Angiotensin I converting enzyme (ACE) inhibitory and antioxidant peptides are receiving attention due to their beneficial effects in the prevention/treatment of hypertension. The objective was to explore the effect of high hydrostatic pressure (HP) on proteolysis by different proteases and the release of bioactive peptides from lentil proteins. Pressurisation (100-300 MPa) enhanced the hydrolytic efficiency of Protamex, Savinase and Corolase 7089 compared to Alcalase. Proteolysis at 300 MPa led to a complete degradation of lentil proteins and increased peptide (<3 kDa) concentration by all enzymes. Proteolysis at 300 MPa by Savinase gave rise to lentil hydrolysates (S300) with the highest ACE-inhibitory and antioxidant activities that were retained upon in vitro gastrointestinal digestion. The peptides responsible for the multifunctional properties of S300 hydrolysate were identified as different fragments from storage proteins and the allergen Len c 1. These results support the potential of HP as a technology for the cost-effective production of bioactive peptides from lentil proteins during enzymatic proteolysis.

The influence of solid (SSF) or liquid state fermentation (LSF) for 48 and 96 h on the production of water soluble extracts from kidney beans was investigated. SSF was carried out by Bacillus subtilis, whilst LSF was performed either by natural fermentation (NF) or by Lactobacillus plantarum strain (LPF). SSF extracts showed high soluble phenolic compound content (31-36 mg/g) and antioxidant activity (508-541 μg trolox equivalents/g), whilst LSF extracts exhibited potential antihypertensive activity due to their large γ-aminobutyric acid (GABA) content (6.8-10.6 mg/g) and angiotensin converting enzyme inhibitory (ACEI) activity (>90%). Therefore, fermentation can be considered as a valuable process to obtain bioactive ingredients from kidney beans, which could encourage their utilisation in the formulation of added-value functional foods.

The objective was to identify peptides with dual antioxidant and angiotensin I converting enzyme (ACE) inhibitory activities released from lentil proteins by Savinase®. The influence of gastrointestinal digestion on peptide bioactivity was also assayed. Fragments from vicilin, convicilin and legumin were the most abundant peptides identified. Peptides LLSGTQNQPSFLSGF, NSLTLPILRYL, TLEPNSVFLPVLLH showed the highest antioxidant (0.013-1.432μmol Trolox eq./μmol peptide) and ACE inhibitory activities (IC50=44-120μM). Gastrointestinal digestion of peptides improved their dual activity (10-14μmol Trolox eq./μmol peptide; IC50=11-21μM). In general, C-terminal heptapeptide was crucial for their dual activity. ACE inhibition relies on the formation of hydrogen bonds between C-terminal residues of lentil peptides and residues of the ACE catalytic site. The present study helps clarifying the relationship between structure and dual antioxidant/antihypertensive activity of lentil peptides opening new opportunities to food industry such as the application of lentil protein hydrolysates as ingredients for development of functional foods.

The increasing demand for healthy food products has promoted the use of germinated seeds to produce functional flours. In this study, germination conditions were optimized in barley grains with the aim to produce flours with high nutritional and biofunctional potential using response surface methodology (RSM). The impact of germination time (0.8–6 days) and temperature (12–20 °C) on barley quality was studied. Non-germinated barley was used as the control. The content of vitamins B₁, B₂ and C, and proteins increased notably after germination, especially at longer times, while levels of fat, carbohydrates, fibre, and β-glucan were reduced. Total phenolic compounds, γ-aminobutyric acid and antioxidant activity determined by Oxygen Radical Absorbance Capacity increased between 2-fold and 4-fold during sprouting, depending on germination conditions and this increase was more pronounced at higher temperatures (16–20 °C) and longer times (5–6 days). Procyanidin B and ferulic acid were the main phenolics in the soluble and insoluble fraction, respectively. Procyanidin B levels decreased while bound ferulic acid content increased during germination. Germinated barley flours exhibited lower brightness and a higher glycemic index than the control ones. This study shows that germination at 16 °C for 3.5 days was the optimum process to obtain nutritious and functional barley flours. Under these conditions, sprouts retained 87% of the initial β-glucan content, and exhibited levels of ascorbic acid, riboflavin, phenolic compounds and GABA between 1.4-fold and 2.5-fold higher than the non-sprouted grain.

ABSTRACT:  The content of glucosinolates (GLS), ascorbigen, and ascorbic acid in white cabbage ( Brassica oleracea var. capitata cv. Taler) cultivated in different seasons (summer and winter) was determined, before and after spontaneous and starter‐induced fermentation. Different salt concentrations (0.5% NaCl or 1.5% NaCl) were used for sauerkraut production. Glucoiberin, sinigrin, and glucobrassicin were dominating in raw white cabbage cultivated either in winter or summer seasons. Ascorbigen precursor, glucobrassicin, was found higher in cabbage cultivated in winter (2.54 μmol/g dw) than those grown in summer (1.83 μmol/g dw). Cabbage fermented for 7 d was found to contain only traces of some GLS irrespective of the fermentation conditions used. Ascorbigen synthesis occurred during white cabbage fermentation. Brining cabbage at low salt concentration (0.5% NaCl) improved ascorbigen content in sauerkraut after 7 d of fermentation at 25 °C. The highest ascorbigen concentration was observed in low‐sodium (0.5% NaCl) sauerkraut produced from cabbage cultivated in winter submitted to either natural (109.0 μmol/100 g dw) or starter‐induced fermentation (108.3 and 104.6 μmol/100 g dw in cabbages fermented by L. plantarum and L. mesenteroides , respectively). Ascorbic acid content was found higher in cabbage cultivated in summer and fermentation process led to significant reductions. Therefore, the selection of cabbages with high glucobrassicin content and the production of low‐sodium sauerkrauts may provide enhanced health benefits towards prevention of chronic diseases.