Preharvest Methyl Jasmonate Treatment Affects the Mineral Profile, Metabolites, and Antioxidant Capacity of Radish Microgreens Produced without Substrate.

This study investigated the impact of Methyl Jasmonate (MeJA) application on the nutritional content and yield of five different colored radish microgreens. Microgreens were produced without substrate and subjected to 0.5 mM and 1.0 mM MeJA treatments on the 7th day, three days before harvest. The parameters measured included yield, dry matter, minerals, amino acids, secondary metabolites such as chlorophylls (Chls), anthocyanins, flavonoids, phenolics, glucosinolates (GSLs), vitamin C, and antioxidant capacity. MeJA at 1.0 mM generally improved yield and dry weight across cultivars, and all microgreens exhibited rich mineral and amino acid composition, with the influence of cultivar being more significant than MeJA treatment. However, MeJA enhanced all cultivars' anthocyanins, GSLs, phenolics, flavonoids, and antioxidant activities. Generally, as the antioxidant capacity is the primary factor influencing the nutritional quality of microgreens, MeJA-treated microgreens, especially with selected superior cultivars such as 'Asia purple' and 'Koregon red', could offer a potential for cultivation of value-added, eco-friendly microgreens with substrate-free cultivation.

Effect of ripening conditions on the physicochemical and antioxidant properties of tomato (Lycopersicon esculentum Mill.).

This study was conducted to assess the physicochemical changes and overall nutritional implications of greenhouse-grown "TY Megaton" and "Yureka" tomato cultivars under on-vine and postharvest ripening conditions. In the first group, tomatoes were harvested from a vine at the breaker, pink, and red ripening stages and sampled immediately. The second group was harvested at the breaker stage and allowed to ripen under room conditions to the pink and red stages based on color values, similar to the vine-ripened samples. The results of the present study revealed that fresh weight loss was below the maximum acceptable weight loss and firmness was above the minimum limit of marketing after postharvest ripening to the pink and red stages; moreover, this process did not have any deleterious effect on the antioxidant properties or antioxidant activity of the tomatoes. Hence, the results clearly indicate that breaker-stage tomatoes can be postharvest-ripened under room conditions without affecting their marketability and nutritional components.