Chemical and Photochemical Profiles of Selected Vietnamese Fruit By-Products

Abstract

Aims: This study characterized the chemical, mineral, and photochemical properties of underutilized tropical fruit by-products in Vietnam—banana pseudostems, dragon fruit peels, and durian husks—to assess their potential in biomaterials, nutraceuticals, and circular agriculture. Study design: Experimental cross-sectional compositional analysis with international benchmarking. Place and Duration of Study: Ho Chi Minh University of Industry and Trade, Vietnam. Samples were collected from U Minh Thượng (An Giang), Bình Thuận, and Đắk Lắk. Methodology: Freeze-dried and ground samples were analyzed for proximate composition, minerals, polyphenols, carotenoids, and betalains using AOAC methods, HPLC–DAD, and UV–Vis/fluorescence spectroscopy. All analyses were performed in triplicate (n = 3). Results: Banana pseudostems were rich in cellulose (38.4%) and hemicellulose (22.5%), highlighting their suitability as lignocellulosic feedstocks. Dragon fruit peels contained betalains (2.45 ± 0.12 mg/g DW) and polyphenols (12.4 mg GAE/g DW), confirming strong antioxidant and pigment potential. Ri6 durian husks exhibited distinct carotenoid and phenolic acid profiles, with elevated calcium (355 mg/100 g DW) and phosphorus (138 mg/100 g DW). Photochemical assays revealed UV-absorbing activity of banana phenolics, photolability of dragon fruit betalains, and stability of durian carotenoids. Comparative analysis with India, Thailand, and Malaysia confirmed Vietnamese samples fall within global ranges while demonstrating cultivar-specific advantages. Conclusion: These findings highlight Vietnamese banana pseudostems, dragon fruit peels, and Ri6 durian husks as promising agro-industrial by-products. Their valorization into bioplastics, natural pigments, nutraceuticals, and compost aligns with circular bioeconomy goals and supports sustainable resource utilization.