Study On Extrusion Technology Of Black Rice And Application Of The Extrusive Black Rice Flour

Black rice is a good ingredient of dietary food which has many health benefits and contains abundant nutritive materials. This study's goal was to improve the technology level of black rice processing. It applied advanced and new technology of modern food processing, modern statistical analysis method and chemical analysis technology as core techniques to study the technology of black rice extrusion and applications of the extrusive black rice flour. The main results and conclusions were as follows:1. We used gelatinization degree as an index, adoping single-factor experiment and response surface methodology. The best condition for black rice extrusion was 60 material diameters, 26% material water content, 350 r/min screw speed, 160℃extrusion temperature. Under this process condition, the actual black rice gelatinization degree was 85.62%, which relative error is 3.38% compared with the theory.2. We studied influence of extrusion on the flowability, water-solubility, expansive force, foaming, viscosity, and content of reducing sugar, starch, fat of extrusive black rice flour. The result proved that after extrusion, flowability decreased, high of foaming decreased from 0.3 cm to 0.38 cm, water-solubility index changed from original 3% to 19.5%, expansive force strengths from original 0.4mL/g to 5.2mL/g, and viscosity changed very significantly from original 3.33mpa﹒s to 292.50 mpa﹒s. The content of reducing sugar, starch and fat all changed on different degrees.3. We used extrusive black rice flour as a main material to study influence of adding extrusion black rice powder on bread baking quality, flour quality and aging of bread storage,. The result indicated that adding extrusive black rice powder had some side effect to the rheological property of paste. But the effect was very small less than 8% addition amount. And adding extrusion black rice powder could greatly improve the bread's special flavour. Combining with storage experiment, every physicochemical index didn't change much below 8% adding amount. So the addition amount of black rice powder was appropriate not above 8%.4. We adopted single-factor experiment, orthogonal experiment to study how adding amount of black rice powder and sugar, inoculation amount and incubation time influence on yoghourt. The research confirmed the best condition of black rice yoghout: 1% adding amount of black rice, 8% sugar adding amout, 6% inoculation amount, and 4 h of incubation time. Under this technological condition, the black rice yoghout had a best texture, flavour and taste.