Investigating the impact of wet rendering (solventless method) on PUFA-rich oil from catfish (Clarias magur) viscera.

Catfish (Clarias magur) is a popular freshwater fish food worldwide. The processing of this fish generates a significant amount of waste, mainly in the form of viscera, which constitutes around 10-12% of the fish's total weight. This study was focused on extracting polyunsaturated fatty acid (PUFA)-rich oil from catfish viscera, aiming to enhance the extraction process and make the production of oil and handling of fish byproducts more cost-effective. The wet reduction method, a solvent-free approach, was used for extraction, with yield optimization done via the Box-Behnken design. The resulting oil was evaluated for its oxidative quality and chemical characteristics. The optimal conditions for the wet rendering process were as follows: viscera to water ratio, 1:0.5 (w/v); temperature, 90℃; and time, 20 min, yielding 12.40 g/100 g of oil. The oil extracted under optimal wet rendering conditions had quality and oxidative stability comparable to solvent extraction and fewer secondary oxidation compounds. This oil had a higher PUFA content, specifically a 4:1 ratio of omega 6 to omega 3. Such oil, derived from catfish viscera, is suitable for the food industry due to its solvent-free extraction method.

An Intensive Study on Algal Diversity in the Ancient Man-Made Aquatic Ecosystem of Tiruvallur, South India: Exploration for Sustainable Development.

Eco-friendly and beneficial nature algae make it prominent in our earth as well as for human life. In recent decades, microalgal applications is sought in varied fields from the remediation of wastes to the production of pharmaceutical products. Still, more extensive research on bioprospecting should to conducted to get the genus-specific or species-specific applications of microalgae with high efficiency. This inquiry was carried out (October 2021 to September 2022) for the effectual understanding of microalgal composition structure along with seasonal physicochemical variations in the age-old holy tank at Tiruvallur, southeast India. This inquiry also acts as the source data and makes the bioprospecting process easier. It also ignites the researchers to address the microalgae seasonal composition structure of peculiar wet environments. A total of 41 microalgae species were recorded, in which six major algal groups were in order of, Chlorophyceae > Bacillariophyceae > Cyanophyceae > Euglenophyceae > Zygnematophyceae > Trebouxiophyceae. Mean seasonal abundance was highest in the summer season (351 cells/L) and lowest in the monsoon (113 cells/L). One-way ANOVA showed seasonal variations of physicochemical parameters, in which the majority of them attained their peak during summer. Mean values of water temperature, pH, salinity, total dissolved solids, total solids, electrical conductivity, chemical oxygen demand, total hardness, total alkalinity, ammonia, nitrite-nitrogen, and nitrate-nitrogen for the summer were 31.43 °C, 8.53, 0.56 ppt, 383 mg/L, 525 mg/L, 0.85 mS/cm, 46.27 mg/L, 300 ppm, 251.67 ppm, 1.51 mg/L, 0.62 mg/L, and 0.70 mg/L, respectively. Karl Pearson's correlation revealed a most significant relationship between water quality factors and algal density. The Shannon's diversity index (2.78-3.39) indicated moderately rich microalgal diversity in the study area. Palmer's pollution index stated that the temple tank was organically polluted all over the study period except November.

Deciphering Microalgal Diversity of Peculiar Lentic Ecosystem in Chennai, South India: A Way Towards Sustainability.

Microalgae are quickly gaining attention among the researchers in various aspects such as biofuel applications, biogas, biomass production, waste water treatment, carbon fixation, animal feed ingredients, pigment production, and pharmaceutical products. One of the approaches to choose microalgae for biotechnological applications is to investigate their diversity and abundance in all possible wet environments. Samples were collected from three sampling sites for the period of 1 year (October 2021-September 2022) in Vadapalani temple tank at Chennai. Physicochemical parameters in current investigation were estimated according to APHA, 2017. Qualitative and quantitative analyses of phytoplankton were done throughout the study period. One-way ANOVA (Analyses of Variance) and Karl Pearson's correlation coefficient were estimated using SPSS (V.26.0). A total of 11 diversity indices were estimated using PAST (V 4.0). A total of 52 algal species were identified, prevailed over by Chlorophyceae (15 species), followed by Zygnematophyceae, Bacillariophyceae, Cyanophyceae, and Trebouxiophyceae. Chlorophyceae quantitatively structured the major category. The maximum and minimum values of density were observed during the season of summer (287 Cells/L) and monsoon (80 Cells/L), respectively. Chlorophyceae showed dominance with a density of 168 cells/L. The maximum and minimum densities of Chlorophyceae were recorded in the summer season (55 cells/L) and monsoon season (24 cells/L), respectively. Shannon's index (H') attained its zenith in February and April month of 2022 (3.60). This study further ignites the researchers to phycoprospect various temple water to address the nature of microalgae occurrence and for biotechnological purposes.

Extraction and Physico-Chemical Characterization of Chitosan from Mantis Shrimp (Oratosquilla nepa) Shell and the Development of Bio-Composite Film with Agarose.

Mantis shrimp (Oratosquilla nepa) exoskeleton, a leftover generated after processing, was used as a starting material for chitosan (CS) production. CS was extracted with different deacetylation times (2, 3 and 4 h), termed CS−2, CS−3 and CS−4, respectively, and their characteristics and antimicrobial and film properties with agarose (AG) were investigated. Prolonged deacetylation time increased the degree of deacetylation (DDA: 73.56 ± 0.09−75.56 ± 0.09%), while extraction yield (15.79 ± 0.19−14.13 ± 0.09%), intrinsic viscosity (η: 3.58 ± 0.09−2.97 ± 0.16 dL/g) and average molecular weight (Mν: 1.4 ± 0.05−1.12 ± 0.08 (×106 Da)) decreased (p < 0.05). FTIR spectra of extracted CS were similar to that of commercial CS. Among all the CS samples prepared, CS−3 had the best yield, DDA, Mν and antimicrobial activity. Therefore, it was chosen for the development of composite films with AG at different ratios (CS−3/AG; 100/0, 75/25, 50/50, 25/75 and 0/100). As the proportion of AG increased, the tensile strength (29.96 ± 1.80−89.70 ± 5.08 MPa) of the composite films increased, while thickness (0.056 ± 0.012−0.024 ± 0.001 mm), elongation at break (36.52 ± 1.12−25.32 ± 1.23%) and water vapor permeability (3.56 ± 0.10−1.55 ± 0.02 (×10−7 g m m−2 s−1 Pa−1)) decreased (p < 0.05). Moreover, lightness of the films increased and yellowness decreased. CS−3/AG (50/50) composite film exhibited high mechanical and barrier properties and excellent compatibility according to FTIR and SEM analyses. According to these finding, mantis shrimp exoskeleton could be used to produce CS. The developed bio-composite film based on an appropriate ratio (50/50) of CS−3 and AG has potential for being used as food packaging material.

Influence of chitosan-gelatin edible coating incorporated with longkong pericarp extract on refrigerated black tiger Shrimp (Penaeus monodon).

Chitosan-Gelatin (CHI-Gel) based edible coating incorporated with longkong pericarp extract (LPE) was developed and investigated for its impact on the quality of black tiger shrimp (Penaeus monodon) during refrigerated storage (4 â€‹°C) for 20 days. Shrimp coated with CHI-Gel-LPE (1.5%) had better quality indices than control (no coating), those coated with CHI, CHI-Gel, and CHI-Gel-LPE at lower concentrations (0.5 and 1%). The CHI-Gel-LPE inhibited melanosis and polyphenol oxidase (PPO) and controlled the pH changes in a dose-dependent manner. Lipid oxidation indices such as TBARS, PV, p-anisidine, and totox values were significantly controlled by the treatments throughout the storage. The CHI-GEL-LPE-1.5% coated sample had the lowest protein oxidation, and it's ascertained by the lowest loss of sulfhydryl groups, with the lowest carbonyl content throughout the storage (P â€‹< â€‹0.05). CHI-Gel-LPE (0.5-1.5%) coated samples had the lowest microbial growth (total viable count, lactic acid bacteria, Enterobacteriaceae, and Psychrotrophic bacteria) relative to the other treatments. Efficacy in quality maintenance of shrimp by LPE incorporated coating was improved with augmenting concentration used. Overall, LPE in the CHI-Gel edible coating served as a natural antioxidant, with antimicrobial activity and inhibiting melanosis, thus retain the quality and extend the shelf-life of shrimp stored at a refrigerated temperature.

Assessment of different proteases on degree of hydrolysis, functional properties and radical scavenging activities of salted duck egg white hydrolysate.

The impact of different proteases (alcalase, ficin, protamex, and neutrase) on the hydrolyzation, foaming and radical scavenging potency of salted duck egg white was studied. Egg white without protease hydrolyzation served as control. Regarding the degree of hydrolysis, neutrase and protamex were more capable of hydrolyzing duck egg white than the others. The α-amino nitrogen content in the egg whites was highly correlated with hydrolysis ability of the enzymes, and it had gradually increased with curing. Foam stability, capacity and emulsion stability were significantly influenced by proteases and curing period. However, the solubility of the egg white hydrolysate was not much affected by curing but showed significant differences between hydrolyzed and control samples. Emulsion stability of hydrolysate decreased with curing times. Neutrase and alcalase hydrolysates gave the best foaming and emulsion properties. Moreover, neutrase and protamex hydrolysates showed good scavenging potency against the DPPH radicals, hydroxyl radicals, hydrogen peroxide, and ferrous ion radicals. Overall, the hydrolysate from neutrase hydrolyzed duck egg white showed the highest foaming and radical scavenging capacities among the other hydrolysis treatments in this study.

Properties and characteristics of nanocomposite films from tilapia skin gelatin incorporated with ethanolic extract from coconut husk.

Impacts of ethanolic extract from coconut husk (EECH) at 0-0.4 % (w/w, on protein basis) on properties of films from tilapia skin gelatin and gelatin/Cloisite Na(+) nanocomposite films were investigated. Young's Modulus, tensile strength and elongation at break of both films decreased with addition of EECH (P < 0.05). The lowest water vapour permeability (WVP) was obtained for gelatin film containing 0.05 % EECH (w/w) (P < 0.05). Nevertheless, the nanocomposite film showed the lowest WVP when incorporated with 0.4 % EECH (w/w) (P < 0.05). Generally, L*- value (lightness) decreased and a*- value (redness) of films increased (P < 0.05) with increasing levels of EECH, regardless of nanoclay incorporation. Transparency of both films generally decreased as the level of EECH increased (P < 0.05). Intercalated or exfoliated structure of nanocomposite films was revealed by wide angle X-ray diffraction (WAXD) analysis. Based on scanning electron microscopic (SEM) analysis, the rougher surface was found when EECH was added. EECH had varying impact on thermal stability of films as revealed by thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. Thus, the incorporation of EECH determined the properties of both gelatin film and nanocomposite film in which the improved water vapour barrier property could be obtained.

Effects of pHs on properties of bio-nanocomposite based on tilapia skin gelatin and Cloisite Na+.

Effects of various pHs (4-8) of film forming suspensions (FFS) on the properties of nanocomposite film based on tilapia skin gelatin and hydrophilic nanoclay (Cloisite Na(+)) were investigated. Intercalated/exfoliated structure of nanocomposite films was revealed by WAXD analysis. Young's Modulus (YM) and tensile strength (TS) of nanocomposite films increased up to pH 6 (P<0.05). Nevertheless, the further increases in pH levels resulted in the decreases in both YM and TS (P<0.05). The highest water vapour barrier property of the film was observed when the pH of FFS was 6 (P<0.05). Lightness (L*) and yellowness (b*) of nanocomposite films generally increased with increasing pH levels. Transparency of nanocomposite films was affected to some extent by pHs. Homogeneity and smoothness of film surface were obtained for nanocomposite films with pH 6 as confirmed by SEM micrographs. Thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses indicated that thermal stability of nanocomposite films varied with different pH levels. In general, mechanical and water vapour barrier properties of nanocomposite films were improved when FFS having pH 6 was used. Thus, the pH of FFS directly affected the properties of nanocomposite gelatin films incorporated with hydrophilic nanoclay.

Film forming ability of gelatins from splendid squid (Loligo formosana) skin bleached with hydrogen peroxide.

Properties of gelatin films from splendid squid (Loligo formosana) skin bleached with hydrogen peroxide (H(2)O(2)) at various concentrations (0-8% w/v) were investigated. Tensile strength (TS) and water vapour permeability (WVP) of films decreased, but elongation at break (EAB) increased (p<0.05) as the concentration of H(2)O(2) increased. Among all films, that prepared from gelatin with 2% H(2)O(2) bleaching showed the lowest ΔE(∗)-value (total colour difference), which was concomitant with the highest L(∗)-value (lightness). Generally, higher concentration of H(2)O(2) resulted in increased b(∗)-value (yellowness) of resulting films. Electrophoretic study revealed that α-chains of gelatin in films became lowered with increasing H(2)O(2) concentrations used for bleaching. Thermogravimetric analysis indicated that heat susceptibility and weight loss of different films varied with H(2)O(2) concentrations. Rougher surface was obtained in gelatin films prepared from skin bleached with H(2)O(2) concentrations above 4%. Thus, the concentrations of H(2)O(2) used for bleaching of squid skin prior to gelatin extraction directly affected the properties of corresponding gelatin films.

Properties of film from splendid squid (Loligo formosana) skin gelatin with various extraction temperatures.

Properties of film from splendid squid (Loligo formosana) skin gelatin extracted at different temperatures (50-80°C) were investigated. Tensile strength (TS) and elongation at break (EAB) of films decreased, but water vapour permeability (WVP) increased (P<0.05) as the extraction temperature increased. Increase in transparency value with coincidental decrease in lightness was observed with increasing extraction temperatures. Electrophoretic study revealed that degradation of gelatin became more pronounced with increasing extraction temperatures. As a consequence, their corresponding films had the lower mechanical properties. FTIR spectra of obtained gelatin films revealed the significant loss of molecular order of the triple helix. Thermogravimetric analysis indicated that F80 exhibited the higher heat susceptibility and weight loss. Loosen structure was observed in film prepared from gelatin with increasing extraction temperatures. Thus, the temperature used for gelatin extraction from splendid squid skin directly affected the properties of corresponding films.