tannins and ethylene

The effects of three different hulling methods wiz natural heaping/traditional (T1), steeping (T2), and spraying (T3), on moisture, colour, fat, free amino acids, fatty acids, antioxidant activities, flavonoids, tannins, total phenolic content, and organoleptic qualities of walnut kernels were examined in this study. The kernels extracted from walnuts subjected to T3 method recorded significantly (p ≤ 0.05) highest DPPH inhibition (68.61 %), ABTS (54.56 %inhibition) and FRAP (0.106 μM trolox/100 g); flavonoids (1993.08 mg QE/100 g), tannin content (0.312 %) and phenols (0.736 mg GAE/g) compared to T1 and T2. Walnut kernels of T3 treatment group were rated better in terms of taste (3.8), odour (3.6) and overall acceptability (3.78) Furthermore, walnut kernels obtained from T3 treatment group exhibited the highest percentage of unsaturated fatty acids (UFAs) and sweet free amino acids. The outcome of the present study offers a fresh viewpoint regarding the hulling processes of green walnuts to meet the quality requirements of walnut kernels.

Topics: Amino Acids; Antioxidants; Ethylenes; Fatty Acids, Unsaturated; Flavonoids; Fruit; Juglans; Phenols; Polyphenols; Tannins

This study aimed to investigate the combined effects of a coating based on shellac and the active agent tannic acid (TA) on the storability and physiological variations of mangoes stored at room temperature. Results showed that TA-shellac prolonged shelf life and improved overall quality of mangoes to a higher extent compared with controls, which was reflected in the extension of shelf life for approximately 10 days, maintaining of tissue firmness and weight loss, slowing down of respiration rate, improvement of physical properties and chemical qualities, suppression of browning, reduction of lipid peroxidation, preservation of aromatic volatiles, and regulation of the related enzymes activities. Addition of TA to shellac coating also improved the antifungal effect of the formulation. The results suggest that a synergistic effect took place between TA and shellac, which demonstrates the high potential for shelf life extension and quality improvement of mangoes of this formulation.

Topics: Antioxidants; Color; Edible Films; Ethylenes; Food Packaging; Fruit; Gas Chromatography-Mass Spectrometry; Malondialdehyde; Mangifera; Resins, Plant; Tannins; Temperature; Volatile Organic Compounds

Tannins are frequently a main focus in the investigation of de-astringency treatments of persimmon, and the effect of a controlled atmosphere on other phytochemicals is often overlooked. In the present study, changes in the content of total soluble and insoluble phenolics, soluble tannins, saponins, and carotenoids, as well as changes in primary metabolites, were monitored.. Generally, treatment with ethylene induced a decrease in total phenolic content, whereas, when treated with CO. The results obtained in the present study show that the content of metabolites in persimmon was affected markedly and variedly using post-harvest technology. Apart from the treatment used, changes in the content of metabolites are also affected markedly by the persimmon variety. © 2018 Society of Chemical Industry.

Topics: Diospyros; Ethylenes; Food Preservation; Fruit; Phenols; Saponins; Tannins

The quality of zein (Z)- and zein-tannic acid (ZTA)-coated guavas was monitored throughout 12 days of storage. Coated fruit showed lower changes in terms of visual appearance, chlorophyll contents and color. Weight loss, softening, and changes in soluble solids were also decreased by the coatings. The respiration peak as well as H

Topics: Chlorophyll; Color; Cross-Linking Reagents; Ethylenes; Food Quality; Food Storage; Fruit; Hydrogen Peroxide; Oxidative Stress; Psidium; Superoxide Dismutase; Tannins; Temperature; Zein

A hypoxic environment is generally undesirable for most plants and stimulates anaerobic metabolism. It is a beneficial treatment, however, for the removal of astringency from persimmon to improve the fruit quality after harvest. High soluble tannins (SCTs) content is one of most important causes of astringency. High CO2 (95%) treatment effectively reduced SCTs in both "Mopan" and "Gongcheng-shuishi" persimmon fruit by causing increases in acetaldehyde. Using RNA-seq and realtime PCR, twelve ethylene response factor genes (DkERF11-22) were isolated and characterized, to determine those responsive to high CO2 treatment. Only two genes, DkERF19 and DkERF22, showed trans-activation effects on the promoters of deastringency-related genes pyruvate decarboxylase genes (DkPDC2 and DkPDC3) and the transcript levels of these genes was enhanced by hypoxia. Moreover, DkERF19 and the previously isolated DkERF9 had additive effects on activating the DkPDC2 promoter. Taken together, these results provide further evidence that transcriptome changes in the level of DkERF mRNAs regulate deastringency-related genes and their role in the mechanism of persimmon fruit deastringency is discussed.

Topics: Carbon Dioxide; Diospyros; Ethylenes; Fruit; Gene Expression Regulation, Plant; Hypoxia; Promoter Regions, Genetic; Tannins; Transcription Factors

Thirteen ethylene signaling related genes were isolated and studied during ripening of non-astringent 'Yangfeng' and astringent 'Mopan' persimmon fruit. Some of these genes were characterized as ethylene responsive. Treatments, including ethylene and CO(2), had different effects on persimmon ripening, but overlapping roles in astringency removal, such as increasing the reduction in levels of soluble tannins. DkERS1, DkETR2, and DkERF8, may participate in persimmon fruit ripening and softening. The expression patterns of DkETR2, DkERF4, and DkERF5 had significant correlations with decreases in soluble tannins in 'Mopan' persimmon fruit, suggesting that these genes might be key components in persimmon fruit astringency removal and be the linkage between different treatments, while DkERF1 and DkERF6 may be specifically involved in CO(2) induced astringency removal. The possible roles of ethylene signaling genes in persimmon fruit astringency removal are discussed.

Topics: Carbon Dioxide; China; Diospyros; Ethylenes; Fruit; Gene Expression Regulation, Plant; Genes, Plant; Genetic Variation; Genotype; Plant Growth Regulators; Signal Transduction; Tannins

Witches' broom disease (WBD) is caused by the hemibiotrophic basidiomycete fungus Crinipellis perniciosa, which is one of the most important diseases of cocoa in the western hemisphere. In this study, the contents of soluble sugars, amino acids, alkaloids, ethylene, phenolics, tannins, flavonoids, pigments, malondialdehyde (MDA), glycerol, and fatty acids were analysed in cocoa (Theobroma cacao) shoots during the infection and development of WBD. Alterations were observed in the content of soluble sugars (sucrose, glucose, and fructose), asparagine and alkaloids (caffeine and theobromine), ethylene, and tannins. Ethylene and tannins increased prior to symptom development and declined with the death of the infected tissues. Furthermore, MDA and glycerol concentrations were higher in infected tissue than in the controls, while fatty acid composition changed in the infected tissues. Chlorophylls a and b were lower throughout the development of the disease while carotenoids and xanthophylls dropped in the infected tissue by the time of symptom development. These results show co-ordinated biochemical alterations in the infected tissues, indicating major stress responses with the production of ethylene. Ethylene levels are hypothesized to play a key role in broom development. Some of the other biochemical alterations are directly associated with ethylene synthesis and may be important for the modification of its effect on the infected tissues.

Topics: Agaricales; Amino Acids; Brazil; Cacao; Carbohydrate Metabolism; Ethylenes; Fatty Acids; Flavonoids; Glycerol; Malondialdehyde; Phenols; Pigments, Biological; Plant Diseases; Plant Leaves; Plant Stems; Tannins