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[Display omitted] • Niacin deficiency decreased the growth performance of fish. • Niacin deficiency affected muscle amino acid and fatty acid compositions of fish. • Niacin deficiency exerted negative impacts on flesh physicochemical properties. • Niacin deficiency may quicken flesh pH drop by promoting glycolysis. • Niacin deficiency impaired mitochondrial homeostasis. Energy metabolism exerts profound impacts on flesh quality. Niacin can be transformed into nicotinamide adenine dinucleotide (NAD), which is indispensable to energy metabolism. To investigate whether niacin deficiency could affect energy metabolism and flesh quality, six diets with graded levels of 0.49, 9.30, 21.30, 33.30, 45.30 and 57.30 mg/kg niacin were fed to grass carp (Ctenopharyngodon idella) for 63 days. The results showed that niacin deficiency declined flesh quality by changing amino acid and fatty acid profiles, decreasing shear force, increasing cooking loss and accelerating pH decline. The accelerated pH decline might be associated with enhanced glycolysis as evident by increased hexokinase (HK), pyruvate kinase (PK) and lactic dehydrogenase (LDH) activities, and mitochondrial dysfunction as evident by destroyed mitochondrial morphology, impaired respiratory chain complex I and antioxidant ability. Based on PWG and cooking loss, the niacin requirements for sub-adult grass carp were 31.95 mg/kg and 29.66 mg/kg diet, respectively. [ABSTRACT FROM AUTHOR]

Fu brick tea (FBT) is a unique post-fermented tea product which is fermented with fungi during the manufacturing process. In this study, we investigated the biochemical compositional changes occurring during the microbial fermentation process (MFP) of FBT based on non-targeted LC–MS, which was a comprehensive and unbiased methodology. Our data analysis took a two-phase approach: (1) comparison of FBT with other tea products using PCA analysis to exhibit the characteristic effect of MFP on the formation of Fu brick tea and (2) comparison of tea samples throughout the MFP of FBT to elucidate the possible key metabolic pathways produced by the fungi. Non-targeted LC–MS analysis clearly distinguished FBT with other tea samples and highlighted some interesting metabolic pathways during the MFP including B ring fission catechin. Our study demonstrated that those fungi had a significant influence on the biochemical profiles in the FBT and consequently contributed to its unique quality. [ABSTRACT FROM AUTHOR]

Highlights: [•] Changes in key metabolites in albino tea leaves were analysed. [•] Chlorophyll a/b ratio and contents of zeaxanthin and many free amino acids increased. [•] Abundance of total carotenoids, catechins and caffeine decreased. [•] Metabolites for less astringency/bitterness and better umami taste were suggested. [•] OPLS-DA identified the key determinants for distinct albino tea metabolite profiles. [Copyright &y& Elsevier]

Abstract: Lipid peroxidation, protein oxidant and antioxidant status of muscle, intestine and hepatopancreas in juvenile Jian carp (Cyprinus carpio var. Jian) fed graded levels of myo-inositol (MI) (163.5, 232.7, 384.2, 535.8, 687.3, 838.8 and 990.3mg/kg diet) for 60days were investigated. Total tissue malondialdehyde (MDA) and protein carbonyl (PC) content showed a downward trend to a point (P <0.05). Conversely, total tissue anti-hydroxyl radical (AHR), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx), glutathione reducase (GR) activities and glutathione (GSH) content were generally higher in MI-supplemented diets than MI-unsupplemented diet (P <0.05). Muscle and intestinal superoxide dismutase (SOD), and intestinal anti-superoxide anion (ASA) were increased by MI supplementation (P <0.05), whereas these parameters in the other tissue showed no alterations (P >0.05). These results indicated that antioxidant status was improved, and lipid peroxidation and protein oxidant were depressed in muscle, intestine and hepatopancreas by MI. [Copyright &y& Elsevier]

Abstract: Maillard reaction products (MRPs) were prepared from a casein–glucose reaction and ultrafiltrated to provide six fractions. The high molecular weight glycated proteins (melanoprotein) were further purified with a Sephadex G-75 column. Two fractions were obtained and analysed for their reducing power and Fe2+ chelating activity. Results obtained from the first fraction, analysed by Fourier transform infrared spectroscopy (FT-IR) indicated that the amide I, II and III bands of casein were changed by the Maillard reaction. The obtained samples were also hydrolysed with pepsin and trypsin in vitro, and the proteolytic hydrolysates were evaluated for their antioxidant activities. Non-hydrolysed melanoproteins exhibited the highest reducing power, but peptic hydrolysates of different MRPs were more efficient in radical-scavenging activity. [Copyright &y& Elsevier]

Abstract: A methanolic extract from a soybean broth fermented by Paecilomyces militaris was analysed by HPLC–PDA–HRMS. It mainly contained mannitol, uracil, adenosine, cordycepin, daizein, genistein, and three new isoflavone glycosides. The isoflavonoids were isolated by preparative HPLC and identified with the aid of HPLC–PDA–HRMS, 1H NMR, 13C, H–H COSY, HMBC, and HMQC NMR analysis as: 7,4′-dihydroxyisoflavone-7-O-(4′′-O-methyl)-β-d-glucopyranoside, 7,4′-dihydroxy-6-methoxyisoflavone-7-O-(4′′-O-methyl)-β-d-glucopyranoside, and 5,7,4′-trihydroxyisoflavone-7-O-(4′′-O-methyl)-β-d-glucopyranoside. The three novel compounds are transformation products of soybean isoflavones. The results of metabolites analysis revealed that the fermentation broth reserved the main functional molecules of soybean and P. militaris or Cordyceps militaris. This suggested that soybean fermented with P. militaris may be able to create a combined healthy food. However, isoflavones are also parts of anti-nutrients of soybean products, and cordycepin is a known antibiotic. This means that the fermentation broth may not suit to be used as normal food. At the same time the safety and bioactivity of the novel methylated glycosides need also further approval. [Copyright &y& Elsevier]

Abstract: Chinese herbs employed in traditional Chinese medicine (TCM) have been used for centuries in the practice of medicated diet and dietetic therapy. The seed of Cuscuta chinensis Lam. (Convolvulaceae), a commonly used traditional Chinese herb, is frequently added in Chinese cooking and preparation of refreshments, including porridge and alcoholic beverages, to nourish the human body. In the present study, we compared the antioxidant activities of water and ethanol extracts from the seeds C. chinensis and also of its different organic fractions, including n-hexane, ethyl acetate, n-butanol and organic water, by assessing their DPPH (1,1-diphenyl-2-picryl hydrazine) free radical-scavenging, superoxide anion scavenging, anti-superoxide anion formation and anti-lipid peroxidation abilities. The flavonol contents of all test samples were analyzed by high-performance liquid chromatography with an ultraviolet (HPLC–UV) detector. The results showed that there is a direct correlation of the flavonol content with the antioxidant activities from the extracts and fractions of C. chinensis. Moreover, the ethyl acetate fraction demonstrated significantly better and higher antioxidant effects, and also had a higher flavonol content than had the remaining samples (P <0.05). The water fractions, however, exhibited the weakest antioxidant activity, and had low concentrations of flavonols. Thus, we suggest that the ethanol extract of C. chinensis, but not its water extract, could be used as a dietary nutritional supplement to promote human health and prevent oxidation-related diseases, due to its antioxidant properties. [Copyright &y& Elsevier]

[Display omitted] • Changes in characteristic aroma-active compounds occur during processing at an industrial scale. • Pile fermentation increases the proportion of olefinic aldehyde compounds. • Methoxybenzene compounds formed during pile fermentation were weakened by aging. • Olefinic aldehydes, ketones, and methoxybenzenes were the characteristic volatiles of aged fragrances. Changes in key odorants and aroma profiles of Qingzhuan tea (QZT) during its manufacture were determined using headspace solid-phase microextraction gas chromatography-mass spectrometry/olfactometry. An aroma profile was constructed to illustrate sensory changes during manufacture. The characteristic aroma of QZT was aged fragrance, which was mostly developed during pile fermentation and was enhanced during the aging and drying stages. Using volatile compounds found in the raw materials, sun-dried green tea and QZT finished product were compared by orthogonal partial least square-discriminant analysis. Among 108 detected volatiles, 19 were significantly upregulated and 15 were downregulated. (E)-β-Ionone, (E,Z)-2,6-nonadienal, 1-octen-3-one, (E,E)-2,4-heptadienal, (E,E)-2,4-nonadienal, safranal, (E)-2-nonenal, α-ionone, and 1,2,3-trimethoxybenzene were found to be significant contributors to the aged QZT fragrance, reflecting their high odor-activity values and aroma intensities. Finally, the metabolic transformation of key aroma-active compounds was systematically analyzed. This study provided a theoretical basis for improving the processing and quality of QZT. [ABSTRACT FROM AUTHOR]

Growth performance, flesh quality, antioxidant status and antioxidant-related signalling molecule expression in the muscle of young grass carp, which were fed graded levels of arginine (6.9–24.5 g/kg diet) for eight weeks, were investigated. Muscle protein, lipid and nitric oxide contents, shear force, hydroxyproline concentration, and pH were significantly improved by appropriate arginine. Cooking loss, lactate content, cathepsins activities, malondialdehyde and protein carbonyl contents exhibited an opposite tendency. Additionally, optimum arginine significantly enhanced glutathione content and the activities and gene expression of copper/zinc superoxide dismutase, catalase and glutathione peroxidase in muscle. Moreover, the expression levels of glutamate–cysteine ligase, target of rapamycin, ribosome protein S6 kinase 1, casein kinase 2 and NF-E2-related factor 2 in muscle were significantly elevated by appropriate arginine. However, optimum arginine significantly decreased Kelch-like ECH-associated protein 1 mRNA levels in muscle. In conclusion, arginine improved the flesh quality and muscle antioxidant capacity and regulated antioxidant-related signalling molecule expression. [ABSTRACT FROM AUTHOR]

Highlights: [•] Natural Cordyceps formosana and the cultured mycelia have different cytotoxicity. [•] The most toxic compound exists mainly in the cultured mycelia. [•] The toxic compounds were identified as rugulosin and skyrin. [•] The compounds were isolated from the genera Cordyceps and Hirsutella for the first time. [•] Special attention should be taken on safety in the substitution of natural Cordyceps. [ABSTRACT FROM AUTHOR]

[Display omitted] • Smartphone-based multicolor MIRECL sensing system was proposed. • Visual and portable optical device integrated with machine learning was designed. • App based on yolov5x algorithm with five different linearting algorithms. • A smartphone-based handheld device for on-site and rapid detection TYM. We designed a novel, portable, and visual dual-potential molecularly imprinted ratiometric electrochemiluminescence (MIRECL) sensor for tyramine (TYM) detection based on smartphone and deep learning-assisted optical devices. Molecularly imprinted polymer-Ce 2 Sn 2 O 7 (MIP-Ce 2 Sn 2 O 7) layers were fabricated by in-situ electropolymerization method as the capture and signal amplification probe. Oxygen vacancies in Ce 2 Sn 2 O 7 not only enhance the electrochemical redox capability but also accelerate the energy transfer, thereby enhancing the luminescence of cathode ECL. Under optimal conditions, the ECL signals of MIP-Ce 2 Sn 2 O 7 at the cathode and the anode response of Ru(bpy) 3 2+ was reduced, thus a wide linear range from 0.01 μM to 1000 μM with the detection limit as low as 0.005 μM. Interestingly, combined with an artificial intelligence image recognition algorithm and the principle of optical signal reading by smartphone, the developed MIRECL sensor has been applied to the portable and visual determination of TYM in aquatic samples, and its practicability has been satisfactorily verified. [ABSTRACT FROM AUTHOR]

[Display omitted] • Threonine enhanced the growth performance of fish. • Threonine improved muscle amino acid and fatty acid compositions of fish. • Threonine improved muscle essential amino acid chemical score of fish. • Threonine enhanced muscle hardness may be related to collagen biosynthesis. To further explain the improvement effect of threonine (Thr) on the fillet quality of fish, a 9-week feeding experiment was conducted. After feeding graded levels of Thr (2.38, 5.38, 8.38, 11.38, 14.38 and 17.38 g/kg), the compositions of fillet hydrolyzed amino acid and fatty acid, and the muscle hardness associated with collagen biosynthesis were mainly analyzed in grass carp (Ctenopharyngodon idella). The results showed that Thr increased the pH value, changed the amino acids and fatty acid composition of fillets, especially essential amino acid (EAA), C22:6n3 (DHA) and C20:5n3 (EPA). Furthermore, this study revealed for the first time that the improvement of muscle hardness by Thr was associated with collagen biosynthesis, and the TGF-β1/Smads, LARP6a and Hsp47 regulate transcriptional processes, translation initiation and post-translational modifications in collagen biosynthesis, respectively. This study offered a basis for exploring the contribution of Thr in improving muscle quality in sub-adult grass carp. [ABSTRACT FROM AUTHOR]

• Solid-state fermentation of summer Keemun black tea by Cordyceps militaris. • Fermentation decreased bitterness and astringency and produced unique fungal aroma. • LC-MS metabolomics and GC–MS analyses revealed non-volatile and volatile components Changes in KBT and SSF-KBT. • Linalool I oxide and dihydro- β -ionone showed the highest concentrations and OAV values in SSF-KBT. Cordyceps militaris (C. militaris) has been approved and widely used in healthy food. The present study aimed to improve the flavor of summer Keemun black tea (KBT) using C. militaris solid-state fermentation. Combined with sensory evaluation, the volatile and non-volatile components of solid-state fermentation of KBT (SSF-KBT) and KBT were analyzed. The results showed that after the solid-state fermentation, the contents of total polyphenol, total flavonoid, and total free amino acids were significantly reduced. Further non-targeted metabolomics analysis revealed that the contents of non-galloylated catechins and d -mannitol increased, while the galloylated catechins and flavonoid glycosides decreased as did the bitterness and astringency of KBT. Dihydro- β -ionone and β -ionone (OAV = 59321.97 and 8154.17) were the aroma-active compounds imparting woody and floral odors in SSF-KBT, respectively. Current study provides a new avenue to develop summer-autumn KBT. [ABSTRACT FROM AUTHOR]

Zijuan tea is a special cultivar of Yunnan broad-leaf tea ( Camellia sinensis var . assamica ) with purple buds, leaves, and stems. Phytochemical study on this tea led to the discovery of three hydroxycinnamoylated catechins (HCCs) ( 1 – 3 ), seven other catechins ( 4 – 10 ), three proanthocyanidins ( 11 – 13 ), five flavones and flavone glycosides ( 14 – 18 ), two alkaloids ( 19 , 20 ), one steroid ( 21 ), and one phenylpropanoid glycoside ( 22 ). The isolation and structural elucidation of the caffeoylated catechin ( 1 ) by means of spectroscopic techniques were described. We also provide the first evidence that 1 is synthesized via a two-step pathway in tea plant. The three HCCs ( 1 – 3 ) were investigated on their bioactivity through molecular modeling simulation and biochemical experiments. Our results show that they bind acetylcholinesterase (AChE) tightly and have strong AChE inhibitory activity with IC 50 value at 2.49, 11.41, 62.26 μM, respectively. [ABSTRACT FROM AUTHOR]

Flesh quality is evaluated according to nutritional value and sensory quality. Cinnamaldehyde (CIN) improves mammalian meat quality, but research relating this to aquaculture is scarce. In this study, five doses of CIN (0, 36, 72, 108, 144 mg/kg diet) were fed to grass carp (Ctenopharyngodon idella) for 60 days. The results show that CIN supplementation increased nutritional value by increasing crude protein content. CIN also improved the sensory quality by increasing the pH and collagen content, decreasing shear force, lactate, and cooking loss. These changes may be related to changes in muscle fiber growth by increasing myofiber diameter. The increased myofiber diameter induced by CIN is associated with TOR mRNA and protein levels, and down-regulated FOXO3a mRNA levels, which might be associated with PTP1B/IGF1/PI3K/AKTs-TOR/FOXO3a signaling. Based on muscle crude protein content, optimal CIN supplementation dosage was 88.01 mg/kg. [ABSTRACT FROM AUTHOR]

Flesh quality, muscle antioxidant status and related signalling molecule expressions were investigated in young grass carp fed six levels of tryptophan (Trp) for 8 weeks. The results indicated that fish fed 0.7 (deficiency) and 6.1 g Trp g/kg (excess) diets exhibited lower muscle water-holding capacity, tenderness, cathepsin activity, protein levels, lipids and collagen contents. Optimal Trp reversed these negative effects, which were related to enhanced glutathione (GSH) content and glutathione peroxidase (GPx) activities regulated at gene transcription levels, rather than to superoxide dismutase (SOD) or catalase (CAT). The expression of signalling molecules [Kelch-like ECH-associated protein 1, target of rapamycin (TOR) and ribosomal S6 protein kinase 1] involved in the NF-E2-related factor 2 (Nrf2) pathway revealed a potential method of Trp-enhanced antioxidant defence. Collectively, the present study indicated that appropriate Trp levels improved flesh quality partly related to the enhancement of antioxidant ability through Nrf2 and TOR signalling. [ABSTRACT FROM AUTHOR]

Highlights: [•] Noncollagenous proteins in Stichopus Japonicus body wall (SjBW) were identified. [•] Major yolk protein (MYP) and actin were major noncollagenous proteins in SjBW. [•] Optimum autolysis of noncollagenous proteins was at 46.3°C and pH 6.1. [•] Cysteine proteases were partially involved in autolytic degradation of MYP and actin. [ABSTRACT FROM AUTHOR]