Abstract:

Objective: To develop a suitable industrial method for efficient separation of pectin from soluble soybean-hull
polysaccharide. Methods: Based on single factor experiments, the effects of soluble solids content (A), calcification pH
value (B), washing cycles (C) and acidification pH value (D) on the purities of pectin and neutral sugar were investigated
through L9(34) orthogonal experiments. Results: All the investigated factors affected more significantly the purity of
pectin than that of neutral sugar. The influences of the four factors on the purity of pectin followed the descending order:
C > A > B > D, while the order of their effects on the purity of neutral sugar was as follows: A > B > C > D. Based on
comprehensive consideration the optimum separation conditions were determined as 2.5%, 8, 5, and 2 for soluble solids
content, calcification pH value, washing cycles, and acidification pH value, respectively. Experiments conducted under these
conditions resulted in a pectin purity of 85.48%, a pectin yield of 31.3%, a neutral sugar purity of 80.01% and a neutral
sugar yield of 64.9%. Conclusion: The proposed separation method is effective, practical, easy to operate, low-cost, green
pollution-free, and suitable for industrial production.

Key words: soluble soybean-hull polysaccharide, separation, pectin, neutral sugar