Physicochemical and thermal properties of pepsin- and acid-soluble collagen isolated from the body wall of sea cucumbers (Stichopus hermanni).

The main objective of this work was to characterize the acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from the body wall of the sea cucumber scientifically called, Stichopus hermanni. For the extraction of ASC and PSC, the pre-treated sea cucumber body walls were subjected to 0.5 M acetic acid and 5 g L-1 pepsin, respectively. The yield of ASC (7.30% ± 0.30%) was found to be lower than the PSC (23.66% ± 0.15%), despite both ASC and PSC having similar chemical compositions except for the quantity of protein. The collagens produced from ASC and PSC show maximum peaks on ultraviolet-visible spectroscopic profiles at wavelengths of 230 and 235 nm, respectively, with no significant difference in the maximum temperature (Tmax ) of the extracted ASC and PSC. The ASC's coloration was whiter than that of the PSC. As a result, the collagen obtained from the body wall of the sea cucumber showed promise for usage as a substitute for collagen derived from marine sources. PRACTICAL APPLICATION: The two most popular methods of collagen extraction were acid hydrolysis and enzymatic hydrolysis. To determine whether the extracted collagen is a suitable substitute for animal collagen in different industries, it is required to characterize its physicochemical qualities. This study discovered a new application for marine collagen in the food industry: The sea cucumber has collagen with a greater yield in pepsin extraction with good physicochemical qualities.

Effect of Extraction Time on the Extractability and Physicochemical Properties of Pepsin-Soluble Collagen (PCS) from the Skin of Silver Catfish (Pangasius sp.).

The current study aimed to determine the effects of extraction time on the extractability and physicochemical properties of collagen from the skin of silver catfish (Pangasius sp.). Pepsin soluble collagen (PSC) was extracted for 24 and 48 h and analysed in terms of chemical composition, solubility, functional group, microstructure, and rheological properties. The yields of PSC at 24 h and 48 h extraction time were 23.64% and 26.43%, respectively. The chemical composition exhibited significant differences, with PSC extracted at 24 h showing better moisture, protein, fat, and ash content. Both collagen extractions indicated the highest solubility at pH 5. In addition, both collagen extractions exhibited Amide A, I, II, and III as fingerprint regions for collagen structure. The morphology of the extracted collagen appeared porous with a fibril structure. The dynamic viscoelastic measurements of complex viscosity (η*) and loss tangent (tan δ) decreased as temperature increased, and the viscosity increased exponentially as the frequency increased, whereas the loss tangent decreased. In conclusion, PSC extracted at 24 h showed similar extractability to that extracted at 48 h but with a better chemical composition and shorter extraction time. Therefore, 24 h is the best extraction time for PSC from silver catfish skin.

Recent Advances in In Vitro and In Vivo Studies of Antioxidant, ACE-Inhibitory and Anti-Inflammatory Peptides from Legume Protein Hydrolysates.

Consumption of legumes has been shown to enhance health and lower the risk of cardiovascular disease and specific types of cancer. ACE inhibitors, antioxidants, and synthetic anti-inflammatories are widely used today; however, they have several undesirable side effects. Thus, researchers have focused on finding ACE inhibitors, antioxidant, and anti-inflammatory peptides from natural sources, such as legumes. Recently, in vitro and in vivo research has shown the bioactive peptides generated from legume protein hydrolysates, such as antioxidant, anti-hypertensive, anticancer, anti-proliferative, anti-inflammatory, etc., in the context of different disease mitigation. Therefore, this review aims to describe the recent advances in in vitro and in vivo studies of antioxidant, anti-hypertensive and anti-inflammatory peptides isolated from legume-derived protein hydrolysates. The results indicated that antioxidant legumes peptides are characterized by short-chain sequence amino acids and possess anti-hypertensive properties by reducing systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR).

Gelatin-Based Film as a Color Indicator in Food-Spoilage Observation: A Review.

The color indicator can monitor the quality and safety of food products due to its sensitive nature toward various pH levels. A color indicator helps consumers monitor the freshness of food products since it is difficult for them to depend solely on their appearance. Thus, this review could provide alternative suggestions to solve the food-spoilage determination, especially for perishable food. Usually, food spoilage happens due to protein and lipid oxidation, enzymatic reaction, and microbial activity that will cause an alteration of the pH level. Due to their broad-spectrum properties, natural sources such as anthocyanin, curcumin, and betacyanin are commonly used in developing color indicators. They can also improve the gelatin-based film's morphology and significant drawbacks. Incorporating natural colorants into the gelatin-based film can improve the film's strength, gas-barrier properties, and water-vapor permeability and provide antioxidant and antimicrobial properties. Hence, the color indicator can be utilized as an effective tool to monitor and control the shelf life of packaged foods. Nevertheless, future studies should consider the determination of food-spoilage observation using natural colorants from betacyanin, chlorophyll, and carotenoids, as well as the determination of gas levels in food spoilage, especially carbon dioxide gas.

Physical and Mechanical Characteristics of Gelatin-Based Films as a Potential Food Packaging Material: A Review.

This review discusses the potential application of gelatin-based film as biodegradable food packaging material from various types of gelatin sources. The exploitation of gelatin as one of the biopolymer packaging in the food industry has rising interest among researchers as the world becomes more concerned about environmental problems caused by petroleum-based packaging and increasing consumer demands on food safety. Single gelatin-based film properties have been characterized in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as thickness, color, and biodegradability were much influenced by total solid contents in each film. While, for mechanical and light barrier properties, poultry-based gelatin films have shown better properties compared to mammalian and marine gelatin films. This paper detailed the information on gelatin-based film characterization in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as color, UV-Vis absorption spectra, water vapor permeability, thermal, and moisture properties are discussed along with their mechanical properties, including tensile strength and elongation at break.

Purification, characterization and molecular docking study of angiotensin-I converting enzyme (ACE) inhibitory peptide from shortfin scad (Decapterus macrosoma) protein hydrolysate.

Hypertension is a threatening chronic disease, which become a global killer among the adult population. The mortality rate increasing day by day even several Angiotensin I-converting enzyme (ACE) inhibitor drugs were introduced. Bioactive peptides derived from aquatic resources exhibits potential ACE inhibitory activity. The objective of this work is to report the purification and molecular docking studies of angiotensin-I converting enzyme (ACE) inhibitory peptide isolated from shortfin scad (Decapterus macrosoma) waste protein hydrolysate (SWH), enzymatically prepared by using alcalase. The purification process included ultrafiltration, gel filtration and reverse phase high performance liquid chromatography (RP-HPLC). Results showed that ultra-filtered peptide fraction (< 3 kDa) possessed the highest ACE inhibitory activity, followed by the fraction 14 by gel filtration. Fraction P obtained by RP-HPLC, with the amino acid sequence of RGVGPVPAA (IC50 = 0.20 mg/ml) was identified. In terms of ACE inhibition, the Lineweaver-Burk plot showed that the SWH peptide obtained acted as a competitive ACE inhibitor. The molecular docking studies showed that the SWH peptide exhibit hydrogen bonds and Pi-interactions with ACE by Z-dock scores. These results showed that the purified peptide isolated from shortfin scad waste hydrolysate has potential antihypertensive properties which could potentially be used as functional food ingredients.

Extraction of bioactive compounds from Psidium guajava leaves and its utilization in preparation of jellies.

Psidium guajava L. (guava) is predominantly grown throughout the world and known for its medicinal properties in treating various diseases and disorders. The present work focuses on aqueous extraction of bioactive compounds from the guava leaf and its utilization in the formulation of jelly to improve the public health. The guava leaf extract has been used in the preparation of jelly with pectin (1.5 g), sugar (28 g) and lemon juice (2 mL). The prepared guava leaf extract jelly (GJ) and the control jelly (CJ, without extract) were subjected to proximate, nutritional and textural analyses besides determination of antioxidant and antimicrobial activities. GJ was found to contain carbohydrate (45.78 g/100 g), protein (3.0 g/100 g), vitamin C (6.15 mg/100 g), vitamin B3 (2.90 mg/100 g) and energy (120.6 kcal). Further, the texture analysis of CJ and GJ indicated that both the jellies showed similar properties emphasizing that the addition of guava leaf extract does not bring any change in the texture properties of jelly. GJ exhibited antimicrobial activity against various bacteria ranging from 11.4 to 13.6 mm. Similarly, GJ showed antioxidant activity of 42.38% against DPPH radical and 33.45% against hydroxyl radical. Mass spectroscopic analysis of aqueous extract confirmed the presence of esculin, quercetin, gallocatechin, 3-sinapoylquinic acid, gallic acid, citric acid and ellagic acid which are responsible for antioxidant and antimicrobial properties.

Optimization of chicken skin gelatin film production with different glycerol concentrations by response surface methodology (RSM) approach.

This study investigated the optimization of chicken skin gelatin film production using different concentrations of glycerol as plasticizer, specifically for use as biodegradable food packaging. Response surface methodology (RSM) was used to optimize the production of gelatin films by following a central composite design (CCD) for two quantitative modulators-(A) gelatin at 1.0, 2.5 and 4.0 g; and (B) glycerol at 0, 0.75, 1.50 g-with outcome metrics to predict tensile strength (TS), elongation at break (EAB) and water vapor permeability (WVP). Potentially optimized conditions were experimentally validated to confirm the model's suggestions of 4.0 g for gelatin and 1.5 g for glycerol. Experimental results yielded a TS of 3.81 N/mm, which was higher than the RSM predicted value of 3.09 N/mm (p < 0.05). Both EAB and WVP experimental results were slightly lower than predicted values (3.04 vs. 3.14%) (p < 0.05); and (1.27 × 10-9 vs. 1.31 × 10-9 kPa) (p < 0.05), respectively. Overall, experimental results agreed with the model's predicted values. Hence, this study demonstrates that optimized conditions for the production of chicken skin gelatin films are affected by glycerol concentration and gelatin quantity. Results also suggest that chicken skin gelatin-glycerol film blends have excellent potential for the production of biodegradable food packaging with improved properties.