Effect of processing on the microstructure of finger millet by X-ray diffraction and scanning electron microscopy.

Usha, Dharmaraj and Parameswara, P. and Somashekar, R. (2014) Effect of processing on the microstructure of finger millet by X-ray diffraction and scanning electron microscopy. Journal of Food Science and Technology, 51 (3). pp. 494-502. ISSN 0022-1155

PDF Jl of Food Sci & Tech_2014_51_3_494.pdf - Published Version Restricted to Registered users only Download (593kB)

Abstract

Finger millet is one of the important minor cereals, and carbohydrates form its major chemical constituent. Recently, the millet is processed to prepare hydrothermally treated (HM), decorticated (DM), expanded (EM) and popped (PM) products. The present research aims to study the changes in the microstructure of carbohydrates using X-ray diffraction and scanning electron microscopy. Processing the millet brought in significant changes in the carbohydrates. The native millet exhibited A-type pattern of X-ray diffraction with major peaks at 2θ values of 15.3, 17.86 and 23.15°, whereas, all other products showed V-type pattern with single major peak at 2θ values ranging from 19.39 to 19.81°. The corresponding lattice spacing and the number of unit cells in a particular direction of reflection also reduced revealing that crystallinity of starch has been decreased depending upon the processing conditions. Scanning electron microscopic studies also revealed that the orderly pattern of starch granules changed into a coherent mass due to hydrothermal treatment, while high temperature short time treatment rendered a honey-comb like structure to the product. However, the total carbohydrates and non-starch polysaccharide contents almost remained the same in all the products except for DM and EM, but the individual carbohydrate components changed significantly depending on the type of processing.

Item Type:	Article
Uncontrolled Keywords:	Finger millet . Microstructural parameters . Hydrothermal treatment . High temperature and short time treatment
Subjects:	600 Technology > 08 Food technology > 21 Cereals > 05 Ragi (Finger Millet) 600 Technology > 08 Food technology > 05 Processing and Engineering
Divisions:	Grain Science and Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	28 Apr 2014 05:14
Last Modified:	28 Apr 2014 05:14
URI:	http://ir.cftri.res.in/id/eprint/11472

Actions (login required)

View Item