Different Maturity Quality Research Of High Oleic Peanut

Peanut is the important oil crop in China, and oil content is about 50% in kernel.Fatty acid composition is an important factor of nutrition and storage quality in peanut and there are 80% oleic acid and linoleic acid in kernel. Oleic acid with a less number of unsaturated olefinic bond than linoleic acid, is more stable to oxygen, high temperature and other environmental factors, so benifits coming from oleic acid depend on content of oleic acid in peanut. Oleic acid when more than 72% is affirmed as high oleic oil peanut with high temperature stability and good storability.High oleic peanut is quite valuable basing on health function coming from unsaturated olefinic bond and a long shelf-life of the product. Because oleic acid is mainly accumulated in the last month before harvest,classification methods and quality of different maturity are necessary in high oleic oil peanut.L61 high oleic peanut varieties (Fuxin) is selected as experimental peanut grading method on maturation for improvement farther more, and changes of nutritional quality, sensory properties and resistance to Aspergillus flavus of high oleic peanut also studied with different maturity. The results are as follows:1 The research on maturity classification of high oleic peanut: high oleic peanut is divided into 10 maturity levels with the traditional methods in order to see the embryos' apparent characteristics of high oleic peanut with different maturity levels.We find out that the size of the embryo increase gradually at first with the increase of maturity, but the change is not that significant after maturity 4. At the same time, the number of germ branches shows the similar pattern. The microstructure of the cotyledon sections shows that the dyed protein of peanut cotyledon cells gradually increase with the increase of maturity. Then we study the ultrastructure of the embryos through the electron microscope. We find something important. In maturity 1-2,amyloplasts have large volume and large quantity, and then in the maturity 3-5 amyloplasts have less volume but many starch grains, in maturity 6-7, amyloplasts disappear,starch grains decrease while liposome content increase,in maturity 8-9, the content of liposome is very high,and it is almost full of the whole cell. It is difficult to observe other structures. In maturity 10, there are some albuminous bodys with large cross sectional area. We also find that the ratio of oleic acid to linoleic acid was highly correlated with the maturity of high oleic acid peanut. The above can be used as a criterion for judging the maturity of high oleic peanut.2 Research on nutritional quality of high oleic peanut with different maturity:With the increase of maturity, the sugar content, free fatty acid and free amino acids of the high oleic acid peanut decrease gradually; while the content of fat, protein and amino acids increase gradually with the increase of maturity. And they are all changing fast in the beginning and slow in the end, which shows that the accumulation of nutrients is relatively fast in the early stage of maturity, but slow in the late. The above rules were similar to those in the control group with normal oleic acid peanut, which indicated that the high oleic acid peanut had no change in the accumulation of nutrients and other nutritional characteristics.3 Research on sensory evaluation and grey relational analysis of high oleic peanut with different maturity: different maturity of high oleic peanut edible quality were identified by sensory evaluation method of high oleic peanut of different maturity grades, the sensory evaluation score with maturity upgrade increased gradually. The statistical analysis of data shows that the result is reliable. The grey correlation analysis shows that the edible quality improve with the increase of maturity, this also shows that there is a significant link between the classification of peanut maturity and the sensory characteristics of peanut as well as its edible quality.4 Research on Aspergillus flavus resistance of high oleic peanut with different maturity: application of apparent identification and HPLC method, found Aspergillus flavus resistance have increased with the maturity of the promotion, it also shows that the low maturity of peanut is more susceptible to Aspergillus flavus.In summary, we determine high oleic peanut maturity grading methods, it is helpful to accurate determination the maturity grades of high oleic peanut, so that peanut digging time can be forecast better, double decline in yield and quality can avoided more. For the research of different maturity of high oleic peanut's nutritional quality, accumulation trend of nutrients of high oleic peanut is found out. A better understanding of the effect of maturity of high oleic acid peanut on its nutritional quality comes out. Research on sensory evaluation and grey relational analysis of high oleic peanut with different maturity shows the influence of the maturity to the high oleic peanut's sensory traits and edible quality. The correlation between the maturity and the resistance to Aspergillus flavus also is identified. Important influence of maturity for the high oleic peanut is elaborated, it has an important guiding significance for the edible peanut industry.