Enzymatic Treatment Research Articles

Variety effect of distinct enzyme treatments during prefermentative maceration of white winegrapes on volatile organic compounds and chromatic traits

The impact of prefermentative addition of five single-enzyme activities (pectin lyase, polygalacturonase, pectin methyl esterase, xylanase, and arabinase) on the phenolic content, colour characteristics, and volatile composition of grape musts resulting from pellicular maceration of Chardonnay, Arneis, Greco, and Falanghina white varieties was studied with the aim of enhancing aroma composition without negatively affecting colour perception. In addition, standard physicochemical parameters were determined. Pectin lyase, polygalacturonase, and arabinase enzymes reduced the must browning, when compared with untreated control, as reported by lower total polyphenol index, absorbance at 420 nm, and a* colour coordinate for all varieties tested. Regarding the volatile composition determined by solid-phase extraction and GC-MS analysis, variety effect was observed for the enzyme treatments studied. The concentration of free vanillin decreased significantly in these last three varieties using polygalacturonase and arabinase treatments whereas 4-vinylguaiacol increased in pectin lyase-treated samples. Free terpene compounds, such as furan linalool oxide, increased in Chardonnay and Falanghina varieties using polygalacturonase, xylanase, and arabinase for the second variety whereas pectin lyase for the first one. Contrarily, glycosylated terpenes, such us (Z)-8-hydroxylinalool, decreased when using pectin lyase and xylanase for Arneis; however, it also occurred for Falanghina using polygalacturonase treatment. The xylanase activity influenced mostly the volatile composition of the Arneis variety whereas arabinase did for Greco and Falanghina. The differences between enzyme-treated grape musts and control samples were less evident on the Chardonnay variety. Therefore, enzyme activity can affect the volatile composition of grape must differently depending on the target variety.

Comparing DNA isolation and sequencing strategies for 16S rRNA gene amplicon analysis in biofilm containing environments

Bacteria are primarily responsible for biological water treatment processes in constructed wetland systems. Gravel in constructed wetlands serves as an essential substrate onto which complex bacterial biofilms may successfully grow and evolve. To fully understand the bacterial community in these systems it is crucial to properly isolate biofilms and process DNA from such substrates. This study looked at how best to isolate bacterial biofilms from gravel substrates in terms of bacterial richness. It considered factors including the duration of agitation during extraction, extraction temperature, and enzyme usage. Further, the 16S taxonomy data subsequently produced from Illumina MiSeq reads (using the SILVA 132 ribosomal RNA (rRNA) database on the DADA2 pipeline) were compared with the 16S data produced from Oxford Nanopore Technologies (ONT) MinION reads (using the NCBI 16S database on the EPI2ME pipeline). Finally, performance was tested by comparing the taxonomy data generated from the Illumina MiSeq and ONT MinION reads using the same (SILVA 132) database. We found no significant differences in the effective number of species observed when using different bacterial biofilm detachment techniques. However, enzyme treatment enhanced the total concentration of DNA. In terms of wetland community profiles, relative abundance differences within each sample type were clearer at the genus level. For genus-level taxonomic classification, MinION sequencing with the EPI2ME pipeline (NCBI database) produced bacterial abundance information that was poorly correlated with that from the Illumina MiSeq and DADA2 pipelines (SILVA132 database). When using the same database for each sequencing technology (SILVA132), the correlation between relative abundances at genus-level improved from negligible to moderate. This study provides detailed information of value to researchers working on constructed wetlands regarding efficient biofilm detachment techniques for DNA isolation and 16 s metabarcoding platforms for sequencing and data analysis.

Modes and methods of treatment of blackcurrant pomace with an enzyme preparation to increase juice yield

Blackcurrant is a multivitamin crop with high dietary and medicinal properties and is a source of exceptionally valuable raw materials for juice production, but its extraction is complicated by its chemical composition. The endocarp of blackcurrant fruit (the actual pulp) is formed by the slimy arylus surrounding the seeds, which prevents juice extraction. The purpose of this study was to scientifically substantiate the modes and methods of effective extraction of blackcurrant juice with preliminary enzymatic treatment of the pomace while preserving its natural chemical composition and biologically active substances. The study was conducted with blackcurrant fruits of the varieties Mynai Shmyrev, Belarus sweet, Novyna Prykarpattia in the laboratory of the Department of Technology of Storage and Processing of Plant Production and the Training and Production Department of the Uman National University of Horticulture. Research methods (physical, chemical, physical-chemical) and statistical processing of results (analysis of variance) are generally accepted. Blackcurrant fruit usually yields an unsatisfactory juice yield of 18-24%, which lacks its inherent colour. According to Harrington’s desirability assessment, enzymatic treatment with pectofoetidine increases the juice yield from crushed fruit to satisfactory (37-44%) and very good (57-60%) for crushed fruit (pomace), which is 2-3 times higher. During the fermentation of pomace, three stages are distinguished: the first is the destabilisation of the colloidal system of the pomace (up to 1 hour); the second is the degradation of the pomace structure (up to 2 hours); and the third is the stabilisation of the process (after 3 hours). Optimum conditions for pomace fermentation are ensured by using 0.03% by weight of the preparation suspension, a temperature of 42-45 °C, and a process duration of 2 h. This results in up to 60% juice extraction, 96-102% acid conversion and up to 97% ascorbic acid content. The increase in juice yield by 6-15% correlates with the characteristics of the variety. In juices with sugar, the content of ascorbic acid is 1.7 times lower, but its preservation reaches 98-99%. Sugar and hot bottling are the factors that stabilise ascorbic acid in juices. Increasing juice yield and improving its quality is economically and technologically feasible

The Effect of Type and Duration of Digestive Enzyme Treatment on Coffee Bean Composition

During kopi luwak production, coffee fruit is subjected to enzymatic and microbial treatment. While microbial modification of coffee fruit or beans is often investigated, there is little information regarding the influence of the enzymatic part of the process. In this study, green Arabica and Robusta beans were modified using basic animal digestive enzymes (pepsin or trypsin with α-amylase) and various treatment times (3, 6 or 12 h) to determine their effect on bioactive and other quality-affecting compounds. Analyses of coffee composition were performed using spectrophotometric and HPLC methods. Modified and control samples were significantly affected by the treatment. Among enzymes used, only proteases exhibited noticeable impact on target compounds by increasing soluble protein content in green beans. The most advantageous modification time was 3 h. The composition of beans was altered by the roasting step, with the effect not quite corresponding to the previous stage. In conclusion, enzymatic treatment of green coffee beans provides a way to alter coffee composition, which can further influence its quality.

Douglas fir bark: composition, extracts utilization and enzymatic treatment for enrichment of bioactive constituents

Abstract Bark residues from Douglas fir are an abundant resource that is currently used primarily in low-value energy recovery or is landfilled. Bark extractives are rich in diverse compounds like terpenes, fatty acids, phenols, and sugars with potential uses in a variety of high value applications. The study explores the potential of enzymatic hydrolysis to improve phenolic compounds from Douglas fir bark. It also assesses differences in chemical composition among rhytidome, phloem, and comingled bark fractions from an industrial waste pile. Phloem fractions exhibit higher yields of extractives, rhytidome fractions have elevated lignin levels, while the comingled fraction lies between the two except in ash content which was higher than in the separated fractions. Fungal decay tests with Gloeophyllum trabeum and Coniophora puteana on extract treated wood suggest potential for growth inhibition in extracts, about 58–31 % and 30–7% mass loss (in average) respectively, but due to high mass loss at low concentrations an enzymatic modification approach seems crucial for enhanced inhibition. Growth responses in whole-cell fermentation approach display variability depending on the participating microorganisms. Enzymatic hydrolysis with beta-glucosidase improved the antioxidant properties of bark extracts and holds promise for altering the chemical composition and enhancing bioactivity.

Effects of Cellulase and Xylanase on Fermentation Characteristics, Chemical Composition and Bacterial Community of the Mixed Silage of King Grass and Rice Straw.

This study was to investigate the effects of cellulase and xylanase on fermentation characteristics, nutrient composition and the bacterial community of the mixed silage of king grass and rice straw. Lab-scale bag silage was produced and seven groups were studied: blank control (CK); added 1%, 2% cellulase (CE1, CE2); added 1%, 2% xylanase (XY1, XY2); and added 0.5% cellulase +0.5% xylanase, 1% cellulase +1% xylanase (CX1, CX2). The results showed that the application of additives in six treated groups exerted a positive effect on lactic acid (LA) content and their pH values decreased significantly (p < 0.05). The addition of cellulase and xylanase decreased (p < 0.05) the content of neutral detergent fiber (NDF) and acid detergent fiber (ADF) significantly and increased (p < 0.01) the crude protein (CP) and water-soluble carbohydrate (WSC) content. Filter paper enzyme activity (FPA) declined and xylanase activity (XA) intensified (p < 0.05) as ensiling was prolonged, where most of the enzymatic treatments (especially XY2, CX2) resulted in increased enzyme activities. Moreover, the addition of cellulase and xylanase reduced the abundance of harmful bacteria such as Acinetobacter and Klebsiella and increased the abundance of lactic acid bacteria such as Lacticaseseibacillus, Lactiplantibacillus. In conclusion, the addition of cellulase and xylanase would improve fermentation quality and nutrient preservation via altering the bacterial community, with 1% cellulase or complex enzyme best.

Effects of thermal treatment on quality of biosimilar and originator monoclonal antibodies

Investigating products under stress conditions provides valuable information for assessing stability, biosimilarity, and degradation behaviors during monoclonal antibody (mAb) development. Proper sample preparation is crucial for accurately evaluating the biosimilarity and effects of stress conditions in comparability assessment, where these studies guide biosimilar mAb development steps. Enzymatic and chemical treatments applied during sample preparation of mAbs generally require treatment of samples in temperatures higher than the storage temperatures of antibodies.In this study, samples of a TNF-α inhibitor IgG1 biosimilar (BIO) and its originator (OR) were treated for 7 days at commonly used temperatures during sample preparation. Alterations in the intact IgG, size variants, charge variants, binding kinetics, and post-translational modifications (PTMs) were investigated with CE-SDS, SE-UPLC, icIEF, SPR, and LC-MS/MS, respectively. Samples treated at 50 °C exhibited significant degradation, while minor differences were observed in samples treated at 37 °C. Monomer and intact IgG levels were decreased to levels below 97 % and 94 %, respectively, after 7 days of thermal treatment at 50 °C for both BIO and OR samples. Similar rates of degradation were observed between the treated biosimilar and originator samples. The percent monomer degradation rate between the biosimilar and the originators was similar at 50 °C (p = 0.32). Thermal treatment increased acidic variant levels in the products of the BIO (23.10 %) and OR (23.16 %). During post-translational modification monitoring, an increase in pyroglutamic acid formation and a decrease in C-terminal lysine were observed after thermal treatments. Acidic variant alterations were associated with asparagine deamidation and N-terminal pyroglutamic acid formation. Post-translational modifications were mainly located at the Fc domain, with methionine oxidation and asparagine deamidation as the main modifications occurring at the Fab domain.In conclusion, these results revealed that prolonged thermal treatment under elevated temperatures induces molecular alterations, thereby facilitating the degradation of IgG1. In addition, our findings indicate that both BIO and OR lots exhibit similar degradation profiles when subjected to thermal treatments.

Diagnosis of multiple tuberculous muscle abscesses in a patient with systemic lupus erythematosus by metagenomic next-generation sequencing- a case report and literature review

BackgroundEarly diagnosis of muscular tuberculosis (TB) without coexistent active skeletal involvement is often challenging because the disease is very rare and its clinical manifestation is nonspecific and misleading. To raise the awareness and emphasize early diagnosis of muscular TB, we present a case of multiple tuberculous muscle abscesses in a systemic lupus erythematosus (SLE) female, but without pulmonary tuberculosis (PTB), in order to increase awareness of and stress the need of early detection of muscular TB.Case presentationA 44-year-old woman with a 6-year history of SLE who had been treated with methylprednisolone for a long time complained of erythema on her trunk and extremities for five months, along with edema and myalgia for two months, and fever for one month. The patient was first misdiagnosed as SLE overlap dermatomyositis. However, an ultrasound-guided drainage of muscle abscesses revealed positive acid-fast staining combined with positive deoxyribonucleic acid fragment of Mycobacterium tuberculosis using metagenomic next-generation sequencing (mNGS). The patient was cured and released following standard anti-tuberculosis medication, local puncture drainage, and an intravitreal injection of streptomycin. Literature search found only 19 cases of tuberculous muscle abscesses occurring in the extremities reported from 1999 to 2023.ConclusionsExtrapulmonary TB with predominantly muscle involvement is rare and with no specific clinical presentation. Muscular tuberculosis may be disdiagnosed for dermatomyositis due to the high muscle enzyme levels, delaying diagnosis and treatment. mNGS technology is helpful in the early and rapid diagnosis of muscular TB. On the basis of traditional anti-tuberculosis treatment, an ultrasound-guided percutaneous puncture drainage and intracavitary injection of streptomycin for the treatment of tuberculous muscle abscess is easy to operate, safe and effective, which is worthy of clinical popularization and application.

Order matters: Methods for extracting cellulose from rice straw by coupling alkaline, ozone and enzymatic treatments

Rice straw is a widely produced residue that can be converted into value-added products. This work aimed at using greener processes combining mild alkali (A), ozone (O) and enzymatic (engineered xylanase) (E) treatments to extract cellulose and other value-added compounds from rice straw and to evaluate the effects of the order of the treatments. Solid (S) and liquid (L) fractions from the process were collected for physicochemical characterization. AOE treatment showed the best capacity to extract high purity cellulose and other valuable compounds. The lignin content was significantly decreased independently of the order of the treatments and, its content in the extract obtained after the AOE process was lower than the one obtained after the OAE process. Moreover, thermal stability of the samples increased after the enzymatic process, being higher in SAOE. The alkaline treatment increased the hemicellulose and polyphenol content (antioxidant activity) in the liquid fractions (LA and LOA). In contrast, the ozonized liquid fractions had lower polyphenol content. Therefore, alkali was fundamental in the process. In conclusion, the AOE strategy could be a more environmentally friendly method for extracting cellulose and other valuable compounds, which could be used to develop active materials in the future.

Influence of Cellulose-Cellulase Enzyme Digestibility in the Production of Glucose from Lignocellulosic Biomass Waste

A comprehensive understanding of the factors and ability of cellulase enzyme to completely hydrolyze the structural lignocellulosic biomass has been a major research focus over the years. A comparative analysis of cellulose-cellulase digestibility of Kraft-pretreated sawdust from twenty different Nigeria wood wastes was carried out with increasing enzyme (Trichorderma viride) loading of 0.4 mg cm−3, 1.0 mg cm−3, 2.0 mg cm−3, and 4.0 mg cm−3 at constant substrate application of 10 mg cm−3 biomass concentration, temperature of 40°C and 2 h incubation period. This was carried out in order to establish the optimum cellulase-cellulose ratio for maximum biodegradation of the lignocellulosic biomass to produce glucose, a fermentable sugar. The influence of the cellulose-cellulase interaction from 0.4 mg cm−3 to 1.0 mg cm−3 enzyme treatment resulted in 144% increase in glucose yield from E. suaveolen and 121% from S. pustlatas. while 2.0 mg cm−3 cellulase concentration gave 674%, 641% and 617% increase from E.suaveolen, H. ciliate and A. germinans respectively. A general trend of increasing sugar formation was observed with an increasing enzyme loading due to enhanced cellulose accessibility by the cellulase enzyme leading to effective saccharification of the lignocellulosic materials for more sugar production. However, further increase of 4.0 mg cm−3 enzyme concentration failed to produce a commiserate amount of fermentable sugar.

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.

Changes in the Main Physicochemical Properties and Electrochemical Fingerprints in the Production of Sea Buckthorn Juice by Pectinase Treatment.

Enzymatic hydrolysis using pectinase is critical for producing high-yield and quality sea buckthorn juice. This study determined the optimal temperature, time, and enzyme dosage combinations to guide manufacturers. A temperature of 60 °C, hydrolysis time of 3 h, and 0.3% enzyme dosage gave 64.1% juice yield-25% higher than without enzymes. Furthermore, monitoring physicochemical properties reveals enzyme impacts on composition. Higher dosages increase soluble solids up to 15% and soluble fiber content by 35% through cell wall breakdown. However, excessive amounts over 0.3% decrease yields. Pectin concentration also declines dose-dependently, falling by 91% at 0.4%, improving juice stability but needing modulation to retain viscosity. Electrochemical fingerprinting successfully differentiates process conditions, offering a rapid quality control tool. Its potential for commercial inline use during enzymatic treatment requires exploration. Overall, connecting optimized parameters to measured effects provides actionable insights for manufacturers to boost yields, determine enzyme impacts on nutrition/functionality, and introduce novel process analytical technology. Further investigations of health properties using these conditions could expand sea buckthorn juice functionality.

Use of olive and sunflower protein hydrolysates for the physical and oxidative stabilization of fish oil-in-water emulsions.

Olive and sunflower seeds are by-products generated in large amounts by the plant oil industry. The technological and biological properties of plant-based substrates, especially protein hydrolysates, have increased their use as functional ingredients for food matrices. The present study evaluates the physical and oxidative stabilities of 50 g kg-1 fish oil-in-water emulsions where protein hydrolysates from olive and sunflower seeds were incorporated at 20 g kg-1 protein as natural emulsifiers. The goal was to investigate the effect of protein source (i.e. olive and sunflower seeds), enzyme (i.e. subtilisin and trypsin) and degree of hydrolysis (5%, 8% and 11%) on the ability of the hydrolysate to stabilize the emulsion and retard lipid oxidation over a 7-day storage period. The plant protein hydrolysates displayed different emulsifying and antioxidant capacities when incorporated into the fish oil-in-water emulsions. The hydrolysates with degrees of hydrolysis (DH) of 5%, especially those from sunflower seed meal, provided higher physical stability, regardless of the enzymatic treatment. For example, the average D [2, 3] values for the emulsions containing sunflower subtilisin hydrolysates at DH 5% only slightly increased from 1.21 ± 0.02 μm (day 0) to 2.01 ± 0.04 μm (day 7). Moreover, the emulsions stabilized with sunflower or olive seed hydrolysates at DH 5% were stable against lipid oxidation throughout the storage experiment, with no significant variation in the oxidation indices between days 0 and 4. The results of the present study support the use of sunflower seed hydrolysates at DH 5% as natural emulsifiers for fish oil-in-water emulsions, providing both physical and chemical stability against lipid oxidation. © 2024 Society of Chemical Industry.

The Effect of Enzymatic Hydrolysis and Maillard Reaction on the Flavor of Chicken Osteopontin.

To reveal the changes in the flavor quality of chicken osteopontin (CO) before and after enzymatic hydrolysis and a thermal reaction, the present study was carried out to evaluate the volatile compounds and non-volatile compounds in CO. The results show that the chicken boneset enzymatic solution (CBES) presented a notably richer aroma after the enzymatic hydrolysis treatment. At the same time, the concentrations of the total free amino acids (FAAs) and 5'-nucleotides in the CBES increased dramatically. The ERP (enzymatic reaction paste) scores and the ORC (osteopontin reactive cream) scores were exceptionally high in terms of the umami and salty flavor profiles. As precursors, FAAs and 5'-nucleotides also boosted the Maillard reaction, leading to the generation of wide volatile compounds. Compared to CO, CBES, and ORC, the sensory evaluation showed that ERP scored the highest. In summary, the enzymatic hydrolysis treatment coupled with the Maillard reaction significantly enhanced the flavor profile of CO. These findings offer valuable insights into the high-value utilization of bone by-products, making a significant advancement in the field.

Hydrolysate derived from sugarcane bagasse by hydrothermal and enzymatic treatment as an external carbon source for wastewater nitrogen removal

Research on the preparation of denitrifying carbon sources from agricultural wastes persists with problems of environmentally unfriendly pretreatment methods and unstable carbon release. In this study, a hydrolysis method without secondary waste liquid generation was used and the obtained hydrolysate was applied as a denitrifying carbon source. Firstly, the optimum hydrothermal condition of sugarcane bagasse (SCB) was explored, which showed a higher reducing sugar concentration (13.68 g/L) and COD concentration (20,691.67 mg/L) at 200 °C, 40 min with relatively low energy consumption (EC) requirement (1.81 kW·h). Afterward, all three bio-additives (tea saponins, rhamnolipids, and whey proteins) were found to enhance enzymatic hydrolysis, with whey proteins being the most effective, increasing the reducing sugar and COD concentrations by 29.40 % and 17.51 %, respectively. The enzymatic reaction was optimized using the following conditions: whey protein concentration of 0.2 %, pH 5.0, temperature 50 °C, cellulase to the β-glucosidase ratio of 4:1, and total enzyme amount of 30 mg. Moreover, the nitrogen removal effect of SCB hydrolysate as a carbon source was determined, and the average TN removal was 98.23 % at C/N of 5 and HRT of 8. Finally, the microbial community was analyzed, and the dominant phylum was denitrifying bacteria (Proteobacteria), and organic matter utilizing bacteria (Bacteroidetes, Acidobacteriota, and Patescibacteria), and the relative abundance of the latter both improved with increasing C/N, which further demonstrated the feasibility of SCB hydrolysate as a carbon source. This research provides a reference for the application of agricultural waste hydrolysate in wastewater nitrogen removal.

Single-bath-single-stage enzymatic treatment of denim

Denim has been a popular choice of apparel worldwide, prized for its versatility and long-lasting qualities. Being a core part of fashion trends for ages, a variety of techniques are being introduced in the denim industry to create a diverse and aged look. This research investigates the application of a combination of amylase, cellulase, and laccase at different temperatures on denim to achieve desired aged or faded appearance. The samples from 9 different washing recipes were analyzed properly for tensile strength, seam strength, color changes, back staining, stiffness, and chemical oxygen demand (COD). The results led to the finding of an optimal washing condition. An aged look on denim fabric can be varied by varying washing temperatures and amounts of laccase enzyme. The highest fading of denim garment was obtained when washed at a temperature of 65 °C for 45 min using 1.5 g/L of amylase, 1.5 g/L of cellulase, and 2 g/L of laccase enzyme. This was confirmed by the lowest whiteness index of the pocketing fabric (70.1) with an improved fabric feel as evident from the lowest bending length of 2.254 cm. The enzymatic process was found to be significantly environment-friendly as generated wastewater required almost 4 times less oxygen to degrade than the wastewater from the conventional process. Notably, this temperature selection did not negatively impact the fabric's tensile strength and abrasion resistance, emphasizing the efficiency of enzymatic processes. It further strengthened the position of single-bath-single-stage enzymatic treatment of denim as an alternative to conventional denim washing.

Effect of combined enzyme and ultrasound treatment on the structure and gel properties of soy protein isolate: A comparative study of alkaline protease and pepsin

This study aimed to research the effects of enzyme and ultrasound combined modification on the structure and gel properties of soy protein isolate (SPI). Different modified protein samples were obtained by hydrolyzing soy isolate with alkaline protease and pepsin at 0%, 0.1%, 0.5%, and 1.0% of hydrolysis by ultrasound treatment (400 W, 20 min). The results showed that the SPI particle size, which modified by combined enzyme and ultrasound treatment (co-modified), was significantly lower (P < 0.05) and the particle size was more evenly distributed compared with those of the single modified samples. The best improvement in solubility and turbidity was observed for the co-modified SPI. The Fourier transform–infrared spectroscopy showed the most significant changes in the secondary structure content of the co-modified SPI. The protein structure was unfolded, and the contents of free sulfhydryl and H0 were improved. Additionally, the co-modified SPI gel had a uniform and compact gel network and higher water-holding capacity (WHC) and gel strength. After frozen storage, the combined enzyme and ultrasound treatment showed better frozen storage stability than single treatment: the WHC of the gel decreased slightly, the gel strength increased slowly, and the gel network was less damaged. In conclusion, combined enzyme and ultrasound treatment could be effective in improving the SPI structure and gel properties.

Characterization of Brevibacillus biofilm isolated from pasteurized milk and evaluation of the efficacy of sodium hypochlorite, CIP, and enzymatic treatment against the biofilm

Bacterial biofilms pose significant food safety threats to the dairy industry. This study identified Brevibacillus contamination in pasteurized milk at a processing plant, with biofilm formation observed on polyethylene plastic and stainless steel surfaces. The presence of milk promoted robust growth of Brevibacillus, facilitating biofilm formation and spore production. Biofilm structure, nanowires, and potential swelling were visualized on SEM images. Raman spectroscopy analysis revealed enrichment of lipids and amide I in milk-formed biofilms, resulting in a hydrophobic tendency as evidenced by contact angle measurements. Cultivable cell counts in milk-formed biofilms post-treatment with sodium hypochlorite or the alkaline and acid regime were approximately 7 and 3 log CFU/well, respectively. Effective biofilm removal was achieved through enzymatic treatment (lipase and DNase I) followed by an alkaline and acid regime. These findings underscore the pivotal role of biofilms in contaminating milk processing plants and highlight the urgent need for effective biofilm control strategies to safeguard the dairy industry.

Optimal Enzyme-Assisted Extraction of Phenolics from Leaves of Pongamia pinnata via Response Surface Methodology and Artificial Neural Networking.

This research work seeks to evaluate the impact of selected enzyme complexes on the optimised release of phenolics from leaves of Pongamia pinnata. After preliminary solvent extraction, the P. pinnata leaf extract was subjected to enzymatic treatment, using enzyme cocktails such as kemzyme dry-plus, natuzyme, and zympex-014. It was noticed that zympex-014 had a greater extract yield (28.0%) than kemzyme dry-plus (17.0%) and natuzyme (18.0%). Based on the better outcomes, zympex-014-based extract values were subsequently applied to several RSM parameters. The selected model is suggested to be significant by the F value (12.50) and R2 value (0.9669). The applicability of the ANN model was shown by how closely the projected values from the ANN were to the experimental values. In terms of total phenolic contents (18.61 mg GAE/g), total flavonoid contents (12.56 mg CE/g), and DPPH test (IC50) (6.5 g/mL), antioxidant activities also shown significant findings. SEM analysis also revealed that the cell walls were damaged during enzymatic hydrolysis, as opposed to non-hydrolysed material. Using GC-MS, five potent phenolic compounds were identified in P. pinnata extract. According to the findings of this study, the recovery of phenolic bioactives and subsequent increase in the antioxidant capacity of P. pinnata leaf extract were both positively impacted by the optimisation approaches suggested, including the use of zympex-014.

Structural, physicochemical, prebiotic properties of guava pulp insoluble dietary fiber and its quality enhancement ability on cow/goat yogurt: Impacts of ultrasound-assisted enzyme treatment

This study explores the effect of ultrasound-assisted cellulase (UE) processing on the structure, functional performance, and prebiotic properties of guava insoluble dietary fiber (RIDF). As the ultrasound exposure time increased (0–40 min), the particle size (from 126.3 μm to 38.7 μm) and crystallinity (from 30.72% to 14.42%) of RIDF significantly decreased, while its soluble carbohydrate content (from 1.40% to 6.17%) and water solubility (from 8.6% to 16.4%) notably increased. These crucial changes suggested the degradation and disorganization of RIDF. Meanwhile, UE-RIDF (modified RIDF) demonstrated a honeycomb network microstructure with a larger surface area, indicating distinct structural and morphological properties compared to RIDF. Consequently, UE-RIDF showed stronger retention/adsorption capacity and improved in vitro prebiotic activity. Interestingly, UE treatment increased RIDF fermentability, leading to additional shifts in its modulation of human fecal microbiota, including a higher abundance of Proteobacteria and Phascolarctobacterium. Furthermore, compared to pure cow/goat yogurt, yogurt fermented with UE-RIDF displayed a lower pH, better stability, and improved texture and rheological properties during a 21-day refrigeration period. These findings highlight the potential application of RIDF as a novel prebiotic active ingredient in fermented foods for the first time, underscoring the critical role of UE treatment in enhancing its performance.