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Yeast cell wall (YCW) polysaccharides, including β‐glucans, mannans, chitins, and glycogens, can be extracted from the waste of beer industry. They are environmentally friendly, abundant, inexpensive raw materials, and have shown broad biological activities and application potentials. The exploitation of yeast polysaccharides is of great importance for environmental protection and resource utilization. This paper reviews the structural features and preparation of YCW polysaccharides. The solubility and emulsification of yeast polysaccharides and the properties of binding metal ions are presented. In addition, biological activities such as blood glucose and lipid lowering, immune regulation, antioxidant, promotion of intestinal health, and promotion of wound healing are proposed, highlighting the beneficial effects of yeast polysaccharides on human health. Through modification, the physical and chemical properties of yeast polysaccharides are changed, which emphasizes the promotion of their biological activities and properties. In addition, the food applications of yeast polysaccharides, including the food packaging film, emulsifier, thickening agent, and fat alternatives, are focused and discussed. [ABSTRACT FROM AUTHOR]

Currently, the use of synthetic pigments in foods is restricted since synthetic pigments are proven and suspected to be harmful to human health. Phycobiliproteins (PBPs), existed in phycobilisomes (PBSs) of algae, are a kind of pigment-proteins with intense color. The specific color of PBPs (red and blue) is given by the water-soluble open-chained tetrapyrrole chromophore (phycobilin) that covalently attaches to the apo-protein via thioether linkages to cysteine residues. According to the spectral characteristics of PBPs, they can be categorized as phycoerythrins (PEs), phycocyanins (PCs), allophycocyanins (APCs), and phycoerythrocyanins (PECs). PBPs can be used as natural food colorants, fluorescent substances, and bioactive ingredients in food applications owing to their color characteristics and physiological activities. This paper mainly summarizes the extraction and purification methods of the PBPs and reviews their characteristics and applications. Moreover, the use of several strategies such as additives, microencapsulation, electrospray, and cross-linking to improve the stability and bioavailability of PBPs as well as the future outlooks of PBPs as natural colorants in food commercialization are elucidated. [ABSTRACT FROM AUTHOR]

The increasing incidence and rapid spread of bacterial resistance to conventional antibiotics are a serious global threat to public health, highlighting the need to develop new antimicrobial alternatives. Antimicrobial peptides (AMPs) represent a class of promising natural antibiotic candidates due to their broad-spectrum activity and low tendency to induce resistance. However, the development of AMPs for medical use is hampered by several obstacles, such as moderate activity, lability to proteolytic degradation, and low bioavailability. To date, many researchers have focussed on the optimization or design of novel artificial AMPs with desired properties. Unnatural amino acids (UAAs) are valuable building blocks in the manufacture of a variety of pharmaceuticals, and have been used to develop artificial AMPs with specific structural and physicochemical properties. Rational incorporation of UAAs has become a very promising approach to endow AMPs with strong and long-lasting activity but no toxicity. This review aims to summarize key approaches that have been used to incorporate UAAs to develop novel AMPs with improved properties and better performance. It is anticipated that this review will guide future design considerations for UAA-based antimicrobial applications. [ABSTRACT FROM AUTHOR]

SUMMARY: Ripening is the last, irreversible developmental stage during which fruit become palatable, thus promoting seed dispersal by frugivory. In Alisa Craig fruit, mRNAs with increasing m5C levels, such as STPK and WRKY 40, were identified as being involved in response to biotic and abiotic stresses. Furthermore, two mRNAs involved in cell wall metabolism, PG and EXP‐B1, also presented increased m5C levels. In the Nr mutant, several m5C‐modified mRNAs involved in fruit ripening, including those encoding WRKY and MADS‐box proteins, were found. Targets of long non‐coding RNAs and circular RNAs with different m5C sites were also found; these targets included 2‐alkenal reductase, soluble starch synthase 1, WRKY, MADS‐box, and F‐box/ketch‐repeat protein SKIP11. A combined analysis of changes in 5mC methylation and mRNA revealed many differentially expressed genes with differentially methylated regions encoding transcription factors and key enzymes related to ethylene biosynthesis and signal transduction; these included ERF084, EIN3, AP2/ERF, ACO5, ACS7, EIN3/4, EBF1, MADS‐box, AP2/ERF, and ETR1. Taken together, our findings contribute to the global understanding of the mechanisms underlying fruit ripening, thereby providing new information for both fruit and post‐harvest behavior. Significance Statement: This is the first study on the regulation of RNA (m5C) methylation and non‐coding RNA (m5C) methylation on tomato fruit ripening in the world, which will establish a great foundation for tomato breeding and fresh fruit ripening regulation research. [ABSTRACT FROM AUTHOR]

Leguminous proteins are important nutritional components in leguminous plants, and they have different structures and functions depending on their sources. Due to their specific structures and physicochemical properties, leguminous proteins have received much attention in food and nutritional applications, and they can be applied as various carriers for binding/encapsulation and delivery of food bioactive compounds. In this review, we systematically summarize the different structures and functional properties of several leguminous proteins which can be classified as ferritin, trypsin inhibitor, β-conglycinin, glycinin, and various leguminous proteins isolates. Moreover, we review the development of leguminous proteins as carriers of food bioactive compounds, and emphasize the functions of leguminous protein-based binding/encapsulation and delivery in overcoming the low bioavailability, instability and low absorption efficiency of food bioactive compounds. The limitations and challenges of the utilization of leguminous proteins as carriers of food bioactive compounds are also discussed. Possible approaches to resolve the limitations of applying leguminous proteins such as instability of proteins and poor absorption of bioactive compounds are recommended. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Postharvest diseases result in major losses in fruits. Tomato is susceptible to postharvest rot caused by Botrytis cinerea and is regarded as a good model system to study postharvest disease and quality deterioration in fruit. To develop a safe and effective technique to alleviate disease and maintain fruit quality, the effects of methyl salicylate (MeSA) and 1‐methylcyclopropene (1‐MCP) either separately or combined on quality and gray mold caused by B. cinerea in tomato fruit were investigated. RESULTS: The results showed that application of MeSA (0.05 mmol L−1) delayed fruit ripening and reduced gray mold. Compared with MeSA treatment, 1‐MCP (0.5 µL L−1) effectively delayed fruit ripening. Further, MeSA combined with 1‐MCP treatment was more effective in inhibiting fungal decay during storage than MeSA treatment alone. The combined treatment not only enhanced pathogenesis‐related protein 1 (PR1) expression, activities of defense enzymes and total phenolic content but also inhibited the increase in electrical conductivity and malondialdehyde content. The combined treatment was also more effective in retaining firmness, color change and titratable acidity content than MeSA treatment alone. CONCLUSION: MeSA combined with 1‐MCP treatment was a useful technique to maintain quality and alleviate gray mold in postharvest tomato fruit during storage. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the effects of low-concentration acidic electrolyzed water (LcEW) combined with ultrasound (US) on fresh-sliced button mushrooms ( Agaricus bisporus), by evaluating the enzymatic browning, physio-biochemical changes, and microbial loads. The sliced button mushrooms were divided randomly into three groups (control, LcEW, and LcEW+US) and treated separately with tap water, LcEW, and LcEW+US for 3 min, and afterwards, they were stored at 5 °C for 8 days. The results indicated that LcEW delayed surface browning and maintained the flesh firmness of fresh-cut mushrooms compared with the control, and ultrasound enhanced these effects. Moreover, LcEW+US slowed down the electrolyte leakage (EL) rate and malondialdehyde (MDA) content, which were 5.29% and 0.5227 μmol/fresh weight less than those in control at day 8, respectively. The combined treatment of LcEW and US also significantly inhibited the activities of polyphenol oxidase (PPO) and peroxidase (POD) and controlled the counts of total bacteria (TBC) and yeast and mold counts (Y&M). Meanwhile, LcEW+US maintained a high level of total soluble protein and total phenolic contents, which were 1.49 and 1.24 times higher than those in control at the end of the storage time, respectively, and the combined treatment was more effective than LcEW treatment alone. These results demonstrated that the combination of LcEW and US could be an effective pretreatment technology in maintaining the product quality and prolonging the shelf life of fresh-sliced button mushrooms. [ABSTRACT FROM AUTHOR]

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Abstract: Background: 1-Aminocyclopropane-1-carboxylate oxidase (ACO) is a key enzyme that catalyses the final step in the biosynthesis of the plant hormone ethylene. Recently, the first ACO homologue gene was isolated in Agaricus bisporus, whereas information concerning the nature of the ethylene-forming activity of this mushroom ACO is currently lacking. Methods: Recombinant ACO from A. bisporus (Ab-ACO) was purified and characterised for the first time. Molecular modelling combined with site-directed mutagenesis and kinetic and spectral analysis were used to investigate the property of Ab-ACO. Results: Ab-ACO has eight amino acid residues that are conserved in the Fe (II) ascorbate family of dioxygenases, including four catalytic residues in the active site, but Ab-ACO lacks a key residue, S289. In comparison to plant ACOs, Ab-ACO requires ACC and Fe (II) but does not require ascorbate. In addition, Ab-ACO had relatively low activity and was completely dependent on bicarbonate, which could be ascribed to the replacement of S289 by G289. Moreover, the ferrous ion could induce a change in the tertiary, but not the secondary, structure of Ab-ACO. Conclusions: These results provide crucial experimental support for the ability of Ab-ACO to catalyse ethylene formation in a similar manner to that of plant ACOs, but there are differences between the biochemical and catalytic characteristics of Ab-ACO and plant ACOs. General significance: This work enhances the understanding of the ethylene biosynthesis pathways in fungi and could promote profound physiological research of the role of ethylene in the regulation of mushroom growth and development. [Copyright &y& Elsevier]

BACKGROUND To understand whether arginine catabolism might be involved in hot air ( HA)-induced chilling tolerance mechanism in tomato fruit, we investigated the effect of HA treatment on endogenous arginine catabolism in relation to chilling injury. RESULTS Tomato fruit were harvested at mature green stage and treated with HA at 38°C for 12 h and then stored at 2°C for 21 days. The effects of HA treatment on fruit chilling injury and gene expression levels or enzyme activity, and metabolites related to arginine catabolism were evaluated. HA treatment reduced the chilling injury symptoms of tomato fruit and enhanced the accumulation of endogenous polyamines, especially putrescine and proline. This accumulation is associated with the increased transcript levels of genes encoding arginase ( LeARG1 and LeARG2), arginine decarboxylase ( LeADC), ornithine decarboxylase ( LeODC) and ornithine aminotransferase ( LeOAT) at most sampling times. However, HA treatment had little effect on nitric oxide synthase activity and nitric oxide concentration. CONCLUSION These results revealed that the reduction in chilling injury by HA treatment may be due to the accumulation of putrescine and proline induced primarily by activating the catabolism of endogenous arginine. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In the past 20 years, the global per capita protein demand has been increasing year by year, and thus the search for sustainable and healthier alternative proteins is the focus of current food research. Yeast proteins are of microbial origin with environmentally friendly advantages. They are high-quality proteins with high bioavailability and are expected to be used as novel alternative proteins for food applications. Although reports on yeast extracts continue to increase, studies on the composition, production methods, and functional properties of yeast proteins lack systematic reviews. In addition, the application of yeast proteins in the food industry has not been summarized previously. This paper reviews the composition of yeast proteins and the approaches for their isolation and extraction, and systematically introduces the functional properties and the wide applications in food fields. Future perspectives for yeast proteins to sustainably and healthily meet the world's growing protein demand are also elucidated. Yeast proteins have great application potential as alternative proteins with a reasonable proportion of amino acid composition. Yeast proteins can be hydrolyzed to produce yeast peptides and can also be used as protein supplements, fining agents, meat extenders, etc. Overcoming the limitations of high nucleic acid content and high cost, and improving the functional properties and sensory acceptability of yeast proteins will greatly promote their market applications. This review will provide ideas and guidance for the research and development of yeast proteins in food applications. Yeast proteins have high nutritional value with an ideal amino acid composition and a wealth of functions and properties. The excellent characteristics allow yeast proteins to be used as sustainable alternative proteins in food applications. [Display omitted] • The compositions and extraction approaches of yeast proteins are overviewed. • The functional properties of yeast proteins are summarized. • The applications of yeast proteins as alternative proteins in food are reviewed. • The strategies to improve the utilization of yeast proteins are emphasized. [ABSTRACT FROM AUTHOR]

Basic helix-loop-helix (bHLH) transcription factors (TFs) are widely distributed in eukaryotes and play an important role in biological growth and development. The identification and functional analyses of bHLH genes/proteins in edible mushrooms (Agaricus bisporus) have yet to be reported. In the present study, we identified 10 putative bHLH members carrying the conserved bHLH domains. Phylogenetic analyses revealed that the 10 AbbHLHs were the closest to sequences of species belonging to 7 different fungal subgroups, which was supported by loop length, intron patterns, and key amino acid residues. The substantial increase after harvest and continuously elevated expression of AbbHLH1 during the development until the disruption of mushroom velum, and the preferential expression in cap and gill tissues suggest the important function of AbbHLH1 in postharvest development of A. bisporus. The relationship of arginine catabolism-related genes with the early stage of postharvest continuing development also was revealed by expression determination. Subcellular localization showed that AbbHLH1 could be localized in nucleus. Importantly, the electrophoretic mobility shift and dual-luciferase reporter assays showed that AbbHLH1 activated the promoters of AbOAT , AbSPDS , and AbSAMDC and suppressed the expression of AbARG , AbUREA , and AbODC , probably for the modulation of arginine catabolism and thus control of postharvest mushroom development. Taken together, the available data provide valuable functional insight into the role of AbbHLH proteins in postharvest mushrooms. • Ten bHLH genes were firstly identified in edible mushrooms (Agaricus bisporus). • AbbHLH1 was a potential regulator in the postharvest development of A. bisporus. • AbbHLH1 could be localized in nucleus. • AbbHLH1 directly bound to the promoters of arginine catabolism-related genes. • AbbHLH1 promoted/inhibited the promoters of arginine catabolism-related genes. [ABSTRACT FROM AUTHOR]

Brown blotch disease caused by Pseudomonas tolaasii infection is one of the major problems affecting the storage quality of postharvest button mushrooms (Agaricus bisporus). In this study, P. tolaasii treatment accelerated the accumulation of pathogen resistance-related substances/proteins, induced disease resistance-related enzyme activities, and promoted the increase of jasmonic acid (JA) during the whole storage. To gain full insight into the defense mechanisms of button mushrooms against P. tolaasii , a transcriptomics analysis of mushroom samples at 12 h was conducted. A total of 2861 differentially expressed genes (DEGs) were identified, among which there were 1557 up-regulated and 1304 down-regulated genes. Further bioinformatic analysis showed that P. tolaasii inoculation mainly activated shikimate pathway, phenylpropanoid metabolism, sulfur metabolism, methane metabolism, arginine and proline metabolism, cysteine and methionine metabolism, JA biosynthesis and signaling pathways, as well as oxidative phosphorylation pathways. Transcriptomics data combined with qPCR verification indicated that 10 DEGs including PIP1 , MET3 , AGX , PAL1 , GCL , LOX 1/3 , PR-like , MYB3R , UCR , and SDHB are the most potential genes involved in the early defense of A. bisporus against P. tolaasii. Additionally, taking the physiological and transcriptomics results together, the existence and important participation of JA biosynthesis and signaling pathways were demonstrated in the disease resistance of A. bisporus , although this organism probably possesses different catalyzing enzymes and transduction pathways with plants. In a word, our findings revealed the mechanism of the button mushroom's early defense response against pathogens, providing a reference for the development of rational approaches to control of mushroom diseases. • Defense mechanisms of Agaricus bisporus against Pseudomonas tolaasii were revealed. • Genes involved in the disease defense of A. bisporus were elucidated by RNA-Seq. • Differentially expressed genes (DEGs) were mainly enriched in 8 pathways. • Ten potential DEGs involved in the disease defense of A. bisporus were selected. • JA biosynthesis and signaling pathways were important for mushroom disease defense. [ABSTRACT FROM AUTHOR]

Abstract: Treatment of tomato (Solanum lycopersicum L. cv. Messina) fruit with hot air (HA) at 38°C enhanced the transcript levels of LeARG1 and LeARG2, the two genes encoding arginase, and arginase activity. The strongest induction of LeARG1 and LeARG2 transcripts was observed after fruit treated with 38°C HA for 12h, which also effectively alleviated chilling injury (CI) of tomato fruit, manifested as decreased CI index, electrolyte leakage and malondialdehyde content during cold storage. To investigate the potential role of arginase in HA-induced chilling tolerance, fruit were treated with HA, or arginase inhibitor Nω-hydroxy-nor-l-arginine (nor-NOHA) combined with HA and then stored at 2°C for up to 28d. The results showed that HA-induced arginase activity was strongly inhibited by pretreatment with nor-NOHA and the reduction of CI by HA was nearly abolished by the arginase inhibitor. In addition, HA treatment increased activities of superoxide dismutase, catalase and ascorbate peroxidase, inhibited peroxidase activities, and promoted the accumulation of arginine, proline and putrescine. These effects were partially counteracted by nor-NOHA except that arginine and putrescine accumulation was unaffected. Our results indicate that arginase induction may be partly involved in HA-induced chilling tolerance in tomato fruit, possibly by a mechanism involving activation of antioxidant enzymes and an increase in proline levels. [Copyright &y& Elsevier]

Abstract: Freshly harvested tomato fruit were pretreated with 0.2mM arginine at −35kPa for 0.5min and then stored at 2°C for 28d to investigate the effect of exogenous arginine treatment on endogenous arginine catabolism in relation to chilling injury (CI). Arginine treatment reduced the CI index of fruit and enhanced accumulation of polyamines, especially putrescine, and proline, which resulted from the increased activities of the catabolic enzymes arginase, arginine decarboxylase, ornithine decarboxylase and ornithine δ-aminotransferase at most sampling times. Nitric oxide synthase activity was also increased by arginine treatment, which at least partly contributed to the increased nitric oxide concentration. These results revealed that the reduction in CI by exogenous arginine may be due to the accumulation of putrescine, proline and nitric oxide induced by activating the different pathways of endogenous arginine catabolism. [Copyright &y& Elsevier]

Abstract: The influence of methyl jasmonate (MeJA) on levels of gene transcripts, enzyme activities and metabolites related to arginine catabolism and chilling injury (CI) was studied in cherry tomato (Solanum lycopersicum L. cv. Messina) fruit stored at 2°C for 21 days. The CI index of fruit pretreated with 0.05mM MeJA vapor for 12h at 20°C was reduced compared with that of untreated fruit. The reduction was associated with up-regulated arginine catabolism. The mRNA levels and activities of arginase, arginine decarboxylase (ADC) and ornithine aminotransferase (OAT) in treated fruit were higher than in control fruit, while those of ornithine decarboxylase (ODC) increased transiently in response to MeJA treatment during the early days of cold storage. Free putrescine (Put) and proline accumulated in MeJA-treated fruit, while levels of other arginine-related amino acids were affected by MeJA. Spermidine (Spd) and spermine (Spm) contents remained unchanged in response to MeJA treatment over most of the storage time. The results indicate that MeJA becomes involved in coordinated catabolism of arginine, and helps to improve chilling tolerance in cherry tomato fruit. [Copyright &y& Elsevier]

• Methyl jasmonate (MJ) induced SlMYC2 expression and fruit resistance to B. cinerea. • MJ induced GLYCOALKALOID METABOLISM gene expressions and α-tomatine content. • MJ induced SPRs expression, total and special phenolic acids and flavonoid contents. • The silence of SlMYC2 counteracted the induced effects of MJ on tomato fruit. • SlMYC2 is involved in MJ-induced resistance to B. cinerea in tomato fruit. The mechanism of SlMYC2, involved in methyl jasmonate (MJ)-induced tomato fruit resistance to pathogens, was investigated. The data indicated that MJ treatment enhanced the accumulation of total phenolics and flavonoids, as well as individual phenolic acids and flavonoids, which might be caused by the increased phenylalanine ammonia-lyase and polyphenol oxidase activities, induced pathogenesis-related gene (PR) expression, β-1,3-glucanase and chitinase activities, as well as α-tomatine, by inducing GLYCOALKALOID METABOLISM gene expression. These effects, induced by MJ, partly contributed to tomato fruit resistance to Botrytis cinerea. Nevertheless, the induction effects of MJ were almost counteracted by silence of SlMYC2 , and the disease incidence and lesion diameter in MJ + SlMYC2 -silenced fruit were higher than those in MJ-treated fruit. These observations are the first evidence that SlMYC2 plays vital roles in MJ-induced fruit resistance to Botrytis cinerea, possibly by regulating defence enzyme activities, SlPRs expression, α-tomatine, special phenolic acids and flavonoid compounds. [ABSTRACT FROM AUTHOR]