Comparison of physicochemical properties, antioxidant and metal-chelating activities of protein hydrolysates fromPhaseolus lunatusand hard-to-cookPhaseolus vulgaris

Effects of processing technologies on the antioxidant properties of common bean (Phaseolus vulgaris L.) and lentil (Lens culinaris) proteins and their hydrolysates

The effects of ultrasound (280 W, 5 min), heat treatment (75 °C and 90 °C for 10 min) and microfluidization (125 MPa, 4 cycles) as pre or post treatments and their combination with enzymatic hydrolysis on the antioxidant properties of common bean and lentil protein hydrolysates were investigated. In general, hydrolysis resulted in increases of antioxidant activity, both in the presence and absence of processing technologies. The increases reached maximum values of 158% (ABTS), 105% (DPPH), 279% (FRAP) and 107% (TAC) for the bean protein hydrolysates submitted to post-treatment with ultrasound (ABTS, FRAP and TAC) and pre-treatment with microfluidization (DPPH), compared to their respective controls (untreated samples). For lentil proteins, the increases reached 197% (ABTS), 170% (DPPH), 690% (FRAP) and 213% (TAC) for samples submitted to ultrasound post-treatment (ABTS), microfluidization pre-treatment (DPPH) and post-treatment (FRAP), and 75 °C pre-treatment (TAC) compared to their respective controls. Surface hydrophobicity and molecular weight profile by SEC-HPLC analysis indicated modifications in the structures of proteins in function of the different processing technologies. For both proteins, electrophoresis indicated a similar profile for all hydrolysates, regardless of the process applied as pre or post treatment. Solubility of bean and lentil protein concentrates was also improved. These results indicated that different processing technologies can be successfully used in association with enzymatic hydrolysis to improve the antioxidant properties of lentil and bean proteins.

Bioactive proteins and phytochemicals from legumes: Mechanisms of action preventing obesity and type-2 diabetes

The Fabaceae family of plants include a variety of seeds with multiple shapes, sizes, and colors; with a great diversity of bioactive compounds found in legume seeds. Legumes are an excellent source of protein, peptides and phytochemicals which are present in significant amounts. These bioactive compounds have been reported to reduce the risk of developing non-communicable diseases (NCD), such as obesity and type-2 diabetes. In this narrative review, we discuss the biological potential of bioactive compounds found in legumes and the health benefits associated with their consumption as an alternative approach in the management of NCD. Current extraction methods, characteristics of the bioactive compounds, and different in vitro and in vivo studies evaluating the bioactivity of legume bioactives are reviewed and discussed.

Buffalo cheese whey hydrolyzed with Alcalase as an antibrowning agent in minimally processed apple

Buffalo whey was hydrolyzed with Alcalase for different times t_i (i = 0, 0.5, 1, 2, 3, 4 or 6 h) and the browning inhibition of minimally processed apples was investigated. The hydrolysis process was followed by determination of the degree of hydrolysis. In order to understand possible modes of action on the enzymatic browning, whey was submitted to the analysis of antioxidant activity (ABTS^·+ radical sequestration, Fe²⁺ chelating activity and reducing power), reactivity with quinones and inhibitory activity on polyphenol oxidases (PPO) extracted from Red Delicious apples. Buffalo whey showed significant increase in degree of hydrolysis, antioxidant activity, reactivity with quinones and PPO-inhibitory activity as a function of the hydrolysis time. Maximum PPO-inhibitory activity was observed from 4 h hydrolysis (t_4h hydrolysate), reaching about 50% inhibition. Then, slices of minimally processed apples were immersed in a buffered solution of the t_4h hydrolysate, packed and subjected to instrumental color evaluation during storage for up to 6 days. As for the ability to inhibit the browning of the minimally processed apples, the hydrolyzate kept the L∗ parameter of the apples during 6 days of storage, not statistically differing from the metabisulfite. In addition to the luminosity, the hydrolyzed whey was able to maintain the browning index of the apples at lower values during this storage time compared to the non-hydrolyzed whey. These results evidence possible applications of buffalo whey hydrolyzed with Alcalase as a natural substitute for additives conventionally used in the control of enzymatic browning in foods.

Bioactive Properties of Phaseolus lunatus (Lima Bean) and Vigna unguiculata (Cowpea) Hydrolyzates Incorporated into Pasta. Residual Activity after Pasta Cooking

The aims of the study were to study the inclusion of P. lunatus (PLH) and V. unguiculata (VUH) protein hydrolyzates with bioactive properties into a pasta-extruded product and determine residual activity after extrusion or pasta cooking. Both protein hydrolyzates showed angiotensin-converting enzyme inhibition (ACEI) and antioxidant activity (TEAC). PLH showed higher ACEI but lower TEAC than VUH (97.19 ± 0.23 vs. 91.95 ± 0.29 % and 244.7 ± 3.4 vs. 293.7 ± 3.3 μmol Trolox/g, respectively). They were included at 5 or 10 % into wheat pasta. Control pasta had the lowest ACEI activity or TEAC (22.01 ± 0.76 % or 14.14 ± 1.28 μmol Trolox/g, respectively). Higher activity remained in pasta with PLH than VUH after extrusion, and higher the level of addition, higher the ACEI was. Pasta had practically the same ACEI activity after cooking, thus active compounds were not lost by temperature or lixiviation. Regarding TEAC, higher activity remained in pasta with 10 % VUH (31.84 ± 0.17 μmol Trolox/g). Other samples with hydrolyzates had the same activity. After cooking, pasta with hydrolyzates had higher TEAC values than control, but these were not modified by the level of incorporation. Moreover, the profile changed because pasta with PLH had the highest TEAC values (21.39 ± 0.01 and 20.34 ± 0.15 for 5 or 10 % hydrolyzates, respectively). Cooking decreased this activity (~ 20 %), for all samples. Although a certain loss of antioxidant activity was observed, pasta could be a good vehicle for bioactive compounds becoming a functional food.

Effect of Dehydration Conditions on the Chemical, Physical, and Rehydration Properties of Instant Whole Bean (Phaseolus vulgarisL. var. Azufrado)

The purpose of this study was to evaluate the effect of dehydration conditions on the chemical, physical, and rehydration properties of instant whole beans (Phaseolus vulgarisL. var. Azufrado) using a 22factorial design (air temperature: 25°C and 30°C, air velocity: 0.5 m/s and 1.0 m/s). To determine the kinetic parameters, the rehydration data were fitted to three models: Peleg’s, First Order, and Sigmoid. The protein, fat, and ash contents of the beans were not significantly affected (P>0.05) by the dehydration conditions. Of the 11 physical properties of the instant whole beans, only water activity and splitting were significantly affected by dehydration conditions (P<0.05), with a range from 0.58 to 0.67 and from 2.90% to 5.87%, respectively. Of the three models tested, the First Order model gave the best fit for rehydration, with no significant differences (P>0.05) between the observed and predicted equilibrium moisture contents of the instant whole beans. Regarding the rehydration kinetics for the instant whole beans, the activation energy values ranged from 23.56 kJ/mol to 30.48 kJ/mol, depending on the dehydration conditions. The dehydration conditions had no significant effect (P>0.05) on the rehydration properties of instant whole beans.

Impact of commercial precooking of common bean (Phaseolus vulgaris) on the generation of peptides, after pepsin-pancreatin hydrolysis, capable to inhibit dipeptidyl peptidase-IV

The objective of this research was to determine the bioactive properties of the released peptides from commercially available precook common beans (Phaseolus vulgaris). Bioactive properties and peptide profiles were evaluated in protein hydrolysates of raw and commercially precooked common beans. Five varieties (Black, Pinto, Red, Navy, and Great Northern) were selected for protein extraction, protein and peptide molecular mass profiles, and peptide sequences. Potential bioactivities of hydrolysates, including antioxidant capacity and inhibition of α-amylase, α-glucosidase, dipeptidyl peptidase-IV (DPP-IV), and angiotensin converting enzyme I (ACE) were analyzed after digestion with pepsin/pancreatin. Hydrolysates from Navy beans were the most potent inhibitors of DPP-IV with no statistical differences between precooked and raw (IC50 = 0.093 and 0.095 mg protein/mL, respectively). α-Amylase inhibition was higher for raw Red, Navy and Great Northern beans (36%, 31%, 27% relative to acarbose (rel ac)/mg protein, respectively). α-Glucosidase inhibition among all bean hydrolysates did not show significant differences; however, inhibition values were above 40% rel ac/mg protein. IC50 values for ACE were not significantly different among all bean hydrolysates (range 0.20 to 0.34 mg protein/mL), except for Red bean that presented higher IC50 values. Peptide molecular mass profile ranged from 500 to 3000 Da. A total of 11 and 17 biologically active peptide sequences were identified in raw and precooked beans, respectively. Peptide sequences YAGGS and YAAGS from raw Great Northern and precooked Pinto showed similar amino acid sequences and same potential ACE inhibition activity. Processing did not affect the bioactive properties of released peptides from precooked beans. Commercially precooked beans could contribute to the intake of bioactive peptides and promote health.