Study On Hypoglycemic,hypolipidemic,hypotensive Activities And Physicochemical Property Of Germinated Highland Barley

Highland barley is a kind of food crop which is rich in a variety of biological active ingredients and can be used as food and medicine.Germination is a relatively fast,simple,safe and effective method of modification of food raw materials,which can significantly improve the content of active substances suc h as?-aminobutyric acid(GABA)and processing performance in highland barley,but usually leads to the degradation of functional components such as?-glucan in highland barley.In this paper,the effect of germination on the nutrient composition and endosperm degrading enzyme of highland barley and the hypoglycemic,hypolipidemic and antihypertensive activities of germinated highland barley were studied.The effect of three stress germination methods on the content of?-glucan and GABA in highland barley were studied.Single factor experiments were carried out to determine the germination process parameters which were beneficial to increase the content of GABA and retain?-glucan of highland barley under low oxygen stress.On this base,the effect of germination on the structure characteristics and cooking properties of highland barley were discussed,providing theoretical support for the subsequent product development and application of highland barley.Firstly,the changes of nutrients and endosperm degrad ing enzymes during germination of highland barley were studied.The results showed that with the extension of germination time(0 h?96 h)of highland barley,the content of?-glucan,starch and protein decreased gradually,and the content of 17 kinds of free amino acids,total polyphenol and total flavonoid increased gradually in highland barley.The content of GABA increased gradually at 0 h?48 h of germination and then decreased gradually with the extension of germination time(48 h?96 h)of highland barley.The activity of?-glucanase,?-amylase,?-amylase and protease increased gradually,while the activity of glutamic acid decarboxylase(GAD)increased gradually at 0 h?48 h of germination and then decreased gradually with the extension of germination time(48 h?96 h)of highland barley.Maximum germination time was 48 h.considering the excessive loss of nutrients in highland barley.At this time,the content of?-glucan in highland barley was 4.46%,degrading 11.68%compared to raw materials,and the content of GABA was 33.18 mg/100g,which was 3.47 times of the raw material.Secondly,tape 2 diabetic mellitus(T2DM)were given high fat diet with 10%highland barley and 5%,10%,20%germinated highla nd barley respectively to study the activities of highland barley and germinal highland barley in lowering blood glucose and blood lipid.Normal rats and spontaneously hypertensive rats(SHR)were given maintenance diets supplemented with 10%highland barley and 5%,10%,20%germinated highland barley to study the activity of highland barley and germinated highland barley in lowering blood pressure.The results showed that germinated highland barley at certain dose can significantly reduce the fasting plasma glucose,insulin level and insulin sensitive index,serum total cholesterol and low-density lipoprotein levels and the content of apolipoprotein B,improve the content of apolipoprotein A?and the activity of lecithin cholesterol acyltransferase(p<0.05),to alleviate the glucose and lipid metabolism disorder in T2DM.High dose of germinated highland barley can significantly reduce blood pressure,the content of serum angiotensin?,angiogenin 2 of SHR(p<0.05),and can significantly improve the content of bradykinin,prostacyclin,nitric oxide,and endothelium-derived hyperpolarizing factor(p<0.05),to alleviate hypertension symptoms of SHR.Next,the changes of the content of?-glucan,GABA,total polyphenol and total flavonoid in highland barley under three kinds stress germination methods(salt,low temperature,low oxygen)were studied.The degradation of?-glucan in highland barley could be inhibited by 40 mg/L,80 mg/L,160 mg/L C u²⁺and 4 mg/L sodium selenite solution but these methods were not conducive to the enrichment of GABA,total polyphenol and total flavonoid.The content of?-glucan in highland barley under low temperature stress germination(-20°C,5°C)was higher than that in the control group(15°C),but the enrichment effect of GABA was not good under low temperature stress germination.The degradation of?-glucan in highland barley could be reduced by three kinds of hypoxia stress germination.The content of GABA,total polyphenols and total flavonoids in highland barley was improved by germination followed by vacuum.Vacuum followed by germination and germination followed by water immersion were not effective for the enrichment of GABA,total polyphenol and total flavonoid.Furthermore,the optimal treatment parameters determined by single factor experiment were as follows:soaking for 10 h,germinating for 24h,storing at 25°C and-0.07 MPa for 24 h.Under this condition,the contents of GABA,total polyphenols and total flavonoids in highland barley were 80.47 mg/100g,317.92 mg/100 g and 298.77 mg/100g,respectively,which were 8.41 times,1.27 times and 1.57 times of the raw materials,and 1.82 times,1.02 times and 1.08 times of the control group.Furthermore,the content of?-glucan was 4.41%,which was 1.05 times of the control group,and 12.68%was degraded compared with the raw material.Finally,the changes of cooking properties and physicochemical properties of highland barley rice before and after germination were studied.The results showed that the surface of highland barley rice appeared cracks,the water absorption rate increased significantly during cooking,the best cooking time shortened 5 min,and the hardness decreased from 5003.43 g to 3272.82 g.After germination,the gelatinization enthalpy of highland barley rice decreased from 5.27 J/g to 3.31 J/g,the gelatinization temperature increased significantly(p<0.05),the gelatinization viscosity decreased significantly(p<0.05),and the regenerative value decreased from 2457 c P to 1393 c P.In addition,the starch crystal structure was destroyed and the relative crystal inity decreased from 10.02%to 5.17%.The results showed that germinated highland barley can be used as the potential of functional food for the prevention and treatment of T2DM and diseases associated with insulin resistance,hyperlipidemia,hypertension and other cardiovascular diseases.The content of GABA,total was significantly increased and the degradation of?-glucan was decreased under hypoxia stress,and the cooking quality of highland barley was improved.