Survey of chloropropanols in soy sauces and related products

A survey of soy sauces and related products available in the USA was conducted to determine the levels of 3-monochloropropane-1,2-diol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) in these products. Fifty-five retail samples were purchased and analysed for 3-MCPD. 3-MCPD determinations were made according to a gas chromatography/mass spectrometry method validated by a collaborative trial. Eighty-five per cent of the samples analysed contained greater than the detection limit of 0.005 ppm (μg g^-1) for 3-MCPD. Thirty-three per cent contained greater than 1 ppm; the highest level was 876 ppm 3-MCPD. Thirty-nine of the samples analysed for 3-MCPD also were analysed for 1,3-DCP by using a modified method developed and validated in-house. Fifty-six per cent of the samples analysed for 1,3-DCP contained greater than the detection limit of 0.055 ppb (ng g^-1) for 1,3-DCP; the highest level was 9.8 ppm 1,3-DCP. Products manufactured in Asia contained the highest chloropropanol levels.     

酱油中黄曲霉毒素B_1的测定意义及测定方法比较

黄曲霉毒素是一种真菌毒素,其存在严重影响农作物的产量及农产品的质量。酱油产品无论在原料上还是在工艺上都有感染黄曲霉毒素的可能性。食品质量安全市场准入制度也将黄曲霉毒素列为酱油产品的必检项目。本文阐述了黄曲霉毒素的测定意义,并将国标中两种测定方法进行比较,供同行参考。     

酱油中黄曲霉毒素B1的测定意义及测定方法比较

黄曲霉毒素是一种真菌毒素，其存在严重影响农作物的产量及农产品的质量。酱油产品无论在原料上还是在工艺上都有感染黄曲霉毒素的可能性。食品质量安全市场准入制度也将黄曲霉毒素列为酱油产品的必检项目。本文阐述了黄曲霉毒素的测定意义，并将国标中两种测定方法进行比较，供同行参考。     

应用抗黄曲霉毒素单链抗体检测酱油中黄曲霉毒素B1

利用本实验室制备的抗黄曲霉毒素B1的单链抗体(ScFv),通过棋盘实验确定了抗原抗体的最适工作浓度,在此之上根据间接竞争酶联免疫法(ELISA)绘制标准曲线,检测酱油中AFB1的含量;通过改变样品的盐浓度及pH来确定其对ELISA检测结果的影响。研究结果表明,利用ScFv检测黄曲霉毒素的最小检测值为0.10ng/mL,平均加标回收率在84%～109%之间,本文建立的ELISA方法在pH5～8,盐浓度小于10%时较稳定。本文建立的利用抗AFB1的ScFv检测黄曲霉毒素含量的方法方便快捷,稳定性较好,并且成本较低,适合于食品中黄曲霉毒素的检测。     

大豆分离蛋白中的亚硝酸盐超声辅助提取分析方法的研究

大豆分离蛋白在肉制品、乳制品和面制品等食品中都具有广泛的应用,是一类重要的食品配料,因此其安全问题十分重要。而亚硝酸盐含量是食品安全控制的重要内容,作为配料的大豆分离蛋白是否含有亚硝酸盐以及亚硝酸盐的含量水平应该得到重视。实验发现,使用国标法中的分光光度法测定大豆分离蛋白中亚硝酸盐的含量,回收率较低,不到80%,这样会造成测定的不准确,不利于亚硝酸盐的含量监控。因此本研究利用超声波400W辅助提取,省去了样品于沸水浴中加热15min的步骤,对大豆分离蛋白中亚硝酸盐含量进行测定。实验结果表明,改进后的大豆分离蛋白亚硝酸盐超声波辅助提取方法回收率高(97.2%)、精密度好(相对标准偏差为2.5%),适合大豆分离蛋白中亚硝酸盐的测定。     

酶联免疫法检测酱油中的黄曲霉毒素B1

目的建立酶联免疫法检测酱油中黄曲霉毒素B_1(Aflatoxin B_1,AFB_1)的分析方法。方法酱油样本经纯乙腈(料液比=1:2,V:V)提取,再做1:9稀释,通过酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)测定样本中AFB_1。结果当加标浓度为2μg/kg和5μg/kg时,纯乙腈对酱油中AFB_1的提取回收率结果分别为121.3%和106.5%;方法检出限为1μg/kg。与国标方法检测结果的相对标准偏差小于10%。结论本方法准确、灵敏度高,可适用于酱油中AFB_1的检测。     

大豆卵磷脂口服液的研制

以卵磷脂、刺五加为原料,佐以其它成分,研制开发出一种营养丰富、口感较好的营养保健治疗口服液。     

Applications of soy protein hydrolysates in the emerging functional foods: a review

Several applications of protein hydrolysates have been documented including gelation, solubility and emulsifying properties. However, very rare reviews have solely explored the potentials of soy protein hydrolysates (SPHs). Varying and abundant pieces of information on the physicochemical properties of soy proteins, such as foaming, solubility, emulsifying, gelling, fat- and water-holding capacities, suggest their hydrolysates to be equally or more important. In this regard, this review highlights the different methods that have been used to prepare SPHs, coupled with the most promising applications and potentials of SPHs. Nonetheless, further investigations are necessary to validate the potentialities of SPHs as food agents for the emerging functional foods.     

酱油防腐剂的应用研究进展

综述了酱油防腐剂剂的种类及发展,重点概述了生物防腐剂以及天然植物提取物防腐剂的研究进展情况,酱油防腐剂的发展趋势以天然化、营养化、功能化占据主导地位,正在向生物防腐、药食同源的天然植物提取物防腐的方向发展.     

微波脱腥技术在大豆粉生产中的应用研究

传统的湿法大豆粉生产工艺不能有效去除豆腥味,采用干法微波脱腥生产工艺,不仅有效地脱除大豆的腥味,且处理后的大豆粉蛋白质的水溶性达63.6%。     

大豆异黄酮代谢终产物——雌马酚的研究进展

雌马酚是大豆异黄酮在人体肠道中的最终代谢产物。众多研究表明大豆异黄酮具有广泛的保健价值,在预防心血管疾病、乳腺癌和前列腺癌等方面均发挥重要作用。大豆异黄酮的生物活性在某种程度上归因于雌马酚,并且雌马酚具有较其前体更高的生物学效用。大豆异黄酮在特定的肠道菌作用下降解产生雌马酚,但并非每个人体内都可代谢产生雌马酚。总结了雌马酚在人体中的生理活性,并且综合论述了化学合成制备混合型雌马酚的方法,以及生物合成雌马酚过程中,动物及人体内可降解大豆异黄酮的肠道菌筛选情况。     

酱油香气成分的研究——头油和生抽香气成分的比较

分别以乙醚提取头油和生抽中的香气成分,气相色谱-质谱联用（GC-MS）分离鉴定其化学组成,以面积归一化法测定其组分的相对含量,头油乙醚萃取物中鉴定出43种化合物,生抽乙醚萃取物中鉴定出36种化合物,其对头油香气成分贡献最大的是：苯乙醇、2-甲基丙醇、3-甲基丁醇、4-羟基苯乙醇、3-甲硫基丙醇、十六酸乙酯、亚油酸乙酯、乙酸、2-呋喃醇等;对生抽香气成分贡献最大的是：2-呋喃醇、乙酸、3,8-二羟基-2-甲基色酮、6-甲基-2-吡嗪基甲醇、糠醛、香茅醇、呋喃酸、1-H-吡咯2甲醛、5,6-二氢-5,6-二乙基吡咯、1-糠基2-甲酸基-吡咯、1-（2-）呋喃基乙酮等。头油香气成分以醇类、酯类化合物为主,而生抽香气成分以杂环类化合物为主。     

典型广式酱油与日式酱油的风味物质差异研究

广式酱油和日式酱油在原料、微生物和工艺均有极大的差异。通过比较研究,广式酱油酱香、豉香浓郁,而日式酱油醇香、酯香和甜味更加突出。在氨基酸分析中,广式酱油的总游离氨基酸为5.220 g/100 mL,而日式酱油则为5.903 g/100 mL,但两者氨基酸种类的相对百分含量没有显著的差异（P＞0.05）。气相色谱-质谱法（GC-MS）鉴定出挥发性化合物134种,其中广式酱油的主要挥发性化合物为酯类（25.39%）、醇类（25.23%）、酸类（13.51%）、酮类（4.24%）、醛类（2.57%）、酚类（0.31%）和烷烃类（28.75%）,而日式酱油主要为酯类（56.02%）、醇类（21.11%）、酸类（5.92%）、酮类（3.42%）、醛类（0.69%）、酚类（0.15%）和烷烃类（12.69%）,酱油挥发性化合物的种类、含量及比例构成是引起两种酱油风味独特差异的重要原因。     

酱油市场发展趋势及生产企业的对策

本文分析目前国内酱油市场产品现状及产品发展趋势和市场格局,提出国内酱油生产企业应以提高生产工艺为突破口,调整酱油产品品种结构和技术含量,走高新技术改造传统产业的道路。     

功能性酸豆奶的研制

研究了大豆膳食纤维、酸豆奶的生产工艺，着重探讨了各种因素包括加碱量、水解温度、时间、pH值、纤维添加量、发酵条件等对制品的影响，最终确定了合适的生产工艺参数，     

大豆多肽深层发酵过程中蛋白质变化的研究

在摇瓶发酵实验的基础上,我们将大豆多肽发酵工艺在5L发酵罐中进行了放大实验。利用各种分析技术对发酵过程中大豆蛋白的变化进行了检测分析,包括蛋白质水解度、多肽分子量分布以及氨基酸组成等。结果显示,大豆蛋白的水解在接种后6～8h后达到高峰期,24h后趋于平缓;发酵时间宜控制在24～36h内,发酵36h所得的多肽分子量主要分布在2000～3500Da范围内;而氨基酸分析的结果表明,发酵法制备的大豆多肽具有与大豆蛋白同样合理的氨基酸组成。     

Effect of non-genetically modified (non-GM) soy varieties on the measured value of GM soy by a quantitative PCR method

It is very important to examine the effect of non-genetically modified (non-GM) soy varieties, which constitute the matrix of the testing sample used to quantify GM soy (RRS), on the measured value of RRS by quantitative PCR methods. Therefore, we quantified the amount of RRS in powder-mixed samples containing 1 or 5% RRS prepared by using 10 different varieties of non-GM soy as the matrix. The results revealed that the measured values were not in agreement with the powder-mixing levels and that the extent of the difference depended on the variety of non-GM soy used as the matrix. The yields of DNA extracted differed among the soy varieties. On the other hand, analysis of DNA-mixed samples, that were prepared with the DNAs extracted from RRS and non-GM soy varieties, showed that the measured values of RRS were in agreement with the DNA-mixing levels. These results strongly suggest that the proportions of DNA derived from RRS and non-GM soy were not consistent with the powder-mixing ratio in the case of some non-GM soy varieties used as a matrix, resulting in the discrepancy between the measured values and the powder-mixing levels.     

Enhancing the anti-adipogenic activity of soy protein by limited hydrolysis with Flavourzyme and ultrafiltration

Limited hydrolysis of soy protein isolate (SPI) with Flavourzyme for 2 h to obtain the hydrolysate (FH2h) revealed much higher suppression of glycerol-3-phosphate dehydrogenase (GPDH) activity and relative lipid accumulation (RLA) than intact SPI in 3T3-L1 preadipocytes during differentiation. Lower GPDH activity or RLA indicates higher anti-adipogenic activity. The GPDH significantly decreased from 673 to 477 U/mg protein (p < 0.05). Sequentially fractionating FH2h with 30–1 kDa (kilo-daltons) molecular weight cut-off (MWCO) membranes to obtain the 1 kDa permeate resulted in further reduction of 59% GPDH activity. When comparing the high-performance size-exclusion chromatography (HPSEC) profiles, the most active peptide fraction for the anti-adipogenic activity was primarily composed of small peptides with molecular weight less than 1300 Da. According to the Western immunoblot analysis, 1 kDa permeate inhibits adipogenesis by affecting the expression of peroxisome proliferators-activated receptor γ (PPARγ) and the CCAAT/enhancer binding protein α (C/EBPα) during 3T3-L1 cells differentiation.     

脱脂豆粕制备高水解度大豆肽酶解条件的优化

目的:研究高水解度大豆肽酶解的最佳条件;方法:以水解度为指标,采用响应面分析考察底物浓度、酶浓度、反应pH等因素对水解度的影响;结果:高水解度大豆肽的最佳酶解条件为:底物浓度8.58%、加酶量8 800 U/g底物、pH 11.20、温度55℃、时间3.0 h,该条件下得到的大豆肽水解度为36.8%;结论:试验结果可为大豆肽的酶解工艺提供依据.     

A study of chemical characteristics of soy sauce and mixed soy sauce: chemical characteristics of soy sauce

Mixed soy sauce is one among the Korean traditional fermented soy sauces consumed as condiment for cooking in Korea, especially mixed soy sauce is made of the fresh seafood and the meat different from the soy sauce. Therefore, mixed soy sauce provides the strong and complicated umami taste, which is stronger than that of soy sauce. The objective of this study was to investigate for the chemical characteristics changes of mixed soy sauce in comparison with soy sauce during fermentation process (0, 120, 240 and 360 days) at different fermentation temperatures (4 and 20 °C), change in moisture, total nitrogen, crude fat, ash, pH, titratable acidity, total acidity, salt content and reducing sugar of mixed soy sauce in comparison with soy sauce. Especially, histidine, arginine, threonine, methionine, phenylalanine, and lysine, essential amino acid and among adenosine triphosphate (ATP)-related compounds, inosine (HxR) and hypoxantine (Hx) were prominent in mixed soy sauce at 20 °C. Otherwise, 2,4-dinitrophenylhydrazine (DNPH) derivative and 3DG content were prominent in soy sauce at 20 °C. The content of 2,4-DNPH derivative and 3DG in soy sauce is correlated with its browning intensity.