Quality analysis of all‐purpose wheat flour pasteurized with radiofrequency‐assisted hot air heating

Abstract

AbstractRadiofrequency (RF) is a promising technology for preheating wheat flour for pasteurization but may influence its quality and functional properties. This study evaluated the quality and functionality change of bleached and unbleached, all‐purpose wheat flours after treating with RF and/or extended hot air heating at three processing temperatures (80, 85, and 90°C). The moisture content, color, sodium dodecyl sulfate (SDS) sedimentation test, flour swelling power, and solvent retention capacity (SRC) tests were measured. The moisture content of both bleached and unbleached samples decreased after the RF treatment, and the extended hot air heating further increased the moisture loss. The ΔE values of color change were less than two for all processing conditions, indicating little color change. The SDS results showed that the sedimentation volumes decreased after the thermal treatments, indicating decreased relative gluten strength. The flour swelling power increased after the RF and the extended hot air heating. The SRC tests measured the flour retention in four different solvents of 5% lactic acid, 5% sodium carbonate, 50% sucrose, and water, and their values were within the reported ranges of a variety of flour samples. The gluten performance index calculated from the four SRC values decreased after RF and extended hot air heating. The results showed that most heating conditions significantly changed the overall quality of flour samples, statistically (p < 0.05). However, the absolute changes of the values were small and within ranges of the reported values. Thus, the RF‐assisted pasteurization may not influence the practical applications of the treated flour for different flour‐based products.Practical ApplicationRF is a promising technology for preheating flour for pasteurization. The study found that the RF‐treated all‐purpose flours showed significant quality and functional properties change, statistically, but the absolute changes of the properties were small and within ranges of the reported values. Thus, RF heating and extended hot air heating can be used to pasteurize wheat flours without influencing their practical application.