Hypotensive effect of potent angiotensin-I-converting enzyme inhibitory peptides from corn gluten meal hydrolysate: Gastrointestinal digestion and transepithelial transportation modifications.

The study examined the antihypertensive effect of peptides derived from pepsin-hydrolyzed corn gluten meal, namely KQLLGY and PPYPW, and their in silico gastrointestinal tract digested fragments, KQL and PPY, respectively. KQLLGY and PPYPW showed higher angiotensin I-converting enzyme (ACE)-inhibitory activity and lower ACE inhibition constant (Ki) values when compared to KQL and PPY. Only KQL showed a mild antihypertensive effect in spontaneously hypertensive rats with -7.83 and - 5.71 mmHg systolic and diastolic blood pressure values, respectively, after 8 h oral administration. During passage through Caco-2 cells, KQL was further degraded to QL, which had reduced ACE inhibitory activity. In addition, molecular dynamics revealed that the QL-ACE complex was less stable compared to the KQL-ACE. This study reveals that structural transformation during peptide permeation plays a vital role in attenuating antihypertensive effect of the ACE inhibitor peptide.

An investigation of correlation between structural and functional properties of Nigella sativa protein isolate.

The physicochemical characteristics, amino acid composition, and functional properties of Nigella sativa (NS) seedcake protein extracts were evaluated to establish their potential in nutraceuticals and functional foods. The highest yield (20.2%) of protein isolate (NSPI) from NS seedcake was achieved at an alkali concentration of 0.16 M, a buffer to sample ratio of 1/25 (w/v), extraction time, 15 min, and extraction temperature, 25°C. Amino acid analysis showed that the isolated protein is a good source of amino acids with a significant essential to total amino acid (E/TN) ratio. Further, the protein isolate exhibited maximum solubility at pH 11. The results of the physicochemical analysis clearly indicated that the protein isolate had good water and oil holding capacity, emulsification property, foaming capacity, and foaming stability. The secondary structure of NSPI contained α-helix, ß-sheet, and ß-turns. In addition, NSPI showed excellent antioxidant, anti-diabetic, and protein digestibility activities. From the experimental data, it could be concluded that NSPI could be an excellent source of proteins for the development of foods with promising functional properties. PRACTICAL APPLICATIONS: Nigella sativa seeds are frequently used as a natural food additive and have been a part of naturopathy for centuries due to their anti-inflammatory, antibacterial, anticancer, antidiabetic, immunomodulatory, and cardioprotective properties. Nigella sativa seedcakes obtained as by-products of the oil extraction process are rich in protein content and can be used as a sustainable source of dietary proteins to cater to a wide range of consumers. Being plant-based, they inherently possess several medicinal properties. Analyzing the physicochemical and functional properties of protein isolated from seedcakes allows us to optimize the protein extraction process while providing a better perspective on its potential in the nutraceuticals and food industries. It can be used as an energy supplement in animal feed as a source of protein to replace soybeans and barley. The antioxidant proteins when added to meat-based products have been known to protect the meat from oxidative stress as well as pathogenic organisms, thus, improving its shelf-life. Nigella sativa protein isolates have several applications in the pharmaceutical industry as well.

Physicochemical and functional properties of ash gourd/bottle gourd beverages blended with jamun.

This paper reports the formulation and storage stability of Ash gourd (Benincasa hispida) and Bottle gourd (Lagenaria siceraria) juice blended with the Jamun (Syzygium cumini). Both the beverages found to be rich in polyphenols, flavonoids, and anthocyanins. The Ash gourd-Jamun (AGJ) and Bottle gourd-Jamun (BGJ) beverages showed significant bio-accessibility of polyphenols, flavonoids, and anthocyanins. Moreover, the addition of sugar was found to enhance the bioaccessibility of these fractions in both the beverages. Further, the biochemical attributes such as physiochemical and functional properties of Ash gourd-Jamun and Bottle gourd-Jamun blended juice were evaluated during the accelerated storage. The total soluble solids and acidity and the sensory score did not change significantly during the storage period. The AGJ exhibited a 35%, 73%, 34% and 35%, whereas BGJ shows 32%, 65%, 35% and 20% decrease in total polyphenol, anthocyanin, DPPH and inflammatory activity during the 2 months of storage period respectively. However, the reduction was less in Bottle gourd-Jamun beverage. Results of the study are promising and add to the necessity and potential of gourd family based functional food development.

An investigation on the effect of polyphenolic extracts of Nigella sativa seedcake on physicochemical properties of chitosan-based films.

Nigella sativa seedcake phenolic extract (NSE), as compared to tannic acid (TA), was evaluated for its effect on film-forming ability of chitosan. These films were evaluated for their tensile strength, elongation, water vapor permeability (WVP), type of bonding, color, surface morphology, polyphenol and in vitro antioxidant activity release profile. At 7.5% (v/v of film-forming solution), NSE led to 42% decrease in tensile strength but improved the elongation by 66%, contradicting the effect of TA in chitosan films. WVP and crystallinity decreased with increasing NSE concentration. Changes in absorbance intensity by FTIR indicated structural modification. The calorimetric analysis showed changes in melting point and degree of crystallinity due to NSE. The release of total polyphenols and subsequent antioxidant activity in the water, 50% ethanol, and 95% ethanol media indicated potential application in active-packaging. This study shall help valorization of N. sativa seedcake after oil extraction for packaging, pharmaceutical, and allied applications.

Cross-linking effect of polyphenolic extracts of Lepidium sativum seedcake on physicochemical properties of chitosan films.

Lepidium sativum seedcake phenolic extract (LSE), as compared to tannic acid (TA), was evaluated for its effect on film forming ability of chitosan. The films were investigated for their structural, mechanical, optical, thermal and in vitro antioxidant activity release profile. At 5% (v/v of film-forming solution), LSE led to improved 32.2% of tensile strength and 109% elongation, compared to the effect of TA in chitosan films. Moisture content, WVP, and crystallinity decreased with the increasing LSE concentration. Changes in absorbance intensity by FT-IR indicated structural modification. The DSC thermograph indicted a change in the melting point. SEM showed smooth and homogeneous surface cross-section composite film with LSE. The films exhibit dose-dependent and time-dependent release of total polyphenols and antioxidant activity in the water, 50% ethanol, and 95% ethanol. Hence, the current work help valorization of L. sativum seedcake after oil extraction for an alternative as novel active-packaging material for food and pharmaceutical application.

LC-ESI-Q-TOF-MS/MS profiling and antioxidant activity of phenolics from L. Sativum seedcake.

Lepidium sativum is widely used as a culinary and medicinal herb and is claimed to cure many diseases. In this study, an attempt was made to investigate the biochemical composition and functional properties of L. sativum ethanolic extract. The extract contained a total phenolic content of 11.03 ± 0.75 (mg GAE/g dw plant material) and a flavonoid content of 4.79 ± 0.24 (mg QE/100 g dw plant material). Further, the extract was characterized by LC-ESI-Q-TOF-MS/MS profiling and the results showed that the ethanolic fraction contains many important phenolics such as Kaempferol, Coumaroylquinic acid, p-Coumaroyl glycolic acid, Caffeic acid. The identified compounds are known for their biological properties and therefore, the functional properties of the extract as a whole were also studied. The extract showed significant antioxidant activity (IC50 values) 162.4 ± 2.3, 35.29 ± 1.02, 187.12 ± 3.4 and 119.32 ± 1.5 µg/ml in terms of DPPH, ABTS, Superoxide scavenging activity and metal chelating property respectively. Further, the extract showed IC50 values, 73.72 ± 1.23 and 121.78 ± 1.03 µg/ml in HRBC membrane stabilization ability and protein denaturation inhibition capacity respectively, which in turn is a measure of its anti-inflammatory activity. The results of the study are promising and serve basis for further investigation into the plant and possible consideration for use in nutraceuticals and functional foods.