Investigation of physicochemical properties of crust and core dietary fiber from date seed

Dietary fiber is one of the important components in diet which possesses positive effects on health, in addition tohaving appropriate functional properties. Among plant sources, date seed is an abundant and inexpensive as well as rich source of dietary fiber. In this research, date seed was first fractionated into two parts including outer part (crust) and inner part (core) and then both parts were defatted. The two kinds of powders obtained from defatting crust and core were named crust fiber and core fiber. Chemical analysis showed that the amount of protein, insoluble dietary fiber and total dietary fiber in core were significantly higher than crust. Fat of crust was significantly higher than core. Also it was understood that the amount of total dietary fiber in both crust and core parts was high (70.68% and 74.17%, respectively). Water retention capacity and oil binding capacity of core fiber (2.80 and 1.29 gram/gram, respectively) were respectively higher and lower than crust fiber (2.66 and 1.40 gram/gram, respectively). Core fiber was lighter than crust fiber. The value of all the three parameters including water retention capacity, oil binding capacity and L* were acceptable in comparison with most of the agricultural by-products and commercial fibers.