Improvement of the characteristics of fish gelatin - gum arabic through the formation of the polyelectrolyte complex

A new edible coating of fish gelatin incorporated into açaí oil to increase the post-harvest shelf life of tomatoes

Açaí oil (Euterpe oleracea) is a new active ingredient, originating from the Amazon Forest, which offers numerous benefits as an antioxidant and antimicrobial agent. Here, we report how açaí oil can be used as an active ingredient in gelatin coatings to increase the shelf life of tomatoes. The optimized viscosity and gel strength conditions were 5.40 % gelatin, 17.25 % açaí oil and 18 % plasticizer. FTIR, XRD and zeta potential analysis reveals that repulsive forces dominate the interactions between açaí oil and gelatin. The optimized coating (GAO) reduced mass loss by 8 % and achieved greater firmness (25 N), proving its effectiveness in maintaining tomato quality during storage. For the first time, it was found that the addition of açaí oil to fish gelatin improves the percentage of acidity and firmness of the tomato, delaying ripening, making it a promising alternative as packaging for climacteric fruits.

Intermolecular Interactions in the Formation of Polysaccharide-Gelatin Complexes: A Spectroscopic Study

Gelatin, due to its gelling and stabilizing properties, is one of the widely used biopolymers in biotechnology, medicine, pharmaceuticals, and the food industry. One way to modify the characteristics of gelatin is molecular modification by forming non-covalent polyelectrolyte complexes with polysaccharides based on the self-organization of supramolecular structures. This review summarizes recent advances in the study of various types and the role of intermolecular interactions in the formation of polysaccharide-gelatin complexes, and conformational changes in gelatin, with the main focus on data obtained by spectroscopic methods: UV, FT-IR, and 1H NMR spectroscopy. In the discussion, the main focus is on the complexing polysaccharides of marine origin-sodium alginate, κ-carrageenan, and chitosan. The prospects for creating polysaccharide-gelatin complexes with desired physicochemical properties are outlined.

Improving method, properties and application of polysaccharide as emulsifier

At present, there are still some problems for the emulsification of polysaccharides such as lack of green, efficient and industrialized methods, lack of systematic and in-depth structure-activity relationship, and need of expanding its application scope. The physical, chemical and biological methods for improving the emulsifying of polysaccharides, the emulsifying properties and influencing factors of polysaccharides and application in food were reviewed herein. It was pointed out that the future research should focus on the effect of physical-biological synergistic function on the emulsification of polysaccharides, the effect of processing process on the structure and emulsification mechanism of polysaccharides, and further expanding the application field of polysaccharides with emulsification activity to improve the quality of products.

The role of emulsification strategy on the electrospinning of β-carotene-loaded emulsions stabilized by gum Arabic and whey protein isolate

This work was aimed to systematically assess the effect of diverse emulsification strategies, i.e., layer-by-layer (LbL), directly mixing (DM), and heteroaggregation (HA) assemblies on electrospinnability of emulsions stabilized by gum Arabic (GA)-whey protein isolate (WPI) blend and their subsequence potential in β-carotene (BC) encapsulation. The designed BC emulsions were characterized in terms of zeta-potential, droplet size, and rheological properties. According to the results, LbL-formulated emulsions possessed the highest zeta-potential; however, HA-produced ones appeared to be more viscous among all emulsions. Properties of electrospun nanofibers varied considerably relying on either the emulsification strategy or the oil phase volume fraction as confirmed by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and fourier transform infrared specroscopy (FTIR). It was found that the resulting nanofibers produced by LbL and HA emulsification guaranteed higher BC encapsulation efficiency (>90%), in comparison to that of DM-engineered samples offering a lower efficiency of ∼71 %. The storage stability of BC emulsions stabilized with WPI-GA blend was in the order of LbL > HA > DM emulsions. Most importantly, the application of LbL assembly exhibited the most thermally/physicochemically stable carotenoid-comprising nanofibers among all studied mixing techniques. These results offer useful information for applications of different emulsification strategies for fabricating BC-loaded nanofibers via emulsion electrospining technique.

A Review of Gum Hydrocolloid Polyelectrolyte Complexes (PEC) for Biomedical Applications: Their Properties and Drug Delivery Studies

The utilization of natural gum polysaccharides as the vehicle for drug delivery systems and other biomedical applications has increased in recent decades. Their biocompatibility, biodegradability, and price are much cheaper than other materials. It is also renewable and available in massive amounts, which are the main reasons for its use in pharmaceutical applications. Gum can be easily functionalized with other natural polymers to enhance their applications. Various aspects of the utilization of natural gums in the forms of polyelectrolyte complexes (PECs) for drug delivery systems are discussed in this review. The application of different mathematical models were used to represent the drug release mechanisms from PECs; these models include a zero-order equation, first-order equation, Higuchi, simplified Higuchi, Korsmeyer–Peppas, and Peppas–Sahlin.

Gum arabic and collagen hydrolysate extracted from hide fleshing wastes as novel wall materials for microencapsulation of Origanum onites L. essential oil through complex coacervation

Renewable resource-based biodegradable materials attract more attention than petroleum-based biodegradable materials to support the sustainable development of ecology. Obtaining collagen hydrolysate (CH) from hide fleshing wastes of leather industry is an environmentally friendly way to develop multifunctional materials that can contribute to technological advances in different industries. In this study, 2:1, 1:1, and 1 2 ratios of gum arabic (GA) and CH extracted from hide fleshing waste were used as wall materials to encapsulate Origanum onites L. essential oil (OOEO) using the complex coacervation method. The encapsulation yield and efficiency, functional group composition, particle size, morphology, and thermal stability of the obtained OOEO microcapsules were characterized. The results showed that the obtained microcapsules had high encapsulation yield and efficiency, as well as good functional properties such as uniform morphology and low water activity. The best mass ratio for the biopolymers (GA:CH) was 1:1. Scanning electron microscopy analysis showed that OOEO microcapsule samples had a spherical shape. FTIR analysis was performed on obtained microcapsules, confirming the molecular interactions between GA and CH. These findings can be useful in designing an ideal wall material using GA and CH for microencapsulation of essential oils by the complex coacervation method.

Heterologous Expression of Recombinant Transglutaminase in Bacillus subtilis SCK6 with Optimized Signal Peptide and Codon, and Its Impact on Gelatin Properties

Microbial transglutaminases (MTGs) are widely used in the food industry. In this study, the MTG gene of Streptomyces sp. TYQ1024 was cloned and expressed in a food-grade bacterial strain, Bacillus subtilis SCK6. Extracellular activity of the MTG after codon and signal peptide (SP Ync M) optimization was 20 times that of the pre-optimized enzyme. After purification, the molecular weight of the MTG was 38 kDa and the specific activity was 63.75 U/mg. The optimal temperature and pH for the recombinant MTG activity were 50°C and 8.0, respectively. MTG activity increased 1.42- fold in the presence of β-ME and 1.6-fold in the presence of DTT. Moreover, 18% sodium chloride still resulted in 83% enzyme activity, which showed good salt tolerance. Cross-linking gelatin with the MTG increased the strength of gelatin 1.67 times and increased the thermal denaturation temperature from 61.8 to 75.8°C. The MTG also significantly increased the strength and thermal stability of gelatin. These characteristics demonstrated the huge commercial potential of MTG, such as for applications in salted protein foods.