Valorization of different low-grade date (Phoenix dactylifera L.) fruit varieties: A study on the bioactive properties of polyphenolic extracts and their stability upon in vitro simulated gastrointestinal digestion.

Nowadays, the development of suitable strategies for the management and valorization of agri-food products is one of the most important challenges worldwide. In this context, the current research study aimed to explore a valorization strategy for different varieties (Khalas, Jabri, Lulu, Booman, and Sayer) of low-grade date fruit by extracting polyphenolic compounds and investigating their health-promoting bioactive properties. The generated extracts were comparatively analyzed for their phenolic contents, antioxidant, anti-inflammatory, anti-hemolytic, and enzyme inhibitory activities upon in vitro simulated gastrointestinal digestion (SGID). The total phenolic contents (TPC) ranged from 217.3 to 1846.9 mg GAE/100 g fresh weight. After complete SGID, the TPC remarkably increased from 570.8 mg GAE/100 g fresh weight (undigested), reaching the highest value of 1606.3 mg GAE/100 g fresh weight with the Khalas cultivar. Overall, gastric and complete-SGID-treated extracts exhibited higher antioxidant activities, compared to the undigested extracts for the five selected date varieties. Similarly, the gastric and complete SGID promoted the release of bioactive components endowed with significantly higher inhibition levels towards digestive enzymes related to diabetes. Moreover, extracts from all varieties revealed an increase in the inhibition of lipidemic-related enzymatic markers and anti-inflammatory activities when subjected to the gastric digestion phase, which decreased after complete SGID. Principal component analysis (PCA) suggested that higher bioactive properties were influenced by the TPC present in the samples. Overall, low-quality dates could be considered as a potential source of bioactive polyphenols with interesting nutraceutical properties, released upon their transit through the gastrointestinal tract.

Novel Plant-Protein (Quinoa) Derived Bioactive Peptides with Potential Anti-Hypercholesterolemic Activities: Identification, Characterization and Molecular Docking of Bioactive Peptides.

Hypercholesterolemia remains a serious global public health concern. Previously, synthetic anti-hypercholesterolemic drugs were used for ameliorating this condition; however, long-term usage presented several side-effects. In this regard, natural products as an adjunct therapy has emerged in recent times. This study aimed to produce novel bioactive peptides with anti-hypercholesterolemic activity (cholesterol esterase (CEase) and pancreatic lipase (PL)) from quinoa protein hydrolysates (QPHs) using three enzymatic hydrolysis methods (chymotrypsin, protease and bromelain) at 2-h hydrolysis intervals (2, 4, and 6 h). Chymotrypsin-generated hydrolysates showed higher CEase (IC50: 0.51 mg/mL at 2 h) and PL (IC50: 0.78 mg/mL at 6 h) inhibitory potential in comparison to other derived hydrolysates and intact quinoa proteins. Peptide profiling by LC-MS QTOF and in silico interaction with target enzymes showed that only four derived bioactive peptides from QPHs could bind in the active site of CEase, whereas twelve peptides could bind in the active site of PL. Peptides QHPHGLGALCAAPPST, HVQGHPALPGVPAHW, and ASNLDNPSPEGTVM were identified to be potential CEase inhibitors, and FSAGGLP, QHPHGLGALCAAPPST, KIVLDSDDPLFGGF, MFVPVPH, and HVQGHPALPGVPAHW were identified as potential PL inhibitors on the basis of the maximum number of reactive residues in these bioactive peptides. In conclusion, QPHs can be considered as an alternative therapy for the treatment of hypercholesterolemia.

Multifunctional bioactive properties of hydrolysates from colocynth (Citrullus colocynthis) seeds derived proteins: Characterization and biological properties.

Citrullus colocynthis (Colocynth) has gained a great deal of interest in their applications as indigenous nutraceutical and as a functional food ingredient. The intact colocynth seed protein was enzymatically hydrolyzed using proteolytic enzymes (alcalase, bromelain, and chymotrypsin) at different time intervals of 3, 6, and 9 h. The highest degree of hydrolysis (87.82%) was observed in chymotrypsin derived colocynth seed protein hydrolysates (CSPH) for 9 h. The CSPHs was further investigated through in-vitro assay to explore its potential biological activity such as antioxidant, inhibition of enzymatic marker related to diabetes (DPP-IV, α-glucosidase and α-amylase) and hyperlipidaemia (cholesteryl esterase and pancreatic lipase). Chymotrypsin hydrolysate showed the strongest DPPH (65.7 mM TEAC) and ABTS (525.2 mM TEAC) radical scavenging activity after 6 h of hydrolysis. Moreover, chymotrypsin-treated CSPH for 6 h inhibited cholesteryl esterase (IC50 = 13.68 µg/mL) and pancreatic lipase (IC50 = 14.12 µg/mL) significantly when compared to native protein. Whereas, bromelain and alcalase treated hydrolysate for 6 h effectively inhibited α-glucosidase and α-amylase at an inhibitory concentration of IC50 = 13.27 µg/mL and of IC50 = 17 µg/mL. Overall, the findings indicated that protein hydrolysates exhibited superior biological activity than intact colocynth seed proteins isolate (CSPI) and could be a sustainable source of bioactive peptides.

Nutraceutical and bioactive potential of high-quality date fruit varieties (Phoenix dactylifera L.) as a function of in-vitro simulated gastrointestinal digestion.

The present study aims to investigate the digestive process (gastric and intestinal phases) effects on the survivability of total and individual phenolic compounds, and the in vitro health-related bioactive properties of four high-quality and commonly consumed dates (Phoenix dactylifera) varieties (Safawi, Khalas, Khudri, and Booman). Phenolic compounds were analyzed by HPLC-UV (at 275 nm) and a higher amount of phenolics were identified in Khalas and Booman intestinal digested extracts, compared to the other date varieties-based extracts, which corroborates with the total phenolic contents in those samples, with respective values of 186.5 and 358.14 mg GAE/100 g. Considering their bioactive potentialities, the highest DPPH radical scavenging activities, of around 320 TEAC µg/mL, were observed with Khalas and Khudri gastric extracts. In contrast, Khalas intestinal extract displayed the highest ABTS radical scavenging potential of 969 TEAC µg/mL. Moreover, the Safawi intestinal extract, along with Khalas and Booman gastric extracts, showed the highest increase in the α-glucosidase inhibition activity, compared to the other date varieties-based extracts. Safawi and Khalas intestinal extracts displayed the highest DPP-IV inhibition activities (IC50 of 2.85 µg/mL). Additionally, regarding the pancreatic lipase and cholesterol esterase inhibition, Khudri and Khalas varieties after intestinal digestion demonstrated the highest activities. These results suggested that the Khalas variety showed more potent bioactive properties than other date varieties, mainly related to the variations in the phenolic content between date varieties. Overall, this study provides additional insight into investigating these dates varieties upon their simulated gastro-intestinal digestion and exhibition of multifunctional bioactive properties.

A comparative analysis of anti-lipidemic potential of soybean (Glycine max) protein hydrolysates obtained from different ripening stages: Identification, and molecular interaction mechanisms of novel bioactive peptides.

This study aims to investigate the potentials of mature (MSPHs) and young (YSPHs) soybean enzymatic protein hydrolysates for the inhibition of pancreatic lipase (PL) and cholesterol esterase (C-Ease) enzymes. Higher proteins degradation levels were recorded with Bromelain compared to Flavourzyme and Alcalase, and upon hydrolysis, improved PL and C-Ease inhibition performances were displayed compared to unhydrolyzed proteins. Afterwards, six PHs with potent anti-lipidemic activities were selected for sequencing using LC-MS QTOF and molecular binding studies. Peptides FPFPRPPHQ, QCCAFEM, FAPEFLK from MSPHs and SFFFPFELPRE, FMYL, PFLL, FPLL, LPHF from YSPHs were predicted to possess potent inhibitory activities against PL. Furthermore, FPFPRPPHQ, FMYL, MMLM from MSPHs, and SFFFPFELPRE from YSPHs were predicted to be potent inhibitors of C-Ease. FPFPRPPHQ and SFFFPFELPRE derived from MSPHs and YSPHs, respectively, demonstrated effective inhibition potentialities against both PL and C-Ease. Therefore, mature and young soybean-derived protein hydrolysates could be recognized as a potential ingredient in the management of hypercholesterolemia.

Identification and characterization of cholesterol esterase and lipase inhibitory peptides from amaranth protein hydrolysates.

Human diet is undergoing a shift towards plant-based diet as a sustainable source of protein compared to animal-derived protein. In this study, cholesterol esterase (CEase) and pancreatic lipase (PL) inhibitory activities of amaranth protein hydrolysates (APHs) were studied. Bromelain, chymotrypsin, and actinase E were used for generating APHs at 2, 4 & 6 h of hydrolysis. Higher PL inhibiting potential were observed in bromelain-derived APHs (IC50 = 0.38-0.66 mg/mL) in comparison to intact amaranth proteins (IC50 = 3.93 mg/mL). Bromelain-4 h hydrolysates (AB4) demonstrated significant inhibitory potential for both CEase (IC50 = 0.47 mg/mL) and PL (IC50 = 0.48 mg/mL) activity. Peptide identification in AB-4 hydrolysate revealed that among 17 bioactive peptides, three peptides (FPFPPTLGY, FGAPR, and FPFVPAPT) were predicted as potential PL inhibitors and only one peptide (FPFVPAPT) was predicted as CEase inhibitor based on the number of substrate binding sites on active site of the enzymes. This is the first study providing insights into amaranth protein derived bioactive peptide possessing CEase and LIP inhibitory potential.

Characterization and identification of novel antidiabetic and anti-obesity peptides from camel milk protein hydrolysates.

In-vitro inhibitory properties of peptides released from camel milk proteins against dipeptidyl peptidase-IV (DPP-IV), porcine pancreatic α-amylase (PPA), and porcine pancreatic lipase (PPL) were studied. Results revealed that upon hydrolysis by different enzymes, camel milk proteins displayed dramatic increase in inhibition of DPP-IV and PPL, but slight improvement in PPA inhibition was noticed. Peptide sequencing revealed a total of 20 and 3 peptides for A9 and B9 hydrolysates respectively, obtained the score of 0.8 or more on peptide ranker and were categorized as potential DPP-IV inhibitory peptides. KDLWDDFKGL in A9 and MPSKPPLL in B9 were identified as most potent PPA inhibitory peptide. For PPL inhibition only 7 and 2 peptides qualified as PPL inhibitory peptides from hydrolysates A9 and B9, respectively. The present study report for the first time PPA and PPL inhibitory and only second for DPP-IV inhibitory potential of protein hydrolysates from camel milk.

Camel milk protein hydrolysates with improved technofunctional properties and enhanced antioxidant potential in in vitro and in food model systems.

Camel milk protein hydrolysates (CMPH) were generated using proteolytic enzymes, such as alcalase, bromelain, and papain, to explore the effect on the technofunctional properties and antioxidant potential under in vitro and in real food model systems. Characterization of the CMPH via degree of hydrolysis, sodium dodecyl sulfate-PAGE, and HPLC revealed that different proteins in camel milk underwent degradation at different degrees after enzymatic hydrolysis using 3 different enzymes for 2, 4, and 6 h, with papain displaying the highest degradation. Technofunctional properties, such as emulsifying activity index, surface hydrophobicity, and protein solubility, were higher in CMPH than unhydrolyzed camel milk proteins. However, the water and fat absorption capacity were lower in CMPH compared with unhydrolyzed camel milk proteins. Antioxidant properties as assessed by 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and metal-chelating activity were enhanced after hydrolysis, in contrast to ferric-reducing antioxidant power which showed a decrease after hydrolysis. The CMPH were also tested in real food model systems for their potential to inhibit lipid peroxidation in fish mince and grape seed oil-in-water emulsion, and we found that papain-produced hydrolysate displayed higher inhibition than alcalase- and bromelain-produced hydrolysates. Therefore, the CMPH demonstrated effective antioxidant potential in vitro as well as in real food systems and showed enhanced functional properties, which guarantees their potential applications in functional foods. The present study is one of few reports available on CMPH being explored in vitro as well as in real food model systems.

Identification of novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides in camel milk protein hydrolysates.

Nine novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides (FLQY, FQLGASPY, ILDKEGIDY, ILELA, LLQLEAIR, LPVP, LQALHQGQIV, MPVQA and SPVVPF) were identified in camel milk proteins hydrolysed with trypsin. This was achieved using a sequential approach combining liquid chromatography tandem mass spectrometry (LC-MS/MS), qualitative/quantitative structure activity relationship (QSAR) and confirmatory studies with synthetic peptides. The most potent camel milk protein-derived DPP-IV inhibitory peptides, LPVP and MPVQA, had DPP-IV half maximal inhibitory concentrations (IC50) of 87.0 ±â€¯3.2 and 93.3 ±â€¯8.0 µM, respectively. DPP-IV inhibitory peptide sequences identified within camel and bovine milk protein hydrolysates generated under the same hydrolysis conditions differ. This was linked to differences in enzyme selectivity for peptide bond cleavage of camel and bovine milk proteins as well as dissimilarities in their amino acid sequences. Camel milk proteins contain novel DPP-IV inhibitory peptides which may play a role in the regulation of glycaemia in humans.