Nitrogen Filling The Soybean Storage And Processing Quality Research

Soybean is a main grain and oil plant. Its quality can obviously influenced by thestorage method and storage period. Compared with conventional storage, the changes oftwo kinds of soybean quality for180days’ storage at different temperatures undercontrolled atmosphere storage with N2（CA storage, N2concentration is above98%） werestudied. Quality indicators were determined at regular time. The results show that:With the increasing of temperature and the extending of the storage time, thegermination percentage, catalase activity, water-soluble protein, nitrogen solubility index（NSI）, free sulfhydryl content of two groups have a decreasing trend gradually. After180days storage under35℃in conventional storage, the germination percentage of YanJinsoybean reduced to0, NSI of DongBei soybean had decreased from93.1%to37.5%,catalase activity of DongBei soybean had decreased from19.0mgH₂O₂/g to16.8mgH₂O₂/g;The fat acid value and disulfide bond contents increased gradually. After180days storageunder CA35℃and35℃, fat acid value of DongBei soybean had increased to13.5、20mg/100g respectively; Lipase activity increased at first and then reduced; The content ofcrude fat and crude protein which had no obvious change were respectively at about20%and42%. The quality deterioration of CA group was lessen than controlled group evidently.Correlation between storage temperature and quality indicators were greater than thatbetween storage conditions and quality indicators. The quality were greater influenced bystorage temperatures than by storage conditions.Extract crude fat of Dongbei soybean using Soxhlet. Colour, saponification value,iodine value and phosphatide content of crude fat were changed slowly by the influence ofstorage conditions、 temperatures and time. The saponification value is between190mgKOH/g and196mgKOH/g. And the iodine value is between126gI₂/100g and133gI₂/100g. Phosphatide content fluctuate from6.9%to7.7%. Peroxide value and acidvalue have a increasing trend gradually with the increasing of temperature and theextending of the storage time.After180days storage under CA35℃and35℃, peroxidevalue increased from0.82mmol/kg to1.93、2.95mmol/kg respectively. After180daysstorage under CA30℃and30℃, acid value increased from0.61mgKOH/g to1.12、1.28mgKOH/g respectively. CA storage could markedly restrain the increasing of peroxidevalue and acid value. Correlation between storage temperature and quality indicators weregreater than that between storage conditions and quality indicators. In the crude fat, linolic acid which has the highest content accounts for about55%inthe fatty acid composition. And oleic acid, palmitic acid, linoleic acid, stearic acid asfollowing. The unsaturated fatty acid accounts for above82%in the composition. After180days storage, the content of linolic acid and linoleic acid decreased. While palmitic acid,stearic acid and Oleic acid content increased accordingly. The content of trans-fatty acids isvery low and mainly is n-9trans-oleic acid. It had no obvious changes by the influence ofstorage temperature and time.