EFFECT OF TEMPERATURE AND STORAGE TIME ON SACCHARIDES AND FRUCTO-OLIGOSACCHARIDES (FOS) OF ONION BULB ALLWM CEPA L. VAR. TENSHIN

摘要

The effects of temperature and long-term storage on the saccharides and fructo-oligosaccharides (FOS) content of onion bulb var. Tenshin stored at 10 and 20°C for 24 weeks were investigated. Initial glucose, fructose and sucrose contents averaged 18%, 23% and 18% respectively of total carbohydrates. Trisaccharides averaged 12%, while tetra-saccharides averaged 10% of total carbohydrates. High-polymerized fructo-oligosaccharides averaged 7%, 5%, 2%, 2% and 4% for DP 5, 6, 7, 8 and up to 12 respectively. After six months, glucose content was relatively the same at 20°C and higher at 10°C, while fructose content decreased more significantly at 20°C than at 10°C. FOS contents decreased significantly and were largely consumed after six months storage at both temperatures. However, no significant difference of DP 8 to up to 12 FOS content was observed between 10 and 20°C. Finally, temperature and storage time influenced significantly the FOS than saccharides contents of onion bulbs.