Enzymatic Hydrolysis Method Research Articles

Enhanced fermentative hydrogen production from potato waste by enzymatic pretreatment

ABSTRACT Biological pretreatment and enzymatic hydrolysis have a potential role in the economic production of sugars and fuels from starch biomass. In this study, the Inoculum/Substrate (I/S) ratio effect and enzymatic pretreatments of potato peels for biohydrogen production in batch reactors were investigated. Two enzymes, α-Amylase and Cellulase, were tested separately and coexistent. Results showed that enzymatic hydrolysis using α-Amylase in mesophilic conditions enhanced carbohydrate concentration from 24.10 g/L to 53.47 g/L, whereas, the use of Cellulase and equi-volumetric mixture of both tested enzymes resulted in 47.16 and 48.16 g/L, respectively. The maximum biohydrogen cumulative production of 263 mL (equivalent to 430.37 mL H2/gVSadded) was obtained using the optimum I/S ratio of 1/6 gVS/gVS at pH 5.5 and incubation temperature of 55°C after 20 days of dark fermentation of potato waste without enzymatic treatment. Under the same operating conditions of the I/S ratio, pH, temperature and the best enzymatic treatment (3 h of substrate enzymatic hydrolysis by α-Amylase), the maximum yield of biohydrogen was 1088 mL (1780.39 mL H2/gVSadded). The enzymatic hydrolysis method adopted in this study can make overall biohydrogen production an effective process. The modified Gompertz model was found to be an adequate fit for biohydrogen production.

One-pot simultaneous extraction and enzymatic hydrolysis to prepare glycyrrhetinic acid via ionic liquid-based two-phase systems

With wide applications in the treatment of hepatitis and other diseases, glycyrrhetinic acid (GA) has a huge clinical and market demand. However, the current production methods of GA usually induce serious environmental pollution, urgently calling for an environmentally friendly production strategy. Aiming to fill this research gap, we designed a novel method to efficiently prepare GA at low environmental costs by the simultaneous extraction and enzymatic hydrolysis of glycyrrhizin based on ionic liquid-based two-phase systems. The best extractant achieved was 20% (v/v) of 1-butyl-3-methylimidazolium hexafluorophosphate/acetate buffer. Extraction conditions were optimized by the single-factor optimization and response surface methodology (RSM): solid-to-liquid ratio = 1/37, 41.2 °C, 171 rpm, and 64 min. The highest extraction ratio of glycyrrhizin was 74.36% in 64 min, with the average yield of GA reaching 120.53 mg per 10 g of licorice. The result was 52.7% of the theoretical yield, much higher than traditional methods. Consequently, the one-pot simultaneous extraction and enzymatic hydrolysis method demonstrated a high capacity to facilitate convenient preparations of natural active compounds with the potential for wider industrial applications.

Efficient Preparation of High-Purity Fucoxanthinol by SpyTag-Tailored Active Cholesterol Esterase Aggregates.

A novel approach to producing high-purity fucoxanthinol (FXOH) was exploited as a sustainable method to maximize fucoxanthin (FX) utilization. Through fusing the genes of cholesterol esterase and SpyTag and then expressing them in Escherichia coli, the fusion chimera was self-assembled into insoluble active aggregates by SpyTag, which could be regarded as carrier-free immobilization. The immobilization yield of the active cholesterol esterase aggregates could reach 60%. They have expressed good activity retention at 92.48% and 60.13% after 3 and 12 cycles, respectively, which is an exciting finding. The conversion ratio of FX to FXOH is 95.02%, which is remarkably higher than those realized via the conventional chemical reduction method (55.86%) and the enzymatic hydrolysis method by free cholesterol esterases (84.51%). The purity of FXOH obtained by this method is as high as 98%, which is much higher than those obtained by other methods. Thus, a promising method for simultaneously purifying and immobilizing active cholesterol esterase aggregates is demonstrated in this study by SpyTag tailoring. In addition, this study provides an eco-friendly method for producing high-purity FXOH from FX in a highly efficient manner.

Pembuatan Bioetanol Dari Air Limbah Cucian Beras Menggunakan Metode Hidrolisis Enzimatik Dan Fermentasi

This study aims to utilize rice washing wastewater as a potential raw material for bioethanol production using enzymatic hydrolysis and fermentation methods. The wastewater is treated with amylase enzyme to break down starch into simple sugars, which are then fermented using yeast to produce ethanol. The research involves optimizing process conditions such as temperature, pH, enzyme concentration, and fermentation time. The results indicate that rice washing wastewater has the potential to be an efficient raw material for bioethanol production. Thus, this study contributes to the development of renewable energy sources and the utilization of agricultural waste to create a more sustainable economic cycle.

Steroidal Saponins from the Rhizomes of Smilax china and Their Inhibitory Effects on Lipopolysaccharide-Induced Proinflammatory Cytokines Expression.

Four new furostanol saponins (1: - 4: ) and a new pregane-type saponin (5: ) along with six known steroidal saponins (6: - 11: ) were isolated from the rhizomes of Smilax china. The structures of 1: - 5: were elucidated by extensive analysis of NMR and HR-ESI-MS data in addition to enzymatic hydrolysis and other chemical methods. Compounds 1, 4: , and 11: showed inhibitory activity against the expression of proinflammatory mediators, inducible nitric oxide synthase, interleukin-1β, interleukin-6, and tumor necrosis factor-α in lipopolysaccharide-induced RAW264.7 cells. Compound 1: , at a concentration of 20 µM, decreased the production of inducible nitric oxide synthase, interleukin-1β, interleukin-6, and tumor necrosis factor-α by 36, 62, 72, and 67%, respectively, which is comparable to that of the positive control dexamethasone.

Preparation and nutritional properties of xylooligosaccharide from agricultural and forestry byproducts: A comprehensive review.

Xylooligosaccharide (XOS) are functional oligosaccharides with prebiotic activities, which originate from lignocellulosic biomass and have attracted extensive attention from scholars in recent years. This paper summarizes the strategies used in the production of XOS, and introduces the raw materials, preparation methods, and purification technology of XOS. In addition, the biological characteristics and applications of XOS are also presented. The most commonly recommended XOS production strategy is the two-stage method of alkaline pre-treatment and enzymatic hydrolysis; and further purification by membrane filtration to achieve the high yield of XOS is required for prebiotic function. At the same time, new strategies and technologies such as the hydrothermal and steam explosion have been used as pre-treatment methods combined with enzymatic hydrolysis to prepare XOS. XOS have many critical physiological activities, especially in regulating blood glucose, reducing blood lipid, and improving the structure of host intestinal flora.

Insights into flavor and key influencing factors of Maillard reaction products: A recent update.

During food processing, especially heating, the flavor and color of food change to a great extent due to Maillard reaction (MR). MR is a natural process for improving the flavor in various model systems and food products. Maillard reaction Products (MRPs) serve as ideal materials for the production of diverse flavors, which ultimately improve the flavor or reduce the odor of raw materials. Due to the complexity of the reaction, MR is affected by various factors, such as protein source, hydrolysis conditions, polypeptide molecular weight, temperature, and pH. In the recent years, much emphasis is given on conditional MR that could be used in producing of flavor-enhancing peptides and other compounds to increase the consumer preference and acceptability of processed foods. Recent reviews have highlighted the effects of MR on the functional and biological properties, without elaborating the flavor compounds obtained by the MR. In this review, we have mainly introduced the Maillard reaction-derived flavors (MF), the main substances producing MF, and detection methods. Subsequently, the main factors influencing MF, from the selection of materials (sugar sources, protein sources, enzymatic hydrolysis methods, molecular weights of peptides) to the reaction conditions (temperature, pH), are also described. In addition, the existing adverse effects of MR on the biological properties of protein are also pointed out.

PRODUCTION OF GLYCOSAMINOGLYCAN (GAG) FROM CHICKEN STERNUM BY ENZYMATIC HYDROLYSIS AND OPTIMIZATION OF PROCESS PARAMETERS

Bu çalışmada tavuk sternumundan enzimatik hidrolizasyon yöntemiyle sülfatlanmış glikozaminoglikan (GAG) ekstraksiyonu gerçekleştirilmiş ve optimum enzimatik hidrolizasyon işlem koşulu belirlenmiştir. İşlem koşullarının optimizasyonu için Yanıt Yüzey Yöntemi kullanılmıştır. Enzim miktarı, pH değeri, ekstraksiyon sıcaklığı ve süresi olarak seçilen dört parametrenin GAG verimi üzerindeki etkilerini açıklamak için Merkezi Kompozit Tasarımıyla oluşturulan deneme deseni uygulanmıştır. En yüksek GAG verimine en kısa ekstraksiyon süresi ve en az enzim miktarı ile ulaşmak hedeflenmiştir. Ekstraksiyon işlemi için en uygun işlem koşulları %0.6 enzim miktarı, 6.99 pH değeri, 62.96°C ekstraksiyon sıcaklığı ve 10.79 saat ekstraksiyon süresi olarak bulunmuştur. Bu koşullarda, ekstraksiyon verim değerinin %26.07 olması öngörülmüş ve deneysel olarak da doğrulanması sağlanmıştır.

Enzymatically Hydrolysed Common Buckwheat (Fagopyrum esculentum M.) as a Fermentable Source of Oligosaccharides and Sugars

Common buckwheat (Fagopyrum esculentum M.) is highly rich in starches and polysaccharides. Nowadays, the use of common buckwheat in brewing processes and functional product development is gaining popularity as it is gluten-free and therefore suitable for those suffering from coeliac disease. Moreover, enzyme-assisted extraction for common buckwheat releases these oligosaccharides as well as bioactive substances, which can be further used for developing new products. This research aims to compare different enzymatic hydrolysis methods and their effect on roasted common buckwheat flour. The degradation of buckwheat flour using these hydrolytic enzymes was captured using SEM. Oligosaccharide and sugar molecular mass distributions were identified using HPLC-SEC. The extract with the highest fermentable monomeric sugar content was further fermented with ancient lactic acid bacteria starters: Tibetan kefir grains and birch sap. Ferment extracts were analyzed for antimicrobial activity against ten different pathogenic bacteria. The results indicated that the incorporation of enzymes into the extraction process lead to the release of a wide variety of DP3-DP4. Furthermore, the successful fermentation of these extracts with ancient starters revealed promising antimicrobial activity against nine different pathogenic bacteria, including E. coli and L. monocytogenes. In general, common buckwheat is a suitable ingredient for developing beverages and products with high value and has high potential in pharmaceutical applications.

Effect of radio frequency, ultrasound, microwave-assisted papain, and alcalase hydrolysis on the structure, antioxidant activity, and peptidomic profile of Rosa roxburghii Tratt. seed protein.

Traditional enzymatic hydrolysis methods have defects such as low efficiency and poor bioactivity in the production of active peptides. In this study, radio frequency (RF) technology was innovatively used to assist the hydrolysis of Rosa roxburghii Tratt. seed protein (RTSP) by papain and alcalase. RF-assisted hydrolysis was compared with ultrasound-(US) and microwave (MW)-assisted techniques in terms of the degree of hydrolysis, structure, antioxidant properties, and changes in the peptidome of the hydrolysates to clarify the mechanism of functional change of physically-assisted hydrolysate. All three methods improved hydrolysis efficiency. The degree of hydrolysis (DH) of papain group increased from 6.38% to 7.97%, 9.97% and 8.37% after US-, MW- and RF-assisted hydrolysis, respectively, while the DH of alcalase-treated group increased from 21.13% to 25.66%, 26.03%, and 23.01%, respectively. The in vitro antioxidant capacity and intracellular antioxidant capacity of RTSP and its hydrolysates were measured and evaluated by fuzzy statistical evaluation, and MW-assisted alcalase hydrolysis had the highest in vitro and intracellular antioxidant activity scores of 0.713 and 0.820, respectively. Fourier transform infrared and amino acid composition analysis explained the enhanced antioxidant properties of the hydrolysates. Further peptide profiling showed the physical assistance led to an increase in the species and contents of small molecule antioxidant peptides compared to enzyme treatment alone. Pearson's linear correlation analysis showed that AY, LY, IY, PHW, SVL, LHL, YYV, VYY, and NHAV were significantly correlated with the antioxidant properties of hydrolysates. Our data suggested that physical assistance such as US, MW, and RF were effective to improve the efficiency of enzymatic hydrolysis and produce novel antioxidant peptides. PRACTICAL APPLICATION: In this study, it was found that electromagnetic wave-assisted enzymatic hydrolysis could improve the efficiency of hydrolysis and enhance the antioxidant activity of hydrolysates compared to unassisted means. Compared with MW treatment, RF has the comparable hydrolysis effect, but has the advantages of high penetration ability, good uniformity, and low energy consumption and has greater potential for the production of bioactive peptides.

A novel approach based on enzymatic hydrolysis for the valorisation of edible Parmigiano Reggiano cheese rinds

The growing market for shredded cheeses (such as flakes, internal cylinders, snacks and portions without rind) generates a large amount of Parmigiano Reggiano (PRRE) rind by-products. With the aim to provide a valorisation route for edible PRRE rinds, enzymatic hydrolysis methods were performed to produce a protein hydrolysate starting from the rinds at two ripening stages (12 and 24 months), which were previously characterised for their proximate composition. The results showed that, compared with the inner, the rind section has significantly higher protein (42.4% versus 29.7%) and lipid percentages (36.6% versus 29.7%), due to the lower moisture content (15.7% versus 32.4%). Then, after a single step of enzymatic hydrolysis, high-quality high-protein ingredients with low lipid amount (10–20%) and high digestibility (especially for the high amount of free amino acids at about 50 g 100 g−1 cheese) were obtained, to be potentially used in different food applications.

Purification and Characterization of a Novel α-L-Rhamnosidase from Papiliotrema laurentii ZJU-L07 and Its Application in Production of Icariin from Epimedin C.

Icariin is the most effective bioactive compound in Herba Epimedii. To enhance the content of icariin in the epimedium water extract, a novel strain, Papiliotrema laurentii ZJU-L07, producing an intracellular α-L-rhamnosidase was isolated from the soil and mutagenized. The specific activity of α-L-rhamnosidase was 29.89 U·mg−1 through purification, and the molecular mass of the enzyme was 100 kDa, as assayed by SDS-PAGE. The characterization of the purified enzyme was determined. The optimal temperature and pH were 55 °C and 7.0, respectively. The enzyme was stable in the pH range 5.5–9.0 for 2 h over 80% and the temperature range 30–40 °C for 2 h more than 70%. The enzyme activity was inhibited by Ca2+, Fe2+, Cu2+, and Mg2+, especially Fe2+. The kinetic parameters of Km and Vmax were 1.38 mM and 24.64 μmol·mg−1·min−1 using pNPR as the substrate, respectively. When epimedin C was used as a nature substrate to determine the kinetic parameters of α-L-rhamnosidase, the values of Km and Vmax were 3.28 mM and 0.01 μmol·mg−1·min−1, respectively. The conditions of enzymatic hydrolysis were optimized through single factor experiments and response surface methodology. The icariin yield increased from 61% to over 83% after optimization. The enzymatic hydrolysis method could be used for the industrialized production of icariin. At the same time, this enzyme could also cleave the α-1,2 glycosidic linkage between glucoside and rhamnoside in naringin and neohesperidin, which could be applicable in other biotechnological processes.

A Review on Factors and Processing Methods Affecting Antihypertensive Properties of Legumes, and Antihypertensive Properties of Selected Legumes

Hypertension is one of the major risk factors which leads to cardiovascular diseases, and the typical treatment for hypertension is drug therapy. However, as there are side effects to drug therapy, there has been an increase in research on legume proteins as biopeptides have shown antihypertensive effects. Many species of legumes have been cultivated for consumption as they are a good source of protein, carbohydrates, minerals, vitamins, and dietary fiber. Bioactive compounds of legumes potentially improve factors that affect antihypertensive properties, such as angiotensin-converting enzyme (ACE) inhibition activity, renin inhibition activity, and γ-aminobutyric acid (GABA) production. The processing method of enzymatic hydrolysis can improve ACE inhibition activity, as can be seen with horse gram, pigeon pea, and lentil hydrolysates containing potent ACE inhibitory peptides of Thr-Val-Gly-Met-Thr-Ala-Lys-Phe, Val-Val-Ser-Leu-Ser-Ile-Pro-Arg, and Asn-Ser-Leu-Thr-Leu-Pro-Ile-Leu-Arg-Tyr-Leu, while pigeon pea and kidney bean hydrolysates have shown good renin inhibition activity. Fermentation can also be used to process legumes as potent ACE inhibitory peptide Val-Val-Ser-Leu-Ser-Ile-Pro-Arg was identified from fermented pigeon pea, while kidney beans and lentils demonstrated good GABA production through natural fermentation and fermentation with microbial cultures. The germination processing method could also help improve ACE inhibition activity as horse gram has shown good inhibition activity. In vivo study of pigeon pea, kidney bean, and lentils showed potential antihypertensive properties as a significant lowering of systolic blood pressure of test subject was observed. Research done on the structure and function of antihypertensive properties of legumes can help in the development of functional food products which will be beneficial to human health.

Ultrasonication followed by enzymatic hydrolysis as a sample pre-treatment for the determination of Ag nanoparticles in edible seaweed by SP-ICP-MS

Seaweed can bioaccumulate nanomaterials that would be transferred to the trophic chain. This work describes the optimization of a method for the separation of silver nanoparticles (AgNPs) from seaweed using an ultrasound-assisted enzymatic hydrolysis method and ulterior determination by single particle inductively coupled plasma mass spectrometry (SP-ICP-MS).The following parameters affecting the isolation of AgNPs were optimized using a Palmaria palmata (red seaweed) sample previously exposed to AgNPs: type of sonication (bath vs. ultrasonic probe), ultrasound amplitude, sonication time, sonication mode (pulsed vs. continuous sonication), concentration of the enzymes mixture (Macerozyme R-10®), and enzymatic hydrolysis time. The stability of AgNPs during extraction was tested by transmission electron microscopy (TEM) and using a standard of 15 nm of polyvinylpyrrolidone (PVP)-coated AgNPs analyzed by SP-ICP-MS. The analytical performance was evaluated with good results. For total Ag determination, the limits of detection and quantification were 2.2 and 7.7 ng g−1, respectively; and for AgNPs determination, the limits of detection in size and number were 14 nm and 4.34 × 107 part g−1, respectively. Besides, the matrix effect, the repeatability and the analytical recovery were also studied. Finally, the method was applied to the analysis of several red (Palmaria palmata) and green (Ulva sp.) seaweed samples.

Physico-chemical properties, antioxidant activity, and ACE inhibitory activity of protein hydrolysates from wild jujube seed.

Wild jujube seed protein (WJSP) as one kind of functional food material has attracted much attention due to its highly nutritive and medicinal value in anti‐inflammatory and improving immunomodulatory ability. However, owing to its large molecular weight and complex structure, biological activities of WJSP were greatly limited and cannot be fully utilized by the human body. Therefore, how to improve the bioavailability of WJSP and develop promising WJSP nutritious materials is a great challenge. In this work, wild jujube seed protein hydrolysates (WJSPHs) were prepared from WJSP via enzymatic hydrolysis method, and their physico‐chemical properties, antioxidant activity, and angiotensin converting enzyme (ACE) inhibitory activity in vitro have been investigated for the first time. SDS–PAGE electrophoresis and size–exclusion chromatographic results indicate that WJSPHs have lower molecular weight distribution (< 5,000 Da) than WJSP. Circular dichroism (CD) spectroscopy and Fourier transform infrared spectroscopy (FTIR) results illustrated that random coil is the main secondary structure of WJSPHs. Antioxidant experiments indicate that WJSPHs exhibit high radicals‐scavenging ability of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radicals (94.60%), 2,2′‐azinobis‐(3‐ethylbenzthiazoline‐6‐sulfonate) (ABTS+) radicals (90.84%), superoxide radicals (44.77%), and hydroxyl radicals (47.77%). In vitro, WJSPHs can significantly decrease the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and increase the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) in HepG2 cells. Moreover, ACE activity was found that can be significantly inhibited by WJSPHs (73.02%). Therefore, all previously mentioned results suggest that WJSPHs may be a promising antioxidant food to prevent oxidative‐related diseases in future.Practical ApplicationThis study shows that WJSPHs exhibit high antioxidant activity and ACE inhibitory activity in vitro, which provide potential application value as antioxidant peptides to prevent oxidative‐related diseases.

Green and Simple Extraction of Arsenic Species from Rice Flour Using a Novel Ultrasound-Assisted Enzymatic Hydrolysis Method

It is well established that arsenic (As) has many toxic compounds, and in particular, inorganic As (iAs) has been classified as a type-1 carcinogen. The measuring of As species in rice flour is of great importance since rice is a staple of the diet in many countries and a major contributor to As intake in the Asian diet. In this study, several solvents and techniques for the extraction of As species from rice flour samples prior to their analysis by HPLC-ICP-MS were investigated. The extraction methods were examined for their efficiency in extracting various arsenicals from a rice flour certified reference material, NMIJ-7532a, produced by the National Metrology Institute of Japan. Results show that ultrasound-assisted extraction at 60 °C for 1 h and then heating at 100 °C for 2.5 h in the oven using a thermostable α-amylase aqueous solution was highly effective in liberating the arsenic species. The recoveries of iAs and dimethylarsinic acid (DMA) in NMIJ-7532a were 99.7% ± 1.6% (n = 3) and 98.1% ± 2.3% (n = 3), respectively, in comparison with the certificated values. Thus, the proposed extraction method is a green procedure that does not use any acidic, basic, or organic solvents. Moreover, this extraction method could effectively maintain the integrity of the native arsenic species of As(III), As(V), monomethylarsonate (MMA), DMA, arsenobetaine (AsB) and arsenocholine (AsC). Under the optimum extraction, chromatography and ICP-MS conditions, the limits of detection (LOD) obtained were 0.47 ng g−1, 1.67 ng g−1 and 0.80 ng g−1 for As(III), As(V) and DMA, respectively, while the limits of quantification (LOQ) achieved were 1.51 ng g−1, 5.34 ng g−1 and 2.57 ng g−1 for As(III), As(V) and DMA, respectively. Subsequently, the proposed method was successfully applied to As speciation analysis for several rice flour samples collected from contaminated areas in China.

Optimization of Acid-Catalyst Hydrolysis Process in Lactic Acid Production from Rice Husk by Using Lactobacillus bacteria

Lactic acid is an important component of manufacturing polylactic acid (PLA), which can be produced with high-lignocellulosic biomass, still few of them have utilized that. The production process starts with Alkaline Hydrogen Peroxide (AHP) pretreatment, acid-catalyzed (H2SO4) hydrolysis followed by post-hydrolysis, and fermentation using a mixture of Lactobacillus brevis + Lactobacillus rhamnosus and single Lactobacillus delbrueckii bacteria. The effectiveness of pretreatment results was analyzed by using Thermal Gravity Analysis (TGA), which resulted in the removal of lignin and cellulose are 32.60% and 43.18%, respectively. Lignin reduction results are supported by Scanning Electron Microscope (SEM) for morphology analysis; it is shown the surface of rice husk becomes rough and cracks after pretreatment. Cellulose reduction was analyzed by using X-Ray Diffraction (XRD) and shown the Crystallinity Index (CrI) decrease after chemical pretreatment. The optimum operating condition of hydrolysis was also studied using Face Centered Composite Design (FCCD) by Response Surface Methodology (RSM), and get the optimum conditions at a 4 M H2SO4 for 30.7 minutes 63.1 . Followed by post-hydrolysis for 10 minutes at 121 , it resulted in sugar concentration of 15.3056 g/L, which was analyzed by using dinitrosalicylic-acid (DNS) with Root Mean Square Error of 0.78009. The last process is fermentation which is carried out at 125 rpm 37 , for 48 hours. Through High-Performance Liquid Chromatography (HPLC) analysis, the lactic acid concentration of a single bacterium and a mixture was 24.595 and 24.975%, respectively. Similar research has been previously carried out using palm waste raw materials with the enzymatic hydrolysis method without optimization of RSM. This study investigates the effect of AHP pretreatment in the lignin removal process, the effectiveness of acid-catalyzed hydrolysis in the optimized sugar reduction through FCCD, and compares lactic acid concentrations obtained from the fermentation process with L. delbrueckii and culture L. rhamnosus + L. brevis.

In vitro fecal fermentation characteristics of bamboo insoluble dietary fiber and its impacts on human gut microbiota

Bamboo contains abundant hemicellulose, cellulose, and lignin, which are a high-quality insoluble dietary fiber (IDF) raw material. To investigate IDF- induced changes in the production of short-chain fatty acids (SCFAs) and the composition of human gut microbiota, IDF was extracted by alkaline hydrogen peroxide (named BIDF), complex enzymatic hydrolysis method (named OIDF) from bamboo, and commercial bamboo fiber BF90. The in vitro fecal fermentation characteristics of BIDF, OIDF, BF90 and its impacts on human gut microbiota were studied for the first time. Results showed that BIDF, OIDF, and BF90 could promote the production of total SCFAs after 24 h fermentation. Additionally, BIDF could alter the composition and microbial diversity of gut microbiota, especially increase the relative abundance of Bacteroides and decrease the ratio of Firmicutes to Bacteroidetes (F/B) value. These results revealed that the IDF from bamboo could be partially utilized by specific bacteria in human intestines and provide a reference for the study of the effects of IDF fermentation on SCFAs production and microbial composition.

Preparation and Evaluation of Antioxidant Activities of Bioactive Peptides Obtained from Cornus officinalis.

The present study is a preparation of bioactive peptides from Cornus officinalis proteins by the compound enzymatic hydrolysis method. Response surface methodology (RSM) coupled with Box–Behnken design (BBD) is used to optimize the preparation process of Cornus officinalis peptides. The effects of independent variables, such as the amount of enzyme, pH value, time, extraction times and the ratio of material to liquid on the yield of peptides, are also investigated. The analysis results of the RSM model show that the optimum conditions for the extraction of Cornus officinalis peptides were a pH value of 6.76, temperature of 48.84 °C and the amount of enzyme of 0.19%. Under optimal conditions, the yield of peptides was 36.18 ± 0.26 %, which was close to the predicted yield by the RSM model. Additionally, the prepared Cornus officinalis peptides showed significant antioxidant activity; the scavenging rates of the peptides for DPPH and ·OH were 48.47% and 29.41%, respectively. The results of the cell proliferation assay revealed that the prepared Cornus officinalis peptides could promote embryo fibroblast cells proliferation and repair oxidative damage cells. These results have a practical application value in the design of novel functional food formulations by using Cornus officinalis.

Laboratory diagnosis of the Tropicamide non-drug consumption

Introduction. Lately, medical services have reported a lot of cases caused by taking Tropicamide alone or with other drugs together. Moreover, it has been declared that the increase in the number of resistance cases to Tropicamide consumption has. Due to those facts, Tropicamide was included in the List of Drugs for Medical Use that should be served by the prescriptions in 2015. However, nowadays in Russia there are many combinations of medicines, for instance, Tropicamide and α-adrenergic agonist (phenylephrine) (Midrimax, Fenikamid, Appamide plus) that are not under that regulation. As a result, those medicines are served in pharmacies without any prescriptions. Thus, method developing for Tropicamide determination in the hair samples to establish his consumption period has become a perspective one.Aim. The research aimed to develop a method for the isolation and determination of Tropicamide in the hair samples.Materials and method. Reference standard of Tropicamide was used in this research. The following enzymes – papain, chymopsin, chymotrypsin, and hyaluronidase – were applied in the experiment. To design the long-term consumption of Tropicamide, laboratory animals (Guinea pigs, average masses about 200 – 250 g) with fair and brown nature colour hair were used in this research. The hair of laboratory animals was dyed by professional hair-dye "Estel Professional De Luxe". The following equipment was applied: balance "Sartorius СР224S", pH-meter " FiveEasy ", ball mill Retsch MM-200. The hair samples extracts were analyzed by gas chromatography with mass selective detection (Gas chromatograph model 7890А with mass selective detector model 5977 and MassHunter GC/MS software by Agilent Technologies).Results and discussion. All developed methods of enzymatic hydrolysis (by papain, chymopsin, chymotrypsin, and hyaluronidase) revealed comparable results for the Tropicamide determination in the hair samples. The research showed that the amount of the analyte isolated from the pigmented hair was a bit higher in comparison with the other hair samples (fair hair), despite the melanin gives chemical steadiness property to hair stuff. Moreover, the amount of Tropicamide extracted from the dyed hair samples increased by 30 %. The degradation products of the analyte of interest were not found in the extracts obtained for the dyed hair samples. Thus, the colorant does not destroy the xenobiotic during the hair dying procedure and does not impact the enzymatic hydrolysis process. The values of the validation parameters (precision and accuracy) met the required criteria for bioanalytical methods. Therefore, the enzymatic hydrolysis method can be recommended for application in laboratory practice.Conclusion. In the course of the study, a method for laboratory diagnostics of non-drug use of tropicamide was developed, the reproducibility of which meets the acceptance criteria for bioanalytical methods, which makes it possible to recommend it for work in laboratory practice.