Effects of different physical technology on compositions and characteristics of bean dregs

The effects of ultrafine grinding (U), high pressure (HP), microwaves (M), high-temperature cooking (HTC) and combination technologies (U-HP, U-M, U-HTC) on the nutritional compositions and characteristics of bean dregs were investigated. The results showed that both single treatments and combination treatments significantly increased the soluble dietary fiber (SDF) content and water solubility of bean dregs; however, the protein content, fat absorption capacity and swelling capacity of bean dregs were decreased compared with those of the control. The combination technologies significantly increased the contents of K, Ca, Na and Fe in bean dregs. HTC and U-HTC had prominent effects on inhibiting trypsin inhibitor activity, which were decreased from 7365 TIU/g to 1210 and 96 TIU/g, respectively. The bean dregs by ultrafine grinding and combined treatments showed honeycomb structure and small particle distribution, and their processing performances improved. In conclusion, combination technologies were effective methods for improving the quality of bean dregs and expanding their development. Industrial relevance: A combined method may have greater effects than any single approach in improving the quality of bean dregs. Ultrafine grinding technology combined with other physical techniques used in bean dregs can solve quality problems; for example, bean dregs are characterized by poor taste, perishability, low soluble fiber content, and high trypsin inhibitor activity, all of which are related to human health and safety. However, to the best of our knowledge, ultrafine grinding combined with other physical techniques has not been used with bean dregs. The present paper highlights the effects of ultrafine grinding technology (U) combined with high pressure (HP), microwave (M), and high temperature cooking (HTC) technologies on the nutritional and functional compositions of bean dregs. The obtained results contribute to enhance SDF content, reduce anti-nutrition factors, and expand development and utilization of bean dregs, which constitute the basis for its application in baked food, flour products and the food industry.