Effect of harvesting time and microwave treatment on resistant starch content in purple sweet potato flour (Ipomoea batatas (L.) Lam)

Nguyễn Ngọc Thiên Kim; Vương Bảo Thy; Trần Ngọc Điệp; Ngô Lý Cẩm Tú; Nguyễn Ngọc Quí; Trần Hữu Thanh Huy; Bùi Thế Vinh

Issue: Số 17 - Tháng 6 - 2026 Hóa học - Công nghệ thực phẩm

Effect of harvesting time and microwave treatment on resistant starch content in purple sweet potato flour (Ipomoea batatas (L.) Lam)

Published: July 20, 2026

Abstract

Purple sweet potato (Ipomoea batatas (L.) Lam.) is a promising starch source for functional foods due to its ability to form resistant starch (RS). However, RS content is significantly influenced by factors such as harvesting time and heat treatment, with microwave processing emerging as an effective method to enhance starch retrogradation. This study evaluates the effects of four harvesting times and microwave treatments at different power levels (240–640 W/10 g) and durations (1–3 minutes) on RS content in purple sweet potato flour from Binh Tan, Vinh Long. The results show that harvesting at 140 days after planting (DAP) yields the highest natural RS content (6.81%). Microwave treatment at 400 W/10 g for 2 minutes increases RS content to 7.94%, approximately 17% higher than untreated starch. These findings provide a scientific basis for optimizing harvesting time and microwave processing conditions to produce RS-rich purple sweet potato flour.

Keywords

purple sweet potato harvesting time resistant starch microwave

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