Postharvest Technologies Enhance Quality, Antioxidant Activity, Microbial Control, and Shelf-Life of Radish Sango Microgreens

Abstract

This study examines the effects of postharvest techniques, including washing treatments, packaging materials, and storage temperatures, on the quality, antioxidant properties, microbial load, and shelf life of radish sango microgreens stored at 5°C and 25°C. The washing treatments comprised citric acid, sodium hypochlorite, ethanol, calcium chloride, acetic acid, and distilled water, with unwashed samples serving as a control. Various packaging materials, including low-density polyethylene (LDPE), high-density polyethylene (HDPE), metalized polyester (MP), and polystyrene trays (PT), were assessed. Key quality parameters such as antioxidant activity (DPPH and FRAP), ascorbic acid, glucosinolate, anthocyanin, total phenols, flavonoids, pigments, and microbial load were analyzed. Microgreens stored at 5°C in MP packaging combined with calcium chloride, citric acid, or sodium hypochlorite exhibited reduced microbial proliferation and retained higher antioxidant levels. Conversely, storage at 25°C accelerated quality deterioration and increased microbial contamination, especially in PT packaging. Principal component analysis (PCA) indicated strong associations between antioxidant activity, bioactive compounds, and 5°C storage. The findings suggest optimal postharvest approaches to enhance the shelf life and commercial viability of microgreens.