Yield, viscosity, and gel strength of wami tilapia (Oreochromis urolepis hornorum) skin gelatin: Optimization of the extraction process

Fish By-Product Collagen Extraction Using Different Methods and Their Application

The processing of fishery resources results in the production of a growing quantity of byproducts, including heads, skins, viscera, intestines, frames, and fillet cutoffs. These byproducts are either wasted or utilized for the production of low-value items and fish oil. Typically, fish processing industries use only 25%, while the remaining 75% is considered as waste by-products. This review presents a comprehensive review on the extraction of collagen from fish byproducts, highlighting numerous techniques including acid-soluble collagen (ASC), enzyme-soluble collagen (ESC), ultrasound extraction, deep eutectic solvent (DES) extraction, and supercritical fluid extraction (SFE). A detailed explanation of various extraction parameters such as time, temperature, solid to liquid (S/L) ratio, and solvent/pepsin concentration is provided, which needs to be considered to optimize the collagen yield. Moreover, this review extends its focus to a detailed investigation of fish collagen applications in the biomedical sector, food sector, and in cosmetics. The comprehensive review explaining the extraction methods, extraction parameters, and the diverse applications of fish collagen provides a basis for the complete understanding of the potential of fish-derived collagen. The review concludes with a discussion of the current research and a perspective on the future development in this research field.

Tilapia fish waste: An asset for tissue engineering - A review

Fisheries and aquaculture output have exploded due to an alarming increase in consumption due to the global understanding of the nutritional advantages of fish. Inadvertently, the methods produce a massive amount of fish waste, posing a serious environmental threat. Recycling this waste has now become a major point of controversy that must be resolved. It is critical to emphasize the utility of discarded marine by-products for the creation of high-value commodities such as marine collagen (MC), which can be considered a sustainable solution. Because of its biocompatibility, biodegradability, safety, minimal immunogenicity, and low production costs, MC has various benefits over terrestrial collagen. Many academics have recently become interested in the use of MC as a scaffold. This review focuses on the intriguing contribution of MC in the production of MC-based scaffolds.

Optimization of Gelatin Extracting Condition from Korean Native Black Goat Skin and Quality Comparison with Commercial Gelatin

The practical use of Korean native black goat skin as a source of gelatin extraction is limited. The objective of this study was to optimize the extraction temperature and time of gelatin from Korean native black goat skin, and to compare the quality characteristics of goat skin gelatin and other commercial gelatin products. Response surface methodology was applied to optimize the extraction temperature and time of gelatin obtained from native Korean black goat skin. The effects of temperature (50°C-70°C) and time (2-4 h) on extraction yield and gel strength were investigated using a face-centered central composite design with 13 experiments. Gelatin extraction from Korean native black goat skin was prepared through the serial processes of alkali pre-treatment, bleaching, neutralization, hot-water extraction, and freeze-drying. Using the optimization plot of Minitab software, the optimized conditions for extracting temperature and time of goat skin gelatin were 59.49°C and 3.03 h, and the optimized values of extraction yield and gel strength were 12.52% and 263.37 g, respectively. Based on a quality comparison of goat skin gelatin with commercial gelatin, the pH value of gelatin extracted from Korean native black goat skin was 5.57. The color of gelatin extracted from Korean native black goat skin was darker than that of commercial gelatin (p<0.05). Higher emulsifying properties and gel strength of goat skin gelatin were observed when compared to those of commercial gelatin (p<0.05). Therefore, the results of this study indicate that Korean native black goat skin may be a valuable source for gelatin extraction.

Exploration of collagen cavitation based on peptide electrolysis

Electrochemical modification of animal skin is a new material preparation method and new direction of research exploration. In this study, under the action of the electric field using NaCl as the supporting electrolyte, the effect of electrolysis on Glycyl-glycine(GlyGl), gelatin(Gel) and Three-dimensional rawhide collagen(3DC) were determined. The amino group of GlyGl is quickly eliminated within the anode region by electrolysis isolated by an anion exchange membrane. Using the same method, it was found that the molecular weight of Gel and the isoelectric point of the Gel decreased, and the viscosity and transparency of the Gel solution obviously changed. The electrolytic dissolution and structural changes of 3DC were further investigated. The results of TOC and TN showed that the organic matter in 3DC was dissolved by electrolysis, and the tissue cavitation was obvious. A new approach for the preparation of collagen-based multi-pore biomaterials by electrochemical method was explored.

Fish Collagen: Extraction, Characterization, and Applications for Biomaterials Engineering

The utilization of marine-based collagen is growing fast due to its unique properties in comparison with mammalian-based collagen such as no risk of transmitting diseases, a lack of religious constraints, a cost-effective process, low molecular weight, biocompatibility, and its easy absorption by the human body. This article presents an overview of the recent studies from 2014 to 2020 conducted on collagen extraction from marine-based materials, in particular fish by-products. The fish collagen structure, extraction methods, characterization, and biomedical applications are presented. More specifically, acetic acid and deep eutectic solvent (DES) extraction methods for marine collagen isolation are described and compared. In addition, the effect of the extraction parameters (temperature, acid concentration, extraction time, solid-to-liquid ratio) on the yield of collagen is investigated. Moreover, biomaterials engineering and therapeutic applications of marine collagen have been summarized.

Physicochemical, rheological, and molecular characterization of colloidal gelatin produced from Common carp by-products using microwave and ultrasound-assisted extraction

The effects of ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) methods on molecular and physicochemical characteristics of the resultant gelatin were examined. Before extraction procedure, we investigated the optimum pH for swelling of Common carp by-products, which is an important pretreatment for gelatin production. The highest swelling yield was achieved at pH 13 among pH 1-14 with unit intervals. Results indicated that the UAE gelatin has a higher gel strength, viscosity, melting point, and gelling point. The power and time of sonication showed a reverse relation with these characteristics. In addition, as the time of microwave heating was raised, the gel strength, viscosity, melting point, and gelling point were decreased. The FT-IR spectra showed similar peaks but the Amide B in UAE gelatin slightly vanished. The electrophoretic pattern also revealed the higher gel strength and viscosity of UAE gelatin due to the higher intensity of α and β chains compared to MAE gelatin. It can be concluded from all of the results of this study that the produced gelatin using these procedures can be a good source of gelatin in food and drug industries.

Effects of xylitol and stevioside on the physical and rheological properties of gelatin from cod skin

Jelly and confectionery products are high in sugar and calories. Xylitol and stevioside are natural low-calorie sweeteners and they can be used as an alternative; however, their effects on fish gelatin are unknown. The gelatin was extracted from cod skins and added to xylitol or stevioside (0, 2, 6, 10, 14, and 20% (w/v)) to form gel products. This paper investigated how xylitol and stevioside affected the physical and rheological behaviors of fish gelatin, such as color, gel strength, texture profile analysis, storage modulus (G′), loss modulus (G″), and viscosity. Results showed that the change of color and viscosity in gel products were similar when various concentrations of xylitol or stevioside were added to the fish gelatin. But the effects of xylitol/stevioside on texture profile analysis and G′, G″ were different, which might due to the structure variation in xylitol and stevioside. The linear structure of xylitol resulted in ionic interaction, hydrogen bonding, van der Waals forces, and hydrophobic association between xylitol and fish gelatin. Therefore, xylitol is a promising sweetener substitute, which was probably related to its greater solubility and number of –OH groups.

The anti-photoaging effect of antioxidant collagen peptides from silver carp (Hypophthalmichthys molitrix) skin is preferable to tea polyphenols and casein peptides

Applying antioxidants to attenuate skin photoaging has received great attention. In this study, antioxidant collagen peptides (ACPs) with different activities were prepared using different proteases, called high (HCP), medium (MCP) and low antioxidant collagen peptides (LCP). The effects of ACPs, tea polyphenols (TP) and casein peptides (CP) on the photoaged skin of mice were evaluated and compared. Ingestion of ACPs significantly alleviated UV-induced abnormal alterations of skin components and antioxidative indicators in both serum and skin (p < 0.05). In addition, HCP had the best effect on protecting skin from photoaging among the three collagen peptides, with no significant differences between MCP and LCP (p > 0.05). TP and CP, with higher antioxidant activity in vitro, only significantly increased hydroxyproline content (only in the TP group) and CAT activity and decreased protein carbonyl content at week 2, showing a much weaker effect than that of the ACP groups. The histological analysis result further demonstrates that ACPs exerted a stronger beneficial effect on normalizing skin structure and collagen arrangement than TP and CP. Accordingly, ACPs have potential for nutraceuticals as anti-skin-photoaging ingredients.

The effect of collagen hydrolysates from silver carp (Hypophthalmichthys molitrix) skin on UV-induced photoaging in mice: molecular weight affects skin repair

The use of collagen hydrolysates (CHs) as a nutraceutical agent in skin aging has gained increasing attention. Here, the effects of various doses and molecular weights of CH from silver carp skin on photoaging in mice were investigated. The ingestion of CH at 50, 100 and 200 mg per kg body weight led to a dose-dependent increase in the hydroxyproline, hyaluronic acid and moisture contents of the skin, but it had no significant effect on the mice body weight, or on the spleen or thymus index. Furthermore, ingesting CH with lower (LMCH, 200-1000 Da, 65%) and higher molecular weight (HMCH, >1000 Da, 72%) significantly increased the skin components and improved the antioxidative enzyme activities in both serum and skin (p < 0.05); LMCH performed better than HMCH. By contrast, gelatin (>120 kDa) ingestion did not bring a significant change compared to model mice. These results indicated that LMCH exerted a stronger beneficial effect on the skin than did either HMCH and gelatin, which supported the feasibility of using LMCH as a dietary supplement from silver carp skin to combat photoaging.