Complex Modification Orders Alleviate the Gelling Weakening Behavior of High Microbial Transglutaminase (MTGase)-Catalyzed Fish Gelatin: Gelling and Structural Analysis

Abstract

In this paper, the effects of different modification orders of microbial transglutaminase (MTGase) and contents of pectin (0.1–0.5%, w/v) on the gelling and structural properties of fish gelatin (FG) and the modification mechanism were studied. The results showed that the addition of pectin could overcome the phenomenon of high-MTGase-induced lower gelling strength of gelatin gels. At a low pectin content, the modification sequences had non-significant influence on the gelling properties of modified FG, but at a higher pectin content (0.5%, w/v), P0.5%-FG-TG had higher gel strength (751.99 ± 10.9 g) and hardness (14.91 ± 0.33 N) values than those of TG-FG-P0.5% (687.67 ± 20.98 g, 12.18 ± 0.45 N). Rheology analysis showed that the addition of pectin normally improved the gelation points and melting points of FG. The structural results showed that the fluorescence intensity of FG was decreased with the increase in pectin concentration. Fourier transform infrared spectroscopy analysis indicated that the MTGase and pectin complex modifications could influence the secondary structure of FG, but the influenced mechanisms were different. FG was firstly modified by MTGase, and then pectin (P-FG-TG) had the higher gelling and stability properties.

Donkey Gelatin and Keratin Nanofibers Loaded with Antioxidant Agents for Wound Healing Dressings

“…Gel strength of the gelatin is the main parameter for assessing the quality of the gelatin [ 36 ], being induced by the attraction between hydrogen bonds from water and the carboxyl ends of the amino acids [ 37 ]. These interactions lead to the formation of more aggregate macromolecules.…”

“…Table 1 displays the main properties of gelatin extracted from donkey hide and gelatin mixed with keratin hydrolysate extracted from donkey hair. Gel strength of the gelatin is the main parameter for assessing the quality of the gelatin [36], being induced by the attraction between hydrogen bonds from water and the carboxyl ends of the amino acids [37]. These interactions lead to the formation of more aggregate macromolecules.…”