Effect of concentration and temperature on the formation of wheat hydrogel and xerogel pattern

Abstract

The colloidal nature of wheat flour could be utilized in engineering the physical structure of food systems. Gelatinization behavior of starch in wheat flour was studied to develop a wheat hydrogel and the impact of hydrogel characteristics in drying was observed in xerogel surface structure. Effect of variation in wheat flour concentration was analyzed by least gelation concentration and pasting parameters. It showed 10% (w/v) of gelatinized wheat flour suspension can be able to form a three-dimensional polymer network during retrogradation. Influence of hydrogel formation temperature was studied by solubility, swelling power, transmittance, contact angle and surface tension at different temperatures. Increase in solubility and swelling power indicates, leaching of more starch components and binding of more water molecules. The decrease in light absorbance indicates loss of crystallinity and birefringence due to disruption of granular structure. Contact angle and surface tension showed its impact on the increase in spreading coefficient at higher temperatures. Different concentration (5–15% (w/v)) of wheat flour suspension were subjected to heat from 30 to 100 °C; at each 5% (w/v) rise in concentration and 10 °C rise in temperature, a xerogel was developed and observed. It was found that 10% (w/v) of wheat flour suspension gelatinized at 90 °C showed better integrity and surface structure without cracks and deformations. The developed xerogel could serve as a snack food and also a carrier material for bioactive components in functional foods and nutraceuticals.