Forage-cactus based edible coating, packaging, and refrigeration improve the visual and nutraceutical qualities of sweet potatoes

Abstract

Sweet potatoes have high economic relevance in developing countries. Therefore, the adoption of post-harvest technologies for their conservation for long-distance markets is crucial. In this work, the effect of the combined use of cactus-based edible coating, packaging and refrigeration on the quality of sweet potatoes was evaluated. Four coating and packaging treatments were evaluated: (Control, Coating, Packaging, and Packaging + Coating) and seven storage periods (0, 7, and 14 days at 8 °C, and 17, 20, 23, and 26 days at 23 °C simulate refrigerated transport and shelf conditions respectively). Coating treatments consisted of immersion in 0.04 g L−1 of forage cactus mucilage + 300 mL L−1 glycerol for 1 min. After 14 days of cold storage, sweet potatoes were maintained at 23 °C for up to 26 days. Raw and cooked (microwaved for five minutes) sweet potato samples were evaluated at 0, 7, 14, 17, 20, 23, and 26 days. The refrigerated condition maintained sweet potato quality based on visual analysis for up to 14 days, regardless of the use of the edible coating. However, only packaged sweet potatoes, with or without coating, maintained higher visual scores after transfer to room conditions, exhibiting lower fresh weight loss up to 26 days. Sweet potatoes subjected only to edible coating maintained an acceptable visual appearance until 23 days. Additionally, firmness, visual analysis, DPPH and FRAP antioxidant activity, soluble phenolic and starch contents were more stable in raw and cooked sweet potatoes packaged (with or without coating) for up to 26 days, which is a sufficient time to reach more distant markets.