Effects of dry heat treatment temperature on the structure of wheat flour and starch in vitro digestibility of bread

Pre-milling processing has an effect on both nutritional composition and its -<italic>in-vitro</italic> availability. In the present study an attempt was made to find out the effect of different pre-milling processing on the <italic>in-vitro</italic> iron availability. Pearl millet grains were subjected to processing technique <italic>viz.</italic> acid treatment (2 hours, 12 hours, 18 hours and 24 hours), dry heat treatment (30 minutes, 60 minutes, 90 minutes and 120 minutes), blanching treatment (30 seconds, 60 seconds and 90 seconds), and malting treatment to find out the <italic>in-vitro</italic> iron availability. Iron content in raw pearl millet was 11.93 mg/ 100gm. After treatment the total iron content was reduced in all the treatments. The <italic>in vitro</italic> iron availability was found to be higher in all the treatments as compared to raw pearl millet. <italic>In vitro</italic> iron content was noted maximum after dry heat treatment for 120 minutes (i.e. 3.58 mg/100gm) and minimum for 24 hour acid treatment (i.e. 2.39 mg/100gm). Hence the present study indicates that the pre-milling processing may reduce the total iron content but it increases the <italic>in vitro</italic> iron availability.

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Evaluation of dry heat treatment of soft wheat flour for the production of high ratio cakes

Food Research International ◽

10.1016/j.foodres.2018.02.041 ◽

2018 ◽

Vol 107 ◽

pp. 360-370 ◽

Cited By ~ 8

Author(s):

S. Keppler ◽

S. Bakalis ◽

C.E. Leadley ◽

S.S. Sahi ◽

P.J. Fryer

Keyword(s):

Heat Treatment ◽

Wheat Flour ◽

High Ratio ◽

Soft Wheat ◽

Dry Heat ◽

Dry Heat Treatment

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Holistic View of Starch Chemistry, Structure and Functionality in Dry Heat-Treated Whole Wheat Kernels and Flour

Foods ◽

10.3390/foods11020207 ◽

2022 ◽

Vol 11 (2) ◽

pp. 207

Author(s):

Jana van Rooyen ◽

Senay Simsek ◽

Samson Adeoye Oyeyinka ◽

Marena Manley

Keyword(s):

Heat Transfer ◽

Heat Treatment ◽

Wheat Flour ◽

Wheat Starch ◽

Holistic View ◽

Dry Heat ◽

Starch Properties ◽

Heat Treated ◽

Dry Heat Treatment ◽

Wheat Kernels

Heat treatment is used as a pre-processing step to beneficially change the starch properties of wheat flour to enhance its utilisation in the food industry. Heat-treated wheat flour may provide improved eating qualities in final wheat-based products since flour properties predominantly determine the texture and mouthfeel. Dry heat treatment of wheat kernels or milled wheat products involves heat transfer through means of air, a fluidising medium, or radiation—often resulting in moisture loss. Heat treatment leads to changes in the chemical, structural and functional properties of starch in wheat flour by inducing starch damage, altering its molecular order (which influences its crystallinity), pasting properties as well as its retrogradation and staling behaviour. Heat treatment also induces changes in gluten proteins, which may alter the rheological properties of wheat flour. Understanding the relationship between heat transfer, the thermal properties of wheat and the functionality of the resultant flour is of critical importance to obtain the desired extent of alteration of wheat starch properties and enhanced utilisation of the flour. This review paper introduces dry heat treatment methods followed by a critical review of the latest published research on heat-induced changes observed in wheat flour starch chemistry, structure and functionality.

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