC method, [19] and expressed as the amount of glucosamine (g) in protein fraction of 1 kg. The amount of reactable -NH 2 groups of the samples was assayed using the o-phthaldialdehyde (OPA) method, [15] and reported as the amount of -NH 2 groups (in moles) in protein fraction of 1 kg.…”

“…The two indices were estimated by the respective Stokes-Einstein and Henry's equations. [21] Water-binding capacities (WBC) of the samples was assayed as per the method, [19] and expressed as the amount (grams) of water held in the samples on the basis of protein fraction of one gram. In vitro digestibility of the samples was assessed as per the study.…”