Climate change effects on aquaculture production and its sustainable management through climate-resilient adaptation strategies: a review.

Aquaculture witnessed a remarkable growth as one of the fastest-expanding sector in the food production industry; however, it faces serious threat from the unavoidable impacts of climate change. Understanding this threat, the present review explores the consequences of climate change on aquaculture production and provides need based strategies for its sustainable management, with a particular emphasis on climate-resilient approaches. The study examines the multi-dimensional impacts of climate change on aquaculture which includes the shifts in water temperature, sea-level rise, ocean acidification, harmful algal blooms, extreme weather events, and alterations in ecological dynamics. The review subsequently investigates innovative scientific interventions and climate-resilient aquaculture strategies aimed at strengthening the adaptive capacity of aquaculture practices. Some widely established solutions include selective breeding, species diversification, incorporation of ecosystem-based management practices, and the implementation of sustainable and advanced aquaculture systems (aquaponics and recirculating aquaculture systems (RAS). These strategies work towards fortifying aquaculture systems against climate-induced disturbances, thereby mitigating risks and ensuring sustained production. This review provides a detailed insight to the ongoing discourse on climate-resilient aquaculture, emphasizing an immediate need for prudent measures to secure the future sustainability of fish food production sector.

Shelf-Stability of Kiln- and Liquid-Smoked Inulin-Fortified Emulsion-Type Pangasius Mince Sausage at Refrigerated Temperature.

The objective of this study was to investigate the effects of the kiln (SK-S) and liquid smoking (LS-S) processes on the quality of inulin-fortified emulsion-type Pangasius mince sausages. The moisture content during the storage significantly (p < 0.05) decreased in C-S (control) sausages and increased (p < 0.05) in SK-S and LS-S sausages. The protein content decreased (p < 0.05) in C-S, SK-S, and LS-S throughout the storage period. Initially, among the three processed sausages, LS-S showed a lower pH value, and as the days of storage progressed, all the treatments exhibited a declining trend (p < 0.05). A significant (p < 0.05) increase in the PV was observed in all the sausages during the storage days at 5 ± 1 °C, but the intensity of the increase was lower in SK-S and LS-S. The total viable count of C-S and SK-S sausages reached the limit of acceptability (6 log10cfu g-1) on the 20th day and on the 24th day of storage. The electrophoretic protein pattern of LS-S samples exhibited retention of all bands, indicating the lower proteolysis of MHC, actin, and troponin T in comparison with other treatments. The hardness (p < 0.05) and cohesiveness (p > 0.05) values of both SK-S and LS-S reduced as the storage days progressed. The present study indicates that the emulsion-type Pangasius sausages incorporated with inulin powder (2%) exposed to kiln smoking and commercial liquid smoking retained good-to-better sensory attributes up to day 16 (C-S) and day 20 (SK-S and LS-S) under refrigerated storage at 5 ± 1 °C in low-density vacuum polyethylene (LDPE) pouches.

Carboxy Methyl Cellulose, Xanthan Gum, and Carrageenan Coatings Reduced Fat Uptake, Protein Oxidation, and Improved Functionality in Deep-Fried Fish Strips: An Application of the Multiobjective Optimization (MOO) Approach.

In this study, a multiobjective optimization (MOO) approach was utilized for effective decision-making when several variables were changing simultaneously during frying. Carboxy methyl cellulose (CMC), xanthan gum, and carrageenan coatings in different concentrations (0.25-1.50%, w/v) were applied on fish strips to reduce the oil uptake and protein oxidation during frying. The pickup of the strips increased significantly (p < 0.05) with increasing concentration. The CMC was effective in oil uptake reduction and protein oxidation, as revealed by the lower carbonyl and sulfhydryl contents in the fried strip. The hardness and chewiness of the coated fish strips were found to be declined significantly (p < 0.05) with increasing coating concentrations. The moisture, lipid, toughness, hardness, cutting force, oiliness, sulfhydryl content (all min), oil uptake reduction, and carbonyl content (both max) were considered as multiple criteria for the MOO technique, and fried strips coated with 1% CMC, followed by 0.75% xanthan gum and 0.75% carrageenan, emerged as the best optimal coating.

Valorisation of pineapple peel waste as natural surimi gel enhancer and its optimization in Nile tilapia (Oreochromis niloticus) surimi gels.

This investigation explored the preparation of surimi gel enhancer from pineapple peel waste, hugely generated by industries and spreading serious environment pollutions. The peel extracted with 100% ethanol had higher bioactive and antioxidant attributes, which was subsequently fortified in tilapia surimi at levels of 0.20%-1.20%, w/w to improve its physiochemical, textural, protein structural and sensorial properties. Our finding demonstrated that surimi gels enriched with 0.80% ethanolic pineapple peel extract (PAPE) exhibited significant (p<0.05) improvement in water holding capacity, breaking force, gel strength, and other textural properties and sensory attributes. Furthermore, the surimi gels fortified with 0.80% PAPE exhibited the elevated levels of hydrogen and hydrophobic interactions, while sulfhydryl and free amino acid contents demonstrated a contrasting trend. The FTIR spectra displayed that the incorporation of PAPE influenced the secondary structure of the protein, as evidenced by shifts in the α-helix to ß-sheet peaks. In addition, 0.80% PAPE added gels displayed a compact, uniform, and organized microstructure, featuring small cavities. In summary, the fortification of tilapia surimi gels with 0.80% PAPE could improve gelling and other technological properties with higher sensory scores. This study offers an effective approach to utilize the pineapple peel as a gel enhancer additive for the development of functional surimi and surimi-based products enriched with bioactive compounds.

Utilization of primary and secondary biochemical compounds in cotton as diagnostic markers for measuring resistance to cotton leaf curl virus.

Introduction: Cotton (Gossypium hirsutum L.) is one of the most important staple fibrous crops cultivated in India and globally. However, its production and quality are greatly hampered by cotton leaf curl disease (CLCuD) caused by cotton leaf curl virus (CLCuV). Therefore, the aim of the present study was to investigate the biochemical mechanisms associated with CLCuD resistance in contrasting cotton genotypes. Methods: Four commercial cotton varieties with susceptible (HS 6 and RCH-134 BG-II) and resistant (HS 1236 and Bunty) responses were used to analyze the role of primary (sugar, protein, and chlorophyll) and secondary (gossypol, phenol, and tannin) biochemical compounds produced by the plants against infection by CLCuV. The resistant cultivars with increased activity of protein, phenol, and tannin exhibited biochemical barriers against CLCuV infection, imparting resistance in cotton cultivars. Results: Reducing sugar in the healthy plants of the susceptible Bt cultivar RCH 134 BG-II exhibited the highest value of 1.67 mg/g at 90 days. In contrast, the lowest value of 0.07 mg g-1 was observed at 60 DAS in the highly diseased plants of the susceptible hybrid HS 6. Higher phenol content (0.70 mg g-1) was observed at 90 DAS in resistant cultivars, whereas highly susceptible plants exhibited the least phenol (0.25 mg g-1) at 90 DAS. The lowest protein activity was observed at 120 DAS in susceptible cultivars HS 6 (9.4 mg g-1) followed by RCH 134 BG-II (10.5 mg g-1). However, other biochemical compounds, including chlorophyll, sugar, and gossypol, did not show a significant role in resistance against CLCuV. The disease progression analysis in susceptible cultivars revealed non-significant differences between the two susceptible varieties. Discussion: Nevertheless, these compounds are virtually associated with the basic physiological and metabolic mechanisms of cotton plants. Among the primary biochemical compounds, only protein activity was proposed as the first line of defense in cotton against CLCuV. The secondary level of defense line in resistance showed the activity of secondary biochemical compounds phenol and tannins, which displayed a significant increase in their levels while imparting resistance against CLCuV in cotton.

Process optimization and evaluation of the effects of different time-temperature sous vide cooking on physicochemical, textural, and sensory characteristics of whiteleg shrimp (Litopenaeusvannamei).

The objective of the current study was to optimize the cook-chill conditions of high-value whiteleg shrimp (Litopenaeus vannamei) processed using the sous vide (SV) technique and to assess the effects of various time-temperature combinations on the physicochemical, textural, and sensory qualities. For optimization, a Response Surface Methodology (RSM) approach utilizing a Central Composite Design (CCD) was adopted. Optimum SV cooking conditions to acquire minimum texture (hardness) of 7235 g was 13.48 min and 81.87 °C, expressible moisture of 18.48% was 14.5 min and 84.5 °C, and cook loss of 5.58% was 5 min and 75 °C. Texture (hardness) and expressible moisture decreased while cooking loss increased with increasing time-temperature treatment. Redness and yellowness values increased (p < 0.05) with increasing SV cooking time-temperature, but lightness values were nearly consistent in all treatments. With increasing time and temperature, TBARs and total carotenoid content increased (p < 0.05). However, the TBARs values were within accepted limits and ranged from 0.05 to 0.08 mg malonaldehyde/kg. Sensory evaluation indicated that all SV cooked samples were well accepted, with overall scores ≥7. These results suggest that the SV cooking temperature and time had a substantial impact on the textural, physicochemical, and sensory characteristics of shrimp. In addition, increasing time-temperature increased cooking and moisture loss, but decreased hardness and higher sensory scores made the product more acceptable to consumers.

Manipulation of protein structure and bonding pattern to improve the gelling and textural quality of surimi gels from silver carp: incorporation of mosambi (Citrus limetta) peel extract.

BACKGROUND: This investigation focused on the use of mosambi peel extract (MPE) fortification (at 0% to 1.50%, w/w) in silver carp surimi to improve the gelling, textural, and other physicochemical properties of the surimi. RESULTS: The peels were extracted in ethanol (40-100% concentrations, v/v) and water. It was found that 100% ethanol had significantly (P < 0.05) higher yield and total phenolic, flavonoid, and tannin content. The fortification of MPE at optimum level (0.75%) improved the breaking force (55.1%) and gel strength (89.9%) significantly (P < 0.05) in comparison with 0% MPE gel samples. Moreover, 0.75% MPE-fortified gels had higher hydrogen and hydrophobic bonds, higher water-holding capacity, and lower sulfhydryl groups and free amino groups. The myosin heavy chain (MHC) bands in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) disappeared completely in the MPE-fortified gels. Fortification with MPE affected the secondary structures of protein as shifting of peaks was observed in Fourier-transform infrared (FTIR) spectra. Scanning electron microscopy (SEM) images showed relatively organized finer and denser gel networks in MPE-treated gels. CONCLUSION: The surimi gels fortified with 0.75% MPE demonstrated improved gelling properties, with an overall higher acceptability than the unfortified gels (0% MPE). The fortified gels also became enriched with bioactive polyphenols, which are generally not present in surimi. This study provides an efficient way to utilize mosambi peel to develop functional surimi and surimi-based products with improved gel ability. © 2023 Society of Chemical Industry.

Blue agave inulin-soluble dietary fiber: effect on technological quality properties of pangasius mince emulsion-type sausage.

BACKGROUND: The aim of the work was to investigate the influence of supplementing pangasius mince-based emulsion sausages with blue agave-derived inulin at 1% (T1), 2% (T2), 3% (T3), 4% (T4), and 5% (T5) on its technological quality attributes and acceptability. RESULTS: The cooking yield of T-2, T-3, and T-4 sausages (96-97%) exhibited no significant difference (P > 0.05), which was higher than the other lots. The T-2 batter exhibited a significant difference with all other treatments, showing the lowest total expressible fluid (12.20%) value, indicating the highest emulsion stability of the batter. There was a significant effect on the diameter reduction of the cooked sausages as the level of inulin increased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed the proteolysis of raw mince without inulin and new bands in cooked sausage samples were observed. Increasing inulin content increased the hardness of the sausages from 2510.81 ± 114.31 g to 3415.54 ± 75.88. The differential scanning calorimetry melting temperatures of peak 2 of the T-1, T-2, T-3, and T-4 increased as the inulin content increased from 1 to 4%. The scanning electron microscope images exhibited a smooth appearance on the surface as the inulin level increased. CONCLUSION: The sausages incorporated with the 2% and 3% blue agave plant-derived inulin (T-2 and T-3) showed better sensory overall acceptability scores than the control. The results suggested that the blue agave plant-derived inulin could be efficiently utilized at the 2% and 3% levels to enhance the quality of emulsion-type pangasius sausage. © 2023 Society of Chemical Industry.

Moving towards Gel for Fish Feeding: Focus on Functional Properties and Its Acceptance.

To resurrect and establish a low-impact aquaculture practice, gel-based feed applications hold promise. Gel feed is viscoelastic, nutrient-dense, hard, flexible, and appealing, and can be moulded into appealing shapes to ensure rapid acceptance by fish. The purpose of this research is to create a suitable gel feed using various gelling agents and to evaluate its properties and acceptance by a model fish, Pethia conchonius (rosy barb). Three gelling agents, viz. starch, calcium lactate and pectin, were included at 2%, 5%, and 8% in a fish-muscle-based diet. The physical properties of gel feed were standardized using texture profile analysis, sinking velocity, water and gel stability, water holding capacity, proximate composition, and colour. The lowest levels of nutrient leaching protein (0.57 ± 0.15%) and lipid (14.3 ± 14.30%) were observed up to 24 h in the underwater column. The highest score for overall physical and acceptance characteristics was noted for the 5% calcium lactate-based gel feed. Furthermore, a 20-day acceptance feeding experiment was conducted using 5% calcium lactate to examine its suitability as fish feed. The results indicate a better acceptability (3.55 ± 0.19%) and water stability (-2.5 ± 2.5%) of the gel feed compared to the control, with an improvement in nutrient losses. Overall, the study provides an insight into the application of gel-based diets for ornamental fish rearing, besides ensuring an efficient nutrient uptake and minimal leaching to establish a clean aquatic environment.

Gelling properties and microstructure of the silver carp surimi treated with pomegranate (Punica granatum L.) peel extract.

Effects of ethanolic extracts of pomegranate peel (PPE) on the gelling and textural characteristics of silver carp surimi gel was investigated. The peels extracted with 100% ethanol exhibited highest total phenolics, tannin and flavonoid contents. The change of the gelling properties of surimi was explained using infrared spectroscopy, chemical interactions, and scanning electronic microscopy images. Greater number of hydrogen bonds and hydrophobic interactions were found in surimi gel fortified with 0.45% PPE. Amongst all the concentrations of PPE, 0.45% level exhibited the lowest sulfhydryl and primary amino groups and this was concurrent with the highest gel strength. The FT-IR analysis showed a gradual reduction of intensity of the amide I band with the increase of PPE concentration, and also shifting to lower value from control to surimi with PPE 0.90%. Absorption bands like C-N stretching from amide II and N-H deformation from amide III were also detected. The SEM images showed that surimi with 0.45% PPE had most ordered, finest and denser gel network, and was closely integrated with higher breaking force, hardness, and WHC. This study showed the potential of functional components of fruit wastes for improving gelling properties of surimi with additional health benefits for the consumers.

Effects of Pineapple Peel Ethanolic Extract on the Physicochemical and Textural Properties of Surimi Prepared from Silver Carp (Hypophthalmichthys molitrix).

The effects of ethanolic pineapple peel extract (PPE) powder at various concentrations (0-1.50%, w/w) on the gelling properties of silver carp surimi were investigated. The pineapple peel extract produced with 0-100% ethanol, revealed that 100% ethanol had the highest bioactive properties. Surimi gels with added PPE powder demonstrated improved gel strength (504.13 ± 11.78 g.cm) and breaking force (511.64 ± 11.80 g) up to 1% PPE addition; however, as PPE concentration increased beyond 1%, the gel strength decreased. Similarly, with the addition of 1% PPE powder, more hydrophobic bonds and fewer sulfhydryl groups and free amino groups were seen. However, the gels with PPE powder added showed a slight reduction in the whiteness of the surimi gels. FTIR analysis indicated that the fortification with PPE powder brought about the secondary structure of myofibrillar proteins; peaks shifted to the ß-sheet region (PPE gels) from the α-helix region (control). SEM analysis indicated that the gel with 1% PPE powder had a relatively organized, finer and denser gel architecture. Overall results suggested that the addition of PPE powder up to 1% to the surimi gels enhanced the gelling properties as well as the microstructure of the surimi.

Influence of the extent of enzymatic hydrolysis on the functional properties of protein hydrolysates from visceral waste of Labeo rohita.

The study aimed to evaluate the extent of hydrolysis on the functional properties of fish protein hydrolysates from fish wastes. Fish protein hydrolysate (FPH) was prepared from the visceral waste of Rohu (Labeo rohita) using Alcalase®. Independent variables of the hydrolysis conditions, namely, time, temperature and enzyme-substrate ratio were optimized through response surface methodology using a completely randomized factorial design. Functional properties of FPH, such as antioxidant activity, metal chelating activity, emulsifying and foaming capacity were studied. Pre-heating of the raw viscera resulted 83% reduction of lipid content in the FPH. The DH was found to be significantly influenced by the hydrolysis conditions studied. The gel electrophoretic study showed that FPH contained peptides in the range of < 10-25 kDa. Optimum degree of hydrolysis (DH) was obtained as 34.7% at 87.5 min, 48.64 °C and enzyme concentration of 0.99%. The results demonstrated that the antioxidant and metal chelating properties of FPH increased with the increase of DH. The surface active properties like emulsifying and foaming capacity were found to be decreased with the increased levels of hydrolysis. These results suggest that hydrolysates from visceral waste of Rohu could find potential use as supplement in animal feed.

Effect of feeding habits of fish on the characteristics of collagenolytic proteases isolated from the visceral waste.

In this study, influence of feeding habits of fish on the activity of collagenolytic proteases (CP) has been investigated. CP from the visceral waste of freshwater fish (Pangas, Rohu and Common carp) of different feeding habits was isolated and partially purified by 2-steps, (NH4)2SO4 fractionation and dialysis. Enzymatic activity and purification fold was determined in each step. The molecular mass of the enzymes were close to that of serine collagenases. Enzyme was assayed for temperature and pH optima, effect of sodium chloride and inhibitors. Optimum temperature and pH was 40 °C and 7-8 respectively. Soybean trypsin inhibitor inhibited the enzyme activity, whereas, EDTA exerted no effect, led to confirmation of serine collagenases. CP of carnivore was more active over a wide range of temperature and pH compared to herbivore and omnivore. The study revealed that the feeding habit of fish play decides the optimal physiological conditions for maximum activity of CP.

Anti-oxidative enzyme changes associated with chickpea calli tolerant to Ascochyta rabiei culture filtrate.

Ascochyta blight caused by Ascochyta rabiei (Pass.) Labrousse is a major biotic constraint in production of chickpea. In the present investigation, all chickpea genotypes [E100Y (m), Gaurav, Pb-7 and L550] induced 100% callus on standard medium with greenish colour and fragile structure. These calli were used for in vitro screening against pathogen, A. rabiei culture filtrate at 0, 5, 10, 15 and 20% concentrations. Survival rate of calli in all chickpea's genotypes were reduced significantly at higher concentration (15%) of culture filtrate. The culture filtrate concentration of 20 % was lethal for calli of all chickpea's genotypes. Hence, biochemical changes viz. total soluble proteins and activities of anti-oxidative enzymes (polyphenol oxidase, peroxidase and catalase) were estimated at 15% and below concentration of culture filtrate. Tolerant calli of resistant genotype, E100 Y (m) revealed significantly higher total soluble proteins (10.04 mg g⁻¹ f.wt. of callus) and activity of anti-oxidative enzymes, polyphenol oxidase (9.0 unit absorbance change min⁻¹ mg⁻¹ protein) and peroxidase (19.09 unit absorbance change min⁻¹ mg⁻¹ protein) and lower catalase (18.65 µ moles of H2O2 utilized min⁻¹ mg⁻¹ protein) at higher (15%) concentration of culture filtrate followed by moderately resistant (Gaurav), and susceptible genotypes (Pb-7 and L550). Thus, higher polyphenol oxidase and peroxidase and lower catalase activity in chickpea's genotypes against culture filtrate of A. rabiei could be used as parameters for screening resistant genotypes to pathogen, A. rabiei.

Effect of ice storage on the functional properties of proteins from a few species of fresh water fish (Indian major carps) with special emphasis on gel forming ability.

In the present study the effect of ice storage on physico-chemical and functional properties of proteins from Indian major carps with special emphasis on gel forming ability have been assessed for a period of 22 days. The solubility profile of proteins in high ionic strength buffer and calcium adenosine triphosphatase (ATPase) enzyme activity reduced significantly (p < 0.05), while that of total volatile base nitrogen (TVB-N) increased significantly (p < 0.05) at the end of 22 days of ice storage. The major protein fraction showed association-dissociation-denaturation phenomenon during ice storage as revealed by gel filtration profile and viscosity measurements. The gel forming ability of three fish species both in fresh and during different periods of ice storage was assessed by measuring the gel strength of heat induced gel. Among the three species the gel strength of the gel obtained from Catla catla and Cirrhinus mrigala was higher (586 and 561 g.cm) than the gel obtained from Labeo rohita (395 g.cm) in fresh condition. The gel forming ability of three species was significantly affected (p < 0.05) during ice storage. The TVB-N values of fish meat as a function of ice storage was within the prescribed limit up to 17 days of the ice storage.

Evaluation of cleansing methods for previously worn prostheses.

STATEMENT OF PROBLEM: Although there are many product claims that address the issue of denture sanitization, controlled scientific studies on previously worn dentures have not been performed. PURPOSE: The purpose of this study was to evaluate procedures directed at sanitizing previously worn contaminated dentures from two regions of the United States. MATERIALS AND METHODS: This study examined 51 previously worn dentures from two regions. An established method of denture retrieval, sectioning, and culturing was used, including isolation of anaerobes. Evaluation of microbial contamination posttreatment was used to determine the effects of soaking dentures in Polident (US and European formulations) for varying periods of times/temperatures, microwaving dentures with varying temperatures, sonicating dentures, and immersing the dentures while using a vacuum. A combination of analysis of variance (ANOVA) and general linear model (GLM) of the SPSS was used to analyze the data with P < .05 being considered statistically significant when using a two-tailed test. RESULTS: While all Polident treatments were found to significantly reduce microorganism loads in dentures, extended soaking (8 hours) and 65 degrees C (5 minutes) were the most effective. Microwaving was slightly more effective than either sonication or vacuum. Regardless the treatment, dentures underwent sanitization rather than sterilization. CONCLUSIONS: Denture-borne microorganisms can be significantly reduced by using a Polident solution for 8 hours at room temperature or for 5 minutes at 65 degrees C. Microwaving, sonication, and use of a vacuum were less effective. ClLINICAL IMPLICATIONS The importance of daily use of Polident solution for 8 hours or for 5 minutes at 65 degrees C to sanitize worn prostheses must be stressed.

Evaluation of microbial flora found in previously worn prostheses from the Northeast and Southwest regions of the United States.

STATEMENT OF PROBLEM: Denture-induced stomatitis is a recognized clinical challenge. The responsible microorganisms have not been delineated and may differ among regions of the United States. PURPOSE: The purpose of this study was to identify the microorganisms found in dentures from 2 geographic regions. MATERIAL AND METHODS: Previously worn dentures from 51 available subjects living in the Southwest (41) and Northeast (10) were aseptically retrieved in sterile plastic bags. A posterior piece of the mandibular denture was removed and sampled on appropriate media under anaerobic conditions. The remaining denture material was divided into 7 equal pieces. Each piece was touched to appropriate aerobic media and incubated at 37 degrees C. Bacteria and yeasts were identified using standard clinical laboratory procedures. Data were analyzed by using descriptive statistics. Denture fragments were further analyzed by scanning electron microscopy (SEM). RESULTS: A total of 916 isolates were carried to final speciation. Of these, 711 were aerobic bacteria, 67 were anaerobic bacteria, 125 were yeasts, and 13 were amoebae. Microorganisms were found on the denture surfaces and interstices (denture pores). Most subjects wore their dentures for extended periods without sanitization. SEM analyses confirmed substantial porosity of the denture material with microbial penetration and biofilm formation within the pores. CONCLUSIONS: A wide range of potentially pathogenic microorganisms was found in dentures. There were also regional differences in the microbial flora.