•Cysteine improves red beet bioactive compounds.•Betalains content is favored by cysteine application.•Cysteine does not decrease polyphenol oxidase activity in fresh-cut red beet.•Cysteine favors ...the shikimate pathway product concentration in fresh-cut red beet.
This study investigated the effectiveness of cysteine in conservation of bioactive compounds and the antioxidant capacity of minimally processed red beet. After red beet minimal processing increasing cysteine concentrations were applied, corresponding to control, 2 mM, 4 mM, 8 mM and 16 mM. Assay was performed over 15 d to evaluate the polyphenols, betalains, antioxidant capacity and enzymatic activity of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL). Cysteine enhanced the gallic acid, caffeic acid, chlorogenic acid, kaempferol and betalain contents until 6 d of storage. Subsequently, dosages of cysteine above 4 mM maintained gallic acid, kaempferol and betalains contents. Cysteine appears to influence the phenylpropanoid pathway, favoring the accumulation of polyphenols and betalains. In red beet, cysteine did not inhibit PPO activity but enhanced PAL activity. Betalains contribute more than phenolics to the antioxidant capacity, and their relationship with cysteine has not been thoroughly elucidated to date.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Roses were treated with different doses of silicon (Si) (0, 200, 400 and 800 g L
−1
) and different methods of Si application (soil or leaves) in order to determine the better form of pre-harvest Si ...supplementation. The quality of the stems at harvest was improved with Si supplementation. The highest dose of Si provided the best values of stem diameter and floral bud length, resulting in an increase of 0.5 mm and 1.9 mm in relation to control, respectively, when Si application was done directly on the soil. The weight and length of the stem, and the peduncle diameter were improved regardless of the dose and method of application. In the postharvest storage, the stems that received the Si treatment showed reduced fresh mass variation, greater relative content of water of the petals and leaves and greater index of opening floral buds. The peroxidase (POD) activity was also reduced with Si supplementation. On the last day of storage, stems treated with 800 g L
−1
Si directly in the soil had a POD activity of 2.5 U mg
−1
protein, whereas in control this value was 3.10 U mg
−1
protein. The petals with higher POD activity showed reduction in color parameters such. Therefore, the soil application of Si was more favorable in maintaining the quality of the stems during the storage. These results show that Si supplementation at 800 g L
−1
not only favors the quality of rose stems at harvest, but also provides a better conservation of their postharvest vase life.
Highlights
Pre-harvest Si supplementation improves the biometrical parameters of cut rose.
Si application at 800 g L
−1
provides a better quality for cut rose stems at harvest.
Si treatment improves plant water status during postharvest storage.
Soil application of Si favors the color maintenance of stems during storage.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Gamma Radiation in Plant Foods Tezotto-Uliana, Jaqueline V.; Silva, Paula P. M. da; Kluge, Ricardo Alfredo ...
Revista Virtual de Química,
2015, Volume:
7, Issue:
1
Journal Article
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