Alcalase Hydrolysate Research Articles

Enhancement of foaming performance of hempseed protein by limited enzymatic hydrolysis: From the viewpoint of the structural and interfacial rheological attributes

Effects of limited enzymolysis by Alcalase and Protamex on the foaming performance of hempseed protein (HPI) and its correlation with structural and interfacial rheological characteristics were investigated. Proteolysis induced a conformational shift from α-helix and β-sheet to random coil, indicating enhanced molecular flexibility. The surface hydrophobicity of Alcalase hydrolysates encountered an initial increase (5 min) followed by a sharp drop with prolonged hydrolysis, whereas Protamex showed minimal effects. Both proteases reduced total sulfhydryl content and caused a redshift in intrinsic fluorescence, particularly Alcalase. The specific cleavage pattern of Alcalase generated peptides with pronouncedly higher solubility (up to 47.0 %) relative to Protamex. The flexible conformation and increased solubility induced by moderate proteolysis, notably with Alcalase, facilitated viscoelastic interfacial membranes with consolidated intermolecular interactions, consequently contributing to more homogeneous and smaller bubble structures. Optimal foaming capacity (95.0 %) and foam stability (90.9 %) were achieved with Alcalase for 20 min and 5 min, respectively.

Debittering and antioxidant improvement of soy protein hydrolysates using curcumin as hydrophobic core.

Protein hydrolysates possess various bioactive functions (e.g. antioxidant), but their bitter taste is unacceptable to most consumers. In the present study, a novel approach for debittering was introduced, which involved the utilization of a hydrophobic compound, curcumin (Cur). Soy protein hydrolysates (SPH), prepared through alcalase hydrolysis, served as the research model for this investigation. It was found that bitter intensity of SPH was dominated by the hydrophobic amino acid residues, and the addition of Cur could remarkably reduce bitterness. The debittering mechanism is attributed to the direct binding of Cur to the exposed hydrophobic amino acid residues of SPH via hydrophobic interaction, thereby shielding the hydrophobic bitter groups and hindering their interaction with the bitter taste receptors. Moreover, this debittering strategy leads to the generation of stable nanoparticles with a Cur-core/SPH-shell architecture, which can significantly improve the antioxidant capacity of SPH compared to those using biomacromolecules for encapsulation. Using curcumin as a hydrophobic core is a facile and feasible strategy with bifunction of debittering as well as improving bioactive effect of SPH, which may extend its application in foods. © 2024 Society of Chemical Industry.

Moisturizing Effects of Alcalase Hydrolysate Fractions from Haliotis discus Viscera, a Marine Organism, on Human Dermal Fibroblasts, HaCaT Keratinocytes, and Reconstructed Human Skin Tissues.

Haliotis discus, an abalone, is a marine gastropod mollusk that has been cultivated globally owing to its nutritional value and high market demand. However, the visceral parts of H. discus are typically discarded as by-products, highlighting the need to explore their potential value in developing cosmeceuticals and pharmaceuticals. This study investigated the potential moisturizing effects of H. discus visceral tissues. Various hydrolysates from H. discus viscera tissue were evaluated for proximate composition, radical scavenging, and hyaluronidase inhibition activities. Alcalase hydrolysate was isolated using gel filtration chromatography (GFC), and its moisturizing effects were tested on human dermal fibroblasts (HDF), HaCaT keratinocytes, and reconstructed human skin tissue. The Alcalase hydrolysate showed the highest extraction yield, radical scavenging, and hyaluronidase inhibition activities. The Alcalase hydrolysate GFC fraction 1 increased collagen synthesis-related molecules, including procollagen type 1 in HDF and hyaluronic acid-related molecules in HaCaT cells. These moisturizing effects were confirmed in reconstructed human skin tissues by increased levels of aquaporin 3 and filaggrin. Fraction 1 consisted of two main peptides: DNPLLPGPPF and SADNPLLPGPPF. In conclusion, H. discus Alcalase hydrolysate and its fractions have potential moisturizing properties and can be used as cosmeceuticals.

Enhancing zein functionality through sequential limited Alcalase hydrolysis and transglutaminase treatment: Structural changes and functional properties

This study investigated the effects of sequential enzymatic hydrolysis using Alcalase, followed by transglutaminase conjugation on the secondary and tertiary structures, hydrophobicity, free amine content, protein-protein interactions, and functional properties of zein. Fourier-transform infrared spectroscopy showed that the most significant secondary structural changes, characterized by a decrease in α-helix content and an increase in β-turns, occurred at a higher degree of hydrolysis. At a 2 % degree of hydrolysis, it revealed notable emulsifying activity (65.96 m2/g), while at 5 % hydrolysis, it achieved the highest solubility (75.06 %). Additionally, the zein hydrolysate with a 7 % hydrolysis degree, treated with transglutaminase, demonstrated improved H0 values (2992.33), enhanced foam capacity (65.95 %), and increased solubilized protein content in a dithiothreitol extractant (31.35 %). Meanwhile, native zein treated with transglutaminase showed the highest water holding capacity (4.47 g/g). Overall, the combined enzymatic approach modified zein structure and properties, suggesting potential for improving functionality in plant-based food applications.

Anti-Photoaging Effects of Antioxidant Peptide from Seahorse (Hippocampus abdominalis) in In Vivo and In Vitro Models.

Overexposure to ultraviolet (UV) radiation can lead to photoaging, which contributes to skin damage. The objective of this study was to evaluate the effects of an antioxidant peptide (SHP2) purified from seahorse (Hippocampus abdominalis) alcalase hydrolysate on UVB-irradiated skin damage in human keratinocyte (HaCaT) and human dermal fibroblast (HDF) cells and a zebrafish model. The data revealed that SHP2 significantly enhanced cell viability by attenuating apoptosis through the reduction of intracellular reactive oxygen species (ROS) levels in UVB-stimulated HaCaT cells. Moreover, SHP2 effectively inhibited ROS, improved collagen synthesis, and suppressed the secretion of matrix metalloproteinases (MMPs) in UVB-irradiated HDF cells. SHP2 restored the protein levels of HO-1, Nrf2, and SOD, while decreasing Keap1 expression in UVB-treated HDF, indicating stimulation of the Keap1/Nrf2/HO-1 signaling pathway. Furthermore, an in vivo study conducted in zebrafish confirmed that SHP2 inhibited photoaging by reducing cell death through the suppression of ROS generation and lipid peroxidation. Particularly, 200 µg/mL of SHP2 exerted a remarkable anti-photoaging effect on both in vitro and in vivo models. These results demonstrate that SHP2 possesses antioxidant properties and regulates skin photoaging activities, suggesting that SHP2 may have the potential for use in the development of cosmetic products.

Characteristics and Bioactivities of Protein Hydrolysate from Cricket (Acheta domesticus) Powder Defatted Using Ethanol with Aid of Vacuum Impregnation.

Cricket is a potential proteinaceous source used for protein hydrolysate (PH) preparation, having several biological activities. Nevertheless, cricket has high lipid contents, which are susceptible to oxidation during PH preparation. Thus, ethanol was used together with vacuum impregnation (VI) to enhance defatting efficacy before PH preparation. Also, bioavailability of the digest of PH after gastrointestinal tract (GIT) digestion via the Caco-2 monolayer was assessed. Cricket powder was defatted using ethanol for 1-4 h. Lipid contents were decreased with enhancing time until 2 h. Additionally, the defatting efficacy was augmented when ethanol combined with VI at 4 cycles for 2 h (VI-E-2) was implemented. Lowered mono- and polyunsaturated fatty acid contents were also observed in the VI-E-2 sample. The VI-E-2 sample was used to prepare PH using Alcalase and Flavourzyme (0.2-0.4 units/g dry sample). PH prepared by Alcalase hydrolysis at 0.2 units/g dry sample (A-0.2) showed the higher ABTS radical-scavenging activity and FRAP, compared to that prepared by Flavourzyme hydrolysis (p < 0.05). Thus, the A-0.2 sample was selected for digestion via the GIT system. The obtained digest (500-1000 μg/mL) had bioavailability of peptides, depending on the levels used. Therefore, PH from defatted cricket powder could be a promising ingredient for food applications.

Structure, antioxidant activity, and neuroprotective effect of black soybean (Glycine max (L.) merr.) protein hydrolysates

The potential biological properties of protein hydrolysates have generated considerable research interest. This study was to hydrolyze black soybean protein (BSP) using five different commercial enzymes, and elucidate the influence of these enzymes on the structure and biological activities of the resulting hydrolysates. Enzymatic treatment changed secondary and tertiary structures of BSP, decreased particle size, α-helix and β-sheet. Alcalase hydrolysate had the highest hydrolytic degree (29.84 %), absolute zeta potential (38.43 mV), the smallest particle (149.87 nm) and molecular weight (<3 kDa). In silico revealed alcalase hydrolysate had the strongest antioxidant potential. This finding was further validated through the lowest IC50 (mg/mL) in DPPH (2.67), ABTS (0.82), Fe2+ chelating (1.33) and·OH (1.12). Moreover, cellular antioxidant assays showed alcalase hydrolysate had the strongest cytoprotective effects on H2O2-induced PC12 cells. These results suggest BSPEHs, especially those prepared by alcalase, have potential as bioactive ingredients for nutrition, healthcare and food industry.

Impact of Alcalase Hydrolysis and Simulated Gastrointestinal Digestion on the Release of Bioactive Peptides from Erythrina edulis (Chachafruto) Proteins.

Amidst increasing awareness of diet-health relationships, plant-derived bioactive peptides are recognized for their dual nutritional and health benefits. This study investigates bioactive peptides released after Alcalase hydrolysis of protein from chachafruto (Erythrina edulis), a nutrient-rich South American leguminous plant, focusing on their behavior during simulated gastrointestinal digestion. Evaluating their ability to scavenge radicals, mitigate oxidative stress, and influence immune response biomarkers, this study underscores the importance of understanding peptide interactions in digestion. The greatest contribution to the antioxidant activity was exerted by the low molecular weight peptides with ORAC values for the <3 kDa fraction of HES, GD-HES, and GID-HES of 0.74 ± 0.03, 0.72 ± 0.004, and 0.56 ± 0.01 (μmol TE/mg protein, respectively). GD-HES and GID-HES exhibited immunomodulatory effects, promoting the release of NO up to 18.52 and 8.58 µM, respectively. The findings of this study highlighted the potential of chachafruto bioactive peptides in functional foods and nutraceuticals, supporting human health through dietary interventions.

Physicochemical properties, antioxidant and antidiabetic activities of different hydrolysates of goat milk protein

There is growing interest in the origin, preparation, and application of bioactive peptides. This study investigated the impact of 6 enzymes on the structural, physicochemical properties, antioxidant activities, and antidiabetic potential of defatted fresh goat milk. Structural and functional changes resulting from enzymatic hydrolysis were assessed using gel electrophoresis, laser particle size analysis, multi-spectroscopy, and evaluations of foaming and emulsification properties. Antioxidant capacity was determined through free radical scavenging, Fe2+ chelation, and reducing ability experiments. Additionally, the inhibitory effects of the hydrolysates on α-glucosidase and α-amylase were measured to evaluate antidiabetic activity. Results showed that enzymatic hydrolysis disrupted the spatial structure of goat milk protein and reduced its molecular weight. Papain hydrolysate exhibited the highest degree of hydrolysis (32.87 ± 0.11%) and smallest particle size (294.75 ± 3.33 nm), followed by alcalase hydrolysate (29.12 ± 0.09%, 302.03 ± 7.28 nm). Alcalase hydrolysate showed the best foaming properties, while papain hydrolysate demonstrated the strongest DPPH and hydroxyl radical scavenging activity, Fe2+ chelation, and antidiabetic potential. These findings provide solid theoretical basis for utilizing defatted goat milk as functional ingredients or excipients in the food, medical, and cosmetic industries.

Angiotensin-Converting Enzyme and Renin-Inhibitory Activities of Protein Hydrolysates Produced by Alcalase Hydrolysis of Peanut Protein.

Hypertension is a major controllable risk factor associated with cardiovascular disease (CVD) and overall mortality worldwide. Most people with hypertension must take medications that are effective in blood pressure management but cause many side effects. Thus, it is important to explore safer antihypertensive alternatives to regulate blood pressure. In this study, peanut protein concentrate (PPC) was hydrolyzed with 3-5% Alcalase for 3-10 h. The in vitro angiotensin-converting enzyme (ACE) and renin-inhibitory activities of the resulting peanut protein hydrolysate (PPH) samples and their fractions of different molecular weight ranges were determined as two measures of their antihypertensive potentials. The results show that the crude PPH produced at 4% Alcalase for 6 h of hydrolysis had the highest ACE-inhibitory activity with IC50 being 5.45 mg/mL. The PPH samples produced with 3-5% Alcalase hydrolysis for 6-8 h also displayed substantial renin-inhibitory activities, which is a great advantage over the animal protein-derived bioactive peptides or hydrolysate. Remarkably higher ACE- and renin-inhibitory activities were observed in fractions smaller than 5 kDa with IC50 being 0.85 and 1.78 mg/mL. Hence, the PPH and its small molecular fraction produced under proper Alcalase hydrolysis conditions have great potential to serve as a cost-effective anti-hypertensive ingredient for blood pressure management.

In Vitro Multi-Bioactive Potential of Enzymatic Hydrolysis of a Non-Toxic Jatropha curcas Cake Protein Isolate.

The Jatropha curcas cake, a protein-rich by-product of biofuel production, was the subject of our study. We identified and quantified the ACE inhibitory, antioxidant, and antidiabetic activities of bioactive peptides from a Jatropha curcas L. var Sevangel protein isolate. The protein isolate (20.44% recovered dry matter, 38.75% protein content, and 34.98% protein yield) was subjected to two enzyme systems for hydrolysis: alcalase (PEJA) and flavourzyme (PEJF), recording every 2 h until 8 h had passed. The highest proteolytic capacity in PEJA was reached at 2 h (4041.38 ± 50.89), while in PEJF, it was reached at 6 h (3435.16 ± 59.31). Gel electrophoresis of the PEJA and PEJF samples showed bands corresponding to peptides smaller than 10 kDa in both systems studied. The highest values for the antioxidant capacity (DPPH) were obtained at 4 h for PEJA (56.17 ± 1.14), while they were obtained at 6 h for PEJF (26.64 ± 0.52). The highest values for the antihypertensive capacity were recorded at 6 h (86.46 ± 1.85) in PEJF. The highest antidiabetic capacity obtained for PEJA and PEJF was observed at 6 h, 68.86 ± 8.27 and 52.75 ± 2.23, respectively. This is the first report of their antidiabetic activity. Notably, alcalase hydrolysate outperformed flavourzyme hydrolysate and the cereals reported in other studies, confirming its better multi-bioactivity.

Angiotensin-I-converting enzyme and renin inhibitions by antioxidant shrimp shell protein hydrolysate and ultrafiltration peptide fractions

Protein hydrolysates with 20% and 30% degrees of hydrolysis (DH) were produced from alcalase hydrolysis of Pacific white shrimp shells. The study aimed to investigate the antioxidant and antihypertensive activities of these protein hydrolysates, focusing on peptide fractions of various molecular weights (MW) obtained through ultrafiltration. The 30% DH protein hydrolysate (SSPH) showed the highest antioxidant activities and was subjected to ultrafiltration to produce peptides of various molecular weights (MW) (F1:10–50, F2:5–10, F3:3–5, F4:1-3, and F5:<1 kDa). SSPH showed higher hydrophilic and non-essential amino acid content, among which alanine and aspartic acid were at higher levels. The obtained peptide fractions were analyzed for various antioxidant activities and inhibitory activities against angiotensin-converting enzyme and renin. F4 and F2 samples showed the highest DPPH (2.00 mM TE/g sample) and ABTS (60.68 mM TE/g sample) radical scavenging activities, respectively. Superoxide and hydrogen peroxide radical scavenging activity augmented with decreasing MW, aside from for F1, which showed higher activity than F2–F4 (p < 0.05). The highest ACE-inhibitory activity was found for the F2 fraction (44%–55%), and renin inhibitory activity increased with decreasing MW, in which F5 (12%–22%) was the most effective (p < 0.05). F5 showed 6 major peptides, among which KLVRGSKS and LPKKCLSARPG were the dominant sequences. Thus, this study suggests that shrimp shell protein isolate could be an alternative protein source for peptides with various antioxidant and antihypertensive activities, with potential applications in functional foods and nutraceuticals aimed at mitigating oxidative stress and hypertension.

Commercial Production of Highly Rehydrated Soy Protein Powder by the Treatment of Soy Lecithin Modification Combined with Alcalase Hydrolysis.

The low rehydration properties of commercial soy protein powder (SPI), a major plant-based food ingredient, have limited the development of plant-based foods. The present study proposes a treatment of soy lecithin modification combined with Alcalase hydrolysis to improve the rehydration of soy protein powder, as well as other processing properties (emulsification, viscosity). The results show that the soy protein-soy lecithin complex powder, which is hydrolyzed for 30 min (SPH-SL-30), has the smallest particle size, the smallest zeta potential, the highest surface hydrophobicity, and a uniform microstructure. In addition, the value of the ratio of the α-helical structure/β-folded structure was the smallest in the SPH-SL-30. After measuring the rehydration properties, emulsification properties, and viscosity, it was found that the SPH-SL-30 has the shortest wetting time of 3.04 min, the shortest dispersion time of 12.29 s, the highest solubility of 93.17%, the highest emulsifying activity of 32.42 m2/g, the highest emulsifying stability of 98.33 min, and the lowest viscosity of 0.98 pa.s. This indicates that the treatment of soy lecithin modification combined with Alcalase hydrolysis destroys the structure of soy protein, changes its physicochemical properties, and improves its functional properties. In this study, soy protein was modified by the treatment of soy lecithin modification combined with Alcalase hydrolysis to improve the processing characteristics of soy protein powders and to provide a theoretical basis for its high-value utilization in the plant-based food field.

Purification and identification of novel osteogenic peptides from sea cucumber intestine hydrolysates and their pro-osteogenesis effects on MC3T3-E1 cells

The present study aimed to purify and identify osteogenic peptides from sea cucumber intestine hydrolysates (Mw＜3 kDa) and further evaluate their pro-osteogenesis properties on MC3T3-E1 cells. Two novel osteogenic peptides, RPQYPQYPS and LSFSPY, were purified and identified from the alcalase hydrolysate of sea cucumber intestine by gel filtration chromatography, ion exchange column chromatography, RP-HPLC, which were further sequenced by LC-MS/MS and synthesized with solid-phase synthesis method. Peptides RPQYPQYPS and LSFSPY significantly increased the proliferation of MC3T3-E1 cells by 38.7% and 32.8%. Alizarin red staining also confirmed that peptides RPQYPQYPS and LSFSPY significantly promoted MC3T3-E1 cell mineralization in a dose-dependent manner. Further, molecular docking results showed that RPQYPQYPS and LSFSPY had a higher affinity with integrin α5β1. Western blot results confirmed that RPQYPQYPS and LSFSPY significantly upregulated the expression of integrin downstream signals PI3K, ERK and Wnt10b. These findings provided evidence for the osteogenic peptides from sea cucumber intestines as a functional food ingredient.

Turning discarded blue shark (Prionace glauca) skin into a valuable nutraceutical resource: An enzymatic collagen hydrolysate

Marine-derived collagen, particularly from blue shark (Prionace glauca) skin, represents a sustainable resource for the nutraceutical industry, yet its effective utilization remains underexplored. This study aims to optimise the enzymatic hydrolysis of blue shark skin collagen using alcalase and bromelain to enhance the bioactive properties of the resultant hydrolysates. We employed a multifactorial experimental design to determine the optimal hydrolysis conditions, assessing factors including enzyme concentration, pH, and temperature. The alcalase-treated hydrolysates demonstrated superior antioxidant and anti-inflammatory activities compared to those treated with bromelain, with increased solubilised proteins and a higher degree of hydrolysis. Notably, peptide profiles indicated that alcalase hydrolysates favoured the production of smaller peptides, suggesting enhanced bioavailability and digestive stability. In vitro gastrointestinal simulations demonstrated the functional stability of these peptides, indicating that while they undergo structural changes during digestion, their potential for gastrointestinal health remains significant. Our findings highlight the feasibility of converting blue shark skin, a commonly discarded by-product, into valuable nutraceutical ingredients, thus contributing to marine sustainability and waste reduction This research advances the biotechnological application of marine collagen and opens avenues for developing functional foods and pharmaceuticals.

Conformation-Activity Mechanism of Alcalase Hydrolysis for Reducing In Vitro Allergenicity of Instant Soy Milk Powder.

Effective reduction of the allergenicity of instant soy milk powder (ISMP) is practically valuable for expanding its applications. This study optimized the enzymolysis technology of ISMP using single-factor experiments and response surface methodology, combined serological analysis, cellular immunological models, bioinformatics tools, and multiple spectroscopy techniques to investigate the effects of alcalase hydrolysis on allergenicity, spatial conformation, and linear epitopes of ISMP. Under the optimal process, special IgE and IgG1 binding abilities and allergenic activity to induce cell degranulation of alcalase-hydrolyzed ISMP were reduced by (64.72 ± 1.76)%, (56.79 ± 3.72)%, and (73.3 ± 1.19)%, respectively (P < 0.05). Moreover, the spatial conformation of instant soy milk powder hydrolysates (ISMPH) changed, including decreased surface hydrophobicity, a weaker peak of amide II band, lower contents of α-helix and β-sheet, and an enhanced content of random coil. Furthermore, the linear epitopes of major soy allergens, 9 from glycinin and 13 from β-conglycinin, could be directionally disrupted by alcalase hydrolysis. Overall, the structure-activity mechanism of alcalase hydrolysis to reduce ISMP allergenicity in vitro was preliminarily clarified. It provided a new research direction for the breakthrough in the desensitization of ISMP and a theoretical basis for revealing the potential mechanism of alcalase enzymolysis to reduce the allergenicity of ISMP.

Protein hydrolysates of Moringa oleifera seed: Antioxidant and antihyperglycaemic potential as ingredient for the management of type-2 diabetes

New plant proteins with high nutritional quality and biological properties are actively searched worldwide. Moringa oleifera seed protein isolate was prepared from defatted flour and hydrolyzed using four proteases namely trypsin, pepsin, Alcalase, and thermolysin. Then, antioxidant activity and cellular glucose uptake properties of the hydrolysates were assessed. A high degree of hydrolysis was obtained for hydrolysate prepared using trypsin (60.07%), followed by pepsin (57.14%), Alcalase (50.68%), and thermolysin (45.45%). Thermolysin hydrolysate was the most antioxidant efficient (IC50 0.15 and 0.74 mg/mL for 2,2′-azino-bis(acide 3-ethylbenzothiazoline-6-sulfonique) diammonium salt (ABTS) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, respectively). Trypsin hydrolysate stimulated high glucose uptake by yeast cells (12.34–35.28%). In the absence of insulin, Alcalase hydrolysate was the most efficient for glucose uptake by the muscle, with the rate ranging from 22.03% to 29.93% after 30 min, then from 29.55% to 34.6% after 60 min. The four hydrolysates improved glucose uptake by the muscle in the presence of insulin with the rate ranging from 46.88% to 58.03% after 30 min, and from 50% to 58.18% after 60 min. Therefore, Moringa oleifera seed proteins could be used to prepare peptides as components of functional foods for the management of type-2 diabetes.

Comparison of prediction models for soy protein isolate hydrolysates bitterness built using sensory, spectrofluorometric and chromatographic data from varying enzymes and degree of hydrolysis

The bitterness of soy protein isolate hydrolysates prepared using five proteases at varying degree of hydrolysis (DH) and its relation to physicochemical properties, i.e., surface hydrophobicity (H0), relative hydrophobicity (RH), and molecular weight (MW), were studied and developed for predictive modelling using machine learning. Bitter scores were collected from sensory analysis and assigned as the target, while the physicochemical properties were assigned as the features. The modelling involved data pre-processing with local outlier factor; model development with support vector machine, linear regression, adaptive boosting, and K-nearest neighbors algorithms; and performance evaluation by 10-fold stratified cross-validation. The results indicated that alcalase hydrolysates were the most bitter, followed by protamex, flavorzyme, papain, and bromelain. Distinctive correlation results were found among the physicochemical properties, influenced by the disparity of each protease. Among the features, the combination of RH-MW fitted various classification models and resulted in the best prediction performance.

Antioxidant, Antibacterial Properties of Novel Peptide CP by Enzymatic Hydrolysis of Chromis notata By-Products and Its Efficacy on Atopic Dermatitis.

This study investigated the antioxidant, antimicrobial, and anti-atopic dermatitis (AD) effects of a novel peptide (CP) derived from a Chromis notata by-product hydrolysate. Alcalase, Flavourzyme, Neutrase, and Protamex enzymes were used to hydrolyze the C. notata by-product protein, and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity was measured. Alcalase hydrolysate exhibited the highest ABTS radical-scavenging activity, leading to the selection of Alcalase for further purification. The CHAO-1-I fraction, with the highest ABTS activity, was isolated and further purified, resulting in the identification of the peptide CP with the amino acid sequence Ala-Gln-Val-Met-Lys-Leu-Pro-His-Arg-Met-Gln-His-Ser-Gln-Ser. CP demonstrated antimicrobial activity against Staphylococcus aureus, inhibiting its growth. In a 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin model in mice, CP significantly alleviated skin lesions, reduced epidermal and dermal thickness, and inhibited mast cell infiltration. Moreover, CP suppressed the elevated levels of interleukin-6 (IL-6) in the plasma of DNCB-induced mice. These findings highlight the potential of CP as a therapeutic agent for AD and suggest a novel application of this C. notata by-product in the fish processing industry.

Process control of rice protein enzymolysis by field monitoring

By devising a novel near-infrared (NIR) in-situ online monitoring system, this study proposed a new process control method for rice protein (RP) enzymatic hydrolysis in order to address the challenge of monitoring certain chemical indices in real-time. The endpoint of the enzymatic hydrolysis reaction and the flexible switching point of dual-enzyme hydrolysis were determined through real-time spectrum collection. Correction and prediction models were constructed to predict the angiotensin I-converting enzyme (ACE) inhibitory activity of RP hydrolysis as well as the endpoint and the dual-enzyme flexible switching point at different substrate concentrations in an attempt to establish the new control system. At the RP substrate concentrations of 35, 40, and 45 g/L, the R2 of predicted and measured ACE inhibitory activity values under hydrolysis with a single alcalase were 0.8852, 0.8360, and 0.8613, respectively. In addition, the ACE inhibitory activity of dual-enzyme hydrolysis showed a high growth trend before and after the flexible switching point, and the hydrolysis time was significantly shortened at the same endpoint threshold as that of single alcalase hydrolysis. The results indicated that this method is capable of accurately determining and regulating the endpoint and adaptable transition point of RP hydrolysis. Consequently, this approach holds promise for the regulation of food basic materials during large-scale processing operations.