Papain Concentration Research Articles

Comparison and Optimization of Three Extraction Methods for Epimedium polysaccharides

Epimedium is used in traditional Chinese medicine. Epimedium polysaccharides have a variety of physiological properties. This study compared three different processes for the extraction of polysaccharides from Epimedium spp., including ultrasonic, aqueous enzymatic, and microwave extraction, to optimize the extraction conditions and determine the optimal extraction method. The optimal parameters for each method were analyzed. The results showed that the optimal process for ultrasonic extraction was an ultrasonic power of 250 W, an extraction time of 60 min, a temperature of 50 °C, and a solid–liquid ratio of 1:35. The optimal conditions for the aqueous enzymatic method were a papain concentration of 70 U/mL, extraction time of 70 min, a temperature of 50 °C, and a material-to-liquid ratio of 1:30, while those for microwave extraction were a microwave power of 650 W, an extraction time of 50 min, a temperature of 40 °C, and a material-to-liquid ratio of 1:25. The polysaccharide yields were 4.85%, 4.72%, and 3.98% for the three methods, respectively, indicating that ultrasonic extraction resulted in the highest yield of polysaccharides from Epimedium brevicornum. After purification with DEAE-cellulose, the polysaccharide yields were 4.13%, 3.67%, and 3.12%, respectively. A comprehensive comparison demonstrated the superiority of the ultrasonic extraction method in terms of both extraction yield and purification efficiency. Characterization of the extracted Epimedium polysaccharides showed the presence of five monosaccharides, i.e., glucose, galactose, mannose, galacturonic acid, and rhamnose, and a number average molecular weight Mn of 1.65 × 105 Da and weight average molecular weight Mw of 6.61 × 105 Da. These results provide a scientific basis for the in-depth study and application of Epimedium polysaccharides.

Impact of adding papain to sous vide cooking on texture and sensorial traits of marinated semitendinosus beefsteaks.

Sous vide meat is an emerging food category, the consumption of which has increased owing to greater convenience, sensory traits, elderly consumers acceptance, and low-cost cuts use. However, required prolonged thermal treatment to achieve desired tenderness, impact energy-consumption besides triggering lipid oxidation, undesired off-flavors, and cooked meat profiles. Using a response surface methodology (RSM), this study evaluated the effects of the vegetal proteolytic papain (0 to 20 mg/kg) and low-temperature sous vide cooking (SVC) time (1 to 8 h at 65°C) in low-value marinated M. semitendinosus beefsteaks on technological characteristics associated with tenderness, and lipid oxidation. Additionally, the sensory profile traits of the pre-selected treatments were described using check-all-that-apply (CATA) and preference mapping. Shear force (WBsSF) was reduced with greater papain addition, whereas higher cooking losses (CL) were observed with longer SVC cooking times. Both the released total collagen and TBARS values increased with increasing papain concentrations and SVC times. Combining high levels of papain (>10 mg/kg) and SVC time (>6 h) resulted in lower WBsSF values (<20 N) but higher CL (>27%) and the CATA descriptors "aftertaste" and "mushy." The optimized conditions (14 mg/kg papain; 2 h SVC) also reduced WBsSF values (<26 N) with lower CL (<20%) and were most preferred and described as "juicy" and "tender" by consumers. Observed results suggest that combined mild SVC and papain may potentiate tenderness, conjointly favor juiciness and oxidation, further representing a promising tool for reducing SVC time without compromising valued sous vide sensory traits.

Impact of papain on the treatment of raw diluted dromedary semen.

A variety of parameters, including liquefaction and semen viscosity, affect the sperm's ability to travel and reach the egg for fertilization and conception. Given that the details behind the viscosity of the semen in male camels have not yet been fully clarified, the purpose of this study was to ascertain how the addition of papain affected the viscosity of fresh diluted camel semen. The study examined semen samples derived from camels that had distinct viscosities. Sperm motility, viability, abnormal sperm percentage, concentration, viscosity, morphometry, acrosome integrity and liquefaction were among the evaluations following 0, 5, 10, 20 or 30 min of incubation at 37°C with papain (0.004 mg/mL, 0.04 mg/mL or 0.4 mg/mL; a semen sample without papain was used as a control). A statistically significant interaction between the effects of papain concentrations and incubation time was found (F = 41.68, p = .0001). Papain concentrations (p = .0001) and incubation times (p = .0001) both had a statistically significant impact on viscosity, according to a simple main effects analysis. A lower viscosity was found (p < .05) at 0.04 mg/mL (0.1 ± 0.0) after 10 min of incubation. A simple main effects analysis showed that papain concentrations and incubation time have a statistically significant effect on sperm motility (p = .0001). At 0.04 mg/mL papain, the sperm motility % was higher (p < .05) after 10 min (64.4 ± 4.8), 20 min (68.4 ± 6.2), and 30 min incubation (72.2 ± 6.6) compared to 0, 5 min (38.3 ± 4.1 and 51.6 ± 5.0, respectively). In conclusion, the fresh diluted camel semen had the lowest viscosity properties after 10 min of incubation with 0.04 mg/mL papain, without compromising sperm motility, viability, acrosome integrity and sperm morphology.

Papain assisted preparation of chitosan: Feasibility study for candidate in-house reference material and antibacterial agent

Chitosan preparation assisted by papain was carried out to reduce the use of chemicals in the extraction of chitosan. This research aims to modify the chitosan extraction method to be more environmentally friendly and improve the physicochemical properties. Chitosan preparation is carried out in 4 main steps which include depigmentation, demineralization, deproteination, and deacetylation. Deproteination uses papain extract with varying concentrations of 5 - 25% for 7–11 h. The results of characterization using FTIR confirmed that the chitosan preparation was successful. The characteristic FTIR spectra are shown by the presence of a wideband at 3000–3600 cm−1 from stretching vibrations of the –OH and –NH and a peak at 1500–1700 cm−1 which indicates the N–H and CO stretching vibrations of the amino group. The XRD pattern verifies the peak characteristic of chitosan at an angle of 2 theta 9.39, 19.16, 25.96, 32.31, and 34.17°. SEM-EDX imaging shows the chitosan morphology whose particle arrangement is a uniform, smooth, and non-aggregated arrangement of its particles with the main composition of chitosan consisting of carbon, oxygen, and nitrogen atoms. The optimum papain concentration of 25% and deproteination time of 7 h with a deacetylation degree of 70.83% are the recommended conditions for chitosan preparation. The extracted chitosan was confirmed to satisfy the homogeneity and stability requirements as a candidate for in-house reference material. The homogeneity test results of the MSB and MSW values obtained F-test < F-critical (2.7858 < 3.1789) and the results of ANOVA (α = 95%, df = 9) obtained F-test < F-critical (0.4466 < 4.4139). The chitosan produced is validated as a stable material with a value of | X̅i - X̅HM | < 0,3 x nIQR (0.2501 < 1.7345). The chitosan produced has antibacterial activity against P. acnes, S. aureus, K. pneumoniae, P. aeruginosa, and E. coli.

Effects of Low Temperature-Ultrasound-Papain (LTUP) Combined Treatments on Purine Removal from Pork Loin and Its Influence on Meat Quality and Nutritional Value.

A combined pretreatment method of "low temperature-ultrasound-papain" (LTUP) was proposed to remove the purine of pork loins. Compared with untreated pork loin, under optimal conditions (temperature 58 °C, ultrasound density 100 W/cm2, and papain concentration 0.085%), the purine removal rate of treated pork loin could reach 59.29 ± 1.39%. The meat quality of pork loin treated with the LTUP method such as hardness and chewiness decreased by 58.37% and 64.38%, respectively, and the in vitro protein digestibility was increased by 19.64%; the cooking loss was decreased by 15.45%, compared with the simulated household blanching process (HT). In view of the high purine removal rate, the losses of free amino acids and soluble peptides were acceptable and reasonable. SEM and LF-NMR results showed that low temperature and ultrasound combined with papain treatment opened a channel for purine transfer and promoted purine dissolution by affecting the protein structure of pork loin. In addition, the migration of water within the muscle tissue was also related to purine removal. In summary, LTUP is recommended as an efficient and green way for the meat industry to remove purine.

Effects of different concentrations of bromelain and papain enzymes on shear bond strength of composite resin to deep dentin using an etch-and-rinse adhesive system.

The dentin substrate can be modified by proteolytic agents, which may affect the bonding strength of adhesive systems to the treated dentin surface. Papain, a cysteine protease enzyme with antibacterial and anti-inflammatory properties, can be used for deproteinization of dentin. An alternative deproteinizing enzyme is bromelain. This study aimed to evaluate the impact of deproteinization on the shear bond strength (SBS) of composite resin to deep dentin using different concentrations of bromelain and papain. Sixty upper premolars were extracted and randomly divided into 5 groups (n = 12 per group). In all groups, the dentin surface was etched with 37% phosphoric acid. Group 1 did not receive any enzyme treatment, group 2 was treated with a 10% papain solution, group 3 was treated with a 15% papain solution, group 4 was treated with a 6% bromelain solution, and group 5 was treated with a 10% bromelain solution. After applying an etch-and-rinse adhesive system, the specimens were restored with composite resin and the SBS was measured. Statistically significant differences were found between groups 2 and 3 (10% papain and 15% papain, p = 0.004), groups 2 and 4 (10% papain and 6% bromelain, p = 0.017), groups 4 and 5 (6% bromelain and 10% bromelain, p = 0.021), and groups 3 and 5 (15% papain and 10% bromelain, p = 0.005). Deproteinization with papain and bromelain at different concentrations after acid etching did not affect the SBS of composite resin to deep dentin when using an etch-and-rinse adhesive system. However, the group deproteinized with 15% papain demonstrated a higher SBS than the group deproteinized with 10% papain, and the group deproteinized with 6% bromelain showed a higher SBS compared to the group deproteinized with 10% bromelain.

Optimization of the Process for Obtaining Antioxidant Protein Hydrolysates from Pumpkin Seed Oil Cake Using Response Surface Methodology

Pumpkin seed cake, a byproduct of cold-pressed oil production, represents a food waste material with a great potential for valorization. The objective of the present study is to optimize the papain enzymatic hydrolysis process of pumpkin seed cold-pressed oil cake (CPC) to obtain protein hydrolysates with the highest antioxidant activity. Box–Behnken Response Surface Methodology (RSM) was used to optimize the simultaneous effects of an enzyme concentration of papain, a temperature, and a reaction time on the process of enzymatic hydrolysis on pumpkin seed cold-pressed oil cake (CPC). For these three input factors, different values are used—1, 2, and 3% for papain concentration, 20, 30, and 40 °C for temperature, and 60, 120, and 180 min for hydrolysis time. Thus, the design generated a total of 21 experimental runs. The aim is to obtain protein hydrolysates with the highest antioxidant activity. The responses DPPH and ABTS were calculated and the determined regression models were statistically analyzed and validated. The results revealed that optimal conditions included a papain concentration of 1.0%, a temperature of 40 °C, and a hydrolysis time of 60 min to retrieve the highest level of bioactive compounds.

Effect of papain enzyme surface modification on hydrophilic and comfort properties of polyester/cotton blend fabric

In this study, the authors used an enzyme called papain sourced from the Carica Papaya to improve the comfort and water-absorbing properties of a fabric made from a blend of polyester and cotton (65/35). The experiment was designed using the Box Behnken method to determine the most important variable and the best levels of parameters. The focus was on testing the wettability, moisture regain, and surface characteristics of the material. The results showed that all the comfort properties of the fabric improved after treatment with papain enzyme. After testing different parameters, the best conditions for treating the fabric with papain enzyme were determined to be a temperature of 30 °C, a papain concentration of 14%, and a treatment time of 50 min. Under these optimized conditions, the moisture regain and wettability of the polyester/cotton blend fabric treated with papain enzyme improved to 1.9 ± 0.02% and 6 cm capillary rise (measured with a 2-s drop test and 2-s sinking time) within just 3 min of wicking time. The Polyester/cotton blend fabrics treated with papain enzyme exhibited several noteworthy characteristics, including a significantly reduced susceptibility to fabric pilling (4–5), a limited capacity to attract oily impurities, and a high oil-soil-release capability with a stain removal index of 85%. Additionally, the fabrics showed a one-order-of-magnitude decrease in surface resistivity under normal conditions, with a half-life decay time of 513 s. Observations of the treated fabrics revealed the presence of cracks, grooves, nanostructures, and a high degree of roughness on the surfaces that were treated with papain enzyme. To further evaluate the effects of the lipase enzyme treatment on the fabric properties, several tests were conducted, including Fourier Trasform Infrared spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Differential scanning calorimetry (DSC), Moisture Regain, Tensile Strength, Stain Repellency, pilling resistance, and Anti-static charge generation.

Antisolvent Crystallization of Papain

Protein crystallization plays a crucial role in the food and pharmaceutical industries, enhancing product quality and efficiency by improving purity and controlled particle characteristics. This study focused on the crystallization of the versatile protein papain, extracted from papaya. Antisolvent crystallization was performed. This method is cost-effective and is a simple and energy-efficient approach. Beyond protein crystal production, the antisolvent crystallization process serves as a method for encapsulating active pharmaceutical ingredients (APIs). The study investigated organic solvents like ethanol, acetone, and acetonitrile as potential antisolvents. Additionally, the impact of variables such as the solvent-to-antisolvent (S:AS) volume ratio and papain concentration on particle size, particle size distribution, zeta potential, crystallization yield, and residual activity of papain crystals were examined. Ethanol emerged as the optimal antisolvent, reducing the solubility of papain and preserving papain’s crystalline structure with minimal activity loss. Optimal conditions were identified at a 1:4 S:AS volume ratio and a papain concentration of 30 mg/mL, resulting in nanosized spherical crystals with a high yield and preserved activity. This research underscored the crucial role of thoughtful parameter selection in antisolvent crystallization to achieve specific particle characteristics while maintaining the functionality of the crystallized substance.

Liposomes and transferosomes in the delivery of papain for the treatment of keloids and hypertrophic scars

Hypertrophic scars and keloids are characterized by an excessive collagen deposition. The available treatment options are invasive and can result in recurrence of scar formation. Using liposomes and transferosomes for the topical delivery of papain, a proteolytic enzyme, can be effective treatment. The objective of the study is to formulate papain-loaded liposomes and transferosomes, characterize the formulations, and study in vitro permeation using shed snake skin and Sprague-Dawley rat skin as models for stratum corneum and full thickness skin. Papain-loaded liposomes and transferosomes were formulated using the thin-film hydration method for the delivery of papain across the stratum corneum barrier. An in vitro permeation study carried out using shed-snake skin and Sprague-Dawley rat skin models showed that transferosomes were able to deliver papain across the stratum corneum barrier, while papain solution and papain liposomes were not able to cross the barrier. However, transferosomes were not able to deliver papain across the full thickness rat skin model suggesting the deposition of papain loaded transferosomes in the epidermal or dermal layer of skin. In addition, an ex-vivo model was used to analyze the effect of papain exposure on the morphology of the epidermis taken from rat skin exposed to papain solution, papain in transferosomes and papain in liposomes. Papain in solution resulted in a noticeable degradation of the epidermis, but when embedded in either transferosomes or liposomes there was no noticeable change when compared to control animals. The cytotoxicity study performed using HeLa cells showed that the cells were viable at papain concentrations lower than 0.01 mg/ml.

Permeabilization of the cell wall of Chlorella sorokiniana by the chitosan-degrading protease papain

To enhance the nutritional value of Chlorella microalgae for use in food and feed, it is crucial to improve the bioavailability of nutrients and bioactive compounds from whole-cell biomass in a cost-effective manner. In this study, papain – a plant-derived cysteine protease with additional chitosanase-like activity – was applied to partially degrade the cell wall of Chlorella sorokiniana at ambient temperature, whereas the cell wall of the closely related species Chlorella vulgaris remained unaffected and generally appeared more stable. Three commercial enzymes - cellulase, lysozyme and papain - were evaluated for their suitability to digest the fresh C. sorokiniana and C. vulgaris biomass suspended in acetate buffer at pH 4.8. The accessibility of algal carotenoids to acetone extraction, performed on analytical scale, proved to be a simple and reliable measure for the degree of cell wall degradation, while on the contrary the enzyme-induced release of reducing sugars did not strictly correlate with the actual permeabilization of the cell. Ultimately, papain was found to be more active than lysozyme, while cellulase showed almost no effect. This is in line with the knowledge about the C. sorokiniana cell wall composition with regard to its framework of chitosan-like fibers and high protein content. Papain concentration, enzyme-to-biomass ratio and duration of the enzyme treatment were varied. Papain was equally efficient in acidified BG11 medium, therefore enzymatic permeabilization of the cell wall directly after harvesting the microalgae seems possible– either for valorization of whole-cell biomass or as an energy-efficient process step to increase yields in biorefinery approaches. Main drawback of the approach is the high enzyme dose of estimated 5 g papain per 100 g of C. sorokiniana dry mass, that was needed to gain sufficient effect. Future research is required to optimize dosage in combination with synergistically acting enzymes and under the conditions of the actual application.

Evaluating different levels of papain as texture modifying agent in bovine meat loaf containing transglutaminase

In this study, bovine meat loaves were produced with different levels of papain (0.00125%, 0.0025%, 0.00375%, and 0.005%) combined with transglutaminase (1%). The effect of this reformulation on pH, instrumental color, water activity, proximate composition, texture, yield, and scanning electron microscopy (SEM) of meat loaves was investigated. In addition, the enzymatic activity of papain was also analyzed. The papain addition increased the pH and the yield of the samples. The hardness was progressively reduced with the increase of papain level. Such changes could be seen through the images recorded by SEM, where an extremely fragmented structure was observed in treatments with higher papain concentration. Papain showed an optimum temperature of 80 °C. This study allowed to observe an intense proteolytic effect in all treatments, despite the papain concentration. Therefore, lower levels should be applied so that the product does not alter its sensory characteristics, such as soft and crumbly texture.

The peroxidase-like activity of papain colorimetrically detects H2O2 and glucose with high sensitivity

To date, several glucometer methods are available for patient-guided glycemic control, which diminishes the onset and severity of diabetic complications. In a dipstick urine glucose test, horseradish peroxidase (HRP) oxidizes tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2) to quantitatively produce a colorimetric signal and predict glucose concentration. Papain, a sulfhydryl protease secreted by the latex of Carica papaya, displays HRP-like activity with high selectivity. However, the current papain-based glucometer method lacks sensitivity. We hypothesized that catalyzing the oxidation of papain under varying buffer conditions (e.g., papain, TMB, and acetic acid concentrations) would improve glucose detection sensitivity. To test this, we performed glucose oxidase (GOx)-mediated glucose oxidation and papain-mediated TMB oxidation under varying sample conditions in vitro and spontaneously coupled them. The aims of this study were to validate the coupling of GOx-mediated glucose oxidation and papain-mediated TMB oxidation and identify the optimized conditions that maximize catalytic activity. We confirmed that glucose oxidase quantitatively produces H2O2 (in a glucose concentration-dependent manner), the presence of which catalyzes papain-mediated production of a colorimetric signal. When two oxidation reactions were coupled, we identified that the sensitivity of papain’s glucose detection increased by ten-fold compared to previous studies with a markedly high correlation (R2 = 0.99). In particular, substituting sodium acetate-acetic acid (HAc-NaAc) buffer with acetic acid and increasing the sample incubation time and papain concentration markedly increased the sensitivity of colorimetric signals. The optimized protocols can be integrated into emerging hydrogel technology to develop a non-invasive glucometer patch predicting blood glucose from the patient’s produced sweat.

Hydrolysis of Soybean Milk Protein by Papain: Antioxidant, Anti-Angiotensin, Antigenic and Digestibility Perspectives.

The objective of the investigation was to understand the biochemical activities of hydrolysate of soybean milk protein (SMP). Hydrolysis was carried out by different concentrations of papain (0.008 g·L−1, 0.016 g·L−1, 0.032 g·L−1 and 0.064 g·L−1). The antioxidant capacity was measured by the ferric-reducing ability of plasma (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays. The anti-angiotensin activity of hydrolysate was measured by the recombinant angiotensin converting enzyme and substrate Abz-FRK(Dnp)-P. The contributions of the Kunitz trypsin inhibitor (KTI) and Bowman–Birk inhibitor (BBI) on antigenicity, and the in vitro digestion of papain-hydrolyzed SMP were studied. Rabbit polyclonal anti-KTI and anti-BBI antibodies together with peroxidase-labelled goat anti-Rb IgG secondary antibody were used to identify the antigenicity of KTI and BBI in unhydrolyzed and papain-hydrolyzed SMP. The antioxidant capacity and anti-angiotensin activity of SMP were increased after the papain hydrolysis of SMP. The KTI- and BBI-specific antigenicity were reduced in SMP by increasing the concentration of papain. However, there was interaction between papain-hydrolyzed SMP and trypsin in native gel, while interaction with chymotrypsin was absent. The interaction between trypsin and SMP was reduced due to the hydrolysis of papain in a concentration-dependent manner. According to the in vitro gastrointestinal digestion simulation protocol (Infogest), the digestibility of SMP was not statistically increased.

In vitro effect on the proteolytic activity of papain with proteins of the skin as substrate.

This work aims to evaluate the effects of enzyme concentration, pH, temperature and time course degree of hydrolysis (DH) of papain regarding further development of pharmaceutical and cosmetic formulations. The hydrolysis of casein, collagen, keratin and porcine skin at pH and temperature ranges of the human skin was evaluated. Also, low contact times of enzyme-substrate were studied. The incorporation of 3mM of cysteine improved the caseinolytic (PU), collagenolytic (CU) and keratinolytic (KU) activities of papain. In general, the increase from 0.1 to 1.0 or 2.0mgmL-1 of papain improved PU, CU and KU. When 2.0mgmL-1 of papain was used, the highest DH of casein, collagen and keratin was obtained at 240min (14%, 35% and 6% respectively). The decrease in pH and temperature reduced all proteolytic activities, but papain maintained at least 50% and 40% of its activity at 26°C and pH 4.5 respectively. Scanning electron micrographs of the surface of the skin showed that papain application had exfoliating activity. This preformulation study demonstrated that papain concentration, time of application and pH of the product should be evaluated when developing a product to promote the hydrolysis of the proteins of the skin.

Разработка технологии выделения и исследования иммунотропного действия бурсальных пептидов на мышах с экспериментальным иммунодефицитом

Peptides are biologically active. This quality depends on the technological modes of protein hydrolysis. The research objective was to isolate peptides from the bursa fabricii and evaluate their immunotropic effect on mice of various lines with experimental immunodeficiency and the morphofunctional state of their immunopoiesis organs, i.e., thymus and spleen.&#x0D; The research featured bursa fabricii hydrolysate and peptides, as well as thymus and spleen of male mice. Amine nitrogen was determined according to State Standard R 55479-2013; molecular weight of peptides was determined by gel electrophoresis. The morphometry of the thymus and spleen was calculated using VideoTesT-Morphology 5.0. &#x0D; The research revealed the rational modes of enzymatic hydrolysis of the bursa fabricii protein by papain with subsequent isolation of peptides by ultrafiltration. According to the content of amine nitrogen in the bursa fabricii hydrolysate, the rational concentration of the papain enzyme was 0.15%. The molecular weight of peptides after ultrafiltration of bursa fabricii hydrolysate through membranes with a 43 kDa permeability had different values and depended on the concentration of papain, hydrolysis time, and temperature. The maximal amount of 27–18 kDa peptides was isolated at 36°C (85%) when the concentration of papain was 0.15% (73%), the hydromodule was 1:3 (78%), and the hydrolysis time of the raw material was 6 h (82%). The rational technological parameters of the hydrolysis of the bursa fabricii protein were as follows: concentration of papain – 0.15%, temperature – 36°C, hydromodule – 1:3, and hydrolysis time – 6 h. In immunodeficient mice, bursal peptides prevented a decrease in total cellularity in the thymus, sustained the content of CD3+ cells, activated the maturation of T-lymphocytes and proliferation of B-lymphocytes, and reduced the immunocytotoxic effects of cyclophosphamide.&#x0D; The article offers a new technology for obtaining peptides with a pronounced immunotropic effect that can be used in functional food production.

Optimization of enzymatic hydrolysis of boso fish (Oxyeleotris marmorata) protein based on the degree of hydrolysis and the physical properties of the resultant hydrolysates

Fish protein hydrolysates (FPHs) were produced from boso fish (Oxyeleotris marmorata) through enzymatic hydrolysis using papain as the hydrolysis agent. Papain concentration (0.2–0.4%), temperature (45–55°C), and time (4–12 hrs) were chosen as the independent factors while the degree of hydrolysis (DH), viscosity, and turbidity of the resultant FPHs were recorded as the responses. This study aimed to optimize the enzymatic hydrolysis of boso fish protein using the Box-Behnken Response Surface Methodology (RSM) design. The optimum condition for the boso fish protein hydrolysis based on the DH was predicted at 0.2% of papain concentration, 55°C, and 12 hrs, which would give a DH of 18.63% and an R2 of 90.90%. The FPHs prepared with moderate hydrolysis conditions (0.3% of papain concentration at 50°C for 8 hrs) were spray-dried with the yield ranging from 5.37% to 16.70% (w/w). The spray-dried FPH displayed a globular structure with a diameter of 1–7 μm as observed under the scanning electron microscope (SEM). The total colour difference of the dried FPH was 10.15 compared to the standard white tile. The particle size analysis in distilled water exhibited some distinct peaks which were distributed within 200–1,100 nm with an intensity of 18.1%. This study showed the potential of boso fish for FPH production by using the papain enzyme.

Novel antioxidant peptides identified in millet bran glutelin-2 hydrolysates: Purification, in silico characterization and security prediction, and stability profiles under different food processing conditions

Based on a model generated from response surface methodology, the optimum hydrolysis conditions of millet bran glutelin-2 (MBG-2) were obtained with a concentration of Papain of 8.17 mg/g MBG-2, at pH 7.83 and 51.6 °C for 5.9 h. Through Sephadex G-15 gel chromatography, RP-HPLC and UPLC-ESI-MS/MS analysis, three novel antioxidant peptides (CFMTY, CTGTPYC and RGLLLPSMSNAP) were identified in MBG-2H. The antioxidant activity, stability profiles of these peptides against different pH values, thermal treatments, treatment of glucose and NaCl, and simulated gastrointestinal digestion were studied. Moreover, the physicochemical property, potential toxicity and allergenicity were predicted in silico. Results showed that CFMTY, CTGTPYC and RGLLLPSMSNAP all had no potential toxicity and allergenicity, and showed high scavenging activity on ABTS+ (IC50: 80.85, 87.78 and 214.17 μmol/L), ·OH and superoxide radical. Both CFMTY and CTGTPYC showed excellent ferrous chelating ability (98.97%–99.24%, at 100 μg/mL) which was close to Glutathione. Moreover, these peptides were relatively stable against different pH values (2.0–8.0), pasteurization conditions and treatments of glucose and NaCl (<4 mg/mL). These peptides except RGLLLPSMSNAP were resistant to the gastrointestinal digestion. Therefore, the antioxidant peptides derived from MBG-2H have potential to be added into foods for preservation.

Improving the poor texture and technological properties of chicken wooden breast by enzymatic hydrolysis and low-frequency ultrasound.

Wooden breast (WB) is a recurrent myopathy in fast‐growing birds, which alters the appearance, functionality, and the texture of the breast muscle. The objectives of this study were (i) to evaluate the effect of a combined use of papain enzyme and ultrasound on the texture of WB chicken using response surface methodology and (ii) to assess the effect of marinating on the quality of WB chicken meat. Full factorial experimental design method was used to obtain the ideal conditions to soften the WB meat. The independent variables were the concentration of papain (0.1%–0.3%) and the time in ultrasonic bath (10–30 min); shear force (SF) was the dependent variable. The optimum results were obtained at a concentration of 0.2% papain and 20 min on ultrasound. Papain enzyme had a great influence on the texture of WB meat, reducing its hardness. However, the effect of the ultrasound time on the SF response was not observed. The marinated WB meat showed similar SF values and texture profile than those from normal (N) meat, with reduction in the parameters of protein and lipid oxidation. The use of papain without ultrasound bath proved to be an efficient means for improving the tenderness of WB breasts.Practical ApplicationThis study shows the efficiency of the application of two technological procedures (enzymatic treatment and ultrasound) to improve the texture profile and technological properties of chicken breasts affected by the wooden breast myopathy. The economic loss caused by the world‐wide occurrence of wooden breast is enormous, and the application of papain has been found to counteract the impaired properties of this abnormal chicken breasts. Since papain is already widely used in the food industry to tenderize meat, its application in improving the quality of WB meat is straightforward.

Effects of papain concentration, coagulation temperature, and coagulation time on the properties of model soft cheese during ripening

Cheese is a nutritious food that is a good source of bioactive compounds. Therefore, it is important to understand the effects of different processing parameters on cheese properties during the ripening process. Here, we prepared model soft cheeses by using different concentrations of papain (0.2, 0.3, and 0.4%), coagulation temperatures (30, 34, and 37 °C), and coagulation times (20, 30, and 40 min) to evaluate changes in yield, moisture content, pH, lactic acid bacteria population, texture, proteolysis, volatile compounds, and instrumental sensory analysis during a 50 days ripening period. The moisture contents were 53%–62%, and moisture-adjusted yields ranged from 11.2 kg to 15.6 kg per 100 kg milk. Moreover, during the ripening period, the number of lactic acid bacteria increased by approximately 0.5 log CFU/g. A significant increase in the total concentration of free amino acids in response to increases in papain concentration and coagulation temperature was observed. Coagulation temperature was also found to have a significant effect on the hardness and springiness of cheese. In addition, we detected 34 volatile compounds in the model soft cheeses. This study contributes to advancing our current understanding on the quality changes of model soft cheese using papain as a substitute for rennet.