Effects of galactooligosaccharide glycation on the functional properties of soy protein isolate and its application in noodles

Soybean protein has high nutritional value, but its functional properties are easily affected by external factors,which limits its application in food industry. In the study, soybean protein isolate(SPI) was modified by dry heat glycation of galactooligosaccharides(GOS). The gel properties, antioxidant properties and structural changes of SPI-GOS conjugates were investigated. The application of SPI-GOS conjugates in noodles was also explored. The results observed that the glycation degree of SPI increased with the increasing reaction time. SDS-PAGE and spectral analysis showed the changes of spatial conformation of SPI after glycation. The antioxidant activity of SPI increased after glycation and DPPH radical scavenging activity of SPI-GOS peaked at 48 h of reaction. The hardness, elasticity and resilience of soybean protein gel reached their relative maximum at 48 h, 48 h and 12 h of glycation reaction, respectively. Moreover, the appropriate addition of glycated SPI improved the quality of noodles. The noodles with 4% addition of SPI-GOS had higher hardness, elasticity and tensile properties. This study will provide an effective method to modify soybean protein and expand the use of soybean protein in food industry.

Comparative effects of soy protein concentrate,enzyme‑treated soybean meal,and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

A Review of Soy-Tannin Gelling for Resins Applications

Soy flour(SF),soy protein and soy protein isolates(SPI)have been the focus of increasing research on their application as new materials for a variety of applications,mainly for wood adhesives and other resins.Tannins too have been the focus of increasing research for similar applications.While both materials are classed as non-toxic and have achieved interesting results the majority of the numerous and rather inventive approaches have still relied on some sort of hardeners or cross-linkers to bring either of them or even their combination to achieve acceptable results.The paper after a presentation of the two materials and their characteristics concentrates on the formation of gels,gelling and even hardening in the case of soy-tannin combined resins.The chapter than finishes with details of the formation of resins giving suitable wood adhesive of acceptable performance by the covalent coreaction of soy protein and tannin without any other hardener,thus totally bio-sourced,non-toxic and environment friendly as a base of further advances to expect in future by these two materials combination.

Effect of ionic strength and mixing ratio on complex coacervation of soy protein isolate/Flammulina velutipes polysaccharide

Soy protein isolate(SPI)is a commercial protein with balanced amino acids,while the poor solubility impedes its use in traditional foods.To overcome the problem,the complex coacervation of SPI/Flammulina velutipes polysaccharide(FVP)were investigated.Initial results revealed that the suitable amounts of FVP contributed to reducing the turbidity of SPI solution.Under electrostatic interaction,the formation of SPI/FVP coacervates were spontaneous and went through a nucleation and growth process.Low salt concentration(C_(NaCl)=10,50 mmol/L)led to an increase in the critical pH values(pHc,pHφ1)while the critical pH values decreased when C_(NaCl)≥100 mmol/L.The concentration of NaCl ions increased the content ofα-helix.With the increase of FVP,the critical pH values decreased and the content ofβ-sheet increased through electrostatic interaction.At SPI/FVP ratio of 10:1 and 15:1,the complex coacervation of SPI/FVP were saturated,and the coacervates had the same storage modulus value.SPI/FVP coacervates exhibited solid-like properties and presented the strongest storage modulus at C_(NaCl)=50 mmol/L.The optimal pH,SPI/FVP ratio and NaCl concentration of complex coacervation were collected,and the coacervates demonstrated a valuable application potential to protect and deliver bioactives and food ingredients.

Supplementing the early diet of broilers with soy protein concentrate can improve intestinal development and enhance short-chain fatty acid-producing microbes and short-chain fatty acids,especially butyric acid

Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth.To explore the importance of early nutrition regulation in animals,soy protein concentrate(SPC)was added to the early diet of broilers to investigate its effects on amino acid digestibility,intestinal development,especially intestinal microorganisms,and broiler metabolites.A total of 192 oneday-old Arbor Acres(AA)male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 birds.The control group was fed a basal diet(control),and the treatment group was fed a basal diet supplemented with 12%SPC(SPC12)during the first 10 d(starter phase).From d 11 to 21(grower phase)and d 22 to 42(finisher phase),a basal diet was fed to both treatment groups.Results:SPC reduced the pH value and acid-binding capacity of the starter diet(P<0.05,d 10);SPC in the early diet enhanced the gizzard weight(P<0.05,d 10 and d 42)and the ileum weight(P<0.05,d 10)and decreased the weight and length of the jejunum(P<0.05,d 10)and the relative length of the duodenum and jejunum(P<0.05,d 10).At the same time,SPC enhanced villus height(P<0.05,d 10)and muscle thickness in the jejunum and ileum(P<0.05,d 10)and increased the number of goblet cells in the duodenum(P<0.05,d 10).Meanwhile,SPC increased the Chao1 index and the ACE index(P<0.05,d 10)and altered the composition of caecal microflora at d 10.SPC also increased the relative abundance of Alistipes,Anaerotruncus,Erysipelatoclostridium,Intestinimonas and Flavonifractor bacteria(P<0.05,d 10).At the same time,the concentrations of caecal butyric acid and total short-chain fatty acids(SCFAs)were also increased in the SPC12 group(P<0.05,d 10).Conclusions:In summary,the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.

MALDI ToF Investigation of the Reaction of Soy Protein Isolate with Glutaraldehyde for Wood Adhesives

Soy protein adhesives are currently a hot research topic in the wood panels industry for the abundant raw material reserves,reasonable price and outstanding environmental features.But their poor water resistance,low bonding strength and intolerance to mold are major drawbacks,so that proper modification before use is essential.Glutaraldehyde is one of the more apt cross-linking agents for soybean protein adhesives,which can effectively improve the bonding strength and water resistance of the adhesive.Equally,glutaraldehyde is also an efficient and broad-spectrum fungicide that can significantly improve the anti-fungal properties of a soy protein adhesive.In the work presented here,matrix assisted laser desorption ionization(MALDI-ToF)mass spectrometry and Fourier transform infrared spectroscopy techniques were used to analyze the reaction mechanism of glutaraldehyde cross-linking soybean protein.The results confirmed the reaction of the aldehyde group with amino groups of the side chains and the amide groups of the peptide linkages constituting the skeletal chain of the protein.The laboratory plywood and particleboard bonded with glutaraldehyde-soy bean protein adhesives were prepared to determine the adhesive bonding properties,the dry strength,24 h cold water soaking wet strength and 3 h hot water(63°C)wet strength of plywood were 2.03,1.13 and 0.75 MPa,respectively,which satisfied the requirements of industrial production.

Drying kinetics of soy protein isolate-corn starch film during preparation and its moisture adsorption characteristics during storage

To better understand the mass transfer process of moisture in the soy protein isolate-corn starch(SPI-CS)films during preparation and storage process,the drying kinetics model of SPI-CS films with different formation conditions during the drying process and the moisture adsorption characteristics of the SPI-CS films under different humidity conditions were investigated.Within the range of experimental conditions,the moisture migration rule in the SPI-CS films during the drying preparation was combined with the Page model which was expressed as MR=exp(-kt^(n)).It was found that the adsorption equilibrium needed shorter time(about 3 h)when the SPI-CS films existed in the environment with lower humidity(RH<54%).Additionally,the secondorder adsorption kinetic equation was successful to describe the moisture adsorption characteristic of the SPICS films during storage under different humidity conditions.

Crosslinking Mechanism of Soy Protein-based Adhesives based on Glyoxal and a Compound of Protein Model

The crosslinking mechanism of glyoxal and asparagine was analyzed,and the relationship between the mechanism and practical performances of soy protein-based adhesives was also discussed.It is shown that when pH=1 and 3,glyoxal reacted with asparagine in the form of major cyclic ether compounds.When pH=5,glyoxal reacted with asparagine in two structural forms of sodium glycollate and cyclic ether compounds.However,amidogens of asparagine were easy to develop protonation under acid conditions.Supplemented by the instability of cyclic ether compounds,the reaction activity and reaction degree between glyoxal and asparagine were relatively small.Under alkaline conditions,glyoxal mainly reacted with asparagine in the form of sodium glycollate.With the increase of pH,the polycondensation was more sufficient and the produced polycondensation products were more stable.The reaction mechanism between glyoxal and asparagine had strong correspondence to the practical performances of the adhesives.Glyoxal solution could develop crosslinking reactions with soy protein under both acid and alkaline conditions.Bonding strength and water resistance of the prepared soy protein-based adhesives were increased significantly.When pH>7,glyoxal had relatively high reaction activity and reaction intensity with soy protein,and the prepared adhesives had high crosslinking density and cohesion strength,showing relatively high bonding strength,water resistance and thermal stability.

Consumption of soybean,soy foods,soy isoflavones and breast cancer incidence:Differences between Chinese women and women in Western countries and possible mechanisms

Breast cancer is one of the most lethal diseases world-wide.However,there is a large difference in breast cancer incidence among Caucasian,Hispanic,African and Asian(e.g.Chinese)women with Caucasian women being the highest and Asian women being the lowest.It has been suggested that the dietary factors may account for approximately 50%of the breast cancer.One of such dietary components which are typical to Asian but not Caucasian diet is soy foods.A number of epidemiological studies have suggested that increasing soy consumption could be related to the decreased risk of occurrence and/or mortality of breast cancer.In this review,we first described briefly different types of soy products and their nutritional functions and consumption.Then,we described briefly soybean isoflavones,i.e.genistein(GEN),daidzein,glycitein,and presented several lines of evidence to demonstrate the possible association of soy flavone food consumption with incidence and prognosis of breast cancer;finally,we summarized several possible molecular mechanisms,including the effects of GEN as an agonist of ER,epigenetic and genome-wide effects,activation of peroxisome proliferator-activated receptors,induction of apoptosis and stimulation of autophagy,involved in the chemo-preventive effects of GEN on breast cancer.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Extruded Soybean Samples for Mechnical Oil Expression

Soybean is generally recognized as a source of edible and the deoiled meal is seen as a source of protein in animal feed.In recent years.However,more interest has been directed toward using soy meal as a protein souce for human consumption.Extrusion expelling of soybean provides an opportunity in this direction.The main focus of this study was to maximize the oil recovery from extruded soybean processed using three different kinds of extrudates and processing conditions.These extruded samples were later pressed uniaxially in a specifically designed test cell and the oil recovery was recorded over time.The effects of process variables,including applied pressure,pressing temperature and sample height,were investigated.Results indicated that over90% of the available oil could be recovered from pressing of extruded soy samples.The information generated is likedly to be useful in interpreting the effect of precess variables and extruding equipment for pretreatment of soybean for subsequent mechanical oil expression.

Effects of fermented soy milk on the liver lipids under oxidative stress

AIM： To investigate the effects of fermented soy milk powder on the antioxidative status and lipid metabolism in the livers of CCh-injected rats. METHODS： Forty-five healthy male Sprague-Dawley rats were randomly assigned to five groups according to five different diets： control （AIN-76）, AIN-76＋high- dose fermented soy milk powder, AIN-76＋low-dose fermented soy milk powder, AIN-76＋high-dose milk yogurt powder and AIN-76＋low-dose milk yogurt powder. The experiment lasted for 8 wk. After 4 wk, all the rats received intraperitoneal administration of CCh （0.2 mL/100 g body weight） every week. Total cholesterol （TC）, triglyceride （TG）, TBARS, ALP, and antioxidative enzymes in the liver were evaluated. RESULTS： There was also no significant difference in TBARS and antioxidative enzymes in the liver. TC and TG in the groups fed with fermented soy milk powder were generally lower than those fed with casein powder. CONCLUSION： Consumption of fermented soy milk was positive in lowering total cholesterol and TG accumulation in the liver under CCh-induced oxidative

Detection and inactivation of allergens in soybeans:A brief review of recent research advances

In the last decade,soybean allergies have been on the increases to such an extent that they have now become a public health issue thus prompting more studies and researches on the topic.The allergenicity of soybean is attributed to its protein fraction.The best way to prevent hypersensitive patients from ingesting allergenic compounds is to exclude such soybean allergens from their diet.As a result,it is essential to provide detailed and reliable knowledge of food ingredients.Therefore,precise and reliable approaches for detecting soybean allergens found in various food products must be used.The main way to reduce allergy risk is the identification of allergenic sites in food and their inactivation by various food-processing methods.It has been reported that food processing may lead to the modification of conformational structure of the protein or protein distortion that inhibit the binding of immunoglobulin E(Ig E)to epitopes on food allergens and also the mechanism of allergic reactions.Food processing technologies employed for inactivating allergenic epitopes used thermal and nonthermal techniques.Currently,several detection methods including protein-based and DNA-based approaches using analytical techniques such as enzyme-linked immunosorbent assay(ELISA),enzyme allergosorbent test(EAST),radioallergosorbent test(RAST),lateral flow immunoassay(LFIA),immunoblotting,realtime polymerase chain reaction(PCR),mass spectrometry and biosensors have been improved for identifying and quantifying these epitopes.This research focused on allergenic proteins of soybean,the most modern approaches for detecting and quantifying these allergens,and finally,the various methods used to inactivate these proteins and their effects on soy allergenicity.

Systematic review of soy isoflavone supplements on osteoporosis in women

Objective:To clarify the effect of soy isoflavones on prevention of osteoporosis,and the effective dosage of soy isoflavones and its duration.Methods:Random control trials that investigated the association of soy isoflavones and osteoporosis were included in the meta-analysis by researching MEDLINE,EMBASE and the Chinese Biomedical Database up to October 2011.The RevMan software was used for all of the statistical analysis.Results:The present meta-analysis found that soy isoflavones significantly increased the bone mineral density by 54%and decreased the bone resorption marker urinary deoxypyridinoline(DPD) by 23%compared to baseline in women. Using random effects model,the effect of isoflavones on bone mineral density(BMD) regarding menopausal status and isoflavone dose revealed higher weighted mean difference changes were found in postmenopausal women and isoflavone dose above 75 mg/d.Subgroup analysis of trials with menopausal status,supplement type,isoflavone dose and intervention duration that used soy isoflavone extracts resulted in significant diflerent overall effect of DPD using by random effects model.Sensitivity analysis indicated that the effect of soy isoflavones on BMD and DPD was robust.Conclusions:The present meta-analysis reveals that soy isoflavone supplements significandy increase bone mineral density and decrease the bone,resorption marker urinary DPD.It shows no significant effect on bone formation markers serum bone alkaline phosphatase. The significant effect of soy isoflavones on BMD and urinary DPD is relative to menopausal status, supplement type,isoflavone dose and intervention duration.

Effect of soy saponin on the growth of human colon cancer cells

AIM:To investigate the effect of extracted soybean saponins on the growth of human colon cancer cells.METHODS:WiDr human colon cancer cells were treated with 150,300,600 or 1200 ppm of soy saponin to determine the effect on cell growth,cell morphology,alkaline phosphatase(AP) and protein kinase C(PKC) activities,and P53 protein,c-Fos and c-Jun gene expression.RESULTS:Soy saponin decreased the number of viable cells in a dose-dependent manner and suppressed 12-Otetradecanol-phorbol-13-acetate-stimulated PKC activity(P < 0.05).Cells treated with saponins developed cytoplasmic vesicles and the cell membrane became rougher and more irregular in a dose-dependent manner,and eventually disassembled.At 600 and 1200 ppm,the activity of AP was increased(P < 0.05).However,the apoptosis markers such as c-Jun and c-Fos were not significantly affected by saponin.CONCLUSION:Soy saponin may be effective in preventing colon cancer by affecting cell morphology,cell proliferation enzymes,and cell growth.

Effects of Dietary Soy Isoflavones on Feed Intake,Growth Performance and Digestibility in Juvenile Japanese Flounder(Paralichthys olivaceus)

An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake,growth performance,and digestion of juvenile Japanese flounder(Paralichthys olivaceus).Four isonitrogenous(49% crude protein) and isoenergetic(20.1 MJ kg-1) diets were formulated to contain four graded levels of soy isoflavones,namely,0,1,4 and 8 g soy isoflavones in 1 kg of diet.Each diet was randomly fed to triplicate tanks of fish(Initial average weight:2.58 g ± 0.01 g),and each tank was stocked with 35 fish.No significant difference was observed among diets with levels of 0,1 and 4 g kg-1 soy isoflavones in feed intake,weight gain,feed efficiency ratio(FER),proximate composition of fish whole body and apparent digestibility coefficients(ADC) of nutrients and energy(P>0.05).However,high dietary soy isoflavones level(8 g kg-1) significantly depressed weight gain,FER,whole-body crude lipid content of fish and ADC of nutrients(P<0.05).These results indicate that high level of dietary soy isoflavones(above 4 g kg-1) significantly depresses growth responses and FER of Japanese flounder.However,as the content of soy isoflavones in soybean meal is around 1 to 3 g kg-1,the adverse effects might be neglected when soybean products are used as a fish feed ingredient.

Effects of total soy saponins on free radicals in the quadriceps femoris,serum testosterone,LDH,and BUN of exhausted rats

Purpose:The aim of this study was to investigate the impact of total soy saponins(TS) on the free radical metabolism from the quadriceps femoris muscle,serum testosterone,lactate dehydrogenase(LDH),and blood urea nitrogen(BUN) in rats exercised to exhaustion.Methods:A one-time exhausted treadmill exercise session was used.Sprague-Dawley rats were divided into 4 groups:a control group—animals receiving no TS and no exercise(NTSNE),animals receiving TS but no exercise group(TSNE),animals receiving no TS but exercised to exhaustion group(NTSE),and animals receiving TS and exercised to exhaustion group(TSE).The TSNE and TSE groups were fed TS at a dosage of 20 mg/kg body weight once per day for 2 weeks.The NTSE group was given a placebo,and the NTSNE group was not given any treatment.The NTSE and TSE groups were exercised at speed of 30 m/min on treadmill until exhausted.The exercise time and exercise distance were recorded when the rats became exhausted and the rats were then decapitated and anatomized immediately.A 10% homogenate of the quadriceps femoris tissue was prepared.The levels of superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA),glutathione peroxidase(GSH-Px),glutathione reductase(GR),reduced glutathione(GSH),total antioxidant capacity(T-AOC),LDH,BUN,and serum testosterone were tested.Results:TS significantly increased the exercise time to exhaustion by 20.62%(p < 0.05).The MDA levels were decreased significantly in the TSNE group than in NTSNE group(p < 0.05);the T-AOC levels increased significantly in the TSNE group than in the other 3 groups(p < 0.01,p < 0.05,p < 0.05).The LDH activity significantly increased in the NTSE group than in TSNE group(p < 0.05).The BUN levels significantly increased in the NTSE group than in the other 3 groups(p < 0.01,p < 0.01,p < 0.05),and significantly increased in the TSE group than in NTSNE and TSNE groups(both p < 0.01).The serum testosterone levels increased significantly in the TSNE group than in the other 3 groups(all p < 0.01).SOD,CAT,GSH-Px,GR,and GSH were not statistically different among the groups.Conclusion:TS can significantly improve the exercised rats' serum testosterone level and antioxidant activity in their quadriceps femoris to varying degrees,decrease MDA and serum LDH and BUN levels,increase the exercise time,and delay the occurrence of the fatigue.

Metabolomics mechanism of traditional soy sauce associated with fermentation time

Given that fermentation time has significant impact on quality and flavor of soy sauce,a global understanding of the metabolic mechanism as fermentation time prolonged is essential for producing satisfactory and consistent quality of traditional soy sauce.Herein,the metabolic compounds changes of soy sauce associated with fermentation time up to 10 years were comprehensively investigated by using Chinese traditional fermented soy sauce(CTFSS)as a demonstration.Results showed that formaldehyde nitrogen,total soluble nitrogen(TSN),non-salt soluble solids,amino acids,free 5’-nucleotides and volatile compounds in CTFSS changed obviously during fermentation.Specifically,glutamic acid and aspartic acid were prominent in CTFSS.Continuous decrease in content of hypoxanthine(Hx)was found from 1 M(1-month soy sauce)to7 M(7-months soy sauce).Furthermore,a significant opposite tendency for changes between some volatile compounds and amino acids was indicated that there was a transformation between these two components.Therefore,a better understanding to the influence of fermentation time on soy sauce had been proposed.As the formation and conversion of amino acids and sugars might be mainly responsible for flavor formation in CTFSS,the ratio of these two reactions rate led the metabolism to be divided into three steps,degradation,conversion and balance.

Effects of soy components on blood and liver lipids in rats fed high-cholesterol diets

AIM: To assess the effects of soy protein, isoflavone, and saponin on liver and blood lipid in rats that consumed high-cholesterol diets.METHODS: High-cholesterol diets (1%) with or without soy material were fed to 6-wk-old male Sprague-Dawley rats for 8 wk. Blood lipids, liver lipids, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) levels were measured. The in vitro bile acid-binding ability of soy materials was analyzed.RESULTS: The results of in vitro studies showed that soy protein isolate had a significantly higher bile acid-binding ability (8.4±0.8%) than soy saponin (3.1±0.7%) and isoflavone (1.3±0.4%, P＜0.05). On the other hand, at the end of the experimental period, rats that consumed soy protein diets had lower GOT and GPT levels than rats that consumed casein under high-cholesterol diets.Rats that consumed soy protein also had lower total cholesterol (TC) levels in the liver than those that consumed casein under high-cholesterol diets. Rats that consumed the soy protein diet containing both saponin and isoflavone had lower hepatic TC level than those that consumed the soy protein diet without isoflavone alone.The effect of different types of proteins on triglyceride was not significant.CONCLUSION: Consumption of soy provided benefits to control lipid levels under high-cholesterol dieting conditions in this rat model of hypercholesterolemia. The major component that reduced hepatic TC was not saponin, but possibly isoflavone.

Estrogen Receptor α and β Expressions in Hypothalamus-pituitary-ovary Axis in Rats Exposed Lactationally to Soy Isoflavones and Bisphenol A

Objectives This paper aims to investigate the uterotrophic activities of lactational exposure to combination of soy isoflavones （SIF） and bisphenol A （BPA） and to examine estrogen receptor α （ERα） and estrogen receptor β （ERβ） expressions in hypothalamus-pituitary-ovary axis and uterus.Methods Maternal rats that were breeding about 8 litters were randomly divided into four groups with seven dams in each group.Dams in different treatment groups received corn oil （control）,150 mg/kg BW of SIF,150 mg/kg BW of BPA or combination of 150 mg/kg BW of SIF and 150 mg/kg BW of BPA,respectively,from postnatal day 5 to 11 （PND5-11） by gavage.On PND12 and PND70,10 female litters were killed and hypothalamus,pituitary,ovary and uterus were collected.ERα and ERβ expressions in these organs were detected with Western blotting assay.And vaginal opening time and estrus cycle were examined in animals fed for PND70.Results On PND12,the relative uterine weight of rats treated with ISF or BPA or their combination was significantly higher than that of untreated rats （P〈0.05）.But the relative uterine weight of rats in the co-exposure group was slightly lower than that in the group only exposed to SIF or BPA.On PND 70,however,the relative uterine weight in each treatment group was not statistically different from that in the control group （P〈0.05）.Vaginal opening time and estrus cycle in groups treated with SIF or BPA or their combination were similar to those in the control group （P〈0.05）.Exposure to SIF or BPA or their combination could up-regulate or down-regulate ERα and ERβ expressions in hypothalamus,pituitary,ovary and uterus on PND12 and PND70.These regulation patterns for ERα and ERβ were different in different organs at different time points.Conclusion Lactational exposure to ISF or BPA or their combination could induce uterotrophic responses in neonate rats,which disappeared in later life.But these data fail to suggest a possibility for synergic actions between SIF and BPA.It was also demonstrated that the uterotrophic effects of SIF and BPA exposure might,at least,involve modification of ERα or ERβ expressions in the hypothalamus-pituitary-ovary axis.

Study on the Soy Protein-Based Adhesive Cross-Linked by Glyoxal

Based on the ESI-MS and ^(13)C-NMR analysis of the forms of glyoxal in acidic and alkaline solutions,the soy-based adhesive cross-linked by glyoxal was prepared in this work.The results showed that glyoxal existed in water in different forms at different pH levels.Under alkaline conditions,glyoxal transformed to glycolate through the intramolecular disproportionation reaction.Under acidic conditions,although some of glyoxal transformed to glycolate as what happened under alkaline conditions,most of glyoxal molecules existed in the form of fiveor six-membered cyclic ether structure.No ethylene tetraol or free aldehyde group was actually detected under these conditions.Although glyoxal reacted with soy protein under both acidic and alkaline conditions,alkaline conditions were more favorable for the improvement of mechanical performance and water resistance of soybased adhesives than acid conditions.