Optimization of Extraction Process of Soluble Dietary Fiber from Papaya（Carica papaya Linn.） Peel from Hainan/Sekaki Variety and Evaluation of Physicochemical Properties

Key words: 
• Papaya peel /
• soluble dietary fiber /
• physico-chemical properties /

Abstract: The single factor experiments and orthogonal experiment was employed to optimize two kind of chemical extraction process of soluble dietary fiber from papaya peel and its physicochemical properties was primarily compared to obtain the functional fraction. The optimum extraction method were as follows: the optimal process of acid hydrolysis method is extraction time 90 min,p H1. 0,extraction temperature 80 ℃,the ratio of water to raw material 1 ︰ 25（ g ︰ m L）,the extraction yield was 20. 70%,while the optimum process of alkali hydrolysis method is Na OH concentration 1. 4%,extraction temperature 75 ℃,the ratio of water to raw material 1 ︰ 20（ g ︰ m L）,extraction time 90 min,the extraction yield was 9. 17%. The extraction yield through acid-alkali is 29. 87%. The results of physicochemical property experiments showed that the solubility in water,water holding capacity and cation exchange capacity of the soluble dietary fiber extracted by the acid hydrolysis method were lower than that extracted by the alkali hydrolysis method. While the oil holding capacity was higher. In conclusion,the soluble dietary fiber extracted from papaya peel by the two hydrolysis method both showed their different practical application values,which makes sense to the further processing and practical application of papaya.