Thermo-mechanical, rheological, structural and antimicrobial properties of bionanocomposite films based on fish skin gelatin and silver-copper nanoparticles

A comprehensive review on the application of active packaging technologies to muscle foods

Fish fillet is easily spoiled during storage. Antimicrobial edible coating of gelatin extracted from fish skins and bones and tea polyphenol (TP) was developed to inhibit the spoilage of fish fillet during cold storage. For coating containing 0.4 % TP and 1.2 % gelatin, the pH only slightly increased from 6.17 at day 0 to 6.32 at day 17 of cold storage, while the pH of control coating increased to 6.87 at day 17. Atomic force spectrometry was used to analyse the nanostructure of myofibril, which is the major component of fish muscle. The results showed that the length of myofibril from 0.4 % TP and 1.2 % gelatin group was greater than 15 μm, while the diameter and height were 3.38 and 0.59 μm, respectively, which exhibited the most intact nanostructure after 17 days of cold storage. Meanwhile, matrix-assisted laser desorption–ionisation–time-of-flight mass spectrometry result showed that TP delayed the degradation of myosin light chain 3 and troponin T in myofibril. Gas chromatography–mass spectrometry of volatile organic compounds (VOCs) also showed that 0.4 % TP and 1.2 % gelatin coating group had minimal production of spoilage markers, such as 1-octen-3-ol, 2-methyl propanoic acid and dimethyl sulfide. The microbial analysis showed that the aerobic mesophilic/psychrotrophic count, yeasts and moulds of 0.4 % TP and 1.2 % gelatin group were significantly lower than the control group. Therefore, 0.4 % TP and 1.2 % gelatin coating showed the best antimicrobial effect and can be used to maintain the nanostructure of fish fillet and prevent the spoilage during cold storage.

Effects of Fish Gelatin and Tea Polyphenol Coating on the Spoilage and Degradation of Myofibril in Fish Fillet During Cold Storage

Fish gelatin combined with chitosan coating inhibits myofibril degradation of golden pomfret (Trachinotus blochii) fillet during cold storage.

Background Gelatin, one of the most popular biopolymers, is widely used in food, pharmaceutical and cosmetic industries. Mammalian gelatin accounts for the vast majority of commercial gelatin, but due to the socio-cultural and health-related concerns, it has been subjected to constraint and skepticism for many years. Fish gelatin has been considered as an excellent alternative to mammalian gelatin because of similarity of its functional properties with mammalian gelatin. Nevertheless, compared with mammalian gelatin, fish gelatin possesses inferior gelation and rheological properties, which limit its extensive application. Scope and approach This review provides a comprehensive overview of various techniques that have been used to improve gelation properties of fish gelatin underlying their modification mechanisms as well as applications. Finally, a brief discussion on safety and regulatory status, and future potentials of modification fish gelatin is provided. Key findings and conclusions Various approaches have been put forward for improving gelation and rheological properties of fish gelatin. The combination of different modification methods is a novel strategy to overcome the shortcomings of fish gelatin. However, further scientific research studies are still required to better understand the exact mechanism of such modifications and expand their application ranges in food industries.

Fish gelatin modifications: A comprehensive review

Effects of salt and sugar addition on the physicochemical properties and nanostructure of fish gelatin

Combination of sodium alginate with tilapia fish gelatin for improved texture properties and nanostructure modification

Effects of κ-carrageenan on the structure and rheological properties of fish gelatin

Rheological properties and structure modification in liquid and gel of tilapia skin gelatin by the addition of low acyl gellan

Fish gelatin (FG) is more suitable for consumption by religious people than mammalian gelatin. One common modification method of FG is mixing FG with polysaccharides. However, the mechanism is not clear. We found that FG gel containing 0.1 g/100 mL gellan, 20 mmol/L CaCl2 and 6.67 g/100 mL FG (180 Bloom) matched gel strength, hardness, cohesiveness, chewiness as well as gelling temperature (T-g) and melting temperature (T-m) of commercial beef gelatin (BG) (240 Bloom). The modified FG was also observed by the result of helix/coil ratio and spherical aggregates. The modification decreased the diameter of FG's aggregates from 472 to 249 nm, which matched with BG (272 nm, P < 0.05). Coexistence of segregative gellan-gellan fibrous aggregates and associated FG-gellan amorphous structure were also identified at the modified FG by atomic force microscope (AFM). The helix/coil ratio and diameter of spherical aggregates were inversely correlated, the mechanism behind was the strength of gelatin association. The involvement of hydrogen bond and presence of FG-gellan complex have been validated by urea addition and Fourier transform infrared (FTIR) spectroscopy. A schematic model was proposed. As modified FG successfully matched the of texture properties of BG, it is promising to replace BG with FG. (C) 2017 Elsevier Ltd. All rights reserved.

Li Cheng Sow

Papers

Effects of salt and sugar addition on the physicochemical properties and nanostructure of fish gelatin

Combination of sodium alginate with tilapia fish gelatin for improved texture properties and nanostructure modification

Effects of κ-carrageenan on the structure and rheological properties of fish gelatin

Rheological properties and structure modification in liquid and gel of tilapia skin gelatin by the addition of low acyl gellan

Nanostructural analysis and textural modification of tilapia fish gelatin affected by gellan and calcium chloride addition