Hydrolysis Time Research Articles

Optimization of Microcrystalline Cellulose Production from Brewer’s Spent Grain by Acid Hydrolysis

Brewer’s spent grain (BSG) is the main insoluble solid by-product of the brewing industry. To add value to this non-wood material, microcrystalline cellulose (MCC) was prepared from BSG by alkaline pretreatment, bleaching, and subsequent acid hydrolysis to produce non-wood MCC. This study aimed to optimize MCC production using a statistical design (Box-Behnken) with three factors at three levels: acid concentration (0.5–1.5 M), hydrolysis time (70–90 min) and hydrolysis temperature (55–65 °C), to achieve the maximum yield and crystallinity of MCC derived from BSG. Results from 17 experimental runs revealed that the hydrolysis condition of 0.63 M HCl for 70 min at 61 °C yielded the highest output of 15% with a crystallinity index of 60%. The chemical structures and characteristics of MCC derived from BSG were verified by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction analysis (XRD). FT-IR analysis showed that the major wavenumbers of lignin and hemicellulose after the chemical processes (1500 cm–1 and 1735 cm–1) decreased by 21.40% and 4.60%, respectively. The XRD chromatogram revealed that the XRD characteristic peaks were sharper after the chemical treatments, indicating an increase in cellulose crystallinity due to removing lignin and hemicellulose. The crystallinity index of MCC derived from BSG ranged from 55–64%, which is comparable in quality to commercial pharmaceutical MCC, Avicel® PH-101 (67.37%). These results demonstrated that MCC from BSG was successfully prepared by acid hydrolysis under optimized conditions. BSG proved a viable non-wood source for preparing MCC for application in the pharmaceutical and nutraceutical industries.

Antioxidant peptides from silver carp steak by alkaline protease and flavor enzyme hydrolysis: Characterization of their structure and cytoprotective effects against H2O2-induced oxidative stress.

Silver carp steak is a rarely utilized silver carp processing byproduct. This study aimed to optimize a dual enzymatic method to extract antioxidant peptide components from silver carp steak and characterize their structure and in vitro antioxidant activity through ultrafiltration purification, response surface methodology, molecular docking, and radical scavenging activity analysis. The optimal extraction conditions for silver carp steak antioxidant peptides (SCSAP) were determined as 1:6 solid-liquid ratio, 1500 U/g alkaline protease addition, 4 h alkaline protease hydrolysis time, 1946 U/g flavor enzyme addition, and 2.5 h flavor enzyme hydrolysis time. The <3 kDa SCSAP component (SCSAP-3kDa) showed the strongest antioxidant activity, with its 1,1-diphenyl-2-trinitrophenyl hydrazine (DPPH) radical scavenging rate, ABTS radical scavenging rate, hydroxyl radical scavenging rate, metal ion chelating rate, and reducing capacity reaching 88.75%, 91.21%, 67.02%, 69.07%, and 0.985, respectively. Moreover, the three peptides (PF-7, GP-8, and YF-10) of 100 µg/mL could protect HepG2 cells from oxidative stress damage by reducing the oxidative damage level and activating Keap1-Nrf2-ARE pathways, enabling an increase of superoxide dismutases (SOD) activity, and a decrease of malondialdehyde (MDA) content and reactive oxygen species (ROS) level. The integrated results indicate the enormous potential of SCSAP-3kDa as a functional food ingredient in the food industry. PRACTICAL APPLICATION: This study selected the antioxidant capacity of silver carp steak peptides as the index and developed a facile dual enzymatic hydrolysis method to obtain three antioxidant peptides (PF-7, GP-8, and YF-10) with biological activity, providing a theoretical basis for bioavailability of antioxidant peptides from silver carp steak and contributing to their application in new functional foods.

Optimizing extraction of collagen from hazardous leather shaving dusts by crude protease enzyme: Chrome recovery and reuse for leather rechroming

This study explores an eco-friendly method to achieve 99.98 % dechroming (reducing Cr from 7700 to 4.71 ppm) of Chrome-tanned leather shaving dust (CSD), through enzymatic hydrolysis using crude protease. The enzyme exhibited strong activity (>40 U mL−1) across a temperature range of 50 °C to 65 °C and a pH range of 5 to 11. The pH of the mixture containing CSD, water, MgO, and enzyme was maintained at 8.9 during hydrolysis. The temperature, hydrolysis time, and enzyme concentration were optimized using response surface methodology (RSM). Under optimal conditions of 17.57 % enzyme concentration, 62.01 °C, and a hydrolysis time of 7 h, the predicted collagen yield was 31.66 %. Laboratory experiments conducted with these predicted parameters resulted in a collagen recovery of 30.9 %, achieving an accuracy of 97.6 % compared to the predictions. In contrast, hydrolysis with MgO alone achieved only 87.01 % dechroming with about 2 % collagen yield, highlighting the enzyme's superior effectiveness. The enzymatic cleavage of peptide bonds in the leather matrix enhanced collagen solubilization. Characterization techniques, including FT-IR, NMR, XRD, DSC, and TGA, confirmed successful extraction and purity, with the collagen being rich in glycine and proline. Cytotoxicity results demonstrated its non-toxic nature, indicating potential applications in biomedical fields, tissue engineering, food, pharmaceuticals, and cosmetics. The recovered chromium sulfate was reused for rechroming goat wet blue leather, with chrome content in crust leather treated with recovered basic chromium sulfate (rBCS) and fresh basic chromium sulfate (BCS) being 3.23 % and 3.35 %, respectively, both meeting industry standards for goat crust leather. SynopsisAn eco-friendly method for dechroming chrome-tanned leather shaving dust (CSD) and extracting collagen was established. The process achieved 99.98 % dechroming and 30.9 % collagen yield using crude protease enzyme. Characterization confirmed the collagen's purity, and recovered chromium sulfate was reused for rechroming goat leather, meeting industry standards.

Preparation and characterization of ferulic oligosaccharides from different sources by cell-free GH10 and GH11 xylanases

The feruloyl oligosaccharides (FOs) produced by the decomposition of plant hemicellulose have broad potential applications in the food and biomedical areas. FOs were prepared through the specific enzymatic degradation of insoluble dietary fiber from different sources by cell-free GH10 and GH11 xylanases. The cell-free GH10 and GH11 xylanases were obtained by the heterologous expression in Escherichia coli. The enzymatic hydrolysis conditions were optimized as follows: temperature 50 °C, pH 5.5, hydrolysis time 12 h, GH10 xylanase addition 101.74 U, and GH11 xylanase addition 121.60 U. The compositions and structural characterization of wheat bran FOs (WB-FOs), corncob FOs (CC-FOs), and buckwheat straw FOs (BS-FOs) were identified by fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), high-performance liquid chromatography (HPLC), and electrospray ionization tandem mass spectrometry (ESI-MS). Degrees of polymerization (DP) of WB-FOs, CC-FOs, and BS-FOs were 3–11, 3–7, and 3–6, respectively. Ultraviolet (UV) radiation was investigated in vitro. The results demonstrated that BS-FOs possessed excellent UV resistance and photostability, followed by effectiveness in WB-FOs and CC-FOs. These results have improved our understanding of the relationship between FOs with different structural types and their UV radiation.

Red dragon fruit (Hylocereus polyrhzus) syrup: evaluation of parameters affecting the production process

Studies on the production of red dragon fruit syrup (Hylocereus polyrhzus) were carried out based on investigating the influence of concentration (0.1 - 0.4%) and hydrolysis time (15 - 45 mins) of pectinase enzyme on the process of pectinase hydrolyzed red dragon fruit juice. The recipe for red dragon fruit syrup with factors that change the concentration of citric acid (0.05 - 0.15%) and the concentration of Aspartame (0.1 - 0.5%) was investigated. At the same time, the concentration temperature was determined to achieve the quality syrup within the concentration temperature range (70 - 80℃). Research results showed that the 0.3% pectinase enzyme used for hydrolysis of fruit juice in 25 mins will yield a high juice recovery yield. Red dragon fruit juice (after hydrolysis) supplemented with 0.1% citric acid and 0.1% Aspartame at a concentrated temperature of 80℃ will produce a red dragon fruit syrup with a mildly sour taste, pungent taste and colour characteristic of red dragon fruit.

Preparation and tissue structure analysis of horse bone collagen peptide

Horse bone is rich in collagen, with a composition similar to that of human collagen. Collagen peptides supply nutrients needed for human growth that act as antioxidants, lower blood pressure. This study explored the extraction of collagen and the preparation of collagen short peptides from Mongolian horse bones. Bones were collected from horses of varying ages, and the collagen content along with calcium salt distribution were observed through staining and imaging analyses. Next, the bones were processed into a powder and then subjected to ultra-high-pressure processing for degreasing. The degreasing conditions were optimised by single-factor and orthogonal tests. Following this, collagen was extracted using an acid-enzymatic method, and its structural characteristics and thermal stability were assessed. The collagen short peptides were extracted from the collagen samples, and the effects of the enzymatic hydrolysis time, temperature, pH, and enzyme amount on the extraction rate were evaluated. Finally, the resulting collagen peptides were analysed for antioxidant activity. In summary, this experiment optimised the extraction conditions for horse bone collagen, demonstrating that the ultra-high-pressure method minimally affects collagen structure, and the extraction rate was high. Hence our method has significant development potential.

Optimization of Cassava-Peel Derived Nanostarch Via Sulphuric Acid Hydrolysis Using Taguchi Method

Untreated cassava peel waste generated during harvesting and processing poses significant environmental challenges. Synthesis of starch nanoparticles from cassava peels for various applications offers a sustainable solution to waste reduction and contributes to environmental conservation. The unique characteristics of nanostarch such as thermal stability, high solubility, non-toxicity, and low cost enable its application in the food industry, cosmetics, enhanced oil recovery, and textiles. The current study employed the Taguchi method design to optimize sulphuric acid hydrolysis in synthesizing cassava peel-derived nanostarch. Additionally, the derived cassava peel nanostarch was characterized using Fourier Transform Infrared Spectroscopy (FTIR). Starch was extracted from cassava peels, followed by synthesizing starch nanoparticles via sulphuric acid hydrolysis. Optimization of nanostarch synthesis was based on randomized experimental runs using the Taguchi method generated by the Minitab software, with the experiments conducted in duplicates. The optimum conditions for the experiment were found to be 3 hours, at 25°C using an H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;SO&amp;lt;sub&amp;gt;4 &amp;lt;/sub&amp;gt;acid concentration of 2M. These conditions produced a yield of 92.28%. ANOVA analysis identified sulphuric acid concentration as the most significant factor that affected cassava nanostarch yield, with p-values of 0.026 and 0.003 for the signal to noise (S/N) ratios and means, respectively. The least significant factor based on the analysis was the hydrolysis time. However, according to the S/N ratios main effect plot, the most optimum conditions predicted by the Taguchi method design was 9 hours, 25°C using H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;SO&amp;lt;sub&amp;gt;4 &amp;lt;/sub&amp;gt;acid concentration of 2M. A confirmation experiment conducted at 25°C, using an H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;SO&amp;lt;sub&amp;gt;4 &amp;lt;/sub&amp;gt;acid concentration of 2M for 9 hours gave a nanostarch yield of 97.01%. In conclusion, the Taguchi method design identified sulphuric acid concentration as the most significant factor in synthesizing cassava peel-derived nanostarch via acid hydrolysis.

Isolation of a novel Bacillus strain with industrial potential of producing alkaline chitosanase

A novel Bacillus strain, designated as HZ20-1, was discovered. This strain can produce naturally alkaline chitosanase without induction. Genomic analysis revealed that this chitosanase belongs to glycoside hydrolase family 8. When colloidal chitosan is used as a substrate, the maximum enzyme activity of 2.39 ± 0.03 U/mL is observed at a pH range of 8.5–9. This alkaline enzyme holds advantages over common acidic enzymes in various fields such as medicine, the environment, and daily chemical products, and thus has great market value. Moreover, as the chitosanase is a constitutive enzyme, there is no need for substrate induction. This can simplify fermentation equipment and reduce production cost. Additionally, in a preliminary study, we found that this strain can also degrade chitin and chitosan derivatives. After analysis, it was discovered that it has genes in glycoside hydrolase families 18 and 23. By controlling the enzymatic hydrolysis time, it is possible to produce products with different molecular weights, including N-acetylglucosamine, glucosamine, chito-oligosaccharides, and chitin oligosaccharides. Consequently, Bacillus sp. HZ20-1 is considered to have great potential for future industrial production of enzymes and oligosaccharides.

Investigation of Coffee Instant Premium by Subcritical Water Hydrolysis: Enhance of Caffeine and Antioxidant Contents

The current study observed a basic investigation into instant coffee production through subcritical water (SBW) hydrolysis. A series of SWB research in lab-scale were carried out to optimize the product qualities by adjusting the process parameters such as temperature, solvent amounts, and time for hydrolysis. The caffeine, antioxidant, pH changes, and morphologies of modified and unmodified coffee powder (commercial products) were also evaluated by SEM. The result showed that the optimum conditions were observed for SBW process at 170°C/11.18 ml/20 min with obtained 0.48 mg/ml and 29.40 µg/ml for antioxidant and caffeine, respectively. SEM images represented physical degradation of coffee extracted powder during hydrolysis. Further, the amount of coffee in the blend with mineral amount could be important sources of minerals to the human diet, as evident by EDX analysis. Further, the change of chemistry surface was also confirmed by FTIR. In summary, flow-through SBW hydrolysis of coffee extract promises for enhance caffeine and antioxidant.

Lactose hydrolysis in sheep and cow milk with varying fat levels to evaluate enzymatic production of lactulose

AbstractThis study aimed to perform lactose hydrolysis using free and immobilised β-galactosidase in cow and sheep milk with different fat levels, followed by lactulose synthesis through the isomerisation of glucose to fructose using immobilised glucose isomerase. There was no significant difference (P &gt; 0.05) in lactose hydrolysis (&gt;95%) using the free enzyme in the different types of milk. In contrast, significant differences were observed for the hydrolysis of whole cow milk (WCM) and skimmed cow milk (SCM) with the immobilised enzyme (IE). WCM required a longer hydrolysis time (43 h). Thus, the fat content may have affected the lactose hydrolysis of bovine milk with immobilised β-galactosidase. No difference was observed for whole sheep milk and skimmed sheep milk hydrolysed by IE, possibly due to the presence of smaller fat globules, which did not affect the lactose hydrolysis. No significant differences were observed for lactulose synthesis in whole milk from the different species evaluated. The lactulose synthesis in cow and sheep milk by the enzymatic route may be a promising alternative, though further studies are required to optimise the production of this prebiotic in situ.

Influence of enzymatic hydrolysis conditions on antimicrobial activities and peptide profiles of milk protein-derived hydrolysates from white wastewater

The focus of our investigation lies in the hydrolysis of milk proteins found in the substantial wastewater generated by the dairy industry, particularly in the white and cleaning wastewater resulting from rinsing and cleaning-in-place processes in order to enhance the value of dairy constituents by producing a diverse population of peptides, including potential antimicrobial peptides generated by 4 different enzymes: pepsin, trypsin, pronase E, and thermolysin. The protein/peptide content was influenced by the degree of hydrolysis values ranging from 2 % to 13 %, and UPLC-MS/MS characterization reveals distinct peptide sequences in enzymatic hydrolysates. The impact of hydrolysis time was also examined, revealing significant differences between 30 minutes and 240 minutes, with 555 peptides identified at 30 minutes, increasing to 693 at 240 minutes. After 4 hours, grouping showed variations: 181 peptides (thermolysin), 153 (pepsin), 126 (trypsin), and 83 (pronase E). A comparative analysis of the characterized sequences with antimicrobial peptides databases identified 17 antimicrobial peptides after 240 minutes pronase E and thermolysin hydrolysis, though they were insufficient to inhibit strains like Clostridium tyrobutyricum and Pseudomonas aeruginosa. Antimicrobial assays also revealed that peptides from Pronase T30, Pronase T240, and Thermolysine T240 exhibited antifungal activity against Mucor racemosus (MIC 2.5 mg/mL), but none against Penicillium commune. The effet of enzymatic hydrolysis demonstrated in this study highlights, for the first time, the potential for valorizing dairy white wastewater within the context of a circular economy framework.

Effect of acid and fermented silage hydrolysis time on protein fractionation and digestibility for Nile Tilapia

World aquaculture production currently demands sustainable protein ingredients that can compete with fishmeal regarding nutritional quality and economic feasibility. In this study, the protein fractionation of silages prepared with Nile tilapia processing waste (heads, spine, fins, and viscera) by two processes and three hydrolysis times was evaluated, considering the digestibility coefficients of its crude protein, amino acids, and gross energy of Nile tilapia juveniles. The apparent digestibility coefficients (ADCs) were determined using 360 Nile tilapia juveniles (9.36 ± 0.74 g) distributed in 18 tanks (150 L), following a completely randomized design with six treatments, in a factorial scheme of 2×3, with three replicates. The six test diets were composed of 69.5 % of the reference diet, 0.5 % chromium (III) oxide, and 30 % of either acid or fermented silages produced with three hydrolysis times (24, 96, and 192 hours). The results demonstrated that both the processing type and hydrolysis time influenced the profile and peptide fractions of the silages. The acid silage was faster in relation to the release of free α-amino groups and the degree of hydrolysis (DH), up to 192 hours of hydrolysis. After this period, the fermented silage showed a higher degree and speed of hydrolysis. SDS-PAGE demonstrated that a longer hydrolysis time increased the concentration of the protein band between 150 and 100 kDa, indicating a proliferation of microorganisms using the free amino acids produced during fermentation. Regarding the distribution of peptides, acid silage presented higher values for the concentration of polypeptides, slow degradation and proportion among fractions, with the appearance of di- and tripeptides, as well as free amino acids. For the fermented silage, a higher degradation of polypeptides into oligopeptides was verified, representing the highest fraction, with a small proportion of di- and tripeptides and free amino acids. ADC values were high for all amino acids and proteins, which was not observed for the mean values of energy ADC. The production of silages with 192 hours of hydrolysis proved to be viable, and the fermented processing revealed the highest ADC values in relation to most of the amino acids, thus being the most indicated to be incorporated in fish diets, favoring its utilization by small farmers and reducing the inadequate disposal of biodegradable waste, thereby avoiding environmental pollution.

Seaweed Milk Food Supplement Produced from Hydropuntia eucheumatoides (Harvey)

Objective / Background Hydropuntia eucheumatoides (HE) seaweed is widely distributed in tropical seas and is a common food for coastal people. Our objectives were to prepare seaweed milk from HE, and test is possible utility as a food supplement and source of antioxidants that has an appropriate sensory profile. Methods We used an enzyme from Lactobacillus strains for polysaccharide hydrolysis into HE seaweed milk food supplements. We cultured five Lactobacillus strains with appropriate agarase, cellulase, and amylase enzyme activities. Results We optimized the enzyme concentration (mass of seaweed HE: 40 g/L), substrate concentration (2 mL enzyme/g seaweed), temperature (50 °C), pH (5), and hydrolysis time (96 h). The hydrolyzate included oligosaccharides, monosaccharides, amino acids, and minerals. The product exhibited excellent sensory details and is likely to be safe for consumption. Conclusions We completed our objectives. Our product is ready for initial consumer sensory testing.

Optimization of microwave-assisted hydrolysis of glucose from oil palm empty fruit bunch

Hydrolysis of oil palm empty fruit bunches (OPEFB) using microwave as an energy source is carried out to produce sugar with mild operating conditions. One way to find the best conditions that can obtain high-quality sugar is to optimize the hydrolysis process. In this study, optimization was carried out using Response Surface Methodology (RSM) with a Central Composite Design (CCD) experimental design. Estimated variables to affect the hydrolysis process are the ratio of OPEFB to solvent (X1: 1:20-4:20 g/ml), solvent concentration (X2: 0.5-1.5%), and hydrolysis time (X3: 5-15 minutes). Hydrolysis success parameters were measured by hydrolysis temperature (Y1), glucose (Y2), fructose (Y3), and total sugar (Y4) concentration. The optimization results show that the three independent variables contribute 53.25% to the hydrolysis temperature and 86.42% to the sugar concentration. The recommended operating conditions were hydrolysis with the ratio of OPEFB to solvent of 4:20 g/ml, 0.50% solvent concentration, and done for 10 minutes. The hydrolysis temperature cannot be optimized because there is a mismatch in the temperature model analysis. The application of these conditions is predicted to produce glucose, fructose, and total sugar of 315.51; 258.24; 573.85 mg/L. The last step is to validate these conditions in the laboratory to get the actual value. Actual glucose, fructose, and total sugar obtained were 300.40; 245.44; 545.84 mg/L. The error in this study is less than 5% which indicates the actual value is following the predicted value. © 2001 Elsevier Science. All rights reserved

Preparation and characterization of porous corn starch-based antibacterial sustained-release intelligent film

A novel porous corn starch-based antibacterial sustained-release intelligent film was prepared with the porous corn starch as the substrate, purple corn cob anthocyanin (PCA) as the indicator, and tangerine peel essential oil as the antibacterial agent, and its properties were studied. The results showed that the porous corn starch-based antimicrobial sustained-release indicator film had good mechanical strength, surface hydrophobicity and light transmittance. The tensile strength of the sustained-release indicator film (PLSt-12) prepared by porous corn starch with an enzymatic hydrolysis time of 12 h was 14.35 MPa and the elongation at break was 6.55 %. The water contact angle was 89.10°, and the water vapor transmittance was 6.62 × 10−4 g·mm2·s−1·Pa−1. The PLSt-12 was brown at pH 10 and had a sensitive color response. The PLSt-12 reduced the release rate of anthocyanins by 25.01 %, and the sustained-release mechanism was non-Fick diffusion. It showed a significant color change when the pork quality deteriorated, which can be used to monitor the freshness of the pork. This type of antibacterial sustained-release intelligent film had considerable application potential in indicating food freshness.

Hydrothermal extraction of microcrystalline cellulose from post-consumer indigo denim fabrics and evaluation of its UV blocking property

Abstract Waste cotton clothes, including post-consumer denim fabrics, are abundant biopolymer sources due to their high cellulose content. These waste materials commonly end up in landfills, posing health and environmental concerns and losing valuable cellulosic materials. To address these, this study aims to extract and characterize microcrystalline cellulose (MCC) from post-consumer indigo denim fabrics using a one-step hydrothermal method and evaluate its UV-blocking properties. FTIR and TGA analysis of raw and bleached denim confirmed the presence and purity of cotton cellulose and the indigo dye. Extracted MCC yielded 70-84%, with a degree of polymerization (DP) of 281-299. XRD analysis of the MCC showed a cellulose Type I structure. FTIR suggests the removal of amorphous phases of cellulose, leaving the crystalline structure. SEM meanwhile revealed rod-shaped and rough-surfaced MCC particles with diameters of 10-20 μm and lengths of 45-60 μm. Both FTIR and SEM indicated the retention of indigo dye on MCC surface. Increased acid hydrolysis time led to smaller particle sizes and higher degree of crystallinity (CrI). Indigo PVA-MCC films showed good transparency and effective UV blocking. These results indicate the successful conversion of denim to MCC via the hydrothermal method and the stability of indigo dye in the cellulose matrix.

Statistical-Based Optimization of Modified Mangifera indica Fruit Starch as Substituent for Pharmaceutical Tableting Excipient.

This study aimed to optimize modified starch from Mangifera indica (mango) fruit using acid hydrolysis and pre-gelatinization via computer-assisted techniques as a substituent for pharmaceutical tableting excipients. The hydrolysis and microwave-assisted pre-gelatinization time and temperature were optimized using a three-level factorial design. The modified starches were characterized for flowability, compressibility, and swelling properties. It was found that all parameters fit a quadratic model, which can be used to predict the properties of the modified starch. The optimized hydrolysis reaction was 3.8 h at 56.4 °C, while the pre-gelatinization reaction was 3 min at 150 °C. Structural changes were found, ascertaining that starch modification was successful. The optimized hydrolyzed starch showed superior properties in relative to unmodified M. indica fruit starch and comparable characteristics to conventional excipients. The optimized pre-gelatinized starch presented an excellent enhancement in the flow and compression properties, with %swelling greatly augmented 3.95-fold and 1.24-fold compared to unmodified starch and SSG, respectively. Additionally, the pre-gelatinized starch presented comparable binding effect, while the hydrolyzed powder had reduced binding capacity due to shorter chains. The findings revealed that the use of software-assisted design of experiment facilitated a data-driven approach to optimize the modifications. The optimized modified mango starch demonstrated potential as a multifunctional excipient, capable of functioning as binder, disintegrant, and diluent.

Assessment of the Impact of Pretreatment of Spent Coffee Grounds with Diluted Sulfuric Acid on the Efficiency of Methane and Lactic Acid Fermentation

Lignocellulosic materials are composed of three major biocomponents such as cellulose, hemicellulose and lignin, which form a compact lignocellulosic complex. Characterized by high caloric content, lignocellulosic biomass, including coffee grounds, is a valuable energy source that can be efficiently used in various bioconversion and biotransformation processes. Due to the high consumption of coffee in the world, there is an increasing amount of coffee grounds, which is a rich waste and at the same time a valuable secondary raw material, and its use fits perfectly into a closed-loop economy. Coffee grounds biomass contains polysaccharides, mainly mannans, proteins, lipids, polyphenols, which will allow the development of different biorefinery strategies, the creation of new value-added products with reduced waste generation. The research describes the pre-treatment of coffee grounds with dilute sulfuric acid to evaluate the effect of acid concentration, hydrolysis time on biogas yield, including methane and lactic acid biosynthesis during anaerobic fermentations. A yield of 381.12 mL of CH4/g-VS methane was obtained, accounting for 72.48% of the total biogas composition. It was found that the most efficient sample in terms of substrate pre-treatment for lactic acid biosynthesis was coffee grounds after 90 min hydrolysis with 1.5% H2SO4 at 121 °C.

Formation of thermal-induced microgels from soy protein hydrolysates: Effects of selective proteolysis on glycinin/β-conglycinin

This study explored the impact of selective proteolysis on the formation of thermally induced soy protein microgels. Glycinin hydrolysate (GH) and β-conglycinin hydrolysate (CH) were obtained by subjecting soy protein isolate to selective proteolysis for different hydrolysis time (10–90 min), as confirmed by SDS-PAGE. In the early stages of hydrolysis, free sulfhydryl, surface hydrophobicity, storage modulus (G′) and loss modulus (G″) of GH and CH increased, which enhanced their gelling potential. However, as hydrolysis time increased, the gel properties of the hydrolysates progressively weakened. Structural characterization of microgels revealed that GH yielded microgels with smaller particle sizes and coarser and relatively dispersed granular structures, while CH resulted in microgels with lower potential values, smoother surfaces, and lumps resembling strand-like formations. Analysis of the structure and intermolecular force of microgels showed that the microgel formed by the GH gradually tended to be disordered, whereas the secondary structure of microgels formed by CH showed lower random coil content, resulting in a dense gel network aggregated through disulfide bonding, hydrophobic interactions and hydrogen bonding as demonstrated by frequency-dependent storage moduli measurements. Overall, this study presents a thorough characterization of microgels and shows that they can be tailored by selective proteolysis, which enables controlling the β-conglycinin/glycinin ratio of soy protein.

Enzymatic hydrolysis pretreatment combined with glycosylation for soybean protein isolate applying in dual-protein yogurt

This research investigated the viability of replacing milk protein with glycosylated soybean protein isolate (SPI) treated with different enzymatic hydrolysis times (0, 10, 20, 30, 40, and 50 min) in yogurt. The results showed that enzymatic hydrolysis pretreatment combined with glycosylation for SPI exhibited elevated grafting and solubility. Additionally, the high solubility of SPI (94.77 %) at 40 min facilitates the preparation of dual-protein yogurt (DPY). Compared to ESPI0-G, DPY that incorporates ESPI40-G through partial substitution of milk protein is capable of forming a denser and more stable gel matrix. Especially, the syneresis of DPY40 was reduced by 7.61 % compared to DPY0, which more closely approximates the texture properties of traditional yogurt. Meanwhile, glycosylated SPI treated with enzymatic hydrolysis can effectively degrade the beany flavor and slightly bitter taste in DPY. This study could provide a solid theoretical basis for the broader application and industrialization of plant-based yogurt.