Study On Character And Starch Physico-chemical Properties Of Proso Millet

Proso millet seed were rich in starch, protein, fat, fiber and minerals. The hulling rate,shelling percentage and flour yield of proso millet were all reach more than80%, has wellprocessing quality. With the improvement of people's dietary pattern, the nutrition of prosomillet aroused people's attention. But by now, it still has few reports of nutrition andprocessing for proso millet seed and proso millet starch. So, strengthen the study of prosomillet and other quality has very important practical significance.In this study,14proso millet varieties had been selected as the material, and analyse thenutrition and processing quality of difference varieties of proso millet. Make the proso milletstarch preparation processing optimize. Analyse particle morphology, particle diameter,microcrystalline structure, retrogradation, transparency, freeze-thaw stability, pastingproperties, enthalpy characteristics and textural properties of14varieties of proso milletstarch and effect of food addition on proso millet starch paste properties. The importantconclusions as follows:(1)The hulling rate of proso millet were10.62%~21.60%, the shelling percentage were78.40%~89.30%and flour yield were85.22%~88.68%. The fat of proso millet seed contentwere27.0~52.8g/kg, the protein were content102~147g/kg, the starch were content641.4~725.3g/kg, the ash were content21.4~36.8g/kg and the fiber were content21.8~38.9g/kg. The highest fat content was9103-6-3-1-4(52.8g/kg), Significantly higher thanwheat flour(17.0g/kg), rice flour(4.0g/kg) and buckwheat flour(22.0g/kg), the highest starchcontent was jin cheng shu1(725.3g/kg), higher than corn flour(611.7g/kg).(2) The ideal condition of proso millet starch preparation by water soaking method was:soak temperature40℃, soak time28h and1:9ratio of material to solvent, and the starchextraction rate can reach63.67%. The ideal condition of proso millet starch preparation byalkali soaking method was: Sodium hydroxide mass fraction was0.3%, soak temperature35℃,soak time28h and1:7ratio of material to solvent, and the starch extraction rate can reach75.53%. Compared with the alkali soaking method starch was extracted by water soakingmethod content higher protein, starch purity was lower, whiteness was worse. Compire withwater soaking method, starch was extracted by alkali soaking method has higher peakviscosity, breakdown and setback, but pastingtemp was lower. (3) The particle morphology and particle diameter of proso millet starch were similar tomillet starch, the microcrystalline structure was similar to glutinous rice, corn and buckwheatstarch. The transparency, freeze-thaw stability, viscosity and ageing resistance of waxy prosomillet starch were better than japonica proso millet. But the gel texture properties was betterthan waxy proso millet starch. The transparency, freeze-thaw stability, retrogradation,viscosity and ageing resistance of japonica proso millet starch were similar to millet starch.(4) Adding to sucrose, sodium carbonate and alum, the freez-thaw stability andretrogradation of proso millet starch paste were improved. But alum had significant effect onfreez-thaw stability and retrogradation of proso millet starch paste. Compared with control,adding to alum, the freez-thaw stability and retrogradation of proso millet starch paste wereincreased40.7%and78.8%. Sucrose can improve viscosity but weaken gelation andanti-aging ability of starch paste. Sodium carbonate and alum can improve gelation andanti-aging ability of proso millet starch paste. The results provide a theoretical foundation forthe proso millet starch paste's properties and it further application in frozen products.