Enhanced Extraction and Functional Characterization of Pectin and Pectic Oligosaccharide from Grapefruit Residue Using Sodium Oxalate-Assisted Pressurized CO2

Ms. PATTARAPISITPORN ALISA, a third-year doctoral student at the United Graduate School of Agricultural Sciences, had her research published in the peer-reviewed international journal “Food and Bioprocess Technology” (Impact Factor: 5.8) in January 2025.

The present study investigated methods for efficiently extracting pectin and pectin oligosaccharides (POS) from grapefruit juice residue. Pressurized carbon dioxide (PCO₂) extraction was carried out with sodium oxalate serving as an auxiliary agent. The maximum pectin yield was recorded at 42.7%, which signifies an approximate 40% increase in comparison with conventional conditions. The extracted pectin demonstrated a high galacturonic acid content of 65.8%, as well as adequate structural integrity, as substantiated by FTIR and SEM. The POS obtained via enzymatic hydrolysis promoted probiotic proliferation and acetate production, while also exhibiting antioxidant and angiotensin-converting enzyme inhibitory activities. The pectin exhibited high levels of digestive resistance; however, the POS demonstrated easily digestible properties. The findings suggest that the PCO₂ extraction method is a sustainable and efficient technique for pectin recovery, and the POS holds promise for application in functional foods and nutraceuticals.

■ Publication Information

Title: Enhanced Extraction and Functional Characterization of Pectin and Pectic Oligosaccharide from Grapefruit Residue Using Sodium Oxalate-Assisted Pressurized CO₂
Authors: Alisa Pattarapisitporn, Yuzuka Nagatoshi, Wannaporn Klangpetch, Daisuke Hamanaka, Nao Inoue & Seiji Noma
Journal: Food and Bioprocess Technology
DOI: https://doi.org/10.1007/s11947-025-03967-7