Hydrolysable Chestnut Tannin Extract Chemical Complexity in Its Reactions for Non-Isocyanate Polyurethanes(NIPU)Foams

Non-isocyanate polyurethane(NIPU)foams from a commercial hydrolysable tannin extract,chestnut wood tannin extract,have been prepared to determine what chemical species and products are taking part in the reactions involved.This method is based on two main steps:the reaction with dimethyl carbonate and the formation of urethane bonds by further reaction of the carbonated tannin with a diamine-like hexamethylene diamine.The hydroxyl groups on the tannin polyphenols and on the carbohydrates intimately linked with it and part of a hydrolysable tannin are the groups involved in these reactions.The carbohydrate skeleton of the hydrolysable tannin is also able to participate through its hydroxyl groups to the same two reactions rendering the whole molecular complex able to react to form NIPUs.The analysis by Matrix-Assisted Laser Desorption Ionization(MALDI-TOF)mass spectrometry and 13C Nuclear Magnetic Resonance(13C NMR)to further investigate the reaction mechanisms involved revealed the unsuspected complexity of chestnut hydrolysable tannin,with different fragments reacting in different manners forming a hardened network of considerable complexity.As the morphology and performance of these types of foams changes slightly with the change in the amount of glutaraldehyde and hexamine hardeners,the best performing foam formulation previously determined was scanned by SEM and analysed chemically for the structures formed.

Self-Blowing Non-Isocyanate Polyurethane Foams Based on Hydrolysable Tannins

ABSTRACT Non-isocyanate polyurethane(NIPU)foams using a hydrolysable tannin,also vulgarly called tannic acid,namely here commercial chestnut wood tannin extract was prepared.Compression strength did not appear to depend on the foam apparent density while the formulation composition of the NIPU foams has been shown to be more determinant.These NIPU foams appeared to be self-extinguishing once the high temperature flame is removed.The ignition time gave encouraging results but for improved fire resistance the foams may need some fire-retardant addition.FTIR spectrometry showed the formation of non-isocyanate urethane linkages.Thermogravimetric analysis indicated a good thermal resistance of these foams,with thermal degradation following four phases.First in the interval 25℃–120℃ range,mainly evaporation of water occurs with a maximal loss of 10%weight.In the 150℃–450℃ temperature range foams mass loss is of almost 70%.In particular in the 125℃–275℃ range occurs the degradation of some small molecular weight substances.In the 500℃–790℃ temperature range the foams do not present any further large degradation.

A New C-glycosidic Hydrolysable Tannin from Rhodomyrtus tomentosa

Tomentosin(1), a new C-glycosidic hydrolysable tannin, isolated from the leaves of Rhodomyrtus tomentosa. Its structure determined by chemical method and (1)HNMR spectroscopic analysis.

N-fixing tree species promote the chemical stability of soil organic carbon in subtropical plantations through increasing the relative contribution of plant-derived lipids

Biodiversity experiments have shown that soil organic carbon(SOC)is not only a function of plant diversity,but is also closely related to the nitrogen(N)-fixing plants.However,the effect of N-fixing trees on SOC chemical stability is still little known,especially with the compounding effects of tree species diversity.An experimental field manipulation was established in subtropical plantations of southern China to explore the impacts of tree species richness(i.e.,one,two,four and six tree species)and with/without N-fixing trees on SOC chemical stability,as indicated by the ratio of easily oxidized organic carbon to SOC(EOC/SOC).Plant-derived C components in terms of hydrolysable plant lipids and lignin phenols were isolated from soils for evaluating their relative contributions to SOC chemical stability.The results showed that N-fixing tree species rather than tree species richness had a significant effect on EOC/SOC.Hydrolysable plant lipids and lignin phenols were negatively correlated with EOC/SOC,while hydrolysable plant lipids contributed more to EOC/SOC than lignin phenols,especially in the occurrence of N-fixing trees.The presence of N-fixing tree species led to an increase in soil N availability and a decrease in fungal abundance,promoting the selective retention of certain key components of hydrolysable plant lipids,thus enhancing SOC chemical stability.These findings underpin the crucial role of N-fixing trees in shaping SOC chemical stability,and therefore,preferential selection of N-fixing tree species in mixed plantations is an appropriate silvicultural strategy to improve SOC chemical stability in subtropical plantations.

Food-derived protein hydrolysates and peptides:anxiolytic and antidepressant activities,characteristics,and mechanisms

Globally,the prevalence of anxiety and depression has reached epidemic proportions.Food-derived protein hydrolysates and peptides delivered through dietary supplementation can avoid the negative risks associated with traditional pharmaceuticals while delivering superior anxiolytic and antidepressant effects.This review summarizes current research on food-derived anxiolytic and antidepressant protein hydrolysates and peptides,and subsequently analyses their physicochemical characteristics and elaborates on their mechanisms.The aim of this work is to contribute to the in-depth study and provide a theoretical foundation for the development of related products to better serve patients with anxiety and depression.

The efficiency and safety evaluation of hemoglobin hydrolysate as a non-heme iron fortifier

Hemoglobin hydrolysate is derived from the enzymatic degradation of hemoglobin.This work aimed to evaluate whether hemoglobin hydrolysate promotes the absorption of non-heme iron and the safety of absorbed iron in mice by analyzing the iron binding content,iron circulation,and liver homeostasis.We found that hemoglobin hydrolysate promoted the absorption of non-heme iron with high efficiency in duodenum by spontaneously binding non-heme iron during digestion,and increased hepatic iron content by up-regulating divalent metal transporter 1,zinc transporter 14,but hepatic iron content only increased at 3 weeks.Duodenal iron entered the blood through ferroportin without restriction at 3 weeks,and excessive iron entered the liver and then affected the hepatocyte membranes permeability and lipid synthesis through oxidative stress.With the prolongation of dietary intervention,the up-regulated hepcidin acted on the ferroportin to restrict excess iron from entering the blood,and then the hepatic homeostasis recovered.In addition,hemoglobin hydrolysate enhanced the hepatic antioxidant capacity.Taken together,hemoglobin hydrolysate has a strong ability to promote the absorption of non-heme iron in vivo,and the absorbed iron is relatively safe due to the regulation of hepcidin.

Preparation,characterization and antioxidant activity analysis of three Maillard glycosylated bone collagen hydrolysates from chicken,porcine and bovine

Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides.Hence,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources.In this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and evaluated.The free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction activity.Furthermore,the 3 glycosylated hydrolysates showed no significant cytotoxicity.The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and G-Bbcp.Therefore,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.

Antihypertensive effects of whey protein hydrolysate involve reshaping the gut microbiome in spontaneously hypertension rats

Novel angiotensin-converting enzyme(ACE)inhibitory peptides were identified from whey protein hydrolysates(WPH)in vitro in our previous study and the antihypertensive abilities of WPH in vivo were further investigated in the current study.Results indicated that WPH significantly inhibited the development of high blood pressure and tissue injuries caused by hypertension.WPH inhibited ACE activity(20.81%,P<0.01),and reduced renin concentration(P<0.05),thereby reducing systolic blood pressure(SBP)(12.63%,P<0.05)in spontaneously hypertensive rats.The increased Akkermansia,Bacteroides,and Lactobacillus abundance promoted high short chain fatty acid content in feces after WPH intervention.These changes jointly contributed to low blood pressure.The heart weight and cardiomyocyte injuries(hypertrophy and degeneration)were alleviated by WPH.The proteomic results revealed that 19 protein expressions in the heart mainly associated with the wingless/integrated(Wnt)signaling pathway and Apelin signaling pathway were altered after WPH supplementation.Notably,WPH alleviated serum oxidative stress,indicated by the decreased malondialdehyde content(P<0.01),enhanced total antioxidant capacity(P<0.01)and superoxide dismutase activity(P<0.01).The current study suggests that WPH exhibit promising antihypertensive abilities in vivo and could be a potential alternative for antihypertensive dietary supplements.

Effect of pulsed ultrasound assisted extraction and aqueous acetone mixture on total hydrolysable tannins from pomegranate peel

Pomegranate peels are disposed of as waste even though it is an eminent source of total hydrolysable tannins(THT)and possesses a great worth for recycling.The present study was carried out with the hypothesis that pulsed system ultrasound-assisted extraction(PSUAE)technique optimization would aid in retaining high extract yield and THT recovery yield from pomegranate peel extract(PPE)with enhanced antioxidant potential.The extraction was performed at various conditions regarding solvent concentration(30-90% of acetone),solvent-feed ratio(10-30 mL/g),extraction time(10-20 min),and ultrasound amplitude(40-80%)for maximum extract yield,THT and antioxidant activity(AA).To model and optimize the process conditions tools namely response surface methodology(RSM)and artificial neural network(ANN)were applied.For solvent concentration,solvent-feed ratio,extraction time,and amplitude the optimal conditions attained with aid of RSM and ANN were:56%,26.5 mL/g,15 min,55%,and 45%,23 mL/g,15 min,50% respectively.The extract yield and THT content determined with RSM and ANN optimized values were 51.2%,86.4 mg TAE/g,and 62%,98.1 mg TAE/g,respectively.The mean square error value displayed the minimum and R^(2) exhibited maximum value in case of ANN compared to RSM model.PSUAE significantly augmented the AA of PPE to 77.2±0.50% compared to 49.7±0.35% of conventional extraction.FTIR and HPLC analysis established that PPE produced from PSUAE contains a significant amount of THT compounds(gallic acid and tannic acid derivative).SEM elucidated that the sonication effect resulted in peel cell wall disruptions ensuing in elevated extraction of THT.Therefore,this pulsed mode of ultrasound extraction could be regarded as an easy,cost-effective,and competent technique for the extraction of preferred natural THT from pomegranate peels that possess high prospective to be applied in food and nutraceutical formulations.

Yeast hydrolysate attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage in weaned piglets

Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.

Supplementation with yak (Bos grunniens) bone collagen hydrolysate altered the structure of gut microbiota and elevated short-chain fatty acid production in mice

In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation.

Systematic functional analysis and potential application of a serine protease from cold-adapted Planococcus bacterium

In this study, a gene encoding serine protease(PmSpr288)from cold-adapted bacterium, namely Planococcus maritimus XJ11, was cloned and overexpressed in Escherichia coli BL21(DE3). Bioinformatics analysis revealed that PmSpr288 belongs to serine protease S8 superfamily with a classical catalytic triad comprised by the Asp49, His86 and Ser251. Moreover, PmSpr288 was found to be active over broad alkaline pH and low-moderate temperature, and exhibited wide range of protein substrate specificity. In addition, PmSpr288 was able to hydrolyze the meat proteins actin and myosin, and molecular docking results suggested that the crucial interaction between PmSpr288 and actin/myosin complexes was mainly occupied by hydrogen bonds. The muscle protein hydrolysates of silver carp prepared by PmSpr288 was shown to have antioxidant activity via DPPH radical scavenging assay, which presented an IC_(50) valve of 1.309 mg/mL. In conclusion, these characteristics imply that PmSpr288 has potential biotechnological application prospect for the production of bioactive peptides.

Therapeutic Effects of an Alpha-Casozepine and White Fish Muscle Hydrolyzed Complementary Feed on Canine Separation-Related Disorders and Quality of Life of Dogs and Their Pet Owners

Background: Separation-related disorders are prevalent in dogs and can result in problem behaviours such as inappropriate elimination, destructive behaviour, and distress vocalizations which occur when an owner is absent or perceived as absent. Numerous natural products are marketed for managing anxiety in dogs;however, few, if any, of these products have documented evidence of efficacy in veterinary behaviour. Purpose: This open, multicentric clinical trial aimed to assess the efficacy of a new supplement containing alpha-casozepine and fish muscle hydrolysate on the separation-related problem in dogs and the impact on the quality of life of dogs and their pet owners. Material and Methods: Fifty-one dogs with clinical signs compatible with separation-related problems were included. The dogs were treated with a complementary feed (Zylkene Plus, Vetoquinol, France) for 30 days. Separation-related behaviour assessment (SRP), emotional disorders assessment (EDED) and the quality of life (QoL) of the pets and their pet owner were assessed at baseline and the end of the study by the veterinarians. In addition, owners were asked to rate their dog’s SRP weekly after enrolment using the same questionnaire that the veterinarian used at the beginning of the study. Results: There was a statistically significant improvement in the SRP, EDED, and QoL scores (P Conclusion: The results of this study support the hypothesis that the combination of alpha-casozepine and fish muscle hydrolysate is a promising and effective option to reduce the frequency and severity of separation-related behaviour in dogs and improve the quality of dogs and their owners.

Effects of Growing of Different Types of Crops on Constitution of Soil Available Nitrogen and Conversion and Utilization of Nitrogen Fertilizer

The soybean, cotton, maize and sorghum were planted in pot under low nitrogen, high nitrogen treatments, the soil available nitrogen constitution and con- version and utilization of nitrogen fertilizer were determined, so as to provide techni- cal guidance for reasonable use and improving use efficiency of nitrogen fertilizer for different types of crops. Compared with the control with nitrogen but unplanted crop, growing soybean, cotton, maize, sorghum significantly decreased the soil available N contents by 53. 48%, 51.54%, 33.10%, 55.03%,and influenced the constitution of soil available N. Thereinto, growing soybean, cotton, maize and sorghum significantly decreased soil inorganic N contents by 85.41%, 83.09%, 70.89% and 83.35%,but increased soil hydrolysable organic N contents by 1.41, 1.53, 2.11 and 1.28 times, respectively; growing soybean, cotton, maize and sorghum significantly decreased the rate of soil inorganic N to available N by 68.61%, 65.09%, 56.47% and 63.00%, but increased the rate of soil hydrolysable organic N to available N by 4.18, 4.21, 3.66 and 4.08 times, respectively. Compared with the control, growing soybean, cotton, maize and sorghum significantly increased the transform rate of ammonium nitrogen fertilizer by 93.66%, 38.19%, 32.58% and 38.31% respectively, and growing soybean treatment had the highest increasing range; the nitrification rates of ammo- nium nitrogen fertilizer of growing soybean, cotton, maize and sorghum treatments were negative values, and growing soybean treatment had the highest decreasing amplitude. The ammonium nitrogen fertilizer use efficiency of growing soybean, cot- ton, maize and sorghum treatments were 52.01%, 28.31%, 24.16% and 28.40% re- spectively and growing soybean treatment had the highest value. In conclusion, growing crops suppressed the soil nitrification and accelerated the development of soil hydrolysable organic nitrogen by the utilization of soil available nitrogen and the alteration of soil environment, and hence impacted the constitution of soil available nitrogen and the transform and use of ammonium nitrogen applied in soil. Legumi- nous crops had stronger ability of suppressing nitrification, making use of ammonium compared with non-Leguminous crops.

Changes of Granule Structure and Enzyme Hydrolysability of Starch in Upper Flue-cured Tobacco Leaves During Bulk Flue-curing

[Objective] This study aimed to investigate the changes of granule struc- ture, characteristic and related enzymatic activity of starch in upper flue-cured tobac- co leaves during bulk flue-curing process, to provide theoretical basis for reasonably regulating the starch content in upper flue-cured tobacco leaves and improving the quality of upper flue-cured tobacco leaves. [Method] Changes of amylase activity, enzyme hydrolysability and granule structure of starch in upper flue-cured tobacco leaves were studied during flue-curing process using conventional physical and chemical analysis and SEM. [Result] During the flue-curing process, the starch con- tent of tobacco leaves changed greatly at yellowing stage, and the activity of amy- lase presented the double-peak curve. The SEM observation results showed that most of the starch granules in fresh tobacco leaves were spheroidal and long cylin- drical, while some individuals were in irregular shape, with obvious groove-like in- vagination and layered structure on granule surface; during the flue-curing process, a large amount of starch granules showed layered structure on the surface at yellow- ing stage, and the long cylindrical starch granules were reduced greatly; at the end of flue-curing, there were barely any long cylindrical starch granule in flue-cured to- bacco leaves. Average long-axis-diameter of starch granules in fresh tobacco leaves was 3.21 μm, showing an overall gradually increasing trend during the flue-curing process, which was significantly enhanced at 38 and 42 ℃. The diameter of starch granules increased by more than 60% at the end of 42 ℃ and there was no re- markable difference after 47 ℃. During the flue-curing process, enzyme hydrolysabil- ity of starch in flue-cured tobacco leaves first increased, reached a peak at 38 ~C, and then decreased. [Conclusion] During the bulk flue-curing, the yellowing stage is the critical period for starch content, granule structure and characteristic changes of flue-cured tobacco leaves, it is of positive effects to improve the quality of upper flue-cured tobacco leaves by regulating the flue-curing conditions at yellowing stage.

Land Use Impact on Bioavailable Phosphorus in the Bronx River, New York

Various forms of phosphorus (P) could become bioavailable such as from desorption, dissolution and enzymatic hydrolysis. Potential bioavailable P estimation is critical to minimize eutrophication in freshwater systems. Thus, this study was conducted to predict potential bioavailable P in the water columns and sediments and their relations with enzymatic hydrolysis, and estimate impacts of land use and anthropogenic activities on P bioavailability, P transport and water quality in the Bronx River, New York, USA. In sediment samples collected in 2006, total P (TP), total inor-ganic P (IP), total organic P (OP) and bioavailable P (BAP) were in highest concentrations in sites located at Bronx River Valley upstream in Westchester (site 2), Troublesome Brook (TB, site 4), Sprain Brook (SB, site 7b) and Bronx River estuary near Sound View Park (site 14) respectively. Also, phosphodiesterase and native phosphatases (PDEase and NPase) hydrolyzed distinguishingly high amounts of OP or enzymatically hydrolysable P (EHP) in samples from sites 4, 7b, 10 (New York Botanical Garden) and 14. Microbial P was in negative values (caused by different bacteria and microorganisms could not be paralyzed by chloroform), and the most negative concentrations were appeared at sties 4 and 14. Spatial comparisons among different locations showed distinguished characteristics in tributaries and estuary. In sediments collected in 2007, TP, BAP and IP were in highest concentrations at sites 7-SB, 11-Bronx Zoo, 12-East Tremont Ave Bridge where fresh and saline water meets, 13-estuary facing Hunts Point Waste Water Treatment Plant (HP WWTP) and 14-estuary along Sound View Park. Besides, PDEase-P highest concentrations ap-peared at sties 7, 13 and 11, NPase-P concentrations were highest at 7 and 11. Microbial P was highest at sties 11 and 14. Spatial variations showed that higher P content and more intense enzymatic hydrolysis in silty clay finer sediments at site 7, 11 and 13. Temporal variations between the two years’ data showed land use and other anthropogenic factors’ impacts on P transport in river and deposit in sediments. Analysis of the river water samples showed that average soluble reactive P (SRP, 67 μg.l-1) in 2006 and SRP (68μg.l-1) in 2007 both were greater than background P concentration in most natural water (42 μg.l-1).

Analysis of Molecular Weight Distribution and Antioxidant Activities of Cirrhinus molitorella Skin Collagen Hydrolysates

[Objective] The aim of this work was to identify molecular weight （MW） distribution and antioxidant activity of fish skin col agen hydrolysates. [Method] The MW distribution of hydrolysates was determined using both size exclusion chromatography and matrix-assisted laser desorption ionization time-of-flight mass spec-trometry （MALDI-TOF-MS）. Fish skin were treated by the alkaline protease 2709. [Result] The optional conditions for hyerolysis were time 3 h, temperature 55 ℃, pH 10.0, substrate concentration 80 g/L and E/S 4%. The results of both methods indi-cated that the molecular weight of col agen hydrolysates was from 400 to 1 800 Da, and the peptides’ molecular weight was less than 1 400 Da mostly. The reducing power and antioxidant/radical scavenging activity [1, 1-diphenyl-2-picryl-hydrazyl （DPPH） free radical scavenging activity] were determined. [Conclusion] The results reveal that the fishskin hydrolysate is a potential source of antioxidants.

Terminalic Acid, a New Tannin from the Fruit of Terminalia chebula

Terminalic acid 1, a new hydrolysable tannin, was isolated from the fruit of Terminalia chebula. Its structure was found to be 1-O-galloyl-2,4-chebuloyl-beta-D-glucopyranose by chemical method and H-1-NMR, C-13-NMR, H-1-H-1 COSY, HMQC, HMBC and FAB-MS spectral analyses.

Identification of Odor Volatile Compounds and Deodorization ofPaphia undulata Enzymatic Hydrolysate

Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry （HS-SPME-GC-MS） analysis of volatiles from untreated samples and three deodorized samples （under the optimal conditions） ofPaphia undulata enzymatic hydrolysate revealed that the compounds contrib- uting to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodoriz- ing effects of activated carbon （AC） adsorption, yeast extract （YE） masking and tea polyphenol （TP） treatment on a P. undulata en- zymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained： AC adsorption （35 mg mL-1, 80℃, 40 rain）, YE masking （7 mgmL l, 45 ℃, 30 min） and TP treatment （0.4mgmL-l, 40℃, 50min）. AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of alde- hydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine （TMA） formation in a P. un- dulate hydrolysate solution for a period of 72 h.

Antioxidation Activities of Low-Molecular-Weight Gelatin Hydrolysate Isolated from the Sea Cucumber Stichopus japonicus

Gelatin extracted from the body wall of the sea cucumber （Stichopus japonicus） was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate （LMW-GH） of 700-- 1700 Da was produced using an ultrafiltration membrane bioreaetor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μgmL-1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in B16 cells. Furthermore, LMW-GH notably increased in- traeellular glutathione （GSH）, which in turn suppressed melanogenesis. LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics and pharmaceuticals or nutriceuticals.