Changes in Quality and Antioxidant Enzyme Activities of Bunched and Topped Radish (Raphanus sativus L.) Plants during Storage at 5 or 10C

Abstract

Quality changes of bunched and topped radishes (Raphanus sativus L.) during postharvest storage were investigated. Bunched radish plants, topped roots and detached leaves were stored at 5 or 10C for 9 days. Yellowing and wilting of leaves during storage at 10C were the main visual quality deteriorations in bunched radishes. Leaf detachment reduced respiration and ethylene production rates and weight loss of roots, and resulted in lower ascorbic acid, antioxidant capacity and phenolic content especially during storage at 10C. Root color did not change during storage, with or without leaf detachment. Leaf color did not change at 5C, whereas lightness and chroma increased and hue angle decreased at 10C, with larger changes observed in detached leaves. H2O2 content as well as peroxidase, ascorbate peroxidase and catalase activities in the root tissue were unaffected by leaf detachment, but increased during storage especially at 10C after 9 days of storage. PRACTICAL APPLICATIONSRadishes are marketed with the leaves attached on the enlarged root, which is the edible part of the plant, or are topped so that leaves are removed from the root. Consumers prefer to purchase radishes with the leaves attached because their green color is an indication of freshness. In retail market, higher than recommended temperatures are often encountered, resulting in yellowing of leaves; therefore, plants are topped and only the root is distributed. However, the effects of storage temperature as well as the removal of leaves on nutritional compounds of the edible roots have not been investigated and need to be determined, because nutritional quality is of increasing interest to the consumers. This study provides information on the effect of temperature and leaves removal on metabolism and quality of radish plants during storage, which can be applicable to sustain the quality and increase commercial marketing of radishes. bs_bs_banner Journal of Food Quality

Effects of Packaging on Shelf Life and Postharvest Qualities of Radish Roots during Storage at Low Temperature for an Extended Period

“…To simulate such open storage practices, we stored radishes in plastic crates only with or without curing which depicted higher water loss resulting in shriveling (Figure 2(e)) and deterioration of visual quality from the beginning of storage. Tsouvaltzis and Brecht [20] observed about 1.3% weight loss of topped radish root after 9 days of storage at either 5 ∘ C or 10 ∘ C which supported our weight loss result of unpacked roots as we found nearly 5% loss of fresh weight after 30 days of storage. However, Ayub et al [6] found severe weight loss of radishes (about 52%) just after 3 days of storage when radishes were stored at room temperature (20 ± 2 ∘ C) without leaves.…”

“…This treatment also showed nearly similar values of * and WI until 60 days of storage and therefore received the highest visual quality scores (later discussion) among the treatments. del Aguila et al [19] reported that the * values of whole radish roots (without packaging) remained unchanged during a 10-day storage period regardless of storage temperature up to 10 ∘ C. This implies that color changes of whole radish root are more insensitive to that of leaf or leafy vegetables and well documented by Tsouvaltzis and Brecht [20]. Therefore, many food industries which use radish root as one of the food ingredients store radish carelessly at lower temperature, especially in Korea.…”

“…Controlling storage temperature, on the other hand, is a crucial factors for maintaining physicochemical and other quality attributes of numerous fresh vegetables. In radish, physicochemical parameters that determine quality were well maintained in lower storage temperature [19,20] and, therefore, a temperature of 0 ∘ C was recommended for radish roots in order to maintain their quality for an extended storage period [21]. Although a number of researches have been conducted on radish roots focusing on the potential uses as minimally processed ready-to-use or fresh-cut produces [6,19,22] and as an ingredient of fermented or processed foods [23,24], findings relating to the maintenance of freshness and quality of whole radish roots during storage are very limited.…”

Chemical characterization and antioxidant capacity of red radish (Raphanus sativus L.) leaves and roots

“…The value for radish root is comparable with values reported in a previous work for the same product of 240 mg GAE/100 g d.m. (Tsouvaltzis & Brecht, 2014) but higher compared to the value of 122 mg GAE/100 g d.m. reported by Pushkala et al (2013).…”

“…Moreover, they play a significant role as antioxidants in the protective effect of plantderived foods (Balasundram, Sundram, & Samman, 2006). In particular, Radish (Raphanus sativus L.) is a root vegetable of Cruciferaceae family and it is an important vegetable crop worldwide (Tsouvaltzis & Brecht, 2014). Radish composition was found to be of highly medicinal and nutritional value.…”