The Preparation of RNA Hydrolysates from Okara and Research of Immune Activity
|School||Northeast Agricultural University|
|Course||Of Food Science|
|Keywords||Okara RNA enzymatic hydrolysis immune function|
RNA is an important component in the intracellular, studies have shown that RNA and ribonucleotide have asignificant impact on the normal function of the immune system, growth and development of intestinal, liver tissueand lipid metabolism. The resources of nucleic acid in China is relatively single and it mainly use waste beer yeast asraw materials to extract., but it cannot meet the needs of market because of difficulty in obtaining raw materials andlow extraction yield of RNA. Nucleic acid exists in the form of nucleoprotein of okara that have content as much asyeast nucleic acid, moreover,okara is a natural high quality resources of nucleic acids because of its low prices andabandont resources. But there have not found the research about okara RNA extraction and related function. So in thispaper,using okara as raw material, optimized process of RNA extraction,RNA purification and RNA enzymatichydrolysis, in addition, it evaluate the effects of cellular immunity, humoral immunity and nonspecific immunityfunction on okara RNA and RNA hydrolysates, and compare the differences between the both immunomodulatoryeffects. The main Results as follows:(1) Based on the single factor test and response surface analysis, optimized RNA extraction of okara,the resultsshowed that:extraction temperature of92℃, extracting time for70min, liquid material ratio is10:1, extract pH5.4.On this condition, RNAextraction rate was0.215%.(2) To compare three different RNA precipitating agent,for example, ethanol-NaCl, isopropanol-NaCl and LiClin the purification of total RNA, and the results show that the effect of isopropanol-NaCl precipitating agentpurification effect is best, final RNAyield is0.48%, and OD260/OD280is1.83.(2) Nucleotide content and conversion as the main indexes to research the influence of the enzymatic processmain factors: the enzyme concentration, substrate concentration, pH value, enzyme solution temperature and enzymesolution time. Through the orthogonal test, to determine the optimal enzymatic hydrolysis conditions: enzymeconcentration10%, the temperature is65℃, the pH value of4.5, time1h, substrate concentration was2%, andfinally get nucleotide content is2.2mg/mL, conversion rate reached62.52%.(3)In this research,The okara RNA and RNA hydrolysates immunoregulatory role was evaluated and comparedthat based on immunodulatory functional food evalution. The results showed that compared with the control group,the RNA group and hydrolysates groups significantly increased spleen index, hydrolysates of high-dose group spleenindex was significantly higher than the other dose groups; RNA group and hydrolysates groups of the thymus indexalso increased, but compared with the control group, no significant difference (P＞0.05). In cell-mediated immunity,compared with the control group, the RNA group and hydrolysates group could significantly improve the ability oflymphocyte proliferation, hydrolysates of high-dose group compared with the control group, the difference was highly significant (P＜0.01), compared with the RNA, the difference was significantly (P＜0.05); delayed hypersensitivitytest, the DTH reaction RNAand hydrolysates of each dose group with the control group no significant difference (P＞0.05). In humoral immunity, compared with the control group, RNA and hydrolysates of each dose group couldimprove mouse antibody producing cells, RNA showed no significant difference compare with control group, thehydrolysates group compare with control group showed significant difference (P＜0.05), the hydrolysates of the highdose group was highly significant difference (P＜0.01); in serum hemolysis test, compared with the control group, thegroup of RNA and hydrolysates groups showd a significant increase in the level of serum hemolysin (P＜0.05), thehigh dose group of hydrolysates highly significant difference (P＜0.05); compared with RNA, hydrolysates was nosignificant difference (P＞0.05); in the non-specific immune,compared to the control group,RNA and hydrolysatesgroups were not significantly enhance macrophage carbon clearance index. The above test results show that the RNAand hydrolysates can improve the mice’s immune function by promoting the cellular and humoral immune, andhydrolysates immune function superior to RNA.