EFFECT OF CHRONIC ACE INHIBITIONONGLUCOSE TOLERANCE AND INSULIN SENSITIVITY IN HYPERTENSIVE TYPE 2 DIABETIC PATIENTS

We studied 14 moderately overweight Typo 2 diabetic patients with essential hypertension in stable metabolic control after a run-in period , and again after 3 months of antihypertensive treatment with the angiotensin-converting enzyme (ACF) inhibitor captopril. Glucose tolerance was tested with a 75g oral glucose load (OGTT) and insulin sensitivity was measured by the insulin suppression test (IST) while dietary and drug treatment of the hyperglycemia was maintained constant. In the whole group. mean blood pressure (MBP) fell progressively over 3months from a baseline value of 123± 3 mmHg (1 mmHg= 0. 133 kpa) to a final value of 115± 2 mmHg(P<0. 005). After treatment, fasting plasma glucose, insulin, free fatty acid (FFA). potassium, and glycosylated hemoglobin concentrations were unchanged from baseline. There were no significant differences in glucose tolerance and insulin sensitivity between pre- and post-trearment values. Neither endogenous (oral glucose) nor exogenous (IST) insulin caused any change in plasma potassium concentration. This resistance to the hypokalemic action of insulin was not affected by captopril.

Lima Bean(Phaseolus lunatus)Protein Hydrolysates with ACE-I Inhibitory Activity

Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE) inhibittory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed flours were hydrolyzed with Alcalase 2.4 L or pepsin-pancreatin sequential hydrolysis, and ACE inhibitory activity measured in the different hydrolysis treatments. Protein hydrolysate production was analyzed with a 23 factorial design with four replicates of the central treatment. Evaluated factors were protein concentrate source (ungerminated seeds, PC1;germinated seeds, PC2), enzyme/substrate ratio E/S (1/50 or 1/10) and hydrolysis time (0.5 or 2.0 h for Alcalase;1 or 3 h for pepsin-pancreatin). Degree of hydrolysis (DH) was high for the Alcalase hydrolysates (24.12% 58.94%), but the pepsin-pancreatin hydrolysates exhibited the highest ACE inhibitory activity (IC50 = 0.250 0.692 mg/mL). Under the tested conditions, the hydrolysates with the highest ACE inhibitory activity were produced with sequential pepsin-pancreatin using either PC1 at 1 h hydrolysis time and a 1/10 E/S ratio or PC2 at 1 h hydrolysis time and a 1/50 E/S ratio. Lima bean protein hydrolysates prepared with Alcalase or pepsin-pancreatin are a potential ingredient in the production of physiologically functional foods with antihypertensive activity.

Antioxidant and ACE inhibitory activities of peptides prepared from adzuki bean by semi-solid enzymatic hydrolysis

In this study,adzuki bean peptides were prepared by semi-solid enzymatic hydrolysis(SEH)and their antioxidant and Angiotensin-I-converting enzyme(ACE)inhibitory activities and internal absorption were studied.By modifying different enzymatic hydrolysis times and enzyme additions,the optimal enzymatic hydrolysis condition for SEH could be obtained as adzuki bean powder:water=4:1(w/w),alcalase:neutrase=2:1(w/w),enzyme addition 3.75%(w/w),4 h enzymatic hydrolysis at 50℃ and pH=8.Within these hydrolysis conditions,the content of adzuki bean peptides was 11.37%,the OH−scavenging rate of 1 mg/mL peptides was 72.75%,the total antioxidant capacity was 0.88±0.02 mmol/L FeSO4,the ACE inhibition rate was 77.49%.In vivo absorption test proved that the peptides prepared by SEH were absorbed faster and exhibited higher antioxidant activity compared with liquid enzymatic hydrolysis.In conclusion,the process of SEH can improve not only the efficiency of hydrolysis,but also the antioxidant and ACE inhibitory activity as well as the internal absorption of adzuki bean peptides.

Impact of common gastrointestinal disorders in elderly on in vitro meat protein digestibility and related properties

This study aimed to in vitro evaluate the impact of common gastrointestinal(GI)alterations appearing with aging on protein digestibility,and functional related properties,in four different meats(chicken,turkey,pork and beef).Thus,three elderly digestion models were stated as long as altered GI conditions affected at oral(E1),oral and gastric(E2)and oral,gastric and intestinal stages(E3).Healthy adult GI conditions were also mimicked as standard control model(C).A notable trichloroacetic acid(TCA)soluble protein and the free amino acids(FAA)release reduction(p<0.05)were found under intestinal suboptimal conditions(E3),being more accused in beef than in other meats.Thus,chicken intake would be more advisable,than other meats,in terms of protein digestibility;while beef would provide a greater net supply of FAA under E3 model conditions.Gastric altered conditions,seem to favor protein solubility.Finally,while gastric and intestinal suboptimal conditions diminish the angiotensin converting enzyme(ACE)inhibition of meat digesta,their antioxidant activity was only negatively affected by intestinal altered conditions.

Production of whey protein hydrolyzates and its incorporation into milk

Whey proteins provide an excellent source of low-molecular-weight bioactive peptides with important functional properties and bioactivities like antihypertensive,opioid,and antimicrobial effects.Presence of peptide molecules with lower molecular weight has a great role in food for health promotion.In this investigation,the release of low-molecular-weight peptides from whey protein concentrate was attempted by using enzymatic digestion.The hydrolyzate was then incorporated into milk to obtain enriched milk(EM)with low-molecular-weight peptides.Based on sensory analysis of EM,electrophoretic and RP-HPLC studies,hydrolyzates of 10%protein(degree of hydrolysis 5%;enzyme/substrate E/S,1:50)were finally incorporated into milk at 20%(v/v)to develop an acceptable product enriched with low-molecular-weight peptides.EM had higher protein content,viscosity and emulsifying properties than control milk with 3%fat.It is recommended that EM should not be sterilized as it results in coagulation,but can be safely pasteurized and spray dried without any undesirable effects.Maximum ACE-inhibition activity was obtained in hydrolyzate,followed by EM.This study is expected to boost the opportunity for the dairy industry to venture further into the nutraceutical dairy market.