We have identified the best harvesting periods, related to higher bioactive compound content and post-harvest quality, for minimally processed sweet potatoes with orange pulp and cream pulp. Quality loss in minimally processed sweet potatoes occurred due to browning in cv. Mãe de Familia and ESAM1 and to whitening in cv. Paraná. Both Mãe de Família and ESAM1 presented higher peroxidase and polyphenol oxidase activities at 120 days, and cv. Paraná contained high levels of provitamin A. β-carotene was the major carotenoid (up to 99%) in orange pulp. All cultivars harvested at 150 and 180 days and minimally processed showed the best visual quality, the highest bioactive compound content, and no microbial infection. Delaying the harvest also increase the antioxidant activity in orange roots, which was associated with a high content of carotenoids and phenolic compounds, resulting in an increase in the nutritional quality of the product. PRACTICAL APPLICATIONS: Postharvest techniques can improve the visual and phytochemical quality of vegetables and extend their shelf life. The present research provides the best harvesting periods for minimally processed cream and orange sweet potato roots with higher postharvest qualities. Delaying the harvest resulted in a product with better visual quality, higher levels of bioactive compounds, which are highly beneficial to health, for example, ß-carotene, and no microbiological contamination. Our results may contribute to improvements in the current knowledge about harvesting times for sweet potato growers who aim to produce high quality, minimally processed products with a longer shelf life.
Keywords: Ipomoea batatas; browning; carotenoids; minimal processing; phenolic compounds; white blush.
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