Bioactivities of Mealworm (Alphitobius diaperinus L.) Larvae Hydrolysates Obtained from Artichoke (Cynara scolymus L.) Proteases.

In this study, we aimed to obtain hydrolysates with bioactive peptides from mealworm (Alphitobius diaperinus L.) larvae using an artichoke (Cynara scolymus L.) enzyme extract. Two types of substrates were used: the raw larvae flour (LF) and its protein extract (PE). The hydrolysis yield, considering the peptide concentration of the hydrolysates, was higher in PE hydrolysates than in LF hydrolysates (6.39 ± 0.59 vs. 3.02 ± 0.06 mg/mL, respectively). However, LF showed a higher antioxidant activity against the DPPH radical than PE (59.10 ± 1.42 vs. 18.79 ± 0.81 µM Trolox Eq/mg peptides, respectively). Regarding the inhibitory activity of angiotensin-I-converting enzyme (ACE), an IC50 value of 111.33 ± 21.3 µg peptides/mL was observed in the PE. The identification of the peptide sequence of both hydrolysates was conducted, and LF and its PE presented 404 and 116 peptides, respectively, most with low molecular weight (<3 kDa), high percentage of hydrophobic amino acids, and typical characteristics of well-known antioxidant and ACE-inhibitory peptides. Furthermore, the potential bioactivity of the sequences identified was searched in the BIOPEP database. Considering the antioxidant and ACE-inhibitory activities, LF hydrolysates contained a larger number of sequences with potential bioactivity than PE hydrolysates.

Bioactivity of Hydrolysates Obtained from Chicken Egg Ovalbumin Using Artichoke (Cynara scolymus L.) Proteases.

The aim of this work was to obtain chicken egg ovalbumin hydrolysates using aspartic proteinases present in extracts from the artichoke flower (Cynara scolymus L.) and evaluate their antioxidant, antimicrobial, and angiotensin I-converting enzyme (ACE) inhibitory activity in vitro. Hydrolysis time and molecular weight (<3 kDa) had a significant influence on the hypertensive and antioxidant activity of the hydrolysates. The <3 kDa fraction of the 16 h hydrolysate had an ACE inhibitory activity with an IC50 of 64.06 µg peptides/mL. The fraction <3 kDa of ovalbumin hydrolysate at 2 h of hydrolysis showed a DPPH radical scavenging activity of 30.27 µM of Trolox equivalents/mg peptides. The fraction <3 kDa of the hydrolysate of 16 h had an ABTS+ caption activity of 4.30 mM of Trolox equivalents/mg peptides. The fraction <3 kDa of the hydrolysate of 2 h had an iron (II) chelating activity of 32.18 µg peptides/mL. From the peptide sequences identified in the hydrolysates, we detected four peptides (from the BIOPEP database) that were already in their bioactive form (IAAEVYEHTEGSTTSY, HLFGPPGKKDPV, PIAAEVYEHTEGSTTSY, and YAEERYPIL), and are reported to display antioxidant and ACE inhibitory activity.

Fatty Acids and Free Amino Acids Changes during Processing of a Mediterranean Native Pig Breed Dry-Cured Ham.

The aim of this work is to analyse the intramuscular fatty acids and the free amino (FAA) acids in Chato murciano dry-cured ham. There are several Mediterranean native pig breeds whose characteristics of derived products have been described, but the impact of lipolysis and proteolysis on Chato murciano dry-cured ham has not yet been studied. Fatty acids and free amino acids were determined in the fresh piece and at 14, 18, 22 and 24 months of manufacturing. Monounsaturated fatty acids are the majority in the neutral lipids and free fatty acid fractions. Lipolysis took place mainly until the 18th month, resulting in a decrease in the levels of fatty acids of neutral lipids (from 95.43% to 83.38%) and polar lipids (from 2.57% to 0.41%), accompanied by a corresponding increase in free fatty acids (from 2% to 16.21%). Neutral lipids hydrolysis provides the main free fatty acids as in other native breeds. Results for FAA showed an increase in concentration during the time preceding the 14th month. From this point onwards, until month 18, total FAA concentration remained stable, and the content decreased at the end of the processing (between months 22 and 24).

Characterization of Proteolytic Activity of Artichoke (Cynara scolymus L.) Flower Extracts on Bovine Casein to Obtain Bioactive Peptides.

The aim of this work is to establish the most suitable proteolysis conditions to obtain bovine casein hydrolysates containing peptides with antioxidant and antihypertensive capacity. To this end, the proteolytic activity of Cynara scolymus L. flower extracts was characterized on whole bovine casein, evaluating the effect of several factors (pH, temperature, substrate concentration, enzyme concentration, and hydrolysis time). The optimal conditions to carry out the hydrolysis with the C. scolymus L. extract were as follows: pH 6.2, 50 °C, and 0.023 mg·mL-1 of extract-protein concentration. A Michaelis constant (Km) value of 5.66 mg·mL-1 and a maximum rate of reaction (Vmax) of 8.47 mUAbs∙min-1 were observed. The optimal hydrolysis time was 17 h. The casein hydrolysates obtained with these conditions contained peptides with antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity: 30.89%; Trolox equivalent antioxidant capacity (TEAC) against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free radical (ABTS●+): 4.43 mM Trolox equivalent·mg-1 peptide) and antihypertensive activity, showing 55.05% angiotensin-converting enzyme-I inhibition in vitro.