Study On The Grain Qualities And Oil, Polyphenols Properties Among Oat Varieties

Oats is known for its highly nutritious content and oodles of health benefits, it is now attractingmore attention from some nutrition scholars and the general public. It is well-known that China is veryrich in oat germplasm resources, and the amounts of nutritional compounds in different oat varieties aresignificantly different. The quantity and functional properties of oil and polyphenols in different oatvarieties were investigated in this study, so as to provide theoretical basis for screening superior oatvarieties and processing oat products.In this study,50naked oat samples were collected from the main producing areas of domestic oatand national clonal germplasm repository. The main nutritional indexs of oat were determined. Theextraction process of oat oil and polyphenols were optimized. Meanwhile, the composition of oat oiland polyphenols in different oat samples were analysed. According to the composition of fatty acids,different oat oil samples were selected to detect their effects in human skin moisture retention. And theantioxidant capacities of4oat polyphenols samples which selected by their polyphenols contents wereinvestigated.The nutritional indexs of collected oat samples show that there exist significant distinctions innutritional indexs of different oat varieties and sources, especially the coefficient of variation of crudefat content, β-glucan content and crude protein content are very large. There are correlations among oatnutritional indexs: crude protein content is significant positively correlated with β-glucan content(p<0.01), while they both have significantly negative correlation with total starch content (p<0.01).According to the nutritional indexs, oat samples can be classified into4groups, the cluster results hadbeen affected by environment more than varities.The extraction conditions of oat oil with supercritical CO2are as follows: pressure35MPa,temperature55℃and extraction time4h. Under this condition, about98%oil in oat flour can beextracted.The unsaturated fatty acids in oat oil are about78%, including oleic acid and linoleic acid as themain components. The range of oleic acid content in different oat samples is from30.43%to43.68%,and linoleic acid ranges from31.98%to44.58%. The fatty acids composition of oat oil variessignificantly with oat varieties and sources, linolenic acid and stearic acid have the largest coefficient ofvariation.The extraction of oat polyphenols with ethanol-water solution assayed by microwave was studied byrotatable orthogonal central composite design. The optimum parameters are: microwave power1000W,time125s, liquid-solid ratio45mL/g, ethanol concentration50%. Under this condition, the yield of oatpolyphenols is about107mg/100g. Compared with traditional method of hot water extraction,microwave assisted extraction method improves the polyphenols yield more than55%, and shortenextraction time by60times.The total polyphenols contents in different oat samples are from101.66mg/100g to151.89mg/100g. Avenanthramides (Bc, Bp and Bf) are the main component of the oat polyphenols, whose contentchanges from1.17mg/100g to71.85mg/100g, and the coefficient of variation is up to84.16%.Human skin moisturizing experiment shows that oat oil has favorable moisturizing effect onhuman skin. Ding You1(Gansu) and Bai Yan1(Shanxi) have the effect of both replenishment andlock water, the relatively high content of oleic acid maybe the decided factor.The oxidation experiment in vitro demonstrated that oat polyphenols have excellent antioxidantcapacity to scavenge DPPH, ABTS+and OH. Bai Yan10(Ningxia) has the outstanding overallantioxidant capacity in the4selected oat samples.