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Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chitosan oligosaccharides (COS), derived from chitin, have garnered considerable attention owing to their diverse biological activities and potential applications. Previous investigations into the bioactivity of COS often encountered challenges, primarily stemming from the use of COS mixtures, making it difficult to discern specific effects linked to distinct degrees of polymerization (DP). Recent progress underscores the significant variation in the biological activities of COS corresponding to different DPs, prompting dedicated research towards synthesizing COS with well-defined polymerization. Among the available methods, enzymatic preparation stands out as a viable and environmentally friendly approach for COS synthesis. This article provides a comprehensive overview of emerging strategies for the enzymatic preparation of single COS, encompassing protein engineering, enzymatic membrane bioreactors, and transglycosylation reactions. Furthermore, the bioactivities of single COS, including anti-tumor, antioxidant, antibacterial, anti-inflammatory, and plant defense inducer properties, exhibit close associations with DP values. The potential applications of single COS, such as in functional food, food preservation, and crop planting, are also elucidated. [ABSTRACT FROM AUTHOR]

人乳替代脂是一类模拟母乳脂组成的结构脂质，为促进人乳替代脂的绿色高效生产，介绍了母乳脂的甘油三酯组成，对人乳替代脂的酶法制备工艺以及实际应用的研究现状进行了分析、总结和探讨，并展望了未来的研究方向。我国母乳脂中1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL)含量最高，其次为1,3-二油酸-2-棕榈酸甘油三酯(OPO)。人乳替代脂的酶法制备工艺包括酯-酯交换法、一步酸解法、醇解-酯化两步法、两步酸解法、酯交换-酸解两步法等。提高酶的催化活性与位置选择性、抑制酰基迁移等是未来酶法制备人乳替代脂的研究方向。Human milk fat substitutes are a kind of structural lipids that simulate the composition of breast milk fat. In order to promote green and efficient production of human milk fat substitutes, the triglyceride composition of breast milk fat was introduced, and the enzymatic preparation technology and practical application of human milk fat substitutes were analyzed, summarized and discussed, and the future research direction was prospected. The content of 1-oleoyl-2-palmitoyl-3-linoleoyl glycerol (OPL) was the highest in Chinese breast milk fat, followed by 1,3-dioleoyl-2-palmitoyl glycerol (OPO). The enzymatic preparation of human milk fat substitutes includes ester-esterification, one-step acid hydrolysis, alcohololysis-esterification two-step, two-step acid hydrolysis, transesterification-acid hydrolysis two-step, etc. Improving the catalytic activity and location selectivity of enzymes and inhibiting acyl transfer are the future research directions of enzymatic preparation of human milk fat substitutes.

Malto-oligosaccharides (MOS) are α-1,4 glycosidic linked linear oligosaccharides of glucose, which have a diverse range of functional applications in the food, pharmaceutical, and other industries. They can be used to modify the physicochemical properties of foods thereby improving their quality attributes, or they can be included as prebiotics to improve their nutritional attributes. The degree of polymerization of MOS can be controlled by using specific enzymes, which means their functionality can be tuned for specific applications. In this article, we review the chemical structure, physicochemical properties, preparation, and functional applications of MOS in the food, health care, and other industries. Besides, we offer an overview for this saccharide from the perspective of prospect functional ingredient, which we feel lacks in the current literature. MOS could be expected to provide a novel promising substitute for functional oligosaccharides. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alginate oligosaccharides are a kind of low molecular weight polymer composed of 2~10 monosaccharide molecules linked by the same or different glycosidic bonds. Alginate lyase is an important tool for the enzymatic preparation of AOS. AOS prepared by the enzymatic method is superior to AOS prepared by other methods in purity, performance and structure. In this paper, the origin, structure and enzymatic properties of alginate lyase were reviewed, and the applications of alginate lyase in aquaculture, such as feed additive, microalgae cultivation, immune regulation, antioxidant and antibacterial, were summarized. The research direction of alginate lyase and the application prospect of alginate lyase in aquaculture were prospected, which provided reference for the application of alginate lyase and AOS in aquaculture. [ABSTRACT FROM AUTHOR]

Isomaltooligosaccharides (IMOs) are recognized as functional food ingredients with prebiotic potential that deliver health benefits. IMOs have attained commercial interest as they are produced from low-cost agricultural products that are widely available and have prospective applications in the food industry. This paper focuses on the enzymatic production processes of IMOs, as well as its key technology research, including enzyme conversion, enzyme membrane bioreactors, enzyme immobilization and biocatalysis are analyzed. Moreover, the shortcomings of the existing technology are analyzed. Combined with modern biotechnology, the research direction of related enzyme technology in the field of industrial production of IMOs is prospected, which provide some reference for its industrialization development.

为提高餐厨废弃油脂制生物柴油的储存稳定性，以餐厨废弃油脂为原料，采用生物酶法制备生物柴油，并向其中添加0.2%的抗氧化剂，测定其在90 d储存过程中酸值、水含量、硫含量及氧化安定性的变化。结果表明：酶法制备的生物柴油各项指标满足GB 25199—2017《B5柴油》中BD100生物柴油S10的技术要求，硫含量最低为2.1 mg/kg；当添加0.2%的抗氧化剂时，生物柴油的氧化安定性由3.6 h提高至12.0 h，储存90 d后，生物柴油的硫含量、酸值、水含量、氧化安定性仍符合国标要求。酶法制备生物柴油工艺易于控制产品的各项指标，且工艺更加绿色环保，通过添加抗氧化剂可提高生物柴油的储存稳定性。To improve the storage stability of biodiesel made from waste cooked oil, with waste cooked oil as raw material, biodiesel was produced by enzymatic process and 0.2% of antioxidant was added to it,then the change of acid value, moisture content, sulfur content and oxidation stability of the biodiesel during 90 d storage were determined. The results showed that the indicators of biodiesel prepared by enzymatic method met the technical requirements of BD100 biodiesel S10 in GB 25199-2017 “B5 Diesel fuels”, with a minimum sulfur content of 2.1 mg/kg.When 0.2% antioxidant was added, the oxidation stability of biodiesel increased from 3.6 h to 12.0 h. After 90 d of storage, the sulfur content, acid value, moisture content and oxidation stability were in line with national standard requirements. Enzymatic preparation process of biodiesel is easy to control the various indicators of the product, the process is more green and environmental protection, and through the addition of antioxidant the storage stability of biodiesel can be improved.

In this study, corn husk, a by-product formed during corn processing, was used as raw material, and a combination of enzymes was used to prepare corn husk dietary fiber. Single factor experiments and response surface optimization were used to determine the optimal process parameters and study its functionality. The results showed that the addition of alkaline protease was 0.742%, pH was 10, temperature was 54 ℃, and enzymatic hydrolysis was 4 h. Starch complex enzymatic hydrolysis conditions was as follows: The addtion of starch complex enzyme (amylase:saccharification enzyme=1:1 (m/m)) was 0.727%, pH was 6.76, temperature was 65 ℃, and enzymatic hydrolysis was 2 h. Under the optimal conditions, the dietary fiber content of corn husk reached the highest (86.65%±0.72%). Its water holding capacity was 3.93±0.17 g/g, and its swelling property was 3.70±0.20 mL/g. The oil holding capacity for soybean oil, corn oil, rapeseed oil and lard oil were 1.80±0.04, 2.59±0.01, 2.53±0.06, 3.47±0.19 g/g, respectively. Cholesterol adsorption in gastric environment and intestinal environment were 0.63±0.03 mg/g and 0.31±0.02 mg/g, respectively. The corn husk dietary fiber had good adsorption to different concentrations of glucose solution, and had a strong ability to inhibit fat digestion in vitro.

κ-Selenocarrageenan (KSC) is an organic selenium (Se) polysaccharide. There has been no report of an enzyme that can degrade κ-selenocarrageenan to κ-selenocarrageenan oligosaccharides (KSCOs). This study explored an enzyme, κ-selenocarrageenase (SeCar), from deep-sea bacteria and produced heterologously in Escherichia coli, which degraded KSC to KSCOs. Chemical and spectroscopic analyses demonstrated that purified KSCOs in hydrolysates were composed mainly of selenium-galactobiose. Organic selenium foods through dietary supplementation could help regulate inflammatory bowel diseases (IBD). This study discussed the effects of KSCOs on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in C57BL/6 mice. The results showed that KSCOs alleviated the symptoms of UC and suppressed colonic inflammation by reducing the activity of myeloperoxidase (MPO) and regulating the unbalanced secretion of inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10). Furthermore, KSCOs treatment regulated the composition of gut microbiota, enriched the genera Bifidobacterium, Lachnospiraceae_NK4A136_group and Ruminococcus and inhibited Dubosiella, Turicibacter and Romboutsia. These findings proved that KSCOs obtained by enzymatic degradation could be utilized to prevent or treat UC. [ABSTRACT FROM AUTHOR]

Cu(II), as a toxic heavy metal, has become a global environmental issue with much public concern. Herein, a novel methylcellulose-based adsorbent named MC-PL was prepared for adsorption of Cu(II) using lipase as enzyme catalyst. A series of characterization methods have shown that MC-PL was successfully synthesized with optimal modification degree of 91.39 ± 0.72%. The adsorption experiment result indicated that pH, adsorbent dosage, contact time and initial concentration of Cu(II) affected the adsorption of MC-PL toward Cu(II) with maximum removal performance of 97.58% under the optimal adsorption condition. The adsorption process of Cu(II) on MC-PL conformed to Langmuir and pseudo second-order models and belonged to a single-layer chemical adsorption process on the surface of a homogeneous medium. The maximum adsorption capacity was 126.58 mg·g−1 based on the Langmuir isotherm study. The adsorption mechanism of MC-PL toward Cu(II) was mainly caused by the complexation between the functional groups existing on the surface of MC-PL and Cu(II). Besides, Cu(II) adsorption onto MC-PL showed strong selectivity over the test common cations. Finally, reusability experiments proved that only 13.63% loss in the removal efficiency of MC-PL after five adsorption–desorption cycles. These results showed that this methylcellulose-based adsorbent is expected to be used for adsorption of Cu(II) from wastewater. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The manufacturing of indigo naturalis requires prolonged leaf soaking and lime stirring; the resulting indigo purity is less than 3.00% and the yield of indigo (measured in stems and leaves weight) is less than 0.50%, making it unsuitable for use in industrial procedures like printing and dyeing. An enzymatic method of creating indigo without the requirement for lime was investigated in order to generate high purity indigo. Single factor tests were performed to optimize the enzymatic preparation conditions. The findings showed that 60 °C, pH 5.5, 200 mL of leaves extract containing 0.45 mg/mL indican, and a 4:1 ratio of the acidic cellulose (activity: 9000 U/mL, liquid) to indican were the ideal parameters for enzymatic preparation. The yield of indigo was 40.32%, and the contents of indigo and indirubin were 37.37% and 2.30%, respectively. MALDI-TOF-MS in positive ion mode and UPLC-Q-TOF-MS in both positive and negative ion modes were used to analyze indigo extracts from Baphicacanthus cusia (Nees) Bremek by enzymatic preparation. It has been discovered that 13 alkaloids, 5 organic acids, 3 terpenoids, 3 steroids, 2 flavones, and 7 other compounds are present in indigo extracts. The presence of the indigo, indirubin, isorhamnetin, tryptanthrin, indigodole B, and indigodole C determined by UPLC-Q-TOF-MS was verified by MALDI-TOF-MS analysis. The enzymatic preparation of indigo extracts kept the same chemical makeup as conventional indigo naturalis. Thermal analysis and SEM morphology were used to confirm that there was no lime in the indigo extract. During the enzymatic process, Baphicacanthus cusia (Nees) Bremek was employed more effectively, increasing the yield and purity of indigo. • An enzymatic technique without the need for lime was investigated in order to produce high purity indigo. • The enzymatic preparation of indigo extracts kept the same chemical makeup as conventional indigo naturalis. • The indigo extract obtained through enzymatic production was a loose, inhomogeneous powder that contained 37.37% indigo. [ABSTRACT FROM AUTHOR]

The lipid products that consist of structured lipids rich in palmitic acid (16:0) at the sn-2 position of triacylglycerol (TAG) and rich in low-unsaturated fatty acids (FAs) (LUFAs), such as oleic acid; 18:1 and linoleic acid; 18:2 at the sn-1(3) positions, are useful intermediates for manufacturing human milk fat substitute (HMFS), which contains functional lipid components. In this study, the HMFS intermediate (HMFS-IM) was enzymatically prepared from palm oil without using other oil sources. First, the amount of 16:0 at the sn-2 position of TAG substrate was enhanced from 18.9% to more 34.5% via a random esterification reaction using a non-stereospecific lipase, Novozym® 435, to produce a random-palm substrate. Consequently, 2-monoacylglycerol (2-MAG) rich in 16:0 at the sn-2 position over 88%, together with the FA ethyl ester substrates rich in LUFAs, such as 18:1-Et and 18:2-Et above 93.5% was prepared through ethanolysis reaction using the same lipase from the random-palm substrate and by purification with urea complexation, respectively. As the preferred modified method, a continuous use of the same lipase to these reactions were achieved while reducing the usage of enzyme to half. Finally, an HMFS-IM rich in 16:0 at the sn-2 position more than 60% and LUFA at sn-1(3) positions was prepared using these palm oilbased products, including random-palm, palm-Et, and 2-MAG, via the interesterification reaction using a 1,3-stereospecific lipase, Lipozyme® RM-IM. Thus, HMFS-IM was successfully prepared by palm oil materials with a 65 wt% usage ratio. The concept described in this study will be useful for HMFS manufacturing from a single natural oil substrate, which is not initially rich in 16:0 at the sn-2 position. [ABSTRACT FROM AUTHOR]

A novel fiber-based biosorbent for dyes removal and microbial inactivation was prepared by enzymatic oxidization of viscose fibers and further modification with ε-polylysine. Glucose oxidase (GOx) was first employed as the enzyme for oxidation of viscose fibers. The consequences illustrated that the hydroxyl group on C1 position of viscose fibers was successfully oxidized with oxidation ratio of 2.43 ± 0.31%. Subsequently, ε-polylysine with average molecular weight of 4.44 ± 1.13 KDa and antimicrobial activity to E. coli of 90.48 ± 1.64 was modified with oxidized viscose fibers by lipase. Experimental results showed that oxidized viscose fibers were successfully modified with ε-polylysine with optimum degree of modification (DM) of 13.56 ± 1.05%. This oxidized viscose fiber modified with ε-polylysine (OVF-PL) displayed good dyes adsorption (or dyes removal) capacity for both anionic and cationic dyes, especially for anion dyes. Furthermore, OVF-PL showed excellent antimicrobial activity against E. coli and B. subtilis, particularly for E. coli , with GIB of 92.65%. Such fiber-based may offer a new pathway for preparing economical and efficient biosorbent for environmental remedy purpose. • Enzymatic oxidization of viscose fibers was proposed. • A novel fiber-based biosorbent modified with ε-polylysine (OVF-PL) was prepared. • OVF-PL shows excellent dyes removal capacity and microbial inactivation. [ABSTRACT FROM AUTHOR]

The development of human milk fat substitutes (HMFSs), rich in palmitic acid (16:0) at the sn-2 position of triacylglycerol (TAG) and rich in unsaturated fatty acids (FAs) (oleic acid, 18:1 and linoleic acid, 18:2) at the sn-1(3) positions, has gained popularity. In this study, HMFSs containing polyunsaturated fatty acids (PUFAs) predominantly at the sn-2 position were prepared, and their oxidation stabilities were compared. First, a non-PUFA-containing HMFS (NP-HMFS) was produced by enzymatic reactions using Novozyme® 435 and Lipozyme® RM-IM as the enzymes and lard as the raw material. Second, HMFSs, containing 10% PUFA at the sn-2 or sn-1(3) position, were individually prepared by enzymatic reactions using lard and fish oil as raw materials. Here, sn-2-PUFA-monoacylglycerol (MAG) was extracted from the reaction solution using a mixture of hexane and ethanol/water (70:30, v/v) to produce high-purity sn-2- PUFA-MAG with 78.1% yield. For the PUFA-containing HMFS substrates, comparable oxidation stability was confirmed by an auto-oxidation test. Finally, HMFSs containing 10% or 2% sn-1,3-18:1-sn-2-PUFATAG species were prepared by enzymatic reactions and subsequent physical blending. The oxidative stability of sn-1,3-18:1-sn-2-PUFA-HMFS was two-fold higher than that of 1/2/3-PUFA-HMFS in which each PUFA was located without stereospecific limitations in TAG. The removal of PUFA-TAG molecular species with higher concentrations of unsaturated units had a significant effect. In addition, the oxidation stability increased with the addition of tocopherol as an antioxidant. Thus, the combined use of two strategies, that is, the removal of PUFA-TAG molecular species with high concentrations of unsaturated units and the addition of antioxidants, would provide a PUFA-containing HMFS substrate with high oxidative stability. [ABSTRACT FROM AUTHOR]

Phytosterols are a class of plant-derived steroids that possess a variety of health benefits. However, their application is limited by inadequate oil solubility and limited bioaccessibility. Consequently, numerous studies have focused on modifying the structure of phytosterols to address these limitations. However, only the phytosterols and phytosterol esters (PEs) have been recognized for their safety in many countries and region globally. Therefore, this review focuses on the latest research progress and findings concerning the artificial preparation of PEs in the past five years. A comprehensive evaluation has been conducted by comparing the advantages and disadvantages of different preparation methods. Although recent evidence has revealed multiple functional properties of phytosterols, such as cholesterol-lowering, anti-cancer, anti-inflammatory, and antioxidant effects, a more in-depth exploration of the mechanistic understanding of these properties is required. In particular, the review describes the significant role of phytosterols and PEs in applications such as foods, skin care products and pharmaceuticals. In the future, it is necessary to scientifically design eco-friendly and high-efficiency PE preparation methods to broaden their application and enhance their value. [Display omitted] • Phytosterols are bioactive compounds that exist naturally in many plants. • Phytosterol esters (PEs) have better oil solubility and bioaccessibility. • The preparation of PEs mainly includes chemical synthesis and enzymatic catalysis. • Enzymatic technique is an effective solution for bypassing drawbacks of chemical process. • Phytosterol and PEs have been widely used in foods, skin care products and pharmaceuticals. [ABSTRACT FROM AUTHOR]

• Decarboxylated S-adenosyl-L-methionine (SAM) was effectively biosynthesized in vitro. • Pure decarboxylated SAM was prepared by semi-HPLC and identified by LC–MS. • Prepared decarboxylated SAM was used for impurity control in SAM production. S-adenosyl-L-methionine (SAM) is an important biosynthetic drug used for various diseases such as depression, arthritis syndromes and cirrhosis in clinical therapeutics. In order to ensure the high quality of SAM as a clinical drug, the key impurity, 5′-adenosyl-methylthiopropylamine (decarboxylated SAM, dC-SAM) should be monitored during the whole production process and in end tablet product. In the present work, the SPE2 gene encoding SAM decarboxylase was inserted into pET28a to obtain the expression plasmid pET28a- SPE2 , which was transferred into Escherichia coli BL21 to construct the recombinant strain. With low temperature (26 °C) cultivation and 0.1 mM IPTG induction, the recombinant cells were collected to prepare cell lysates, which can be utilized to effectively prepare dC-SAM in vitro with the addition of SAM as the substrate. Then dC-SAM sample with high-purity (99.7%) was isolated from this biotransformation mixture by semi-preparative high performance liquid chromatography. Further, the molecular structure of the purified dC-SAM sample was confirmed by liquid chromatography-mass spectrometry. Finally, prepared dC-SAM was employed to detect the content of the impurity during one-month industrial SAM fermentation processes. Our work will be very helpful to the control of impurities during the whole production process of SAM and its end products. [ABSTRACT FROM AUTHOR]

Compared with fish oil and microalgae oil, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in chemical form of phospholipids have attracted more and more attention due to their advantages in oxidation stability, bioavailability efficiency and nutritional functions. At present, extracting EPA/DHA containing phospholipids (EPA/DHA-PL) from Antarctic krill and marine roes has been industrialized, but few reports have revealed the enzymatic preparation of EPA/DHA-PL in large scale. The progress in enzymatic preparation of EPA/DHA-PL was summarized from three aspects: acyl-replacement, acyl-conjunction and acyl-removal based on synthesis strategy, attempting to provide reference for the further study of the preparation technology and industrialization. [ABSTRACT FROM AUTHOR]

Alginate is mainly a linear polysaccharide composed of randomly arranged β-D-mannuronic acid and α-L-guluronic acid linked by α, β-(1,4)-glycosidic bonds. Alginate lyases degrade alginate mainly adopting a β-elimination mechanism, breaking the glycosidic bonds between the monomers and forming a double bond between the C4 and C5 sugar rings to produce alginate oligosaccharides consisting of 2–25 monomers, which have various physiological functions. Thus, it can be used for the continuous industrial production of alginate oligosaccharides with a specific degree of polymerization, in accordance with the requirements of green exploitation of marine resources. With the development of structural analysis, the quantity of characterized alginate lyase structures is progressively growing, leading to a concomitant improvement in understanding the catalytic mechanism. Additionally, the use of molecular modification methods including rational design, truncated expression of non-catalytic domains, and recombination of conserved domains can improve the catalytic properties of the original enzyme, enabling researchers to screen out the enzyme with the expected excellent performance with high success rate and less workload. This review presents the latest findings on the catalytic mechanism of alginate lyases and outlines the methods for molecular modifications. Moreover, it explores the connection between the degree of polymerization and the physiological functions of alginate oligosaccharides, providing a reference for enzymatic preparation development and utilization. [Display omitted] • Alginate lyases are important tools for green producing alginate oligosaccharides. • The catalytic mechanisms of various alginate lyases are further distinguished. • Strategies for enhancing alginate lyase properties are delineated. • Modified alginate lyase produces products with a specific degree of polymerization. • Alginate lyase extends the value of alginate application and promising application. [ABSTRACT FROM AUTHOR]

Endo-1,4-β-galactanase is an indispensable tool for preparing prebiotic β-galacto-oligosaccharides (β-GOS) from pectic galactan resources. In the present study, a novel endo-1,4-β-galactanase (PoβGal53) belonging to glycoside hydrolase family 53 from Penicillium oxalicum sp. 68 was cloned and expressed in Pichia pastoris GS115. Upon purification by affinity chromatography, recombinant PoβGal53 exhibited a single band on SDS-PAGE with a molecular weight of 45.0 kDa. Using potato galactan as substrate, PoβGal53 showed optimal reaction conditions of pH 4.0, 40 °C, and was thermostable, retaining >80 % activity after incubating below 45 °C for 12 h. Significantly, PoβGal53 exhibited relatively conserved substrate specificity for (1 → 4)-β-D-galactan with an activity of 6244 ± 282 U/mg. In this regard, the enzyme is in effect the most efficient endo-1,4-β-galactanase identified to date. By using PoβGal53, β-GOS monomers were prepared from potato galactan and separated using medium pressure liquid chromatography. HPAEC-PAD, MALDI-TOF-MS and ESI-MS/MS analyses demonstrated that these β-GOS species ranged from 1,4-β-D-galactobiose to 1,4-β-D-galactooctaose (DP 2–8) with high purity. This work provides not only a highly active tool for enzymatic degradation of pectic galactan, but an efficient protocol for preparing β-GOS. [ABSTRACT FROM AUTHOR]

Pectic oligosaccharides have become novel bioactive components. However, the comprehensive preparation methods, structural features, bioactivities and application of them lack a systematic review. Here, we focused on the enzymatic preparation of pectic oligosaccharides, and attempted to outline relationships among the enzymolysis condition, structure, bioactivities and application of pectic oligosaccharides. Pectic oligosaccharides were characterized by the oligosaccharides with units of →4)-α-Gal p A-(1→4)-α-Gal p A-(1→ or →4)-α-Gal p A-(1→2)-α-Rha p -(1→. Enzymatic method was the most suitable approach for pectic oligosaccharides preparation that was significantly affected by the enzyme's type, time and concentration. Besides, pectic oligosaccharides possessed various bioactivities including prebiotic, anti-glycosylation, antioxidant, anticancer and lipid metabolism-regulation activities, which were closely associated with the molecular weight, the structure of side chain and the monosaccharide composition. Especially, many pectic oligosaccharides with low molecular weight demonstrated high prebiotic activities, and those with arabinogalactan side chains exhibited strong anticancer activities. Moreover, pectic oligosaccharides have been used in food preservatives, dairy product additives and food processing aids. Nevertheless, the industrial application, novel technology exploration, and structure-bioactivity relationship of pectic oligosaccharides remain a demanding and significant task for future work.

Arachidonoyl ethanolamide (AEA) is a bioactive lipid that occurs naturally in animal and plant tissues. In this study, arachidonic acid (ARA) was enriched first from a type of microbial oil by a two-step purification, and the purified ARA concentrate was then used for the enzymatic preparation of AEA by amidation between ARA and ethanolamine. The purity of initial ARA increased from 44.4% to 85.1% after urea complexation and acetonitrile extraction. The purified ARA was subsequently used for lipase-catalyzed synthesis of AEA. The results showed that under optimized conditions (5 mmol purified ARA product, 5.5 mmol ethanolamine, 3 mL hexane, 10% Lipozyme 435, 70 °C for 2 h), fatty acid ethanolamide was obtained with 95.6% yield. The current method for making AEA by the enzymatic amidation of ethanolamine with ARA from fungal oil is effective, practical and economically feasible. [ABSTRACT FROM AUTHOR]

Agricultural byproduct-foxtail millet ( Setaria italic ) bran was explored to extract dietary fiber by enzymatic methods and the physicochemical and functional properties of foxtail millet bran dietary fiber (FMBDF) were investigated. Results revealed that foxtail millet bran was a good source for dietary fiber production. The studies of physicochemical and functional properties showed that the water holding capacity and swelling power of FMBDF were 3.24 g/g and 2.06 ml/g, respectively. Meanwhile, FMBDF exhibited good adsorption capacities to lipophilic substances such as lard (3.34 g/g), peanut oil (2.32 g/g) and cholesterol (5.19 mg/g). Its bile salts adsorption capacity (143.03 μmol/g for sodium cholate and 76.65 μmol/g for sodium taurocholate) indirectly reflected its cholesterol-lowering effect. The chemical composition and microstructure studies of FMBDF demonstrated that these had a lot to do with its functional properties. The results indicate that FMBDF has a great potential to be used as functional ingredient in food products. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study investigated the feasibility of co-production of nanocellulose crystal (CNC) and ethanol using the bleached pine kraft pulp (BPKP) as a substrate by enzymatic hydrolysis. An engineering strain Penicillum oxalicum cEES-XM was constructed to produce suitable cellulase used in enzymatic hydrolysis of BPKP for preparing CNC. The cellulase from Trichoderma reesei SCB18 was used for simultaneous saccharification and fermentation of residues and hydrolysates from enzymatic hydrolysis for producing ethanol. The result showed that the CNC yield reached 7.35 % (w/w) by hydrolysis at 10 % solid content, and the final ethanol concentration was 13.27 mg/mL in fermentation liquor. Using SEM, XRD, TGA, and DLS methods, the characteristics of CNC including, morphology, crystallinity, thermal stability and particle size distribution, were also examined. This work provided a reference for realizing high-efficient application of cellulose in the pulp. [Display omitted] [ABSTRACT FROM AUTHOR]

The genome of the hyperthermophilic archaeon, Archaeoglobus fulgidus , contains three paralogous AglB genes that encode oligosaccharyltransferase (OST) proteins. The OST enzymes catalyze the transfer of an oligosaccharide chain from lipid-linked oligosaccharides (LLO) to asparagine residues in proteins. The detergent-solubilized membrane fractions prepared from cultured A. fulgidus cells contain both OST and LLO. The addition of a peptide containing the glycosylation sequon produced oligosaccharide chains attached to a structurally defined peptide. To facilitate the NMR analysis, the cells were grown in rich medium supplemented with 13 C -glucose, to label the LLOs metabolically. The MS analysis of the glycopeptide revealed that the glucose and galactose residues were nearly fully 13 C-labeled, but the mannose residues were fractionally labeled with about 20% efficiency. An immunodetection experiment revealed that the longest AglB paralog ( Af AglB-L) was expressed in the membrane fractions under our cell culture conditions, while the other two shorter AglB paralogs ( Af AglB-S1 and Af AglB-S2) were not. Thus, the oligosaccharide chain analyzed in this study was the product of Af AglB-L. The N-glycan consists of eight hexose residues, as follows: The α1,3-linked glucose is an optional residue branching from the distal mannose residue. The MS analysis of the minor HPLC peak of the in vitro oligosaccharyl transfer products also revealed an optional sulfate modification on the glucose residue directly linked to the Asn residue. The present data will be useful for structural and functional studies of the N-glycosylation system of A. fulgidus . [ABSTRACT FROM AUTHOR]

Highlights: [•] Oligosaccharides attached to the Asn residue of a peptide were produced in vitro. [•] Membrane fractions of Pyrococcus furiosus cells were used. [•] The structure was established by chemical, 2D NMR, and MS/MS analyses. [•] The N-glycan is a novel heptasaccharide containing two branching xylose residues. [ABSTRACT FROM AUTHOR]

Scientific researches on characterization of the commercial enological preparation of Lallzyme MMX® containing β-glucanase and its influence on autolysis of different yeast strains typically employed in the production of sparkling wine are lacking. The aim of the present work was to plug a gap in this field, studying the β-glucanase activity of Lallzyme MMX® and its interactions with BCS103® and EC1118® yeast strains. The results showed that β-glucanase was slightly inhibited by ethanol, but its residual activity at wine pH was sufficient for the purposes. Kinetic parameters showed a better enzyme–substrate complex formation for the EC1118® strain. The influence on yeast lysis during 12months of bottle-aging was monitored, demonstrating that enzyme addition did not substantially influence either the content and progression of total proteins, or foam characteristics. However, scanning and transmission electron microscopy images and free amino acid analysis indicated β-glucanase improved cell wall degradation of both selected yeasts, evidencing a lower autolytic capacity of the BCS103® strain. Our study demonstrated that addition of β-glucanase catalyzed cell disorganization and promoted release of yeast components into sparkling wine, with strain-dependent effects. Therefore, employment of β-glucanase rich Lallzyme MMX® might effectively accelerate some aging characteristics of traditional sparkling wines. [ABSTRACT FROM AUTHOR]

Highlights: [•] DisA from Bacillus thuringiensis (btDisA) exerts high activity to synthesize c-di-AMP from ATP. [•] The whole process only incorporates enzymatic reaction, HPLC separation, and lyophilization. [•] HPLC separation can ensure the purity of c-di-AMP. [•] More than 100mg of high pure c-di-AMP was obtained using 2 μM btDisA in a 50mL reaction system. [•] The method is convenient to be scaled up and c-di-AMP has promising application prospects. [Copyright &y& Elsevier]

Progenin III, one of the most active spirostanol saponins, is a potential candidate for anti-cancer therapy due to its strong antitumor activity and low hemolytic activity. However, the concentration of progenin III is extremely low in natural Dioscorea plants. In this paper, the progenin III production from total steroidal saponins of Dioscorea nipponica Makino was studied using the crude enzyme from Aspergillus oryzae DLFCC-38. The crude enzyme converting total steroidal saponins into progenin III was obtained from the A. oryzae DLFCC-38 culture. For enzyme production, the strain was cultured for 72 h at 30 °C with shaking at 150 rpm in 5 % (w/v) malt extract medium containing 2 % (v/v) extract of D. nipponica as the enzyme inducer. The crude enzyme converted total steroidal saponins into major progenin III with a high yield when the reaction was carried out for 9 h at 50 °C and pH 5.0 with the 20 mg/ml of substrate. In the preparation of progenin III, 117 g of crude progenin III was obtained from 160 g of substrate, and the crude product was purified with silica gel column to obtain 60.3 g progenin III of 93.4 % purity. [ABSTRACT FROM AUTHOR]

Abstract: Taking advantage of the catalytic promiscuity of pyrimidine-catabolism enzymes (dihydropyrimidinase (E.C. 3.5.2.2), N-carbamoyl-β-alanine amidohydrolase (E.C. 3.5.1.6)), the production of different β-alanine derivatives starting from 5- and 6-monosubstituted dihydrouracils has been evaluated using a mimesis approach. In this work, the S-enantioselective character of dihydropyrimidinase from Sinorizhobium meliloti toward 6-monosubstituted dihydrouracil derivatives has been shown. An inverted R-/S-enantioselectivity of N-carbamoyl-β-alanine amidohydrolase from Agrobacterium tumefaciens toward two different N-carbamoyl-β-amino acids has been proved. Our results have shown for the first time that this mimetic tandem constitutes an interesting biotechnological tool for the preparation of different β-alanine derivatives in an environmentally friendly way, allowing the production of enantioenriched (R)-α-phenyl-β-alanine (e.e.>95%) and (R)-α-methyl-β-alanine (e.e.>90%). [Copyright &y& Elsevier]

Abstract: The objective of this study was to investigate the enzymatic preparation method of soybean oligosaccharides (S0S) from okara by using Viscozyme L, characterize the physicochemical properties as well as antioxidant activity of S0S. The effect of Viscozyme L treatment on the preparation of S0S from okara was researched by orthogonal test. Under the fixed extraction time of 2.5 h and the ratio of okara to water of 1:15 (w/v), the optimal enzymatic preparation conditions of S0S by using Viscozyme L were identified as pH of 3.5, temperature of 45 °C, enzyme dosage of 3% (w/v) with a maximum yield of 10% (w/w). S0S were found to be crude oligosaccharides containing 56.5% neutral sugar, having a low molecular weight distribution range between 860 and 9380 Da, composing of galactose, xylose, rhamnose, arabinose, mannose and glucose. Furthermore, S0S showed the free radical scavenging activity with IC50 value of 1.81 mg/mL. These results suggest that S0S are novel oligosaccharides derived from okara, and could be improve value-added utilization of okara as antioxidants in functional foods and nutraceuticals. [Copyright &y& Elsevier]

In this study, in situ–forming quercetin-conjugated heparin hydrogels to be used to coat metal surfaces for blood compatibility were developed and characterized. Four units of quercetin and poly(ethylene glycol)–tyramine were conjugated per heparin for blood compatibility and hydrogel formation, respectively. The product, quercetin-conjugated heparin–poly(ethylene glycol)–tyramine, was cross-linked in situ via an enzymatic reaction using horseradish peroxidase and hydrogen peroxide to form a hydrogel. The physicochemical properties, such as the gelation time and swelling/degradation time as well as the release kinetics of quercetin, were controlled by changing the catalytic concentrations. The quercetin-conjugated heparin hydrogel, when adhered to a metal surface, enhanced blood compatibility and reduced platelet adhesion by 77%. The release of quercetin inhibited the proliferation of smooth muscle cells. The quercetin-conjugated heparin–poly(ethylene glycol)–tyramine hydrogel is a promising biomaterial with a stable-coated metal surface, with enhanced blood compatibility and antiproliferation effects. [ABSTRACT FROM PUBLISHER]

Platycosides, main pharmacological effective compounds, are known to have several biological activities, including anti-obesity, anti-cancer and anti-diabetes. Although enzymatic preparation of platycosides was considered as effective method to obtain them, few analytical methods have been reported on process control. In the present study, we developed an application of reversed-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous determination of six platycosides during the process of enzymatic preparation of deapio-platycodin D (dPD) and platycodin D (PD). The method employed a Hypersil ODS2 analytical column (250 × 4.6 mm I.D., 5 μm) coupled with UV detector at 210 nm with flow rate of 1.0 mg mL. A step gradient of acetonitrile-water (v/v) was applied, leading to a sample analysis of 60 min. The method was validated in terms of linearity, sensitivity, precision and accuracy. The correlation coefficients ( R) for calibration curves of platycosides were in the range of 0.9995-1.0 when the linearity range was from 0.85 to 10.2 mg mL. The proposed RP-HPLC method was successfully applied to the analysis of enzymatic preparation study and the recoveries of platycosides were in the range of 96.22-102.56% with RSD <3.3%. The method could be of use for rapid and routine evaluation of the quantity of platycosides during the enzymatic preparation process. [ABSTRACT FROM AUTHOR]

Abstract: A new route had been devised for obtain chitosan with stable properties and good quality suitable for medical, cosmetic and other purposes. Waste Aspergillus niger mycelia from a citric acid production plant were used as a source of chitosan. The extraction of chitosan was operated with lysozyme, snailase, neutral protease and novel chitin deacetylase from Scopulariopsis brevicaulis at the optimum condition of every enzyme. The optimum dosage of neutral protease and chitin deacetylase were 0.17g (5100 units) per 100g fresh mycelia and 1200 units per 100g fresh mycelia, respectively. The deproteinization rate was 59.9%. The recovery rate of glucosamine was 50%. Weight-averaged molecular weight, degree of deacetylation of chitosan and the content of glucosamine were 267.97kDa, 73.6 and 84.4%, respectively. Compared with chemical extraction methods, the weight-average molecular weight was three times higher whilst other parameters were very similar. The results of FT-IR, X-ray and elemental analysis proved that the structure of chitosan of enzymatic extraction was very similar to those of shrimp chitosan. [Copyright &y& Elsevier]

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Crude mutanase preparations of Trichoderma harzianum were obtained from the culture supernatant by means of ammonium sulfate salting out, ultrafiltration, freeze-drying, concentration under reduced pressure, and fractional precipitation with organic solvents (methanol, ethanol, propanol, isopropanol, acetone). Ammonium sulfate was the worst precipitant, causing a fall in total mutanase activity by 47%. Other methods of enzyme recovery from the post-culture fluid yielded in most cases very good results in regard to specific and overall activities of the enzymatic preparations. [ABSTRACT FROM AUTHOR]

Optically active 3-trimethyl silylalanine (TMS-Ala) was prepared by hydrolysis of N-acetyl- dl-TMS-Ala catalyzed by acylase I (aminoacylase; N-acylamino-acid amidohydrolase, EC3.5.1.14). Acylase I from porcine kidney (PKA) was found to be more effective than that from Aspergillus melleus in the preparation of l-TMS-Ala. Under the optimized conditions, optically pure l-TMS-Ala (>99% enantiomeric excess, ee) was obtained with a 72% yield. Furthermore, a highly optically pure d-TMS-Ala (96% ee) could also be obtained with a 76% yield by chemical hydrolysis of the residual substrate. Enzymatic synthesis of peptides containing TMS-Ala was also attempted in ethyl acetate. Benzyloxycarbonyl (Z)- l-TMS-Ala served as the substrate for thermolysin, whereas l-TMS-Ala-OMe was inactive as the amino component. In the case of inhibitory activity of dipeptides toward thermolysin, l-Leu-( l-TMS-Ala) was found to be a more potent inhibitor than l-Leu- l-Leu, which is known to be one of the most effective inhibitors of thermolysin among the dipeptides consisting of natural aminoacids. [ABSTRACT FROM AUTHOR]

N -l-Lactoyl phenylalanine ( N -l-lactoyl-Phe) has been identified as a taste-active contributor in many fermented foods. However, its preparation, taste property, and content in foodstuffs are little known to date. In the current study, two preparation technologies of N -l-lactoyl-Phe including heating and enzymatic methods were investigated. Other investigations include its taste property and quantification in several fermented foods. The results indicated that the heating preparation and enzymatic preparation only produced N -l-lactoyl-Phe instead of N -d-lactoyl-Phe in the presence of l-lactate/d-lactate and l-phenylalanine (Phe). A high yield (58.0% ± 0.7%) of N -l-lactoyl-Phe was achieved under the following conditions: Phe, lactate, CaO, and water at molar ratios of 1:8:0.3:9 kept at 100 °C for 3 h. With nine enzymes, a maximum yield of 21.2% ± 0.3% was achieved in the aqueous solution under mild operating conditions: 0.18 M Phe, 0.90 M lactate, 5 g/L Debitrase HYW 20, pH 8, and 55 °C for 24 h. The sensory evaluation revealed that N -l-lactoyl-Phe in water enhanced the salty and umami intensity. It also enhanced the thickness, mouthfulness, and continuity of salt solution, model broth, and chicken broth, revealing that N -l-lactoyl-Phe was a kokumi-active compound. The kokumi thresholds of N -l-lactoyl-Phe in these solutions were 50, 50, and 25 mg/L, respectively. N -l-Lactoyl-Phe was quantified in traditional Chinese fermented foods as 30.12 ± 0.28 mg/kg in preserved pickles, 14.11 ± 0.14 mg/kg in soybean paste, 4.87 ± 0.16 mg/kg in fermented bean, 0.71 ± 0.11 mg/kg in rice vinegar, and 20.34 ± 0.18 mg/kg in soy sauce. These results revealed the potential of N -l-lactoyl-Phe as a taste enhancer, presenting a new opportunity for the food industry.

• Properties of EGs from four glycoside hydrolase families were studied. • Efficiency of different EGs and their interaction in CNC preparation were evaluated. • Hydrolysis of MCC with mixture of Cel7B and Cel5B obtained the highest yield of CNC. • Endoglucanase treatment enhanced the thermal stability of CNC. The preparation of cellulose nanocrystal (CNC) by enzymatic treatment is widely known due to its eco-friendliness, and endoglucanases (EGs) are very important enzyme in the enzymatic process. In this study, the enzymatic properties of four different glycoside hydrolase (GH) families EGs (Cel7B, Cel5B, Cel12A and Cel45A) from Penicillium oxalicum were compared, and their efficiencies and interaction between different recombinant EGs in enzymatic preparation of CNC using microcrystalline cellulose (MCC) as cellulosic substrate were evaluated. Further, the properties of CNC obtained by the single EGs or enzyme mixture were characterized by scanning electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy, and thermogravimetric analysis. The result revealed that the highest CNC yield of 13.18 % was obtained by the optimum combination of Cel7B and Cel5B, and the length distribution was approximately 347 nm. This study provides a valuable reference for screening suitable enzyme or constructing engineering strain of high-efficiency enzymatic preparation of CNC. [ABSTRACT FROM AUTHOR]

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The lipid products that consist of structured lipids rich in palmitic acid (16:0) at the sn-2 position of triacylglycerol (TAG) and rich in low-unsaturated fatty acids (FAs) (LUFAs), such as oleic acid; 18:1 and linoleic acid; 18:2 at the sn-1(3) positions, are useful intermediates for manufacturing human milk fat substitute (HMFS), which contains functional lipid components. In this study, the HMFS intermediate (HMFS-IM) was enzymatically prepared from palm oil without using other oil sources. First, the amount of 16:0 at the sn-2 position of TAG substrate was enhanced from 18.9% to more 34.5% via a random esterification reaction using a non-stereospecific lipase, Novozym ® 435, to produce a random-palm substrate. Consequently, 2-monoacylglycerol (2-MAG) rich in 16:0 at the sn-2 position over 88%, together with the FA ethyl ester substrates rich in LUFAs, such as 18:1-Et and 18:2-Et above 93.5% was prepared through ethanolysis reaction using the same lipase from the random-palm substrate and by purification with urea complexation, respectively. As the preferred modified method, a continuous use of the same lipase to these reactions were achieved while reducing the usage of enzyme to half. Finally, an HMFS-IM rich in 16:0 at the sn-2 position more than 60% and LUFA at sn-1(3) positions was prepared using these palm oil-based products, including random-palm, palm-Et, and 2-MAG, via the interesterification reaction using a 1,3-stereospecific lipase, Lipozyme ® RM-IM. Thus, HMFS-IM was successfully prepared by palm oil materials with a 65 wt% usage ratio. The concept described in this study will be useful for HMFS manufacturing from a single natural oil substrate, which is not initially rich in 16:0 at the sn-2 position.