Effect of Overripening on the Physico-Chemical and Sensory Characteristics of Boneless, Salt-Reduced Iberian Dry-Cured Ham.

The aim of this study was to evaluate the effect of extended maturation and temperature increase on the physico-chemical, biochemical, instrumental color and texture, sensory, and acceptability parameters of cured and boneless Iberian hams. Given the limited knowledge in this area, our objective was to develop a ham with enhanced proteolysis, potentially leading to increased bioactive peptide generation and superior sensory characteristics compared to salt-reduced counterparts. To achieve this, a batch of hams cured up to 38% loss at 30 °C and two batches cured up to 42% loss at 30 °C and 36 °C were evaluated. Results showed that the increase in processing time and temperature significantly enhanced (p < 0.05) ham proteolysis and amino acid content without adversely affecting its texture. No significant differences were observed in instrumental texture parameters or sensory attributes as evaluated by consumers. These processing conditions also increased the content of free amino acids, improving the product quality. Overall, these processing modifications resulted in hams with excellent sensory acceptability and enhanced bioactive potential despite the salt reduction.

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.

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.

Free amino acid content of goat's milk cheese made with animal rennet and plant coagulant.

BACKGROUND: Enzymes present in the flowers of Cynara cardunculus (cyprosins) are used in the production of some traditional Spanish and Portuguese cheeses, replacing animal rennet. The aim of this work was to study the changes that take place in free amino acids during the ripening of a goat's milk cheese (Murcia al Vino) manufactured with plant coagulant (PC) or animal rennet (AR). RESULTS: The total free amino acid (TFAA) concentration increased during ripening, with Ile, Val, Ala, Phe, Gaba, Arg and Lys representing more than 50% of the TFAA content at 60 days in both types of cheese. The TFAA concentration was significantly higher in cheeses made with PC (854 mg 100 g(-1) total solids (TS)) than those made with AR (735 mg 100 g(-1) TS). The concentration of most free amino acids, especially His, Ser, Gln, Thr, Ala, Met and Ile, was higher in the PC cheese. CONCLUSION: Cheese made using PC as coagulant presented higher contents of free amino acid throughout the ripening period than cheese made using AR. Therefore we can conclude that the use of PC to produce Murcia al Vino goat's cheese would accelerate the ripening process as a result of increased cyprosin proteolytic activity.