Search Results (155)

The windowpane oyster (Placuna placenta) is common in coastal areas of the Philippines, thriving in brackish waters. Its shells underpin the local craft industries. While its meat is edible, only small amounts are consumed locally, most going to waste. Utilization of this potential nutrient source is hindered by the lack of information concerning its organic and mineral content, the possible presence of heavy metal ions, and the risk of microbial pathogens. We report extensive analysis of the meat from Placuna placenta, harvested during three different seasons to account for potential variations. This comprises proximate analysis, mineral, antioxidant, and microbial analyses. While considerable seasonal variation was observed, the windowpane oyster was found to be a rich source of protein, fats, minerals, and carbohydrates, comparing well with the meats of other shellfish and land animals. Following pre-cooking (~90 °C, 25–30 min), the standard local method for food preparation, no viable E. coli or Salmonella sp. were detected. Mineral content was broadly similar to that reported in fish, although iron, zinc, and copper were more highly represented, nevertheless, heavy metals were below internationally acceptable levels, with the exception of one of three samples, which was slightly above the only current standard, FSANZ. Whether the arsenic was in the safer organic form, which is commonly the case for shellfish, or the more toxic inorganic form remains to be established. This and the variation of arsenic over time will need to be considered when developing food products. Overall, the meat of the windowpane oyster is a valuable food resource and its current (albeit low-level) use should lower any barriers to its acceptance, making it suitable for commercialization. The present data support its development for high-value food products in urban markets. Full article

This study explores the effects of selenium-enriched yeast supplementation on growth-related and immune-related gene expression in C. gigas, aiming to support feed optimization in oyster aquaculture. Selenium, an essential trace element, is vital for growth, immune function, and metabolism in animals. Selenium-enriched yeast, an organic form, offers superior bioavailability, enabling efficient absorption and utilization. C. gigas, a commercially significant marine shellfish, is rich in protein and nutrients, but the effects of selenium on mollusks remain insufficiently explored. In this study, oysters were divided into three groups: a control group without selenium (THNP), a 2 ppm selenium group (THMP), and a 4 ppm selenium group (THHP). Transcriptome sequencing yielded 388,679,026 clean reads. GO and KEGG enrichment analyses identified key metabolic signaling pathways, and a PPI analysis was performed on the translation products of DEGs involved in the KEGG pathways. qRT-PCR validated the expression of principal DEGs. The combined results of enrichment and PPI analyses highlighted pathways such as glutathione metabolism and collagen signaling. Additionally, three hub genes—FASN, HRAS, and ABCG5—were identified as central to the selenium response. These findings enhance the understanding of selenium’s molecular impact on oysters and support its application in aquaculture. Full article

The clean-label movement has markedly increased consumer demand for meat products free from synthetic additives, such as sodium nitrite, ascorbate, and phosphate. This review summarizes strategies to replace these additives with natural alternatives while preserving the functional and quality properties of traditionally cured meats. Nitrite replacement commonly employs nitrate-rich vegetables, alongside nitrate-reducing starter cultures or pre-converted nitrite powders for adequate nitric oxide production and meat pigment stabilization. Ascorbate substitutes include vitamin C-rich materials and polyphenol-based antioxidants from green tea and rosemary, supporting nitrite reduction and contributing to meat pigment and oxidative stability. To compensate for phosphate functions, natural substitutes such as hydrocolloids, dietary fibers, protein isolates, and calcium powders from eggshells or oyster shells have shown partial success in restoring water-holding capacity, pH buffering, and textural integrity. In addition, non-thermal processing technologies, such as high-pressure processing, ultrasound, and cold plasma are explored as complementary strategies to enhance the efficacy of natural ingredients and support industrial scalability. However, challenges persist regarding ingredient variability, dose-dependent effects, and consistency in functional performance. Future research should focus on synergistic ingredient combinations, formulation standardization, and scalable application in industrial production to ensure the production of high-quality clean-label meat products. Full article

Food security and environmental quality related to food production are global issues that need urgent solutions. Proteins are crucial for diets, and demand is growing for innovative and more environmentally sustainable sources of protein, like vegetables, microorganisms, and insects, and lab-grown food that can meet nutritional and environmental goals. This study analyzes a time series to assess the sustainability of different protein sources by evaluating their effects on emissions of greenhouse gases and the use of agricultural land while accounting for the carbon sink potential across the supply chain. The study also explores future trends in global protein sources, emphasizing shellfish as a key to achieving food security from both nutritional and environmental perspectives. By reviewing terrestrial livestock, farmed seafood, vegetal proteins, and alternative sources like insects and cultured cells, the study assesses sustainability, food security potential, and challenges from nutritional, environmental, and consumer viewpoints. We conclude that shellfish aquaculture, particularly oysters, mussels, clams, and scallops, has significant potential in enhancing food security, fostering sustainable protein consumption, reducing land use, and contributing to climate change mitigation by sequestering significant amounts of atmospheric carbon. Full article

Current food production systems generate and incinerate significant amounts of organic waste, which increases costs and energy consumption. In this study, we show that food waste, including food loss, can be used for mushroom cultivation. We also developed a new mushroom culture medium to replace conventional sawdust. Oyster mushrooms cultivated using food waste, including food loss, as the primary component contain higher levels of ergothioneine than that in the oyster mushrooms grown using sawdust, which has an antioxidant effect. We found that the proportion of nitrogen derived from animal protein in the mushroom culture medium influences ergothioneine content in fruiting bodies. We showed that irradiation with blue LEDs might produce mushrooms with a higher ergothioneine content than T-2 media. Furthermore, we established that ergothioneine is absorbed by the plant body. We aimed to develop an agricultural technology using food waste, including food loss, as growing media for mushrooms. Ultimately, we hope to create a regional cyclical food production system centered on mushroom cultivation, using food waste, including food loss, to promote microcirculation. Full article

Oyster mushrooms (Pleurotus spp.) are a nutrient-rich functional food, packed with protein, fiber, and bioactive compounds, offering a broad range of therapeutic qualities. This paper reports the findings in terms of crude protein, crude fiber, total polyphenols, total flavones, and some phenolic compounds along with the antimicrobial and antioxidant activities of some Pleurotus mushrooms extracts: P. eryngii, P. ostreatus, and P. columbinus. The integration of brewery-spent grains (BSG) into the nutrient media and culture substrate induced a major statistical increase (p < 0.05) for crude protein, total polyphenols, total flavones, and chlorogenic and caffeic acids as well as antioxidant activity. The lowest inhibition concentration IC₅₀ was recorded for P. ostreatus, followed by P. eryngii and P. columbinus. Among the strains, only P. ostreatus and P. columbinus exerted antimicrobial activity against two pathogens: Staphylococcus aureus and Streptococcus pyogenes. These results add and provide evidence of oyster mushrooms’ nutritional properties and possible positive effects on human health. Full article

Essential amino acids and essential fatty acids are vital nutrients that must be obtained from the diet. However, traditional sources face limitations amid increasing global food security and sustainability challenges. This study aims to evaluate the nutritional potential of novel foods, including microalgae (e.g., spirulina and chlorella), fungi (e.g., oyster and shiitake mushrooms), edible insects (e.g., mealworms and migratory locusts), and unconventional plants (e.g., water lentils and canihua). The study will compare their amino acid and fatty acid profiles with those of conventional animal and plant sources. The comparative analysis conducted in this study reveals that these innovative foods offer balanced and high-quality protein and lipid profiles, and contribute essential nutrients needed to prevent deficiencies and support metabolic health. Significantly, the integration of these novel foods into established dietary patterns, such as the Mediterranean diet, has the potential to enhance nutritional quality while promoting environmental sustainability. In conclusion, the adoption of these innovative food sources provides a viable strategy to meet nutritional demands and address global health and ecological challenges, paving the way toward a more resilient and sustainable food system. Full article

Pleurotus ostreatus, or oyster mushroom, is the most widely consumed and studied species. Because of its high protein and amino acid content, it can be used as a meat substitute. Food quality and composition can be improved by utilizing various technologies, including emerging thermal and non-thermal techniques. The study aim was to determine the effect of various pretreatment technologies on the amino acid and biogenic amine content of fresh and fermented oyster mushrooms. An automatic amino acid analyzer was used to perform a chromatographic analysis on free amino acids and biogenic amines. Significant differences were found between fresh and fermented mushroom samples: the fresh samples showed an increased FAA value (+57%), while blanching and microwaving them stabilized the FAA content. In the other groups, a 9–17% reduction was observed. The total biogenic amine composition increased 11- and 15-fold in the fresh and UV-treated samples (1.89 and 5.05 mg/g, respectively). The blanched samples showed no major change while the other groups increased by two to five times. The results of our study provide an excellent basis for the development of oyster-mushroom-based food products, whether for use in meat products or novel vegan products. Full article

Serum amyloid A (SAA) is one of the most abundant acute-phase response proteins and has been extensively studied in vertebrates for its role in modulation of the inflammatory response and as a marker of disease diagnosis. By comparison, SAA is rarely identified in aquatic species and its physical functions are also not well studied. The present study identified the only one gene encoding SAA protein in oyster Crassostrea gigas. The open reading frame (ORF) of CgSAA was of 417 bp, encoding a putative polypeptide of 138 amino acid residues with a predicted molecular weight of 15.66 kDa. CgSAA was composed of a signal peptide (residues 1–22) and a conserved SAA domain (residues 36–138). The mRNA expression of CgSAA in normal individuals was detectable but at a low level, with the lowest expression level in the tissue of labial palp and a slightly higher expression level in hemocytes. The mRNA expression level of CgSAA was significantly up-regulated at 6 h (2.76-fold of that in control group, p < 0.01) post V. splendidus stimulation. It was also significantly induced under environmental stress at high temperature (34 °C) or low salinity (15‰ salinity). The recombinant protein rCgSAA was expressed in Escherichia coli and purified by affinity chromatography. After rCgSAA was injected into oysters or incubated with culture primary hemocytes, the mRNA expressions of the cytokines CgIL17-1, CgIL17-5, and CgTNF were all significantly up-regulated. The results collectively suggested that CgSAA, as a conserved acute-phase response protein in oyster, was quickly induced under environmental stress and promoted the expressions of cytokines, which provide fresh ideas for understanding the roles of SAA proteins in aquatic invertebrates. Full article

Oyster mushrooms are regarded as one of the most significant edible mushrooms in terms of commercial value because of their rich nutritional profile. Many bioactive extracts from Pleurotus species have been found to exhibit antitumor and antioxidant activities. However, to grow oyster mushrooms in this study, the pasteurized Cenchrus fungigraminus was used as culture material, a type of grass that proliferates and has a high root growth rate. It contains high levels of sugar and protein and yields a large amount of biomass. Because of these characteristics, it is considered an efficient and cost-effective energy crop with various applications, including phytoremediation and fodder production. A pasteurization technique for this grass that is suited for the simplest formulation is simple and cost-effective for growing oyster mushrooms on small farms. This study used pasteurized Cenchrus fungigraminus as a substrate to grow three mushroom species: Pleurotus ostreatus, Pleurotus pulmonarius and Pleurotus florida. The aim was to evaluate their enzyme activities, growth rate, and yields. The findings demonstrated that the average growth rate of three species grown in pasteurized C. fungigraminus was between 25 days and 36 days. Therefore, the mycelium growth rate of P. ostreatus was faster than other pleurotus species in this study. The highest biological efficiency was recorded with P. ostreatus at 78.23%, then P. pulmonarius at 59.88, and lastly, 39.66% P. florida. The changes in five enzyme activities in distinct developmental stages of three different pleurotus species were evaluated. Therefore, the laccase had the highest peak with 13.8 U/g on the 20th day during the growth phase and gradually decreased to the fruiting body stage of P. ostreatus. The expression of manganese peroxidase reached the highest activity of 3.6 U/g in P. ostreatus compared to P. florida and P. pulmonarius on the 10th day. The expression of other enzymes varied between species and developmental phases. The results indicate the usefulness of pasteurized C. fungigraminus for cultivating Pleurotus species and expression enzyme activity in different Pleurotus species. Full article

Oyster mushrooms (Pleurotus ostreatus) are one of the most commonly grown edible mushrooms using compost, which contains high concentrations of ammonia. In this study, inoculation of the oyster mushroom culture substrate with ammonia-assimilating bacterium Enterobacter sp. B12, either before or after composting, reduced the ammonia nitrogen content, increased the total nitrogen content of the compost, and enhanced the mushroom yield. Co-cultivation with P. ostreatus mycelia on potato dextrose agar (PDA) plates containing 200 mM NH₄⁺, B12 reduced reactive oxygen species (ROS) accumulation in the mycelia and downregulated the expression of the ROS-generating enzymes NADPH oxidase A (NOXA) and the stress hormone ethylene synthase 1-aminocyclopropane-1-carboxylate oxidase (ACO). It also downregulated the expression of the ammonia-assimilating related genes in the mycelia, such as glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS), ammonia transporter protein (AMT), and amino acid transporter protein (AAT), while upregulating its own ammonia-assimilation genes. These findings suggest that the mechanism by which B12 promoted oyster mushroom growth was that B12 assimilated ammonia, alleviated ammonia stress, mitigated ROS accumulation in the mycelia, and supplied ammonia and amino acids to the mycelia. To our knowledge, ammonia-assimilating bacteria are a novel type of mushroom growth promoter (MGP). Full article

In response to the scarcity and high cost of wheat in Nigeria, this study investigates the potential of oyster mushroom (Pleurotus ostreatus) and okara flour to enhance the nutritional quality and storage stability of wheat biscuits. By incorporating 10–50% oyster mushroom powder into wheat flour, this study observed significant increases in the nutritional profile of the biscuits. The protein content notably increased from 8.26% to 16.12%, while the crude fibre and ash content also saw over a 50% increment. Storage studies revealed that biscuits (baked for 18 min at 180 °C) packaged in cartons within polyethene were more shelf-stable than those in low-density polyethylene (LDPE) bags, maintaining quality over two months at ambient temperature. The inclusion of oyster mushroom and okara flour in wheat biscuits significantly enhances their nutritional value and shelf life, presenting a viable solution to the challenges of wheat scarcity and global malnutrition. The optimal mushroom flour enrichment level was identified at 20% to maintain consumer appeal. Full article

Oyster mushrooms (Pleurotus species) have gained significant attention in food science and nutrition due to their exceptional nutritional and functional properties. This review examines various oyster mushroom species’ comprehensive physicochemical characteristics, functional attributes, and antioxidative properties. Through analysis of current literature, we establish that oyster mushrooms contain substantial amounts of protein (15–30%), carbohydrates (43–60%), dietary fibre, and essential micronutrients while maintaining low-fat content (~1.2%). The mushrooms demonstrate significant antioxidant activity through compounds such as ergothioneine, phenolics, and flavonoids, with different species showing varying levels of bioactive compounds. Scientific studies reveal that processing methods, particularly different drying techniques, significantly impact their nutritional composition and functional properties. Notable findings include the identification of specific compounds in coloured varieties, such as pink chromoprotein in Pleurotus djamor and various melanin types, which contribute to both aesthetic and functional properties. Full article

The Chilean oyster (Ostrea chilensis) is a flat oyster native to Chile and New Zealand. Over-exploitation has led to local extinctions in some areas. Two phenotypes, distinguished by dark or white mantle edge pigmentation, have been identified, with the dark-edged mantle oysters being more commercially valuable due to perceived quality. In this study, transcriptomic data were obtained from the mantles of both phenotypes. Total RNA was extracted of adult Chilean Oyster mantle, and samples were sequenced using HiSeq X Illumina technology. A total of 935,620,583 paired-end reads were de novo assembled, 50,908 transcripts produced, and a reference transcriptome created with 37.92% GC content and an N50 of 1929 bp. Functional annotation showed a total of 51,315 GO terms, with 21,322 annotations on Biological Process, 14,578 annotations on Molecular Functions, and 15,415 annotations on Cellular Component. The RNA-seq analysis revealed 746 differentially expressed transcripts, 573 up-regulated and 173 transcripts down-regulated, between dark- and white-mantle edge Chilean Oyster. KEGG enrichment analysis revealed notable differences in the expression profiles allowing the detection of differential expressed transcripts associated with specific pathways such as Ribosome, Citrate cycle, and Protein processing in endoplasmic reticulum. Other interesting differentially represented pathways include Tyrosine metabolism, Tryptophan metabolism, cAMP signaling pathway, ABC transporters, Notch signaling pathway, Endocytosis, and Calcium signaling pathway. This dataset provides a valuable molecular resource for O. chilensis and the understanding of the molecular mechanisms involved in mantle edge pigmentation. Full article

Cuproptosis is a novel cell death dependent on mitochondrial respiration and regulated by copper. While the study of it is mainly focused on tumor therapy, in the present study, two key cuproptosis-related genes, ferredoxin (FDX1) and dihydrolipoamide S-acetyltransferase (DLAT) homologs (designated as CgFDX1 and CgDLAT), were identified from Crassostrea gigas. CgFDX1 has a Fer2 domain with a 2Fe-2S cluster forming a unique ferredoxin. CgDLAT is composed of a biotin_lipoyl domain, an E3-binding domain, and a 2-oxoacid_dh domain. CgFDX1 and CgDLAT mRNA were expressed in all the examined tissues. After elesclomol treatment, both mRNA and protein expressions of them were reduced in the hemocytes. The mortality rate of the hemocytes increased significantly, and the hemocytes were accompanied with noticeable adhesive abnormalities and heightened secretion after elesclomol treatment. Additionally, the accumulation or depletion of actin was observed in the hemocytes. The integrity of the double membrane structure of the mitochondria was compromised, and the organization of mitochondrial cristae was disrupted. The contents of copper, malondialdehyde (MDA), pyruvic acid and mitoSOX as well as the ratio of cells with low mitochondrial potential increased significantly in the hemocytes upon elesclomol treatment and the content of citric acid decreased significantly. These findings suggest the potential presence of cuproptosis in oysters and its activation mechanism is relatively conserved in evolution. Full article