Sucrose Conversion and Fructo-oligosaccharide Synthesis in Longan Juice Promoted by Enzymatic Treatment
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
This study aimed to reduce the sucrose content in Longan (Dimocarpus longan Lour.) juice and to prepare a Longan juice rich in Fructo-oligosaccharides. Longan juice was used as the main raw material for the investigations on. the effect of a single factor, including substrate concentration (as total soluble solids, TSS), substrate pH, fructosyltransferase addition, enzyme treatment temperature and time, on the conversion of sucrose and oligo-fructose formation in fruit juice. The changes in the contents of sucrose, fructose, glucose and fructo-oligosaccharides in the juice before and after enzymatic conversion were tracked and analyzed by liquid chromatography. The obtained results showed that parameters like substrate concentration, pH, amount of enzyme, treatment temperature and treatment time had significant effects (p<0.05) on the conversion of sucrose to fructo-oligosaccharides in Longan juice. Under the enzymatic conditions of TSS 30 oBrix, pH 6.0, enzyme dosage 9 U/g sucrose, 55°C for 7 h, the sucrose decreased from 164.36 to 22.34 mg/mL, leading to the fructo-oligosaccharide content of 97.88 mg /mL which accounted for 38.21% of the total sugar in the juice. The treatment with fructosyltransferase can effectively reduce the sucrose content in the Longan juice, and facilitate a low-calorie functional juice rich in fructo-oligosaccharide.
