Study On Deepness Processing Technology Of Wheat Bran And Germ

Wheat bran and germ is a byproduct of wheat processing, wheat bran contains bioactive dietary fiber, oligosaccharides and proteins. At present, processed wheat bran is basically applied to the feed industry directly, and very few of them are used for deepness processing and recycling, hence they have less economic value. Wheat germ contains a lot of free fatty acids, and it has poor storage stability. This paper proposes a highly efficient method of exploiting wheat bran, which will extract proteins, water-insoluble fiber and water-soluble fiber in wheat bran; optimize extraction conditions; and improve utilization of wheat bran at the same time. On the other hand, we can improve the stability of wheat germ by microwave processing methods and extending the storage period. Details of this process are as follows.To use wheat bran as raw material, the wheat bran protein and the water-soluble fiber were extracted simultaneously by ethanol alkali extraction - salting out. And then water-insoluble meals textile fiber was extracted usingα– amylase. Based on the single factor experiments, the optimal treatment process was determined using central composite design combined with response surface methodology. The results showed that the optimal extraction process based on the enzyme density is 0.27%, enzyme reaction temperature is 56℃, the material liquid ratio is 1:12, the ethanol/alkali ratio is 1:4, reaction temperature is 51℃, and the ammonium sulfate degree of saturation is 33%. In this optimal condition, the extraction yield of the wheat bran protein the water-insoluble fiber and the water-soluble fiber were 5.23%, 88.76%, and 3.08%, respectively.The studies of functional of proteins, water-insoluble fiber and water-soluble fiber properties have shown that wheat bran protein solubility is better in the environment which the pH is more than 8 with the best emulsifying and emulsion stability of wheat bran protein in alkaline conditions and emulsion stability. Wheat bran is extracted by salt-out method which has better solubility, foaming, foam stability, emulsifying and emulsion proteins than the protein which is extracted by acid- alkaline method, but has lower water retention. There was strong expansive force and water-holding power of insoluble fiber. Water-insoluble fiber showed the best heavy metal adsorption capacity with pH=7 in room temperature, and Cu, Pb and Cd adsorption capacity were 5.08mg/g, 7.67mg/g and 3.00mg/g, respectively. In the DPPH system, water-soluble fiber showed the scavenging capacity. The scavenging rate was 91.77% in the concentration of 20mg/ml.To improve the stability of the wheat germ, water absorption index (WAI) was the evaluation indicator. Based on single factor experiments, the optimal treatment process was determined using central composite design combined with response surface methodology. The results showed that the optimal treatment process was based on 20% moisture content, heating time 52.7s, and wheat germ addition 40.08g. In this condition, germ WAI was 2.346. Microwave processing can greatly enhanced the stability of wheat germ.