Effect of microwave heating on the quality and shelf life of whole grain wheat flour under air-conditioned storage

A study was conducted to evaluate the quality changes that could be occurred in the whole grain wheat flour during the storage and also to study the effect of microwave heating in the quality of the wheat flour. Whole grain wheat flour was packed in low density polyethylene bags separately as microwaved and non-microwaved and the quality changes were assessed for 12 weeks under air-conditioned storage temperature of 27°C. The quality characteristics such as smell, sieve test, long moisture, moisture NIR, protein NIR, ash NIR, wet-gluten, fat acidity, colour and weevil count were evaluated in 2 weeks interval. Fat and fiber content were evaluated in 4 weeks interval. Healthy cake was prepared from microwaved and non-microwaved flour and the sensory characteristics were evaluated using seven point hedonic scale method at the end of 4 weeks. The results of the study revealed that there were no significant differences (p>0.05) in the quality parameters of whole grain wheat flour in protein, ash, smell, fat and fiber whereas moisture, wet gluten, colour and the fat acidity changed significantly during the 12 weeks of storage. There was no any weevil infestation found in both flours. Sensory characteristics of the healthy cake were not affected by storage in both microwaved and non-microwaved flours. It was found from this study that, whole grain wheat flour can be stored under air-conditioned temperature of 27°C for 12 weeks from the date of manufacture.