Study On Rapid Determination Of Main Nutrition Compositions And Hypotensive Effect Of Foxtail Millet

The main objectives of this study were(1)to explore the feasibility of using near infrared nondestructive determination to establish the main nutrition contents of foxtail millet;(2)to evaluate the potential angiotensin I-converting enzyme(ACE)inhibitory activity in vitro and antihypertensive effect in vivo of different foxtail millet protein hydrolysates and to illuminate the possible mechanisms involved;(3)to investigate the antihypertensive effect of foxtail millet diet on boold pressure and the impact on the dysbiosis of intestinal flora in hypertensive patients.The rapid determination models was established with full spectrum and effective wavelengths.The results showed that NIR can be used to determine the content of protein,amino acids and other components in foxtail millet accurately and rapidly.Compared with the full-wavelength models and the models established with the effective wavelengths selected by the Jack-knife(JK)and interval partial least squares(iPLS)algorithms,the models established using the successive projection algorithm(SPA)algorithm included less wavelengths and have higher Ratio performance deviation(RPD)values.It suggested that the models established by the SPA algorithm have a better predictive ability.The digestibility of foxtail millet protein in different treatments(extruded,Rhizopus oryzae and Lactobacillus plantarum fermentation)and the ACE inhibitory and antioxidant activity of hydrolyzed peptides with various treatments and proteases(pepsin+panceatin and alkaline protease)were analyzed.The results showed that the extruded samples had a higher protein digestibility.Low molecule peptides(<2 kDa)were the main constituents of the ACE inhibitory peptides.The peptides hydrolyzed by pepsin+panceatin have higher ACE inhibitory activity and antioxidant activity;and the hydrolysates treated by extrusion and Rhizopus oryzae possesed higher ACE inhibitory activity.It indicated that pepsin+panceatin hydrolysis,extrusion and Rhizopus oryzae fermentation can increase the ACE inhibitory peptide activity of foxtail millet.Three different foxtail millet protein hydrolysates(RPH,EPH and FRPH)were given by gavage to the spontaneously hypertensive rats(SHR)and the blood pressure and related blood indicators such as ACE activity were determined.The results showed that compared with FRPH,consumption of RPH and EPH can be more effective in reducing blood pressure,and the ACE activity was lower in the three treated groups.The administration of EPH can also up-regulate the T-AOC.It has been shown that using antioxidant peptides was also a pathway to improve hypertension.It indicated that extrusion can be used to improve the antihypertensive and anti-oxidative potency of foxtail millet hydrolysates.And to inhibite the ACE activity may be one mechanism of foxtail millet hydrolysates reduce blood pressure.Prehypertensive and mild hypertensive patients were recruited and intervented with foxtail millet staple foods for 12 weeks,and their blood pressure,RAAS indicators,blood lipids,blood glucose and other indicators were determined.The results showed that the SBP and DBP of the subjects were significantly decreased and the RAAS index did not change significantly,which indicated that the millet could decrease the blood pressure significantly,but the other antihypertensive mechanism may not be closely related to the RAAS.The lipid-related Indicators had no significant change,while the blood glucose level,BMI and body fat rate had a significant improvement.We analyzed the gut microbiota of prehypertensive and mild hypertensive subjects who were treated by foxtail millet staple foods.The results showed that the relative abundance of their gut microbiota significantly increased after intervention.The relative abundance of butyrate producing bacteria increased significantly.In adddition,SBP and DBP were negatively correlated with butyrate producing bacteria and acetate producing bacteria,and Akkermansia was negatively correlated with ACE levels.The results suggested that foxtail millet could regulate the blood pressure through the restore of the balance of intestinal flora in hypertensive patients.