Search results

The aim of this research is the evaluation of the profile of peptides isolated from skim milk hydrolysates.

Five hydrolysates were prepared using a protease from Aspergillus Oryzae (AO) separately or in combination with papain (PA) in different reaction times. The hydrolysates were fractionated by size‐exclusion HPLC and the rapid method of correct fraction area (CFA) was used for quantifying the peptides and free amino acids in the chromatographic fractions. The nutritional quality of hydrolysates is directly related to their di‐ and tripeptide contents, several reports show that the amino acid provided by these peptides are more quickly and completely absorbed than those from intact protein.

The results showed a nutritional similarity of the isolated action of AO and its combinations with PA, considering the peptide patterns produced, giving rise to 16 percent of di‐ and tripetides. Increasing the reaction time of the two enzymes led to poorer peptide profiles, while no change was achieved when the reaction time of only one enzyme (AO) in the combination was enlarged. Other hydrolytic conditions could be tested in order to improve the peptide profile of skim milk hydrolysates.

The application of this study relates to the possibility of using these hydrolysates for preparing high nutritional formulation for dietetic purposes. The use of a technique allowing the fractionation of peptides according to their size as well as the use of the skim milk as protein source, instead of casein, which is very expensive in the developing countries, represents a novel approach.

Provides an evaluation of the profile of peptides isolated from skim milk hydrolysates.

The purpose of this study was to evaluate the antioxidant and hypocholesterolemic activities of sardine and bogue protein hydrolysates in cholesterol-fed rats.

In total, 18 male Wistar rats (220 ± 10 g) fed 20 per cent casein, 1 per cent cholesterol and 0.5 per cent cholic acid were divided into three groups and received a daily gavage of 250 mg of sardine (SPH) or bogue (BPH) protein hydrolysates for 30 days. The third group, named control group (CG), received in the same conditions water. Lipoproteins were fractionated by size-exclusion fast protein liquid chromatography, and serum lipids, apolipoproteins and lipoproteins were assayed.

In SPH and BPH groups, serum total cholesterol concentrations were −66 per cent lower than in CG. This corresponded to the decreased very low-density lipoprotein-C in the former groups. Moreover, BPH treatment reduced low-density lipoprotein-C compared with CG and SPH groups. Compared with CG, serum phospholipids were reduced by SPH and BPH. Furthermore, BPH increased significantly APOA4 and sphingomyelin but lowered phosphatidylcholine. In the latter group, serum lecithin cholesterol acyltransferase activity was +23 per cent higher, but with SPH, this activity was −35 per cent reduced compared with CG. Apolipoprotein A-I contents were similar in the three groups. Compared with CG, hydroperoxide and lipid peroxidation contents in serum and lipoprotein fractions were reduced by SPH and BPH. Compared with CG, serum superoxide dismutase and glutathione peroxidase activities were increased in the treated groups, particularly in the BPH group.

These results suggest that sardine protein hydrolysates and particularly those of bogue could be a very useful natural compound to prevent hypercholesterolemia by both improving the lipid profile and modulating oxidative stress in cholesterol-fed rats.

This study aims to evaluate the effect of probiotic provitamin A cassava hydrolysate with Lactobacillus rhamnosus GG (hLGG) on weight and lipid profile of Wistar rats and its glycemic index using Wistar rats and human subjects.

Adult male Wistar rats (n = 40, 120–150 g) were orally administered provitamin A cassava hydrolysate with 1 × 10¹⁰, 2 × 10¹⁰ and 4 × 10¹⁰ CFU/g encapsulated or CFU/mL free Lactobacillus rhamnosus GG for 30 days, during which weight and lipid profile of rats were monitored. Blood glucose levels of rats and human subjects were also measured in Oral Glucose Tolerance Test to determine the Glycemic indices of hLGG.

Rats administered the highest doses of free or encapsulated hLGG [(4 × 10¹⁰ CFU) (PHE4 and PHF4, respectively)] had the lowest (18.2 ± 0.7 and 8.0 ± 0.6%, respectively, p < 0.001) percentage body weight gain compared to control (40 ± 0.6%). Lowest cholesterol and triglyceride (42.4 ± 0.5 and 44.4 ± 0.7 g/dL, p < 0.001, respectively) were observed in rats administered PHE4, with the lowest plasma glucose concentrations in PHE4 and PHF4 groups (43 ± 1 and 49 ± 0.7 g/dL, p < 0.001, respectively). Oral Glucose Tolerance Test for rats and human subjects showed lower peak blood glucose levels and glycemic indices in hLGG groups compared to controls in a dose-dependent manner.

Consumption of soft drinks, which supply non-nutritive energy, may lead to degenerative metabolic disorders such as obesity and diabetes. Beverages with probiotics such as Lactobacillus rhamnosus GG, on the other hand, offer a positive weight management approach. Development of non-dairy beverages such as provitamin A cassava hLGG is ongoing. Provitamin A cassava hLGG showed its ability to control weight gain, blood glucose levels and serum lipids. Thus, the beverage can be consumed as a healthy alternative to soft drinks and for weight management.

The purpose of this study was to determine the effects of chickpea (Cicer arietinum) protein hydrolysates prepared at two degrees of hydrolysis (DH) on lipoprotein profile and on oxidant status in cholesterol-fed rats.

Eighteen male Wistar rats (220 ± 10 g) were divided into three groups and fed for 30 days a diet containing 20 per cent casein supplemented with 1 per cent cholesterol and 0.5 per cent cholic acid. During the experimentation, the first and the second groups received daily by gavage 250 mg of chickpea protein hydrolysates/rat at DH = 8 per cent (CPH8) and DH = 17 per cent (CPH17), respectively. The third group, named control group (CG), received water under the same conditions.

Serum total cholesterol concentrations were reduced in CPH8 (p < 0.0073) and CPH17 (p < 0.0004) groups versus CG. This reduction corresponded to a lower very-low-density lipoprotein (VLDL)-cholesterol (p < 0,0019). CPH17 reduced low-density lipoprotein- and high-density lipoprotein (HDL)-cholesterol (p < 0.0001) but increased apolipoprotein A4 (p < 0.002) concentrations and lecithin-cholesterol acyltransferase activity (p < 0.0001). APOA1 remained unchanged in the treated groups. Liver total and esterified cholesterol contents were twofold lower in both treated groups versus CG. CPH8 increased triacylglycerols and phospholipids (p < 0.0001) contents, while CPH17 decreased those of unesterified cholesterol (p < 0.0016). Compared with CG, CPH8 and CPH17 reduced serum (p < 0.0001) and lipoprotein hydroperoxides by stimulating paraoxonase activity (p < 0.0001). However, only CPH17 treatment reduced serum, VLDL- and HDL-malondialdehyde contents and improved glutathione peroxidase activity (p < 0.061).

Thus, chickpea protein hydrolysates and especially hydrolysed at DH = 17 per cent may have a great potential for use as a nutraceutical to reduce hypercholesterolaemia and, by consequence, oxidative stress. Therefore, the degree of enzymatic hydrolysis has a significant influence on the production of potent bioactive peptides.

This paper aims to investigate the in vivo hypocholesterolemic property of fenugreek proteins (FP), Purafect-fenugreek protein hydrolysate (PFPH) and Esperase-fenugreek protein hydrolysate (EFPH) on high cholesterol (HC)-fed rats.

Rats were randomized into five groups: four were fed for four weeks a hypercholesterolemic diet and the tested products were given by gavage. The fifth group was taken as control (C) receiving the same diet without cholesterol.

Results showed that the elevated aspartate aminotransferase activity in HC group plasma was significantly corrected by FP and EFPH administration (−33 per cent; p = 0.0003). HC liver lipids and total cholesterol (TC) contents were not markedly affected by FP and EFPH. However, liver triglycerides (TG) contents trended to decrease in FP rats vs HC (p = 0.07), while, the TG decrease was significant in groups fed the proteins hydrolysates (p = 0.02). On the other hand, serum TC and TG decreased by 53 per cent (p = 0.0003) and 20 per cent (p = 0.04), respectively, in FP treated rats compared to HC group. This decrease was associated with a high fecal cholesterol excretion (2.5-fold higher in FP vs HC; p = 0.0001). Likewise, EFPH-treated rats exhibited lower TC compared to HC rats (p = 0.004). The very low density lipoprotins was the main affected fraction in these two groups, while there were no significant difference in apolipoproteins (Apo) B, A-I and A-IV contents between the different groups, except in FP group, where Apo A-I and A-IV decreased by 26 and 17 per cent, respectively, compared to C rats (p = 0.02). The high density lipoproteins (HDL) of rats treated with proteins hydrolysates showed a better antioxidant property compared to those of HC rats, which was accompanied with an increase in paraoxonase activity when compared to HC group.

Unlike PFPH which had almost no effect, FPs and EFPH could constitute a nutraceutical ingredient in cardiovascular disease management.

The purpose of the present study was to investigate the effect of camel milk protein hydrolysates (CMPHs) on physico-chemical, sensory, colour profile and textural quality attributes of chevon patties.

Camel milk proteins were hydrolyzed with three different proteolytic enzymes, viz., alcalase (CMPH-A), α-chymotrypsin (CMPH-C) and papain (CMPH-P), and dried to powder form before further utilization. Four treatments were prepared with incorporation of CMPH, viz., CMPH 0 per cent (C), CMPH-A 0.09 per cent (T₁), CMPH-C 0.06 per cent (T₂) and CMPH-P 0.09 per cent (T₃), in the product formulation. The developed goat meat patties were evaluated for physico-chemical (pH; emulsion stability, ES; cooking yield, CY; water activity, a_w), instrumental colour and texture profile and sensory attributes.

The pH, moisture, fat and ES values of goat meat emulsions were comparable amongst treatments as well as with the control; however, treated emulsions had higher ES and moisture content. The pH and moisture per cent of cooked chevon patties varied significantly, whereas other physico-chemical (CY, a_w, per cent protein, per cent fat, per cent ash and per cent dietary fibre) as well as dimensional parameters (per cent gain in height and decrease in diameter) were comparable amongst treatments and the control. Hardness, springiness, stringiness, cohesiveness, gumminess and resilience of chevon patties decreased significantly (p < 0.05) with the incorporation of CMPH than that of the control; however, the values were comparable among all the treated products. Protein hydrolysate in chevon patties resulted in significant increase in redness (a*) values, whereas all other parameters (L*, b* and hue) decreased significantly as compared to that of the control. The colour and appearance, texture, juiciness overall acceptability scores were comparable in all the treated products and were significantly (p < 0.05) higher than the control. The flavour scores of C, T₁ and T₃ were comparable but significantly lower than that of T₂. The overall acceptability scores of T₁ and T₂ were also comparable and significantly higher than C and T₃; however, the highest score was recorded for T₂.

Results concluded that chevon patties with acceptable sensory attributes and improved CY and textural attributes can be successfully developed with the incorporation of CMPH.

The protein hydrolysates of different food proteins could be explored in a same pattern to find out their implication in food matrices.

This study aims to investigate the influence of soy protein isolate hydrolysates (SPIH) obtained using 4 h hydrolysis under 200 MPa on proximate composition, cooking loss, textural properties, color, water distribution, microstructure, thiobarbituric acid reactive substance (TBARS) value and carbonyl and sulfhydryl contents of emulsion sausages.

Sausages with SPIHs at four concentrations (0, 1.0, 2.0 and 3.0%) were prepared, and the sausage with 0.01% butylated hydroxyanisole (BHA) was used as a positive control. Some sausages were selected for the analyses of quality characteristics and microcosmic properties. Other sausages were stored under 4 °C for 0, 7, 14, 21 and 28 days to investigate the oxidative stability.

The addition of SPIHs at various levels (0–3.0%) or 0.01% BHA did not affect the proximate composition (protein, fat and ash) of emulsion sausages. The addition of 2.0% SPIH decreased cooking loss and increased moisture content, hardness, springiness, chewiness, resilience and L* value, compared to the sausages without SPIH and with 0.01% BHA (p < 0.05). Furthermore, low-field nuclear magnetic resonance results suggested that sausages with 2.0% SPIH had the shortest T2 relaxation time. In addition, 2.0% SPIH and 0.01% BHA could inhibit the oxidation of emulsion sausages when compared with the sample without SPIH (p < 0.05). Moreover, there were no differences between sausages with 2.0% SPIH and 0.01% BHA (p > 0.05).

These findings confirmed that the 2.0% SPIH obtained under 200 MPa can be used as a natural additive to improve quality properties and antioxidant potential of emulsion sausages during storage.

This paper aims at testing several conditions using activated carbon for removing phenylalanine (Phe) from protein hydrolysates, in order to prepare dietary supplements for phenylketonurics, based on skim milk.

Six hydrolysates from skim milk were prepared, using a protease from Aspergillus oryzae (AO), isolated or in association with papain (PA). Some parameters were tested for removing Phe, such as amount of activated carbon, temperature and stirring time. The second derivative spectrophotometry was used to evaluate the efficiency of Phe removal.

The best condition for removing Phe was achieved using an activated carbon: casein ratio of 118 (in g), a stirring time of 30 min, at a temperature of 25°C, which produced 96 to 99 per cent of Phe removal. Among the hydrolytic conditions employed, the association of AO and PA (1 hour, 1 per cent and 4 hours, 2 per cent, respectively) led to the lowest absolute value for the final Phe concentration (0.060 × 10⁻⁴ mg/100 mg of protein).

Since we know, there is no formula for PKU on the market based on skim milk hydrolysed proteins. Isolated casein, the main milk protein, is the choice in most cases. This is a factor that may be taken in consideration especially in developing countries, where milk proteins are imported and, consequently, are much more expensive than skim milk.

This study aims to investigate the antihypertensive effect of camel milk hydrolysate in rats with fructose-induced hypertension.

The antihypertensive effect of fermented camel milk was determined using 6 groups comprising 36 Wistar male rats. Blood pressure of rats was altered via exposure to a 10% fructose (w/v) diet in drinking water for 3 weeks before conducting 21 days of treatment. The authors conducted the experiment for short and long term using different doses of 800 and 1,200 mg/kg body weight. Serum was used to assay total cholesterol (TC), triglyceride (TG), glucose and insulin levels using standard biochemical kits.

The group that received 1,200 mg hydrolysate camel milk (HM) has significantly (p = 0.003) reduced systolic and diastolic blood pressure after a short exposure time (4–8 h). These effects were significantly (p = 0.005) comparable to the nifedipine (NIF) drug group. Similar long-term (21 days) effects on blood pressure were observed in 1,200 mg HM and NIF groups. Angiotensin-converting enzyme (ACE) activity and levels were also reduced in a correlation with blood pressure reduction only in HM1200 and HM800 treated groups. The authors observed no significant effect on blood pressure in groups receiving the 800 mg HM or 1,200 mg unhydrolyzed camel milk (UM). Rats receiving the 10% fructose diet showed significant differences from control rats regarding their blood biochemistry, including TG, TC, blood glucose and insulin levels. Rats in groups NIF, HM1200 and HM800 showed a significant (p < 0.05) reduction in serum glucose, insulin, TG and TC levels toward the baseline level.

Further mechanistic investigation on the HM antihypertensive activity is highly recommended before suggesting HM as a product to reduce blood pressure. While drug–food interaction between HM and antihypertensive drugs, especially ACE inhibitors, is probable, UM seems not to affect blood pressure or ACE activity and therefore is expected to have no or minimal effects on the activity of other antihypertensive drugs. Investigation of ACE expression from various organs including lungs and leukocytes is highly recommended in future works using sodium dodecyl-sulfate polyacrylamide gel electrophoresis and western blot analysis or reverse transcription polymerase chain reaction.

No previous studies have measured the antihypertensive activity of milk hydrolysate mediated by the reduction of ACE activity and levels in plasma. Mechanisms involved in attenuating the levels of ACE warrant further investigation.

This paper aims to evaluate the effect of depolymerised glucomannan in regulating blood lipid and glucose concentrations.

Twenty adult volunteers were recruited. Blood samples were taken at Day 0. The volunteers consumed drinks containing 3.0 g active glucomannan hydrolysates (AMH) for 14 days, after which time blood samples were retaken (Day 15). Blood samples were analysed to determine the blood lipid and glucose concentrations.

The average fasting blood glucose at the start of the trial was 2.54 mmol/L but reduced slightly to 2.49 mmol/L after consumption of the glucomannan. The total average cholesterol at the start of the trial was higher (6.69 mmol/L) than desirable ( < 5.0 mmol/L). This was reduced after consuming the glucomannan to 6.44 mmol/L (3.74 per cent). The triglyceride content was also higher initially than recommended (2.88 mmol/L) but was reduced by 11.5 per cent. The high-density lipoprotein (HDL) was within the desirable range before and after consumption (1.57 and 1.52 mmol/L, respectively), while the average low-density lipoprotein (LDL) was higher than recommended ( < 3.0 mmol/L), representing 4.55 mmol/L and 4.40 mmol/L before and after consumption, respectively. Both parameters were reduced by over 3.0 per cent. The consumption of the glucomannan hydrolysates also reduced the total cholesterol/HDL and LDL/HDL ratios.

The AMH was effective in lowering blood cholesterol and glucose concentrations. Consumption of such carbohydrates could prove useful for these physiological disorders. Further studies are desirable to characterise the exact mechanism.