Relationship Between Lipase Activity and Oats Kernel Physical Characters

Session II – Cereal Science, Whole Grain Foods and Processing – Poster II-3

Relationship between Lipase Activity and Oats Kernel Physical Characters

Xinzhong Hu1*, and Changzhong Ren2

1College of Food Science & Engineering, Northwest A & F University, Yangling, Shaanxi, CHINA, 712100,

2Jilin Baicheng Academy of Agricultural Science, Baicheng, Jilin, CHINA 137000；

*Corresponding Author: Tel: (86)29-8709 2159; E-mail:

Abstract: The oat enzyme plays an important role in oat food storage and processing, but it has a bad effect on shortening food storage time and arising free fatty acid oxidation. Deactivation treatment is necessary for prolonging shelf life and increasing value. The common useful method used for deactivation is steaming, but the disadvantage that has been pointed was not convenience for industrialization and their blank flavor of final products. To solve the problems that obstructed naked oats (Avena nuda) for food processing in China, this research focuses on the main factors including enzyme activity distribution around the kernel, and debran treatment which can enhance the mouth feel of the oat final products. Three naked oat varieties and advanced Florence microscopy method are used to analyze the enzyme distribution in the kernel. The results related to the research of lipase enzyme distribution showed: lipase activity had significant positive correlation with kernel length, width, areas, and one thousand kernel weight, but negative correlation with ratio of kernel weight divided by the area. The bigger the kernel, the lower the lipase activity. Lipase was not uniformly distributed around the kernel and most was located in the outer layer. Lipase activity was negatively correlated with oat debran ratio and lipid content. With the peeling time increases for the oat groats, the lipase activity decreases. The oat rice obtained through 20s debran treatment was higher for kernel whiteness, but was lower for β-glucan content, and protein content. 20s debran treatment with Japan Satake mill was selected as the optimum technology for oat rice processing, which provided the basic fundament for naked oat kernel and oat rice enzyme deactivation.

Key words: Naked oats (Avena nuda); enzyme; lipase activity; distribution; physical characters