Spirogyra residue-based edible coating for maintaining postharvest quality and safety of tomatoes

Tomatoes are perishable and prone to postharvest deterioration, leading to quality and safety losses. This study aimed to evaluate the potential of a Spirogyra residue-based coating (SRC) as a natural treatment for maintaining the postharvest quality of tomatoes during storage at 4 °C and 25 °C for 21 days. Tomato samples were coated with the prepared SRC solution, whereas control samples were treated with distilled water. The results showed that at 4°C, SRC-coated tomatoes exhibited lower weight loss, maintained firmness, and reduced microbial growth compared to the control samples. At 25°C, the coating also delayed ripening and minimised spoilage, although quality changes occurred more rapidly than at 4°C. The coating effectively inhibited microbial proliferation, particularly total plate count, yeast and mold, while mitigating physical deterioration such as colour, firmness, and weight loss. These findings demonstrate that SRC can effectively delay physical changes and prevent microbial growth, thereby extending the postharvest quality of tomatoes.