Fish Meal Research Articles

PENGENALAN DIVERSIFIKASI PRODUK HASIL PERIKANAN PADA IBU DAN BALITA SEBAGAI UPAYA PENINGKATAN GEMAR MAKAN IKAN UNTUK MENCEGAH STUNTING DI KB TK YAA BUNAYYA, SURABAYA

Early childhood is the golden age of children's development to obtain an educational process and is also fundamental and strategic education in the development of human resources, therefore we, the Faculty of Fisheries and Maritime Affairs, Airlangga University, collaborate with Day Care- KB-PAUD and YAA BUNAYYA Kindergarten to carry out activities community service related to the introduction of diversified fishery products among mothers and toddlers as an effort to increase their interest in eating fish to prevent stunting. Day Care-KB-PAUD and TK YAA BUNAYYA is an educational institution for early pre-school age in Surabaya City, East Java Province with a total of 130 students and 25 teachers. Indonesia is a developing country that is still facing serious problems regarding stunting and improving nutritional status is a top priority, therefore having a community service program related to the introduction of fishery product diversification is one solution to increase fish consumption as a high protein intake to prevent stunting. In this community service activity, we introduce from an early age the importance of eating fish, the nutritional content, and the benefits obtained from consuming fishery products. The activities carried out were demonstrations distributing fish food products, providing education for children, parents and teachers about the importance of eating fish. Finally, we also share modules related to several types of fisheries food diversification which can be easily practiced at school or by parents at home

Toward Classification of Fish Meat Using Fluorescence Excitation–Emission Matrix and Multivariate Statistics

Frequent intentional mislabeling of particular fish and fish products, such as the sale of frozen and thawed fish instead of fresh fish, occurs on all continents. Therefore, two studies were conducted to classify fish meat using excitation–emission matrix (EEM) nondestructively. The first study assessed EEM for differentiation between fresh and frozen–thawed spotted mackerel fillets. Fresh fillets were yielded with different post-mortem freshness variations (ice storage for 0–40 h). The right-side fillets were used as fresh fillets, whereas the left-side fillets were frozen and stored at −30 °C for three months, then thawed at 4 °C. Subsequently, EEM acquisition and chemical analyses were performed. Results of principal component analysis (PCA) of EEM spectra showed clear discrimination between fresh and frozen–thawed meat of fish fillet. In the second study, post-mortem freshness variations in four fish species (horse mackerel, spotted mackerel, cod, and flounder) were simulated by ice storage (0–48 h) and subsequent freezing. PCA of the EEM demonstrated a clear distinction among the fish meat categories, which was also revealed from the freshness data of chemical analysis. Results show that this novel method can be used to monitor fishery product authenticity.

Plankton food web structure and productivity under ocean alkalinity enhancement.

Ocean alkalinity enhancement (OAE) is a nature-based technology for CO2 removal and storage, but little is known about its environmental safety. We tested a CO2-equilibrated OAE deployment in a close-to-natural community using in situ mesocosms in the oligotrophic subtropical North Atlantic and assessed metazoan zooplankton to inform about food web stability, structure, and production. In addition, a literature review complemented experimental results by summarizing physiological responses of marine animals to decreasing proton concentrations, or increased pH. The food web studied proved resistant, and zooplankton physiologically tolerant, to the OAE tested. We observed short-term effects of OAE on zooplankton reproduction and productivity, which were likely trophically mediated. Yet, these did not affect zooplankton populations or their nutritional value as food for fish. Our study demonstrates an environmentally safe OAE application, but also stresses the risks of more intense OAE options, and the vulnerabilities of other marine ecosystems.

Quantitative Genetics of Feed-Efficiency-Related Traits for the Pacific Whiteleg Shrimp Penaeus vannamei in a Plant-Based Diet Environment

Selecting shrimp strains that perform well on a plant-based diet holds promise for solving the fishmeal (FM) shortage issue, with genetic improvement of feed efficiency (FE) being a key focus. This study compared a plant-based (fishmeal-free) diet with a 25% FM diet for the Pacific whiteleg shrimp (Penaeus vannamei) to determine whether the FE-related traits, including residual feed intake (RFI), average daily weight gain (ADG), and daily feed intake (DFI), exhibit diet-specific genetic variations and genotype-by-diet (genotype × diet) interactions. Results showed that RFI was significantly higher under the plant-based diet treatment compared to the FM-based diet treatment (0.0049 g/d vs. –0.0045 g/d, p < 0.001), while ADG was notably lower (0.043 g/d vs. 0.110 g/d, p < 0.001), indicating that a plant-based diet may lead to reduced yields and impact the profitability of shrimp culture. In the case of being unable to estimate common environmental effects, the heritability estimates of RFI under the plant-based and FM-based diets were 0.743 ± 0.157 and 0.440 ± 0.125, respectively, and those of ADG and DFI ranged from 0.314 ± 0.121 to 0.947 ± 0.158. Genetic correlations between diets for RFI and DFI were 0.646 ± 0.162 and 0.549 ± 0.163, respectively, suggesting a degree of genotype × diet interactions. In contrast, the genetic correlation between diets for ADG was only 0.296 ± 0.259, indicating a strong genotype × diet interaction. These findings highlight the importance of considering selective breeding for improved feed efficiency in a plant-based diet environment.

Effect of Codigestion of Rice Straw, Fish Meal, and Cow Manure on Biogas Production and Quality of Solid Bioslurry Fertilizer

The solid phase bioslurry (sludge) had the potential to be used as organic fertilizer. However, the NPK content in it did not meet SNI standards. This research aimed to study the effect of adding rice straw and fish meal to cow dung substrate for anaerobic processing, on the NPK content of the sludge produced and biogas production. Two digesters were used, which functioned as a control and a codigestion digester. Initially, in both digesters, starter breeding was carried out in batches. After the starter had grew well, then the substrate along with water was fed continuously at 88 mL/day in each digester, and an output of 88 mL/day was also produced. Analysis of COD, sCOD, VFA concentrations, and measurements of the pH values of feed and output were carried out every 3 days. Biogas volume measurements were carried out every day. The process was stopped when conditions were steady. At the end of the process, an analysis of the NPK content in the sludge and the methane content in the biogas were carried out. The results showed that biogas from codigestion content almost no methane. However, the sludge contained NPK within the range of SNI standard. Keywords: Biogas, Cow dung, Fish meal, Rice straw, Solid bioslurry fertilizer.

Development of optimized artificial diets for enhanced growth of Zophobas atratus larvae

AbstractThis study evaluates the effects of various artificial diets on the development of Zophobas atratus larvae. Artificial diets containing various concentrations of agar were also investigated for their ability to reduce death rates during the early stages of larval development. Our results indicated that larvae fed artificial diets experienced a slightly longer developmental period but achieved significantly higher weights. Notably, wheat bran + fish meal 6% resulted in the highest weight gain; however, wheat bran + fish meal 6%, wheat bran + fish meal 5% + ginseng leaf 1%, and wheat bran + fish meal 4% + ginseng leaf 2% yielded higher death rates. The diet with 4% agar resulted in the shortest developmental period, whereas that with 3% agar produced the highest weight gain. However, considering death rates, the diet with 2% agar provided the most balanced outcome across developmental time, weight gain, and survival, making it the most suitable diet for Z. atratus larvae. In conclusion, wheat bran + fish meal + agar 2% artificial diet is more suitable for Z. atratus larval development than wheat bran, leading to greater weight gain, shorter development periods, and higher adult emergence rates. Additionally, this diet showed the potential to reduce the dust issues and labor demands associated with wheat bran usage. Our findings suggest that wheat bran + fish meal + agar 2% could be an effective artificial diet for the optimal development of Z. atratus larvae.

Positive effects of Lithospermum erythrorhizon extract added to high soybean meal diet on growth, intestinal antioxidant capacity, intestinal microbiota, and metabolism of pearl gentian grouper

This study aims to investigate the effects of adding 2‰ Lithospermum erythrorhizon (LE) extract to the high soybean meal diet on the growth, intestinal antioxidant capacity, intestinal microbes, and metabolism of pearl gentian grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂). Three diets included FM, SBM, and SBMLE, in which FM was the whole fish meal diet, SBM was the soybean meal replacing 50% fish meal protein, and SBMLE was the SBM diet supplemented with 2‰ LE extract. After a 56-day feeding trial, the results showed the weight gain rate (WGR), specific growth rate (SGR), and feed efficiency rate (FER) of pearl gentian grouper in FM and SBMLE group was significantly higher than that of SBM (P < 0.05). Furthermore, high soybean meal dietary added LE extract inclusion significantly increased the SOD, CAT, and GSH-Px activity while significantly decreasing the MDA level (P < 0.05). Significant differences were in the gene expression of cytokines il1-β, il8, tnf-α, il10, and tgf-β between the SBMLE and SBM groups (P < 0.05). In addition, Microbiomics results revealed increased ASVs and alterations in gut microbiota composition, characterized by a decrease in Bacteroidota and an increase in Proteobacteria, Nautella, and lactococcus after adding LE extract. Furthermore, the substantial reduction in Firmicutes and Acidobacterota induced by high soybean meal feed was reversed by LE extract. Metabolic pathway enrichment analysis showed that LE extract mitigated soybean-induced enteritis (SBMIE) by affecting two critical metabolic pathways: arachidonic acid metabolism and histidine metabolism. In conclusion, adding LE extract to a high soybean meal diet can improve the growth performance and immunity of the pearl gentian grouper, and LE can play a mitigating role in SBMIE by regulating lipid metabolism, amino acid metabolism, and intestinal flora balance.

Liver Structure and Function in Yellowtail Kingfish, Seriola lalandi, in Response to Reduced Fish Meal Diets

ABSTRACTAlterations to lipid storage, and the consequent effects on liver structure, need to be considered when replacing wild‐derived fish meal (wd‐FM) with alternative ingredients in formulated diets for commercially aquacultured species. The replacement of wd‐FM is likely to alter the available level of precursors for bile acid production, potentially impacting the absorption of dietary lipids and fat‐soluble vitamins. In this 252‐day study, Yellowtail Kingfish, Seriola lalandi (2.52 ± 0.25 kg; 546 ± 20 mm [fork length; mean ± standard deviation]) were fed five different diets. A 30% wd‐FM diet served as a control. Dietary wd‐FM inclusions were reduced to 20% and 10%, replaced with FM by‐product meal. In addition, dietary wd‐FM levels were reduced to 20% and replaced with poultry meal (PM) or soy protein concentrate (SPC) in two other separate diets. Fat deposition in the liver was similar amongst all treatment groups with bile duct proliferation and periductular fibrosis observed in the livers of fish fed diets with wd‐FM replacement with 10% PM or 10% SPC. Fish fed FM by‐product meal at 10% and 20% replacement displayed similar liver structures to control fish. Yellowtail Kingfish fed a 30% wd‐FM diet may have the FM replaced by up to 66.67% FM by‐product, 33.3% PM or 33.3% SPC without any significant impact on total bile acid synthesis, storage and excretion and liver lipid storage. This research expands our ability to deliver cost‐effective nutritional solutions in support of Yellowtail Kingfish culture.

Fishing or farming? Isotopic evidence of human subsistence strategies at the Dashuitian site during the middle Neolithic in the Three Gorges of the Yangtze River, China

The Three Gorges of the Yangtze River, with its deep canyons, abundant freshwater resources, and unique geographic location at the crossroads in the spread of rice-millet agriculture in the Middle Neolithic, is of great significance for understanding the interaction between fishing-hunting-gathering and farming in inland freshwater environments. However, few direct evidence for human subsistence strategies had been published in this region. This study presents results of carbon and nitrogen stable isotope analyses on human bones, animal and millet remains from the Dashuitian site (c. 6000–5500 BP) in the Three Gorges of the Yangtze River, China, to investigate the diet and subsistence and intrapopulation dietary variations in this region. The results indicate that the humans at the site consumed mostly freshwater fish foods and supplemented by terrestrial animals, with no discernable input from millets. They had consistently relied on a fishing, hunting, and gathering economy during the occupation of the site in the Middle Neolithic (c. 6000–5500 BP), differing from humans in other areas especially along the rivers and coasts of the lower Yangtze River valley for the roughly same period, further showing the extensive utilization of and adaptation to the available environmental resources. In addition, intrapopulation dietary variations based on burial style and sex provide evidence that differentiation and inequality, at least regarding to food consumption, existed at the Three Gorges region during the Middle Neolithic. Here, our findings provide isotopic evidence about the Middle Neolithic human subsistence strategies in the Three Gorges of the Yangtze River, providing a glimpse into the complexity related to inequality in food access among fisher-hunter-gatherers in inland areas, and new insights into understanding past human-environment interactions.

SUBSTITUTING FISH MEAL WITH SPIRULINA (ARTHROSPIRA PLATENSIS) MEAL IN DIETS FOR JUVENILE CLARIAS GARIEPINUS

This study was conducted to evaluate the effects of substituting fish meal with spirulina (Arthrospiraplatensis) meal into the diet of juvenilesclarias (Clarias gariepinus) in northern Senegal.This work was carried out on juveniles of 15 g raised in 09 aquariums with a volume of 24.3 L each.Three isonitrogenous diets (35% protein) containing different levels of spirulina meal 0%, 50%, 100% noted respectively A, B and C were prepared, each diet was randomly assigned to three groups of fish, fed to satiation, for 60 days.The results of water quality parameters of the different treatments showed that the average water temperature ranged from 26 to 27 °C, the average pH values ​​measured in the different treatments ranged from 6.3 to 6.6.The best growth and feed efficiency performances were obtained with diets B, the one containing 50% spirulina meal, followed by diets C and A.The results obtained show that the specific growth rates (SGR) varied between 1.58%1.64% and 1.8% respectively in fish fed with diets C, A and B. For the batches of fish receiving diets A, B and C, the feed conversion rate was between 1.01 and 1.38 kg. Regarding survival rates, statistical analyses show that diets B and C obtained the best TS comparedto diet A.The results of the study show that feeding A. platensis increased whole-body protein and ash contents of the fish, but decreased lipid and moisture contents.This study showed that the optimum rate of A. platensis in the fish practical diet is 50% replacement for fish meal in a fishmeal-based diet for of juvenile Clarias gariepinus without any adverse effects on fish growth and proximate composition of carcasses.This information is useful for the proper use of this vegetable protein source in the formulation of inert fish feed, which could reduce production costs and improve farm profitability.

Peptidomic Analysis Reveals Temperature-Dependent Proteolysis in Rainbow Trout (Oncorhynchus mykiss) Meat During Sous-Vide Cooking

Sous vide, a cooking method that involves vacuum-sealed fish at low temperatures, yields a uniquely tender, easily flaked texture. Previous research on sous-vide tenderization has focused on thermal protein denaturation. On the other hand, the contribution of proteases, activated at low temperatures in fish meat, has been suggested. However, the details of protein degradation remain unclear. This study employed SDS-PAGE/immunoblot and peptidomic analysis of rainbow trout to assess proteolysis during sous-vide cooking. The results from SDS-PAGE and immunoblot analysis indicated reduced thermal aggregation of sarcoplasmic proteins and increased depolymerization of actin under low-temperature cooking conditions. A comparison of the peptidome showed that the proteolysis of myofibrillar proteins was accelerated during sous-vide cooking, with distinct proteases potentially activated at different cooking temperatures. Terminome analysis revealed the contribution of specific proteases at higher temperatures in rainbow trout. The results of this study demonstrate the thermal denaturation of sarcoplasmic proteins and proteolysis of myofibrillar proteins in rainbow trout meat during sous-vide cooking and its temperature dependence. The methodology in the present study could provide insights into the optimization of cooking conditions for different fish species, potentially leading to improved texture and quality of sous-vide products.

Cultural ecosystem services and the conservation challenges for an Indigenous people's aquatic protected area practice.

Globally, protected areas associated with sacred sites and cemeteries are an emerging area of research. However, they are biased toward terrestrial systems. In Fiji, funerary protected areas (FPAs) in freshwater and marine systems are culturally protected by Indigenous Fijians following the burial of a loved one on clan land. First documented in the 1800s, FPAs in Fiji have not been researched despite more than 30years of conservation efforts and countrywide comanagement of natural resources. We sought to bridge this knowledge gap by elucidating 8 socioecological attributes of Indigenous FPAs through stratified, purposive, semistructured interviews of 201 key informants across Fiji's 189 districts. Seventy-three districts actively implemented FPAs; another 34 were not being implemented because of low FPA awareness, FPA exclusion from comanagement plans, and conflicts in chief selection. Thirty-three percent of districts established FPAs for chiefs only, and 20% established FPAs for any clan member, resulting in the establishment of numerous FPAs annually. From the 1960s to 2019, 188 FPAs were established. Forty-four percent of FPAs were protected for 100 nights, and 47% protected all resources and associated ecosystems in the FPA. Only 25% of districts harvested edible fish and invertebrates; another 22% harvested edible fish only. For some chiefs' funeral rites, only turtles were harvested, which are protected by law, thereby requiring government exemption for traditional use. The FPA harvest provisions varied from engaging whole communities to engaging specific clans, such as traditional fishers or those who performed the burial. Our results showed that practices associated with FPAs in Fiji are diverse, organically evolving, and more socially nuanced and complex than the fisheries and food provisioning focus they are known for. Erosion of Indigenous knowledge and practices associated with FPAs and FPA exclusion from conservation planning will negatively affect social and ecological resilience, resulting in vulnerable communities.

Monoclonal antibodies against jellyfish collagen.

Collagens are abundant structural proteins found in both mammalian and marine species, and attractive biomaterials used in various fields. Jellyfish collagen-based products have become increasingly popular because of their clinically proven health benefits such as the effects of skin wound healing and immune stimulation. To develop detection tools for jellyfish collagen, we generated four monoclonal antibodies, MCOL1, 2, 3, and 4, by immunizing mice with moon jellyfish collagen. The nucleotide and amino acid sequences of the variable regions of the monoclonal antibodies were determined. The antibody-binding kinetics toward collagens from moon jellyfish were evaluated using a surface plasmon resonance (SPR) biosensor, and the binding specificity was evaluated in comparison with binding to collagens from edible jellyfish, fish scales, and pig and cow skins. MCOL1, 3, and 4 specifically bound to moon jellyfish collagen, whereas MCOL2 bound to both moon and edible jellyfish collagens. Considering the results showing that the SPR responses of MCOL2 binding were greater than those seen with the other antibodies, MCOL2 could recognize the common and repetitive sequences of the two jellyfish collagens. Therefore, this monoclonal antibody will be most applicable for detecting jellyfish collagen.

The Biotechnological Potential of Crickets as a Sustainable Protein Source for Fishmeal Replacement in Aquafeed.

As aquaculture production grows, so does the demand for quality and cost-effective protein sources. The cost of fishmeal (FM) has increased over the years, leading to increased production costs for formulated aquafeed. Soybean meal (SBM) is commonly used as an FM replacer in aquafeed, but anti-nutritional factors could affect the growth, nutrition, and health of aquatic organisms. Cricket meal (CM) is an alternative source with a nutrient profile comparable to FM due to its high protein content, digestibility, and amino acid profile. CM use in aquafeed influences growth and reproductive performance while modulating the gut microbiota and immune response of fish and shrimp. However, consistent regulation and scaling up are necessary for competitive prices and the marketing of CM. Moreover, the chitin content in CM could be an issue in some fish species; however, different strategies based on food biotechnology can improve the protein quality for its safe use in aquafeed.

Prevalence, virulence potential, antibiotic resistance profile, heavy metal resistance genes of Listeria innocua: A first study in consumed foods for assessment of human health risk in Northern Turkey.

Listeria (L.) innocua is typically considered a non-pathogenic bacterium that can sometimes act as an opportunistic pathogen in severely immunocompromised patients. However, it plays an important role in food safety because it acts as an indicator organism for potential contamination and the effectiveness of sanitation methods. The aim of this study was to determine the prevalence, virulence genes, antibiotic resistance profiles, heavy metal and disinfectant resistance genes of L. innocua isolates from animal-derived foods. In this study, we isolated and characterized 39 L. innocua strains recovered from commonly 400 consumed beef meat, fresh fish meat, raw cow milk, and traditional cheese samples collected in Giresun, Turkey. The occurrence of virulence-associated genes was detected, such as plcA (97.4%), iap (35.8%), and hlyA (15.3%). A high incidence of resistance was recorded for fusidic acid (100%), followed by oxacillin (97.4%), clindamycin (82%), trimethoprim/sulfamethoxazole (69.2%), benzylpenicillin (41%), nitrofurantoin (35.8%), and fosfomycin (35.8%). Overall, 100% (39/39) of the isolates were resistant to at least one antibiotic, while 92.3% (36/39) of the isolate strains were multidrug resistant in the antimicrobial susceptibility tested. Among the L. innocua isolates (n = 39), 51.2%, 38.4%, 20.5%, 7.6%, 5.1%, 2.5%, and 2.5% were positive for qacH, cadA1, qacE, qacEΔ1-sul, qacJ, qacF, and qacG heavy metal and disinfectant resistance genes, respectively. The results highlight the need for more comprehensive studies to understand the monitoring and surveillance of L. innocua and their potential hazards to both humans and animals.

Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels

Zebra mussels (Dreissena polymorpha) are invasive species that alter ecosystems and food webs with the potential to affect aquatic mercury cycling and bioaccumulation in fishes, although the effect of zebra mussels on fish tissue mercury has not been tested in inland lakes. We assessed differences in fish tissue mercury concentrations and food webs in Minnesota lakes with and without zebra mussels while controlling for other lake and watershed characteristics. Mercury concentrations in adult walleye (Sander vitreus) and yellow perch (Perca flavescens) were 72 % and 157 % higher, respectively, in lakes containing zebra mussels compared to uninvaded lakes. Mercury in young of year (age-0) fish was also elevated, with mercury concentrations 97 % and 82 % higher in age-0 walleye and yellow perch, respectively, in zebra mussel lakes. Walleye mercury concentrations exceeded 0.22 ppm — a threshold triggering more restrictive human consumption advisories for sensitive populations — at a 23 % smaller size, and average-sized walleye (420 mm) exceeded this threshold at a rate of 77 % in invaded lakes, compared to 35 % in uninvaded lakes. Walleye and yellow perch relied more on littoral resources in lakes with zebra mussels but did not feed at meaningfully higher trophic levels. Increased fish tissue mercury in lakes invaded by zebra mussels have consequential implications for fisheries and human health.

Effect of Poultry By-product Meal as Replacement for Fish Meal in Diets of Gilthead Seabream (Sparus aurata) Juveniles

This study investigated the effects of replacement of fish meal (FM) with poultry by-product meal (PBM) at 55%, 65% and 75% on growth performance and amino acid metabolism of juvenile gilthead seabream (Sparus aurata) with an initial weight of 35.01±0.11 g for 120 days. The study also evaluated protein and amino acid digestibility to determine their influence on protein metabolism in juvenile seabream. The results indicated that partial replacement of FM with PBM in diets of juvenile gilthead seabream is feasible up to 65% without compromising their growth performance, feed consumption and digestibility (P&gt;0.05). Additionally, hepatosomatic (HSI) showed no significant differences between all groups (P&gt;0.05). The viscerosomatic index (VSI) level was at the highest value, whereas the condition factor (K) was at the lowest value in CTRL (P&lt;0.05). The highest feed conversion ratio (FCR) value was in the 75PBM group (P&lt;0.05). However, there was no statistically significant difference between CTRL and the other PBM groups (P&gt;0.05). Similarly, feed intake and whole-body protein content did not significantly differ among dietary groups (P&gt;0.05). The protein efficiency ratio (PER) values suggest that replacing FM with PBM (up to 65%) in diets of juvenile gilthead seabream is effective and produces diets with high-quality proteins and digestibility coefficients comparable to those of the control group (P&gt;0.05). Additionally, amino acid profiles of juvenile gilthead seabream fed with diets containing up to 75% PBM showed no deficiencies in essential amino acids. Nevertheless, we can suggest that 75% PBM substitution for FM can be used in the diets of gilthead seabream, although it causes a slight decrease in growth, FCR and protein digestibility. These results suggest that partial replacement of FM with PBM can be a viable strategy for feeding juvenile gilthead seabream, offering a sustainable advantageous alternative.

A novel self-powered SERS platform PVDF-HFP/BZT-BCT@PDA/Ag based on piezoelectricity for sensitive detection of food contaminants

Electrically modulated surface-enhanced Raman scattering (E-SERS) enhances Raman signals by adjusting the plasmon resonance of noble metal nanostructures with an electric field. However, traditional E-SERS substrates require complex electrochemical setups, limiting portability. Piezoelectric materials, which generate surface charges under external forces, present a promising alternative. This study develops a novel self-powered E-SERS substrate by embedding piezoelectric material 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) in polyvinylidene difluoride-hexafluoropropylene (PVDF-HFP) matrix combined with silver nanoparticles. Experiments with nanogenerator piezoelectricity reveal that pressing the substrate with a finger generates current and voltage, providing an electric field for SERS enhancement. Gradual addition of weights on the substrate significantly boosts Raman signals of molecules like p-aminothiophenol (PATP), crystal violet (CV), thiram, and methyl bromide (MB). The synergy of piezoelectric effect and localized plasmon resonance achieves high sensitivity, reproducibility, and detection limits down to 10−9 M, with an enhancement factor of 109. Moreover, the sensor effectively detects trace MB veterinary drug residues in fish meat and thiram pesticide residues on apple skin, introducing a new self-powered E-SERS platform for sensitive food contaminant detection.

Effects of supplementation with freeze-dried Clostridium butyricum powder after replacement of fishmeal with cottonseed protein concentrate on growth performance, immune response, and intestinal microbiota of Litopenaeus vannamei

The present study was designed to investigate the effects of supplementation with freeze-dried Clostridium butyricum (CB) powder on the growth, immune function and intestinal health of Litopenaeus vannamei after replacing fishmeal in the diet with cottonseed protein concentrate (CPC). Six treatment groups were designed, namely the control group (CON, 25% fish meal) and five alternative groups (CPC replacing 40% fishmeal protein in the control group). Based on the alternative group, 0%, 0.065%, 0.26%, 1.04%, and 4.16% of freeze-dried CB bacterial powder (4.6 × 108 CFU/g) were added, recorded as CB 0, CB 0.065, CB 0.26, CB 1.04, and CB 4.16, respectively. Each treatment had 3 replicates of 40 shrimps (0.29 ± 0.01 g) each and breeding for 8 weeks. After the experiment, serum enzyme activities, muscle amino acids, and intestinal parameters (short-chain fatty acids, digestive enzymes, gene expression, and microbiota) were tested to explore the effects of freeze-dried CB powder in shrimp aquaculture. The results showed that the CB1.04 group had the highest final body weight, weight gain rate, and specific growth ratio (P > 0.05). Freeze-dried CB powder increased the activity of serum superoxide dismutase, glutathione peroxidase, complement 3, and complement 4. Muscle tyrosine, proline, and total essential amino acids were remarkably increased in the CB 1.04 group (P < 0.05). Propionic acid levels were elevated in the CB 1.04 and CB4.16 groups (P < 0.001). The relative expression of Dorsal, Relish, and Target of Rapamycin (TOR) genes was significantly increased in the CB 1.04 group (P < 0.01). Actinobacteria and Demequina abundance was significantly higher in the CB 1.04 group (P < 0.01). The results of the Vibrio parahaemolyticus challenge test showed the highest cumulative mortality rate (43.33%) in the CB0 group and the lowest cumulative mortality rate (20%) in the CB1.04 group. This study confirmed that freeze-dried CB powder alleviated the negative effects of CPC replacement of fish meal protein in Litopenaeus vannamei, and the optimum additive level was 2.11% (9.71 × 109 CFU/kg) as indicated by binary regression analysis of specific growth ratio.

Effects of hydrolyzed hairtail protein partially replacing fish meal in diets on growth and protein turnover rate for hybrid grouper (Epinephelus fuscoguttatus♀×E. lanceolatus♂)

The high protein content and digestibility of hydrolyzed hairtail protein (HHP) promise a superior protein source for aquatic animal diets. In this experiment, the feasibility of HHP as an alternative for fishmeal (FM) in diets of hybrid grouper (Epinephelus fuscoguttatus♀×E. lanceolatus♂) was evaluated by exploring its impact on growth and protein turnover rate. For this, three iso-nitrogenous and iso-energetic extruded diets were formulated: one with FM (33 %, HHP0); two with 10 % (HHP1) and 20 % (HHP2) FM protein replaced by HHP. After a 60-day feeding trial, an independent effect of dietary HHP levels on grouper growth performance, body composition, and nutrient retention efficiency was recorded. However, a second-order increase in the hepatosomatic index (HSI) and dry matter apparent digestibility coefficient (ADC) was plotted with increasing dietary HHP levels. Furthermore, results showed no adverse effect on protein turnover rate in muscle tissue at different dietary HHP levels, while the relative contribution ratio (RCR) from HHP on growth was lower than that from the equal amount of FM. Overall, our finding indicated that up to 20 % FM protein could be replaced by HHP without adverse effects on growth, body composition, nutrient retention efficiency, digestibility coefficient, and protein turnover rate.