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The effect of γ-aminobutyric acid (GABA) treatment at two concentrations (1 mM or 5 mM) on papaya fruit stored at 4°C and 80%-90% relative humidity for 5 weeks was investigated. The application of GABA at 5 mM apparently inhibited chilling injury, internal browning, electrolyte leakage, malondialdehyde (MDA), hydrogen peroxide (H2O2), polyphenol oxidase (PPO), phospholipase D (PLD), and lipoxygenase (LOX) activities of papaya fruit. Fruit treated with 5 mM GABA enhanced the activities of ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD), glutamate decarboxylase (GAD), and phenylalanine ammonia-lyase (PAL). In addition, GABA treatment significantly displayed higher levels of proline, endogenous GABA accumulation, phenolic contents, and total antioxidant activity than the nontreated papaya. The results suggested that GABA treatment may be a useful approach to improving the chilling tolerance of papaya fruit by reducing oxidative stress and enhancing the defense system.
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[This corrects the article DOI: 10.1371/journal.pone.0247249.].
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This study tested a novel combination of hydrocolloid gum arabic (GA) and carboxymethyl cellulose (CMC) to extend postharvest life of tomatoes. For this purpose, tomato fruits were coated with GA 10%, CMC 0.5% and GA 10% + CMC 0.5%, and stored for 20 days at 20 °C and 90 ± 2% RH. Application of biocomposite hydrocolloid coating reduced physiological weight loss, respiration rate, ethylene production, decay percentage and stress markers viz. malondialdehyde and hydrogen peroxide. Biocomposite hydrocolloid coating inhibited change in bioactive compounds (phenolics, ascorbic acid, and lycopene), color, organic acids, soluble sugars and up-regulated enzymatic ROS scavenging mechanism in tomato fruit more than GA or CMC coating. Moreover, biocomposite coatings delayed senescence by reducing activity of cell wall degrading enzymes and maintaining cell wall fractions. Conclusively, the biocomposite coating based on GA and CMC was superior to their individual coating in prolonging ripening phase, delaying senescence and increasing the acceptability of tomato fruits for longer duration.
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Solanum lycopersicum , Antioxidantes/farmacologia , Carboximetilcelulose Sódica/farmacologia , Parede Celular , Frutas , Goma ArábicaRESUMO
The effect of carboxymethyl cellulose [(1%) CMC] was evaluated on mango fruits under storage at 20 ± 1 °C for 20 days. The CMC coating noticeably reduced weight loss and disease incidence. Application of CMC delayed climacteric peak of ethylene and respiration rate with significantly reduced relative ion leakage, malondialdehyde, superoxide anion and hydrogen peroxide content. The treated mangoes showed significantly lower L*, a*, b* and total carotenoids. The CMC treatment reduced the increase in cellulase, pectin methylesterase and polygalacturonase activity that delayed softening of mango fruits. In addition, activities of peroxidase, catalase, ascorbate peroxidase and superoxide dismutase were substantially higher in CMC-treated mango fruits. The treated fruits showed significantly lower soluble solids and higher titratable acidity which thereby reduced the ripening index of mangoes. In conclusion, CMC treatment could be considered a potential pre-storage treatment to delay postharvest ripening and to conserve the eating quality of ambient stored mango fruits.
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Mangifera , Antioxidantes , Ascorbato Peroxidases , Carboximetilcelulose Sódica , FrutasRESUMO
Chitosan is a deacetylated form of chitin and increasingly important amino-polysaccharide used in many various sectors including agriculture, food, and biomedicine. However, chitosan from marine sources has several adverse effects, including allergenic components harmful to human health. Furthermore, marine resources are seasonal, and availability is limited due to dependency on environmental conditions and climate change. In addition, shell infection in crustaceans and environmental contamination make the harvesting of chitin and chitosan problematic. In recent years, chitosan from terrestrial insects has attracted considerable interest. The discoveries show insect chitosan is more advantageous compared to crustacean chitosan. In addition, we were unable to find any literature about the adverse effects of insect chitosan thus far. This review aims to reveal information regarding crustacean and terrestrial insect chitosan and recent advances in chitosan sources. Applications from specific insect orders and perspectives for further study will also be highlighted, including medical and sensing applications.
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Quitosana , Animais , Quitina , Crustáceos , Humanos , Insetos , Alimentos MarinhosRESUMO
Recent postharvest studies have shown that adding an antioxidative agent in a polysaccharide-based edible coating reduces postharvest losses and extends the shelf life of a coated fruit. Therefore, the effect of addition of ascorbic acid (AA, 1%) in chitosan-based coating (CH, 1%) on strawberry fruits under cold storage conditions at 4 ± 1 °C and 85 ± 5% RH was investigated for 15 days. It was observed that addition of AA in CH coating reduced weight loss, decay percentage, malondialdehyde content and hydrogen peroxide compared to CH alone. The combined CH + AA application also suppressed fruit softening by reducing cell wall degrading enzymes (i.e. polygalacturonase, cellulase and pectin methyl esterase) activities. In addition, AA incorporation catalyzed ROS scavenging enzymes (i.e. ascorbate peroxidase, catalase, peroxidase and superoxide dismutase) activities. CH + AA treatment also maintained fruit quality by conserving higher total soluble solids, titratable acidity, ascorbic acid content, total phenolics and antioxidant activity. Sensory quality (color, taste, glossiness and overall acceptability) of fruits coated with CH + AA treatment was also stable during storage. Conclusively, the combined CH + AA application is an effective approach to maintain the postharvest quality of strawberry fruits under cold storage.
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Ácido Ascórbico/farmacologia , Quitosana/farmacologia , Filmes Comestíveis , Armazenamento de Alimentos , Fragaria/fisiologia , Frutas/fisiologia , Antioxidantes/análise , Sucos de Frutas e Vegetais , Peróxido de Hidrogênio/análise , Concentração de Íons de Hidrogênio , Malondialdeído/análise , Solubilidade , Açúcares/análiseRESUMO
DC-SIGN receptor articulated by macrophages and dendritic cells is encoded by CD209 gene and plays a role to activate and proliferate the T-lymphocytes in response of virus attack. The dysfunctional activity of DC-SIGN receptor because of missense SNPs can lead to cause dengue haemorrhage fever, HIV-1 infection etc. Out of 11 transcripts of CD209, all missense SNPs of canonical transcript were retrieved from Ensembl database and evaluated by their deleteriousness by using Polyphen-2, PMut, SIFT, MutPred, PROVEAN and PhD-SNP together with stimulation of its complete 3D structure. 10 nsSNPs were chosen depending on both the significance value of nsSNP and their prediction among SNPs evaluating servers which are based on different algorithms. Moreover, the position and native role of 10 nsSNPs in wild 3D model has been described which assist to acknowledge their importance. This study urges the researcher's community to experimentally validate these SNPs and their association in causing the diseases like dengue fever, Tuberculosis etc.
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Moléculas de Adesão Celular/genética , Biologia Computacional/métodos , Lectinas Tipo C/genética , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/genética , Moléculas de Adesão Celular/química , Simulação por Computador , Predisposição Genética para Doença , Humanos , Ligação de Hidrogênio , Lectinas Tipo C/química , Modelos Moleculares , Conformação Proteica , Estabilidade Proteica , Receptores de Superfície Celular/química , SoftwareRESUMO
The effect of Aloe vera (AV) gel (at 50% or 100%) alone or enriched with Fagonia indica (FI) plant extract at 1% on physiological and biochemical responses of sapodilla fruit were studied during storage at 20⯰C for 12â¯days. Sapodilla fruit treated with AV 100% and FI 1% significantly reduced weight loss, decay incidence, soluble solids concentration, and kept a high level of firmness and titratable acidity compared to the untreated fruit. FI 1% added to AV 50% or AV 100% efficiently maintained higher ascorbic acid, total flavonoids, total phenolics and radical scavenging activity of sapodilla fruit. The panelists did not detect any negative effect of AV gel and FI plant extract on the sensory attributes of sapodilla fruit. Therefore, the addition of FI plant extract to AV gel coating could be a promising approach to prolong the shelf life and preserve the quality of sapodilla fruit during storage.