Optimal Hydrolysis Conditions Research Articles

Oral Intake of Collagen and Collagen Hydrolysate From Takifugu bimaculatus Attenuates Ultraviolet‐Induced Skin Photoaging in Mice

ABSTRACTWith the rapid emergence of pufferfish aquaculture and processing industries, fish skin is underutilized as a byproduct of processing, leading to resource waste. In this study, Takifugu bimaculatus skin collagen (TBSC) was extracted by acetic acid solubilization and its physicochemical properties were analyzed. The effects of TBSC and the TBSC hydrolysate (TBSCH) on ultraviolet (UV) irradiation‐induced photoaging were investigated using a mouse model. The purity of TBSC was 90.02%. Electrophoresis and Fourier infrared spectroscopy characterization of TBSC showed that the type of collagen in TBSC was typical standard type I. The degree of hydrolysis was selected to optimize the hydrolysis conditions for TBSC. The papain enzyme dosage, temperature, pH, and hydrolysis duration of 51,000 U/g, 48.03°C, 5.35, and 4 h have been demonstrated to be the optimum hydrolysis conditions for TBSCH. Oral administration of either TBSC or TBSCH ameliorated UV‐induced skin erythema and hyperkeratosis. TBSC and TBSCH treatment increased collagen content and had an inhibitory effect on matrix metalloproteinase (MMP)‐2 and MMP‐3 expression, whereas MMP‐9 expression was significantly reversed only in the TBSCH‐treated groups. The expression of the c‐Jun protein was much lower in these groups, suggesting that TBSCH had a greater alleviating effect on collagen degradation and extracellular matrix breakdown. Therefore, it is proposed that TBSCH has the potential to be used as a nutricosmetic agent with protective attributes against UV‐induced skin damage and concurrent collagen depletion.

Optimizing β-Lactoglobulin antigenicity through single enzyme hydrolysis: Exploring structural changes and effects on linear epitopes

β-lactoglobulin (β-LG) is the major allergen in dairy products, but research on the optimal conditions for antigen reduction in β-LG using different enzymes remains limited. Therefore, this study aims to investigate the antigenicity, structural characteristics, and peptide distribution of advantageous protease hydrolysates capable of eliminating the allergenic epitopes of β-LG selected via bioinformatics tools. The results showed that under optimal enzymatic hydrolysis conditions, the antigen reduction rates for the four advantageous proteases acting on β-LG were 47.37 % (pepsin), 33.54 % (chymotrypsin A), 38.71 % (papain), and 45.91 % (stem bromelain), respectively. The four proteases effectively degraded β-LG, causing shorter peptide chain formation, reduced content of highly ordered α-helix, decreased fluorescence intensity, and lower surface hydrophobicity. Furthermore, they cleaved the linear epitopes of β-LG into peptides of varying sizes, leading to different antigen reduction rates among the hydrolysates. These findings provide a theoretical basis for developing targeted enzymatic hydrolysis technologies and low-allergenicity dairy-based materials.

Study of the Sodium Borohydride Hydrolysis Reaction's Performance via a Kaolin-Supported Co-Cr Bimetallic Catalyst

Hydrogen is an attractive source of energy because of its properties, which include superior quality, effectiveness, pureness, dependability, and sustainability. Technologies for producing and storing hydrogen are being developed in parallel with fuel cell development. Chemical storage of hydrogen in a metal hydride containing boron eliminates the problem of hydrogen transportation and storage. Through catalytic reactions, hydrogen stored in solid form in boron hydrides can be recovered. In this study, a nowel developed Co-Cr bimetallic catalyst supported by kaolin, a natural mineral, was synthesized to be used for hydrogen production by hydrolysis of sodium boron hydride. The structural characteristics of the produced Co-Cr@Kaolin catalyst were ascertained by EDX, FTIR, and SEM analyses. Next, the ideal conditions for the hydrolysis reaction of sodium borohydride (NaBH4) catalyzed by Co-Cr@Kaolin were examined. These included the concentration of the catalyst, the amount of support material (kaolin), the amount of catalyst, and the concentration of NaBH4. The optimal hydrolysis conditions were found to be 2.5% NaOH concentration, 40 mg of catalyst, and 2% NaBH4 concentration at 303 K. The maximum rate of hydrogen production was determined as 5007 ml g-1 min-1 under optimal conditions. After conducting hydrolysis operations at different temperatures to elucidate the reaction kinetics, it was found that the catalytic hydrolysis reaction was of the 0th order and that the reaction activation energy was 19.36 kJ mol-1. The hydrogen production rate obtained as a result of the hydrolysis reaction accompanied by a Co-Cr catalyst was determined as 3166 ml g-1 min-1. It is therefore established that supporting kaolin to Co-Cr catalyst enhances its efficacy.

Biotransformation of ginsenoside compound K using β-glucosidase in deep eutectic solvents.

Ginsenoside compound K (CK) holds significant potential for application in the pharmaceutical industry, which exhibits numerous pharmacological activity such as cardioprotective and antidiabetic. However, the difficult separation technique and limited yield of CK hinder its widespread use. The study investigated the process of converting ginsenoside CK using β-glucosidase. It aimed to determine the specific site where the enzyme binds and the most favorable arrangement of the enzyme. Molecular docking was also employed to determine the interaction between β-glucosidase and ginsenosides, indicating a strong and spontaneous contact force between them. The effectiveness of the conversion process was further improved using a "green" deep eutectic solvent (DES). A univariate experimental design was used to determine the composition of DES and the optimal hydrolysis conditions for β-glucosidase to convert ginsenoside Rb1 into ginsenoside CK. The employment of β-glucosidase enzymatic hydrolysis in the synthesis of rare ginsenoside CK applying the environmentally friendly solvent DES is not only viable and effective but also appropriate for industrial use. The characterization methods confirmed that DES did not disrupt the structure and conformation of β-glucosidase. In ChCl:EG = 2:1 (30%, v/v), pH 5.0 of DES buffer, reaction temperature 50 ℃, enzyme substrate mass ratio 1:1, after 36h of reaction, the CK yield was 1.24 times that in acetate buffer, which can reach 86.2%. In this study, the process of using β-glucosidase enzymatic hydrolysis and producing rare ginsenoside CK in green solvent DES is feasible, efficient and suitable for industrial production and application.

Production and Optimization of Bioethanol from Mixed Banana and Papaya Peels Using <i>Saccharomyces Cerevisiae</i>

Mixed fruit peels (Banana (BP) and Papaya (PP) bioethanol was produced using Saccharomyces cerevisiae. The proximate and compositional analysis of BP and PP was obtained about 6.67% moisture, 5.75% ash, 82.75% volatile matter, and 5% fixed carbon and 1.1gram, 38.1%, 15.7% and 45.1% extractives, hemicellulose, lignin, and cellulose respectively from BP and 8.165% moisture, 5.5% ash, 81.25% volatile matter and 6% fixed carbon 2.08 gram, 42%, 8.6% and 47.32% extractives, hemicellulose, lignin, and cellulose respectively from PP. After Pretreat with KOH (5% w/v) optimize hydrolysis process parameters based on central composite design (CCD) to maximize fermentable sugars. The optimized hydrolysis conditions were 50:50 w/v% mixing of BP and PP, 1.75% H<sub>2</sub>SO<sub>4</sub>, and pH 5. The reducing sugar content was measured by DNS and results 11.737g/ml from fifty (50) grams of BP and PP. The maximum yield of bioethanol was 22.5% recorded after 72 hours. Fourier Transform Infrared Spectroscopy (FTIR) peaks associated with O-H, C-O, and C-H stretching and vibrations confirmed the presence of bioethanol in the product. The result confirms that the combination of BP and PP boosts bioethanol productivity than single peels.

Optimization of the alcalase and trypsin hydrolysis conditions of an isolated protein from Scenedesmus obliquus microalgae and characterization of its functional properties

This study focused on fine-tuning the enzymatic hydrolysis variables, specifically the duration and enzyme concentrations of alcalase and trypsin, for Scenedesmus obliquus protein using response surface methodology (RSM) with a central composite design (CCD). The aim was to characterize the amino acids, separate hydrolysates based on molecular weight, and assess functional activities such as antioxidant, emulsifying, fat-binding, and foaming capacities. After fractionating the hydrolysates, bioactivities were evaluated through standard assays. The optimal hydrolysis conditions—10.24 g/100 mL alcalase and 2.56 g/100 mL trypsin—yielded the highest protein extraction. Peptides smaller than 5 kDa demonstrated 80% DPPH inhibition and superior fat-binding capacity. Emulsifying capacity peaked at 112 m2/g for peptides under 10 kDa, and the highest foaming index was observed for peptides below 5 kDa. The application of RSM effectively optimized the hydrolysis of microalgal protein isolates for maximum efficiency, highlighting microalgae's potential as a sustainable source of functional ingredients.

Preparation, identification and screening of anti-osteoporosis milk-derived peptides: Intervention effects in osteoporosis rats

To identify milk-derived peptides with both antioxidant and calcium absorption activities in combating osteoporosis, we employed a comprehensive screening approach that included virtual enzymatic hydrolysis, molecular docking, and cellular experiments using osteoblasts. Under the optimal conditions for dual-enzyme hydrolysis, the 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical scavenging rate and soluble calcium binding capacity of the milk-derived peptides were 19.69% and 0.6965 μg/mL, respectively. Six peptide segments, namely KEDVPSER, HKEMPFPK, YPSYG, EDVPSE, VPQLE, and IPAVF, were identified through UPLC-Q-Exactive Orbitrap MS and molecular docking for further validation. Among the peptides, YPSYG significantly promoted the proliferation of MC3T3-E1 cells both with and without CaCl2 (P < 0.05), increasing proliferation by 38.27% and 20.67%, respectively, compared to the control group. Additionally, YPSYG significantly improved proliferation after H2O2-induced oxidative damage (P < 0.05), with a 38.23% higher rate than the model group. Compared with rats in the osteoporosis model group, YPSYG significantly enhanced serum alkaline phosphatase (ALP) and N-terminal propeptide of type I procollagen in rats (s-PINP) levels and decreased tartrate-resistant acid phosphatase (TRAP) levels (P < 0.05). Furthermore, milk-derived peptides and YPSYG significantly increased the bone weight index, maximum load, and bending energy of the femur and tibia in osteoporotic rats (P < 0.05). Additionally, these peptides significantly reduced the number of osteoclasts in the metaphysis of the femur and tibia in osteoporotic rats and alleviated microstructural damage. This study confirmed that milk-derived peptides, including YPSYG, effectively promoted bone formation and improved bone microstructure in osteoporotic rats. These findings provided a foundation for developing functional foods for elderly bone health.

Enzymatic Hydrolysis as an Effective Method for Obtaining Wheat Gluten Hydrolysates Combining Beneficial Functional Properties with Health-Promoting Potential.

The byproduct from wheat starch production contains approximately 70% gluten (WG) and is an inexpensive but demanding protein raw material for the food industry. This study attempted to determine the optimal hydrolysis conditions for such raw material to obtain peptides combining beneficial functional characteristics with health-promoting activity. The proteases Bromelain, Alcalase, Flavourzyme, and a protease from A. saitoi were used for hydrolysis. It was shown that the tested proteases differ both in terms of the effective hydrolysis conditions of gluten and the profile of the released hydrolysates. Bromelain was particularly effective in converting gluten into peptides, combining beneficial health and functional properties. It achieved maximum activity (189 U/g) against WG at pH 6 and 60 °C, and the best-balanced peptides in terms of desired properties were released at a dose of 2.5 U/g. These peptides were free from most allergenic epitopes, effectively inhibited ACE, and, at 0.34 g, were equivalent to the approved dose of BHT. Their emulsifying activity was higher than that of gluten, and the foaming formation and stabilization potential exceeded that of ovalbumin by 10% and 19%, respectively. It seems that Bromelain-released WG hydrolysates are a promising candidate for a safe fat stabilizer and egg white substitute.

The functional attributes of protein hydrolysates from horsegram (Macrotyloma uniflorum)

SummaryThe functional attributes of enzymatically derived horsegram protein hydrolysates from dehulled horsegram were investigated in this study. Hydrolysates were produced using commercial proteases, namely Alcalase® 2.4L and Protex 6L, at varying degrees of hydrolysis (DH) – specifically, 5%, 8%, and 10%. Maximum DH reached 11% with Alcalase® 2.4L and 11.5% with Protex 6L. Optimal hydrolysis conditions entailed a dehulled horsegram concentration of 2.5% (w/v), an enzyme–substrate ratio (E/S) of 0.001% for Alcalase® 2.4L and 0.002% for Protex 6L, at 55 °C and 60 °C, respectively, for 5 h, maintaining a pH of 7.5. Enhanced solubility was observed across a wide pH range (2–10), with HG‐PH exhibiting an increase from 21% to 56%. Analysis of functional properties revealed a significant elevation (P &lt; 0.05) in both water holding and oil holding capacities with increasing DH. Emulsion activity decreased from 0.5 to 0.1 in proportion to DH increase. Conversely, foaming capacity (FC) showed a positive correlation with the hydrolysis extent, rising from 24% to 98%. However, foam stability decreased across all samples, declining from 84% to 12%. These findings underscore the potential of incorporating these hydrolysates into diverse food applications, capitalising on their heightened solubility, water and oil holding capacities, and foam‐forming characteristics. The comprehensive array of functional properties exhibited by HG‐PH renders it a promising ingredient for integration into food product formulations.

Improved Sugar Recovery from Mandarin Peel under Optimal Enzymatic Hydrolysis Conditions and Application to Bioethanol Production

Improved Sugar Recovery from Mandarin Peel under Optimal Enzymatic Hydrolysis Conditions and Application to Bioethanol Production

Optimization of the Preparation Process and Ameliorative Efficacy in Osteoporotic Rats of Peptide-Calcium Chelates from Skipjack Tuna (Katsuwonus pelamis) Meat.

This study aimed to establish the preparation process of peptide-calcium chelates (TMP-Ca) using skipjack tuna meat and investigate the function and mechanism of TMP-Ca in an osteoporosis model of rats. The results indicated that trypsin is more suitable for preparing the Ca-chelating hydrolysates of tuna meat, and the optimal hydrolysis conditions were derived as follows: digestion time 4 h, material-liquid ratio 1:10, and enzyme dose 3%. The conditions for chelating Ca with tuna meat hydrolysate were optimized to be chelation time 50 min, temperature 50 °C, pH 8.0, and a peptide-Ca ratio 1:10. The prepared hydrolysate was subjected to ultrafiltration, and the fraction (TMP) (MW <1 kDa) showed the highest Ca chelation rate (51.27 ± 1.42%) and was made into the peptide-Ca chelates (TMP-Ca). In osteoporotic rats, TMP-Ca significantly improved the decrease in ovarian indexes caused by retinoic acid. It also elevated serum Ca, phosphorus, and bone turnover indexes, increased the number of bone trabeculae, and improved bone microstructure. In addition, we confirmed that TMP-Ca could regulate the OPG/TRAF6 pathway to reduce osteoclast differentiation, inhibit bone resorption, and promote bone formation. Therefore, TMP-Ca could significantly ameliorate osteoporosis, and this study provides a functional component for the preparation of healthcare products using skipjack tuna meat to treat osteoporosis.

Effects and optimization of hydrolysis conditions on the diameter distance ratio for metatitanic acid

Controlling and predicting the narrow particle size distribution of metatitanic acid could help to improve pigment and application performances of TiO2. To prepare metatitanic acid with narrow particle size distribution, the hydrolysis conditions of industrial TiOSO4 solution were optimized by using the response surface methodology of Box-Behnken design method. The effects of hydrolysis conditions such as TiO2 concentration, aging time and hydrolysis time on the diameter distance ratio and structure of metatitanic acid were investigated. The prediction model including the hydrolysis variables with good fitting result was established to predict the diameter distance ratio or optimize the hydrolysis variable values. The regression equation model was significant and reliable with actual correlation coefficient R2 of 0.9989. The hydrolysis conditions greatly influenced the quality and quantity of hydrolysis induced crystal nucleus, hydrolysis rate, completeness degree of hydrolysis, crystallization growth and aggregation rate, and eventually affected the particle size distribution of metatitanic acid. The synergistic interaction for TiO2 concentration and hydrolysis time was very significant. The verification experiments confirmed that the diameter distance ratio could reach the average value of 1.100 under the optimal conditions. The prepared metatitanic acid had anatase TiO2 phase structure, with average particle size of 1.621–1.819 µm. And this helped to improve the high quality and green development of the titanium dioxide industry.

Preparation, characterisation and functional effects of goat milk whey protein isolate with low lactose after heat and non‐heat treatments

This study investigates the physicochemical and functional properties of goat milk whey with heat and non‐heat treatments (pasteurisation, high‐temperature heating, ultrasonic treatment and microwave heating) and lactose hydrolysis. The optimal lactose hydrolysis conditions were obtained through orthogonal test. The results revealed the lactose and glucose in low‐lactose goat milk whey remained largely unchanged through all four treatments, while high‐temperature and microwave treatments induced protein structure alteration. The foaming and emulsifying properties of low‐lactose whey powder were enhanced by heating and ultrasonic treatments, although foam stability decreased. Our findings provide valuable insights into exploiting more nutritional goat milk products.

Valorization of Yellowfin Tuna Tails: From Proteolytic Enzyme Production to Gelatin and Antioxidant Hydrolysate Extraction.

This study investigates the valorization potential of yellowfin tuna (Thunnus albacares) tails to produce high-value commercial products. Firstly, the tuna tails were placed in a perforated stainless-steel cylinder, and hydraulic pressure was applied to separate the skin from the muscle in the tails. The extracted muscle was then utilized as a nitrogen source for the growth of the proteolytic enzyme producer Bacillus subtilis, while the skins were employed for gelatin extraction. The proteases from B. subtilis were partially purified and used to produce antioxidant peptides from the obtained gelatin. The gelatin formed a gel upon cooling, with gelling and melting temperatures of 16 °C and 22 °C, respectively, and a Bloom strength of approximately 160. Response Surface Methodology (RSM) was employed to determine the optimal hydrolysis conditions to achieve the highest antioxidant activity (35.96% measured as DPPH radical scavenging activity), which were 50 °C and 6.5 IU of enzyme. The findings emphasize the importance of an integrated approach to maximize the value of tuna by-products, promoting sustainability within the framework of a circular bioeconomy. Overall, these results contribute to the efficient utilization of tuna by-products, waste reduction, and enhanced economic viability of the tuna industry.

Optimizing the Conditions of Pretreatment and Enzymatic Hydrolysis of Sugarcane Bagasse for Bioethanol Production.

The agricultural waste sugarcane bagasse (SCB) is a kind of plentiful biomass resource. In this study, different pretreatment methods (NaOH, H2SO4, and sodium percarbonate/glycerol) were utilized and compared. Among the three pretreatment methods, NaOH pretreatment was the most optimal method. Response surface methodology (RSM) was utilized to optimize NaOH pretreatment conditions. After optimization by RSM, the solid yield and lignin removal were 54.60 and 82.30% under the treatment of 1% NaOH, a time of 60 min, and a solid-to-liquid ratio of 1:15, respectively. Then, the enzymolysis conditions of cellulase for NaOH-treated SCB were optimized by RSM. Under the optimal enzymatic hydrolysis conditions (an enzyme dose of 18 FPU/g, a time of 64 h, and a solid-to-liquid ratio of 1:30), the actual yield of reducing sugar in the enzyme-treated hydrolysate was 443.52 mg/g SCB with a cellulose conversion rate of 85.33%. A bacterium, namely, Bacillus sp. EtOH, which produced ethanol and Baijiu aroma substances, was isolated from the high-temperature Daqu of Danquan Baijiu in our previous study. At last, when the strain EtOH was cultured for 36 h in a fermentation medium (reducing sugar from cellulase-treated SCB hydrolysate, yeast extract, and peptone), ethanol concentration reached 2.769 g/L (0.353%, v/v). The sugar-to-ethanol and SCB-to-ethanol yields were 13.85 and 11.81% in this study, respectively. In brief, after NaOH pretreatment, 1 g of original SCB produced 0.5460 g of NaOH-treated SCB. Then, after the enzymatic hydrolysis, reducing sugar yield (443.52 mg/g SCB) was obtained. Our study provided a suitable method for bioethanol production from SCB, which achieved efficient resource utilization of agricultural waste SCB.

Non-ionic surfactant PEG: Enhanced cutinase-catalyzed hydrolysis of polyethylene terephthalate

To enhance the enzymatic digestibility of polyethylene terephthalate (PET), which is highly oriented and crystallized, a polyethylene glycol (PEG) surfactant of varying molecular weights was utilized to improve the stability of mutant cutinase from Humicola insolens (HiC) and to increase the accessibility of the enzyme to the substrate. Leveraging the optimal conditions for HiC hydrolysis of PET, the introduction of 1 % w/v PEG significantly increased the yield of PET hydrolysis products. PEG600 was particularly effective, increasing the yield by 64.58 % compared to using HiC alone. Moreover, the mechanisms by which PEG600 and PEG6000 enhance enzyme digestion were extensively examined using circular dichroism and fluorescence spectroscopy. The results from CD and fluorescence analyses indicated that PEG alters the protein conformation, thereby affecting the catalytic effect of the enzyme. Moreover, PEG improved the affinity between HiC and PET by lowering the surface tension of the solution, substantially enhancing PET hydrolysis. This study suggests that PEG holds considerable promise as an enzyme protector, significantly aiding in the hydrophilic modification and degradation of PET in an environmentally friendly and sustainable manner.

Response surface optimization in determining hydrolysis reaction on Barramundi scales gelatin using the box behnken design

Gelatin hydrolysate is a product with a wide range of benefits in pharmaceutical and food applications. Therefore, this study analyzes the best hydrolysis condition to make Barramundi (Lates calcarifer) scales gelatin hydrolysate using ultrasonication and lime juice. The conditions with the best degree of hydrolysis (DH) were optimized using the Response Surface Method (RSM) with Box Behnken Design (BBD). The effects of 3 independent variables, namely time, temperature, and enzyme concentrations, were then examined for model optimization. Based on the extraction method, DH varied between 57.40% and 68.60%. The equation characterizing the variables and DH correlation was DH = 0.01324 – 0.0012A + 0.0013B – 0.0028C -0.0004AB + 0.0019AC – 0.001BC – 0.0004A2 – 0,0042B2 – 0.0012C2 , A, B, and C were time, temperature, and E/S concentration. In addition, the optimized hydrolysis was performed at 31.03 mins, 56.84оC temperature, 1.5% E/S concentration, and pH 8.0. At these optimal conditions, alkaline protease hydrolysis yielded a 1.000 desirability value, with a 64.83% DH. Amino acid (AA) with the highest value in Barramundi scales gelatin hydrolysate was lysine (53.03 g/100 g), while isoleucine (0.05 g/100 g) had the lowest value. Based on the results, optimal hydrolysis conditions could be an excellent reference to increase the potential of Barramundi scales gelatin hydrolysate in developing future functional foods with high amino acids, particularly lysine.

Optimization of Sorghum Starch (Sorghum bicolor L.) Partial Hydrolysis using Microwave-Assisted Acetic Acid Catalyst

Hydrolysis process is relatively slow, requiring the use of catalyst and microwave assistance to accelerate the reaction. There fore, this study aimed to determine the optimum conditions for partial hydrolysis of sorghum starch (Sorghum bicolor L.) using acetic acid as a microwave-assisted catalyst to produce maltodextrin. The experiment was carried out in several stages, namely gelatinization, liquefaction, and drying, while Response Surface Method (RSM) was used for variable design and data analysis. Hydrolysis process was carried out with three independent variables, including acetic acid concentration (9%, 12%, and 15%), microwave power (300 watts, 400 watts, and 500 watts), and liquefaction time (35 minutes, 45 minutes, and 55 minutes). The results showed that the highest DE (Dextrose Equivalent) value of maltodextrin was found at 17.04% acid concentration, 400 watts microwave power, and 45 minutes liquefaction time, valued at 18.921 ± 0.099. The optimum dextrose equivalent of 17.763 would be achieved at 16.879% acetic acid concentration, 390.233 watts of microwave power, and 47.055 minutes of liquefaction time. This study introduces the innovation of using acetic acid as a catalyst and microwave assistance during the gelatinization stage.

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.

Preparation of xylooligosaccharides from rice husks and their structural characterization, antioxidant activity, and probiotic properties

Rice husks are rich in xylan, which can be hydrolyzed by xylanase to form xylooligosaccharides (XOS). XOS are a functional oligosaccharide such as improving gut microbiota and antioxidant properties. In this study, the structure and functional characteristics of XOS were studied. The optimal xylanase hydrolysis conditions through response surface methodology (RSM) were: xylanase dosage of 3000 U/g, hydrolysis time of 3 h, hydrolysis temperature of 50 °C. Under this condition, the yield of XOS was 150.9 mg/g. The TG-DTG curve showed that XOS began to decompose at around 200 °C. When the concentration of XOS reached 1.0 g/L, the clearance rate of DPPH reached 65.76 %, and the scavenging rate of OH reached 62.10 %, while the clearance rate of ABTS free radicals reached 97.70 %, which was equivalent to the clearance rate of VC. XOS had a proliferative effect on four probiotics: Lactobacillus plantarum, Lactobacillus brucelli, Lactobacillus acidophilus, and Lactobacillus rhamnosus. However, the further experiments are needed to explore the improvement effect of XOS on human gut microbiota, laying a foundation for the effective utilization of XOS. XOS have a wide range of sources, low price, and broad development prospects. The reasonable utilization of XOS can bring greater economic benefits.