Studies on pasting and structural characteristics of thermally treated wheat germ.

Sudha, M. L. and Srivastava, A. K. and Leelavathi, K. (2007) Studies on pasting and structural characteristics of thermally treated wheat germ. European Food Research and Technology, 225 (3-4). 351-357 ; 28 ref..

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Abstract

In order to utilize wheat germ, a nutrient-dense by-product of wheat milling industry, in various food products, different moist and dry heat treatments were tested for their ability to stabilize the wheat germ and for their impact on protein sub-unit composition, starch pasting properties and structural characteristics. Heat treatments tested included steaming, steaming + oven drying, steaming + hot air drying, steaming + microwave drying, drum-drying and fluidized bed drying. The raw germ contained 11% moisture, 31.4% crude protein, 18.4% dietary fibre and 7% fat. Heat treatments, except for fluidized bed drying, inactivated lipase activity in the germ completely. On the other hand, various heat treatments inactivated lipoxygenase activity to varying extents (78-92%). Extent of gelatinization, as assessed in electron micrographs was lowest in steamed and fluidized bed dried samples, while steamed and oven-dried germ and drum dried germ samples exhibited greater gelatinization. The extent of gelatinization seemed to be greater in drum-dried samples, as no intact starch granules were observed. Electrophoretic patterns and sub-unit composition of germ samples remained similar, irrespective of treatment. Raw germ had a gelatinisation temp. of 67.9C as measured in visco-amylograph and increased to 80.3-88.3C for treated germ samples, apart for drum-dried samples. Heated germ samples, depending on the extent of pre-gelatinisation, had significantly reduced peak viscosities (221-268 BU) and breakdown values (0-9 BU).

Item Type:	Article
Uncontrolled Keywords:	CARBON-DIOXIDE; FUNCTIONAL-PROPERTIES; GERM-; HEATING-; PROTEINS-CEREAL; WHEAT-; CEREAL-PROTEINS; COMPOSITION-; DRY-ICE; PASTING-PROPERTIES; STRUCTURE-; WHEAT-GERM
Subjects:	600 Technology > 08 Food technology > 16 Nutritive value > 05 Enzymes 600 Technology > 08 Food technology > 21 Cereals > 04 Wheat
Divisions:	Protein Chemistry and Technology Flour Milling Bakery and Confectionary Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	09 Aug 2008 10:19
Last Modified:	28 Dec 2011 09:53
URI:	http://ir.cftri.res.in/id/eprint/6425

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