Proximate compositions, nonvolatile taste components and antioxidant capacities of some dried edible mushrooms collected from Thailand

Reheating-induced gel properties change and flavor evolution of surimi-based seafood: Effects and mechanisms

This study investigated the effect of different reheating treatments on gel properties and flavor changes of surimi products. As the reheating temperature increased from 90 °C to 121 °C, the heat-induced proteolysis produced more abundant umami and sweet amino acids, which took part in the conversion of IMP to AMP, thus enhancing the taste profiles. Reheating increased the exposure of active -NH2 terminals in proteins, which boosted Maillard and Strecker reactions with carbonyl compounds originated from fatty acid oxidation, thus not only reducing the aldehydes and esters contents but also lowering the whiteness of surimi products. Reheating at 90 °C prohibited the production of warmed-over flavor (WOF) and well-preserved the textural characteristics, but high temperatures ≥100 °C were prone to generate furan as the major WOF substance and to destroy gel structures. Collectively, this study provides new insights on understanding the role of reheating on sensory properties of surimi products.

Exploring the Antioxidant Potential of Methanolic Extracts of Wild Medicinal and Edible Mushrooms from Darma Valley, Pithoragaph, Kumaun (Himalaya, India)

This study presents a comprehensive analysis of the methanolic extracts of nine species of wild edible mushrooms (WEM) native to the Darma Valley in the Kumaun Himalaya region. The investigation encompasses the assessment of various biochemical attributes, including total phenolics (TP), total flavonoids (TF), total tannins (TT) contents, the ABTS assay, and the DPPH radical scavenging assay. Among the nine WEM species examined, Clavatia craniiformis stands out for displaying the highest antioxidant capacities, indicated by exceptional TP (54.94 ± 0.54 mg gallic acid equivalenta/g dry weight) and TT (4.23 ± 0.17 mg tannic acid equivalents/g dry weight) contents, along with noteworthy ABTS (10.44 ± 0.34 mg abscorbic acid equivalents/g dw) and DPPH activity (0.335 ± 0.001 mg abscorbic acid equivalents/g dry weight). Subsequent antioxidant potential are mushrooms Ramaria fennica, Ramaria botrytis, Ramaria sanguinea, Ramaria flava, Gomphus. clavatus, Clavaria zollingeri, Pleurotus ostreatus, and Kuehneromyces mutabilis. Variations in antioxidant capacities align with distinct phenolic content. This study underscores as a remarkable source of antioxidants, suggesting its potential suitability for nutraceutical applications. The findings contribute to a deeper understanding of the antioxidant properties inherent in wild edible mushrooms, particularly emphasizing the prominence of C. craniiformis.

Variations of nonvolatile taste components of mushrooms with different operating conditions and parameters from farm to fork

Mushroom is a sustainable food option and a meat substitute which yet needs some strategies to enhance sensory attributes. Especially, their taste characteristics (nonvolatile taste components: soluble sugars, organic acids, free amino acids, and 5'-nucleotides) can vary significantly due to operating conditions and parameters during different stages from farm to fork. This review is aimed to provide an overall view of the determined effects of operating conditions and parameters for mushroom taste attributes, suggestions for future research from lacking variables, and some recommendations for improving the taste perception of mushrooms. Taste compounds of mushrooms alter differently based on cultivation (species, cultivation or maturity stage, substrate composition, part, grade, mycelium strain), cooking (cooking method, time, temperature), preservation, and post-harvest storage conditions (drying parameters, pretreatment, preservation method, gamma irradiation, packaging, storage time and temperature). The dominant tastes of mushrooms given by sweet and umami taste active substances can be enhanced significantly with proper control of parameters during cultivation, cooking, drying, or post-harvest storage. The parameters and variations organized in this review can be used to develop a mathematical model for obtaining optimum taste attributes of mushrooms and mushroom-based meat alternatives and to discover the variables of mushroom species not studied yet.

Mutated Shiitake extracts inhibit melanin-producing neural crest-derived cells in zebrafish embryo

The ability of natural extracts to inhibit melanocyte activity is of great interest to researchers. This study evaluates and explores the ability of mutated Shiitake (A37) and wildtype Shiitake (WE) extract to inhibit this activity. Several properties such as total phenolic (TPC) and total flavonoid content (TFC), antioxidant activity, effect on cell and component profiling were conducted. While having no significant differences in total phenolic content, mutation resulted in A37 having a TFC content (1.04 ± 0.7 mg/100 ml) compared to WE (0.86 ± 0.9 mg/100 ml). Despite that, A37 extract has lower antioxidant activity (EC50, A37 = 549.6 ± 2.70 μg/ml) than WE (EC50 = 52.8 ± 1.19 μg/ml). Toxicity tests on zebrafish embryos show that both extracts, stop the embryogenesis process when the concentration used exceeds 900 μg/ml. Although both extracts showed pigmentation reduction in zebrafish embryos, A37 extract showed no effect on embryo heartbeat. Cell cycle studies revealed that WE significantly affect the cell cycle while A37 not. Further tests found that these extracts inhibit the phosphorylation of Glycogen synthase kinase 3 β (pGSK3β) in HS27 cell line, which may explain the activation of apoptosis in melanin-producing cells. It was found that from 19 known compounds, 14 compounds were present in both WE and A37 extracts. Interestingly, the presence of decitabine in A37 extract makes it very potential for use in the medical application such as treatment of melanoma, skin therapy and even cancer.

Bioconversion of rice straw agro-residues by Lentinula edodes and evaluation of non-volatile taste compounds in mushrooms

Rice straw was substituted for sawdust at five different ratios of 0, 20%, 40%, 60%, and 80% (Control, RS20, RS40, RS60 and RS80, respectively) to obtain five kinds of Lentinula edodes. The effects of adding cropped rice straw to substrate formulas on the proximate composition and non-volatile taste compounds in mushrooms were investigated. The control group had the highest level of MY and BE among the five formulations. The protein levels in mushrooms decreased with the addition of rice straw and the ash levels increased. We found that trehalose, mannitol, and arabitol were the main soluble sugars in the five kinds of mushrooms. The contents of total free amino acids varied from 16.29 to 24.59 mg/g and the highest level of free amino acids was found in mushrooms cultivated from RS20 and RS40. Moreover, the addition of rice straw improved the contents of monosodium glutamate (MSG)-like amino acids in mushrooms. The 5′-Nucleotide levels ranged from 1.66 to 4.48 mg/g and equivalent umami concentration (EUC) value increased with the addition of rice straw. Our results suggest that rice straw is a potential substitute for sawdust to cultivate L. edodes with more non-volatile taste compounds.

Physicochemical properties, microstructures, nutritional components, and free amino acids of Pleurotus eryngii as affected by different drying methods

In this study, we determined the influences of different drying techniques such as natural air (ND), hot-air (HD), vacuum (VD), infrared (ID), microwave (MD), and freeze drying (FD) methods on the color, shrinkage ratio (SR), rehydration ratio (RR), firmness, crispness, microstructures, nutritional components, and free amino acids of Pleurotus eryngii. The results showed that these parameters were markedly influenced by different drying techniques. Among them, FD was the most effective drying method which retained the main characteristics of the fresh P. eryngii in above mentioned indexes, followed by ND and HD at 40 °C. Finally, despite the least drying time, MD treatment was not suitable to the drying process of P. eryngii slices since it damaged physicochemical properties and caused massive losses of the main nutrients and free amino acids. The results will provide a theoretical basis for industrial processing of P. eryngii.

Effect of proteases and alcohols used for debittering on characteristics and antioxidative activity of protein hydrolysate from salmon frames

Protein hydrolysates were obtained from salmon frame using Alcalase or Flavourzyme at 3% (w/w protein) for 180 min. Protein hydrolysates prepared using Alcalase (HA) and Flavourzyme (HF) had DH and yield of 25.1-26.9% and 28.5-32.3 g/100 g sample, respectively. HF showed lower bitterness score (5.78) than that of HA (8.68) (P < 0.05). When HA and HF were further subjected to debittering with 2-butanol or isopropanol, the recovery of 77.88-81.60% was obtained (P < 0.05). HF and HA debittered with 2-butanol possessed less bitterness score, 3.60 and 3.77, respectively (P < 0.05). Surface hydrophobicity of 81.4 and 124.8 was attained when HF and HA were debittered with 2-butanol (P < 0.05). Selected debittered hydrolysates, produced using Flavourzyme, followed by fractionation using 2-butanol (HF-B) contained glutamic acid/glutamine (15.14 g/100 g), aspartic acid/asparagine (10.07 g/100 g) and glycine (9.30 g/100 g) as the predominant amino acids. HF-B had the decreased ABTS radical scavenging activity and metal chelating activity. A₂₈₀ of peptides separated by gel filtration was lowered to some extent and coincided with the lower bitterness score and surface hydrophobicity. Thus, debittered protein hydrolysate from salmon frame could serve as a nutritive ingredient at high levels in health promoting foods.

Effects of a nutritional supplement in dogs affected by osteoarthritis

Osteoarthritis is a form of chronic joint inflammation caused by the deterioration of the joint cartilage, accompanied by chronic pain, lameness and stiffness, particularly after prolonged activity. Alternative treatments of canine osteoarthritis would be desirable and, recently nutraceuticals, have been proposed for this purpose. Twenty cross breed adult dogs affected by osteoarthritis were enrolled and equally divided into two groups (control vs. experimental). The nutritional supplement (Dynamopet srl, Verone, Italy) was administered for 90 days to the dogs of the experimental group in order to evaluate its metabolic and locomotor effects. All the clinical signs (lameness, pain on manipulation and palpation, range of motion and joint swelling) significantly (p < 0.01) improved during the trial as regards the experimental group. This group showed a significantly lower joint score than the control group (mean value 7.40 vs. 3.80). With regard to haematology, the mean corpuscular volume resulted significantly (p < 0.01) higher in the experimental group, i.e. alkaline phosphatase, cholesterol and triglycerides values decreased and were significantly (p < 0.01) lower than the control one, thus suggesting an improvement in bone remodelling and lipid metabolism. A decrease in the reactive oxygen metabolites and an increase in the biological antioxidant potential demonstrated an improvement in oxidative stress during the trial in the experimental group compare to the control group. Interleukins 6 decreased in the experimental group, while interleukins 10 resulted in the opposite trend. Moreover, the administration of up to 3 months of the studied supplement was well tolerated in the dogs and caused no adverse effects.

Protein hydrolysate from salmon frames: Production, characteristics and antioxidative activity

Protein hydrolysates from two forms of salmon frames named "chunk" and "mince" were produced and characterized. Both samples were subjected to hydrolysis using alcalase and papain at 1%-3% (w/w protein) for 0-240 min. Hydrolysate prepared with either protease at 3% for 180 min had the solid yield of 24.05%-26.39%. Hydrolysates contained 79.20%-82.01% proteins, 6.03%-6.34% fat, 9.81%-11.09% ash, and 4.02%-5.80% moisture. Amino acid profile showed that all hydrolysates had glutamic acid/glutamine (113.45-117.56 mg/g sample), glycine (77.86-86.18 mg/g sample), aspartic acid/asparagine (76.04-78.67 mg/g sample), lysine (61.97-65.99 mg/g sample), and leucine (54.30-57.31 mg/g sample) as the predominant amino acids. The size distributions determined by gel filtration chromatography varied, depending on proteases and the form of frame used for the hydrolysis. Different hydrolysates showed varying antioxidant capacities. Thus, protein hydrolysates from salmon frame could be used as a nutritive supplement in the protein deficient foods. PRACTICAL APPLICATIONS: Frames of salmon are by-products from salmon fish processing industries. The frames contained the remaining meat, hence they can be used for the preparation of protein hydrolysates. Generally, hydrolysates from fish by-products have been regarded as a promising food supplement, because they are rich in amino acids. Additionally, hydrolysates possess antioxidant activity, which is of health benefit. To produce the hydrolysate with less time consumption, the use of frame chunk instead of minced frame can be of better choice. Thus, frame of salmon, especially in chunk form, could be used as a raw material for production of protein hydrolysate using alcalase. The hydrolysate produced from salmon frame could serve as an alternative nutritive supplement to tackle the nutrition inadequacies in foods.