OPTIMIZING INULIN RECEIVING FROM BY-PRODUCTS OF LETTUCES (LACTUCA SATIVA) BY ENZYM

Abstract

Fiber is a critical element in nutrition which is present in many types of vegetables. However, it is not provided enough from the daily diet. To get the recommended intake of fiber, it is necessary to supply fiber in pure form. Inulin is a type of essential soluble fiber for the digestive system which is mostly found in some plants such as burdock root, Jerusalem astiso, dandelion and lettuce. Lettuce contains a lot of inulin in the stem, root parts which are discarded by-products. In this study, lettuce by-products were utilized to extract and collect inulin to use as a fiber supplement source. Besides, some factors affecting the hydrolysis process of lettuce stem and root powder for producing inulin including enzyme concentration, temperature, and pH were optimized using the designed Box-Behnken experimental model. The results showed that the yield of inulin was most affected by temperature. At the optimal hydrolysis conditions including enzyme concentration 10.4 U/g, temperature 49.9ºC, pH 5.2, the highest obtained inulin concentrations is 3.9% compared to the initial material.