RESUMO
Nectarine is an important stone fruit after plum and peach. The area under peach cultivation is now getting replaced by nectarine due to its fuzzless nature and high nutritive value. Nectarines are juicy, delicious fruits having low calorific value and have high antioxidant capacity. In India, its cultivation is confined to North-Western and North-Eastern Himalayas. In this study, five major nectarine cultivars growing in India namely, 'Silver Queen', 'Red Gold', 'Spring Bright', 'Independence' and 'Missourie' were harvested at commercial maturity and analyzed for various chemical and nutritional aspects. Our results showed that there were quantitative differences among the genotypes in different parameters analyzed. The predominant sugar in nectarine was fructose which was highest in 'Silver Queen' (14.48 mg 100 g-1 FW) and lowest in 'Independence' (9.04 mg 100 g-1 FW). Major organic acids were malic, succinic, citric and acetic acid. The highest malic acid content was recorded in 'Independence' (1.13 mg 100 g-1 FW) and lowest in 'Red Gold' (0.61 mg 100 g-1 FW). Nectarine genotypes chiefly contained phloridizin dihydrate and chlorogenic acid as the phenolic component. However, chlorogenic acid was highest in 'Spring Bright' (17.63 µg g-1 FW) and lowest in 'Red Gold' (3.67 µg g-1 FW). Similarly, a wider variability was recorded in major and minor mineral concentrations among the genotypes. Based on these observations, it can be concluded that among the major nectarine varieties cultivated in India, 'Silver Queen' have higher mineral nutrients than other varieties, and 'Spring Bright' have higher phenolics and antioxidants.
RESUMO
Nectarines have remarkable nutritional value, low caloric content, and are rich in antioxidants. However, despite substantial local and global demand, their susceptibility to rapid spoilage during peak summer harvest is limited. To address this issue, the current study investigated the potential benefits of using melatonin (MLT), an antioxidant biomolecule, in combination with edible hydrocolloid coatings like carboxymethylcellulose (CMC) and gum Arabic (G.A.) on 'Snow Queen' nectarine fruits. The nectarines were treated with various combinations of coatings, including 1% and 1.5% CMC, 8% and 10% G.A., and 0.1 mM melatonin. These coated and non-coated samples were stored under standard supermarket conditions (18 ± 1 °C, 85-90% R.H.) for 16 days. The outcomes demonstrated that the most effective treatment was the combination of 1% CMC with 0.1 mM melatonin. This treatment significantly (p ≤ 0.05) reduced the rate of respiration, curbed fruit decay by approximately 95%, minimized weight loss by around 42%, and maintained approximately 39% higher levels of total phenol content and roughly 30% greater antioxidant (AOX) activity. These positive effects were accompanied by preserved firmness and overall quality attributes. Moreover, the treatment extended the shelf life to 16 days through retarding senescence and suppressing the activities of lipoxygenase (LOX) and pectin methylesterase (PME), all without compromising the functional qualities of the nectarine.