陶瓷膜在晒制酱油生产中的应用

考察了不同工艺段酱油陶瓷膜过滤的分离效果,并以酱油沉降液为料液,优化陶瓷膜过滤条件。结果表明,陶瓷膜应用在酱油沉降工段后较佳,表现在通量衰减慢、膜污染速度慢等。最佳陶瓷膜过滤操作参数为：选用孔径B陶瓷膜,温度40～50 ℃,跨膜压差280 kPa,膜面流速5.5 m/s,反冲工作压力500～600 kPa,反冲间隔时间4 min,反冲时间3 s,反冲排气5 s,浓缩10倍,平均通量85.7 kg/（h·m2）。陶瓷膜渗透液离心无沉淀,菌落总数低于10 CFU/mL,总酸、氨基酸态氮、总氮、盐分及无机盐固形物透过率均达到98%以上。陶瓷膜技术应用在晒制酱油中值得推广。     

Clarification of Apple Juice by Hollow Fiber Ultrafiltration: Fluxes and Retention of Odor-Active Volatiles

Fresh apple juice was clarified in a pilot scale ultrafiltration (UF) unit, with membranes made of polysulfone and polyamide and plate and frame and vacuum drum filters. Flux of apple juice (L/m² hr) vs UF transmembrane pressure data showed an optimum at a pressure of about 140 kPa. Retention of odor-active volatiles was highest in plate and frame filtered apple juice and lowest in vacuum drum filtered juice; the retention of odor-active volatiles in UF juice was intermediate to the two traditional filtration methods. Retention of odor-active volatiles in the permeate of a polyamide membrane was higher than that of a polysulfone membrane.     

Optimization of Headspace Solid-Phase Micro-extraction (HS-SPME) for Analyzing Soy Sauce Aroma Compounds via Coupling with Direct GC-Olfactometry (D-GC-O) and Gas Chromatography-Mass Spectrometry (GC-MS)

The aim of this study was to develop an effective analytical procedure to analyse the aroma-active compounds of soy sauce using headspace solid-phase micro-extraction (HS-SPME) coupled to gas chromatography-mass spectrometry/olfactometry (GC-MS/O). Optimization of SPME focusing on type of fibre, exposure time, extraction temperature and ionic strength was supported by gas chromatography-mass spectrometry (GC-MS). The optimized HS-SPME conditions were as follows: carboxen/polydimethylsiloxane (CAR/PDMS) fibre, NaCl concentration of 270 g/L, extraction temperature of 45 °C and 30-min exposure time. Under these conditions, 25 aroma-active compounds were detected in soy sauce by HS-SPME-GC-O. 2-Methylbutanal (malty), 3-(methylthio)propanal (cooked potato-like), dimethyl trisufide (sulfury, cooked onion), 2-methoxyphenol (smoky) and 2-phenylethanol (flowery) were the most intense. The overall odour impression of the CAR/PDMS-fibre-derived SPME extract detected via human sniffing resembled that of original soy sauce. The intensity of aromas detected by D-GC-O correlated well with the total peak area of GC-MS analysis. Thus, SPME coupled with D-GC-O offers an automated facile method to allow in situ optimization of SPME performance and ultimately effective analysis of aromas.     

不同截留分子质量超滤膜对酱油过滤性能的比较

分别采用截留分子质量为50 ku、100 ku、150 ku、200 ku的超滤膜对酱油原油进行过滤。试验结果表明,几种型号超滤膜过滤对酱油主要指标氨基酸态氮几乎没有影响。从沉淀去除而言,50 ku和100 ku的超滤膜对酱油原油沉淀的去除率更好,分别达到了91.1%和91.7%。从过滤效果而言,50 ku和100 ku超滤膜更佳,过滤后酱油滤液的OD650 nm值分别为0.10、0.15;浑浊度值分别为1 750、1 800。相同条件下四种超滤膜再生后通量恢复率分别为99.5%、97.5%、95.0%、92.5%。从过滤效果、过滤后滤液稳定性、过滤后清洗膜再生通量恢复率等方面综合考虑,截留分子质量为100 ku的超滤膜更适合应用于酱油的提纯过滤。     

气相色谱-嗅闻/质谱联用分析酵母菌发酵酱油中香气物质

酱油香气物质的形成与酵母菌的代谢息息相关,本文旨在研究酵母菌对发酵酱油中香气物质形成与含量的影响。采用固相微萃取(SPME)结合气相色谱-嗅闻-质谱(GC-O/MS)联用技术分别对不加酵母菌、加AY酵母菌以及加入T酵母菌发酵制得酱油中的香气物质进行检测分析。结果显示:加入酵母菌的酱油中形成的各类香气物质更加丰富,其中AY型鲁氏酵母菌能够产生更多种类的酯类(11种)及醇类(12种)物质;T型鲁氏酵母菌有助于醛类(7种)物质的形成。且AY型鲁氏酵母菌在酱油酿造过程中产生的酯类(155.19 μg/L)、呋喃酮类(68.53 μg/L)、醛类(86.46 μg/L)等物质的含量更高,T型鲁氏酵母菌的产醇类(1260.64 μg/L)物质能力则更加优越。通过对酱油样品中OAV的计算,发现,AY酵母菌酿造酱油中的4-羟基-2-甲基-5-乙基-3(2H)-呋喃酮(HEMF),2/3-甲基丁醛、及苯乙醛的OAV高于其他样品的OAV值,T型鲁氏酵母菌的1-辛烯-3-醇及3-甲硫基丙醛的OAV值高于其他样品的OAV值。将OAV值与PCA结合分析,可以看出,AY型鲁氏酵母菌发酵酱油的香气优势明显,并且T型鲁氏酵母菌发酵酱油以熟土豆气味为主,并伴有蘑菇香气;AY型鲁氏酵母菌发酵酱油以甜香香气为主,并伴有麦芽香气。综上,AY型鲁氏酵母菌的整体产香优于T型鲁氏酵母菌的产香效果。     

红曲在老抽王酱油生产中的应用研究

酱油烧菜发乌、无红亮光泽主要是由生产过程中的原料配比、酱醪发酵、焦糖酱色质量等原因造成。该文对“老抽王”酱油生产工艺中酱醪发酵阶段利用添加红曲提高产品质量进行了试验。结果表明：产品的色率增加21447，红色指数增加1．21，黄色指数增加1．85，试验样品炒出的菜光泽红亮。     

甜油和酱油中氨基酸和还原糖含量的比较研究

探讨甜油和酱油中两种关键营养成分氨基酸和还原糖的含量差异,分析原料不同、工艺相近的两种调味品特征指标存在差异的原因,并提出甜油和酱油存在的优势和缺点。结果表明,甜油中氨基酸总量和鲜味氨基酸谷氨酸低于酱油,甜油和酱油中氨基酸总量分别为15.86～23.21 mmol/L和31.69～46.04 mmol/L,其中谷氨酸含量分别为2.94～7.54 mmol/L和20.62～35.34 mmol/L;但每类氨基酸含量差距不大,比较协调;甜油中甜味氨基酸比例较大,为49.41%,酱油中的鲜味氨基酸比例较大,为71.19%;甜油中还原糖含量（14.24～27.53 g/L）高于酱油（4.80～8.26 g/L）。因此,酱油因高氨基酸和谷氨酸含量鲜味明显、口感厚重,适合烧制菜肴,而甜油口感协调、丰满,适合炒菜和凉拌菜;另外,甜油中高含量的还原糖含量能够改善菜肴质量、色泽和口感。     

Changes of volatiles in soy sauce‐stewed pork during cold storage and reheating

Pork, soy sauce, and pork in soy sauce were cooked separately for 4 h; their volatiles were isolated, analysed and compared. Many of the volatiles reported to be present in pork or soy sauce were lost, and some volatiles identified in this research were generated from precursors in pork and soy sauce during cooking. Water‐boiled pork and soy sauce‐stewed pork were prepared and stored at 4 °C; they were reheated daily and stored again at 4 °C for 10 days. During storage the amount of compounds containing sulphur, such as dimethyl trisulphide and thialdine, was higher in the water‐boiled pork than in the soy sauce‐stewed pork. 3,5‐Dimethyl‐trans‐1,2,4‐trithiolane was found only in the soy sauce‐stewed pork. Significantly more aldehydes produced from lipid oxidation, such as hexanal, 2,4‐decadienal and 2‐undecenal, were present in the water‐boiled pork than in the soy sauce‐stewed pork during storage. These aldehydes reached a maximum quantity at day 6 of storage. In contrast, the soy sauce‐stewed pork contained more hexadecanal, octadecanal and 9‐octadecenal than the water‐boiled pork. © 2001 Society of Chemical Industry     

Enterotoxin C2 Production by S. aureus in Entree Salads

Staphylococcus aureus strain 361 was inoculated into salads containing chicken, macaroni, potato, or artificially flavored soy product. Egg was added to some. The pH averaged 6.2 in the control made with water dressing rather than vinegar, 4.7 with home-style cooked salad dressing, and 4.9 with commercial salad dressing. Following incubation at 37°C for 8 or 24 hr, pH, total counts, and enterotoxin C₂ were determined. Enterotoxin was detected at 8 hr in all macaroni and potato dressing types. At 8 hr, enterotoxin was not detected in most soy product or chicken salads. By 24 hr the lowest levels were in the soy product salads but all products contained toxin. When the inoculum level was reduced below the 10⁵ CFU per g used in the main study, enterotoxin production was delayed but occurred at 8 hr if the inoculum level was 10³.     

Direct determination of free tryptophan contents in soy sauces and its application as an index of soy sauce adulteration

A simple and rapid HPLC method using UV detector for determination of tryptophan (Trp) contents in pure fermented soy sauces, acid-HVP, and commercial soy sauces was developed. The method requires only simple sample pretreatment. The limit of detection (LOD) is estimated at 1 mg/L (signal-to-noise ratio of 3), and the recovery yields ranged from 92% to 108%. The analysis showed that Trp in all of the analysed acid-HVP samples was not detected and there was obvious detection of Trp (ranged from 136.4 to 261.8 mg/L) in all of the analysed fermented soy sauce samples. The observations suggest that Trp is a practical index of pure fermented soy sauce. The absence of Trp contents or lower level of Trp contents than that in pure fermented soy sauces suggests the soy sauces are not pure fermented soy sauces or presence of soy sauce adulteration. Simultaneous determination of levulinic acid (LV) in samples may be a good help in making assessment of soy sauce adulteration with acid-HVP.     

连续流动分析-盐酸萘乙二胺分光光度法测定酱油中的亚硝酸盐和硝酸盐

建立了一种同时测定酱油中亚硝酸盐和硝酸盐的连续流动分析-盐酸萘乙二胺分光光度法。酱油样品经25 ℃超声15 min预处理,乙酸锌-亚铁氰化钾体系沉淀蛋白质后,自动进样且采用气泡隔断样品,并经透析膜透析,采用双通道同时测量亚硝酸盐和硝酸盐。结果表明,亚硝酸盐在0.025～1.0 mg/L质量浓度范围内线性良好,加标回收率在83.54%～98.56%之间,精密度试验结果相对标准偏差（RSD）＜3%;硝酸盐在0.25～5.0 mg/L质量浓度范围内线性良好,加标回收率在92.95%～102.32%之间,精密度试验结果RSD＜2%。该方法准确、高效、灵敏,可以用于测定酱油中亚硝酸盐和硝酸盐。     

Quantification of ethyl carbamate in soy sauce consumed in Korea and estimated daily intakes by age

To estimate the daily intake of ethyl carbamate (EC, a possible human carcinogen) from soy sauce consumed in Korea, 136 soy sauce samples were collected from various regions and analysed by gas chromatography/selected ion mode mass spectrometry (GC/SIM‐MS). The distribution of EC varied significantly among samples, ranging from not detected to 128.9 µg kg^?1, with the highest level in Japanese‐style soy sauce. Based on individual intakes in the Complementary Report on 1998 National Health and Nutrition Survey and EC contents analysed in the present study, the contribution of soy sauce to EC intake was estimated by multiplying the mean concentration of EC by individual soy sauce intake data. Daily intakes of EC kg^?1 body weight by high consumers were particularly high in age groups 1–2 years (78.59 ng), 3–6 years (86.37 ng), 50–64 years (86.24 ng) and ≥ 65 years (76.86 ng). Based on a benchmark dose confidence limit (BMDL) of 0.3 mg EC kg^?1 body weight day^?1, the margin of exposure (MOE) calculated from the daily intake of EC in soy sauce for high consumers ranged from 3488 to 7317, which is of concern. Daily EC intakes are likely to be exceeded in groups who consume other fermented foods as well as alcoholic beverages. Copyright © 2006 Society of Chemical Industry     

Ultrafiltration for Recovery and Reuse of Peptidoglutaminase in Protein Deamidation

Ultrafiltration (UF) of B. circulans cell extract using a 100kd hollow-fiber membrane had no effect on peptidoglutaminase (PGase) activity and allowed 34 and 26% of PGases I and II to permeate. UF, with 30kd spiral membrane, slightly increased PGase activity in retentate but no activity was detected in permeate. Retentate was used to sequentially deamidate four batches of a soy protein hydrolysate at 30°C for 2 hr, then PGase was recovered by UF. The 100kd membrane resulted in substantial PGase loss in sequential tests due to permeation and inactivation. A 100% conversion and 97% of PGase were obtained after tests with the 30 kd membrane. Multiple recovery and use of PGase by a suitable membrane is possible.     

高效液相色谱串联质谱法测定酱油中水解氨基酸

建立了高效液相色谱串联质谱(HPLC-MS/MS)法测定天然酿造酱油原油(FSS)和酸水解植物蛋白调味液(HVP)中多肽的水解氨基酸的组成的方法。FSS多肽总量约是HVP的10倍,其中FSS中多肽的总量为2378.76mg/L,HVP中多肽的总量为247.57mg/L。天然发酵酱油原油中赖氨酸在多肽中的含量21倍高于酸水解植物蛋白液。FSS多肽中赖氨酸、组氨酸、酪氨酸相对百分含量约是HVP的2倍,HVP中丙氨酸、脯氨酸相对百分含量约是FSS的2倍。该研究为鉴别天然酿造酱油与酸水解酱油提供依据。     

Effect of Various Food Additives on the Levels of 4(5)‐Methylimidazole in a Soy Sauce Model System

In this study, the effect of food additives such as iron sulfate, magnesium sulfate, zinc sulfate, citric acid, gallic acid, and ascorbic acid on the reduction of 4(5)‐methylimidazole (4(5)‐MI) was investigated using a soy sauce model system. The concentration of 4(5)‐MI in the soy sauce model system with 5% (v/v) caramel colorant III was 1404.13 μg/L. The reduction rate of 4(5)‐MI level with the addition of 0.1M additives followed in order: iron sulfate (81%) > zinc sulfate (61%) > citric acid (40%) > gallic acid (38%) > ascorbic acid (24%) > magnesium sulfate (13%). Correlations between 4(5)‐MI levels and the physicochemical properties of soy sauce, including the amount of caramel colorant, pH value, and color differences, were determined. The highest correlations were found between 4(5)‐MI levels and the amount of caramel colorant and pH values (r² = 0.9712, r² = 0.9378). The concentration of caramel colorants in 8 commercial soy sauces were estimated, and ranged from 0.01 to 1.34% (v/v).     

不同产地酱香型白酒中挥发性含氮化合物的差异分析

酱香型白酒中含氮类化合物含量虽占比较少,但部分化合物气味阈值较低,对酒体风味贡献较大。以20种酱香型白酒为对象,来源产地包括贵州、广西、湖南、北京、天津、山东、黑龙江,采用液-液萃取结合全二维气相色谱-氮化学发光检测器联用技术对酱香型白酒中挥发性含氮化合物进行定性定量分析。共定性出49种挥发性含氮化合物,包括16种吡嗪类、12种噻唑类、4种吡啶类、6种吡咯类、2种胺类和9种其他化合物;不同产地的酱香型白酒中挥发性含氮化合物的种类差别不明显。对已报道具有香气的挥发性含氮化合物进行定量分析,结果表明:酱香型白酒挥发性含氮化合物中吡嗪类质量浓度最高;贵州酒样的吡嗪类质量浓度[(5.36±0.96)mg/L]最高,其次高的是中北部地区的酒样[(4.12±1.20)mg/L],湖南酒样的质量浓度[(3.05±0.64)mg/L]和广西酒样的质量浓度(3.00mg/L)差别不明显,最低的是黑龙江产地的酒样[(1.68±0.42 )mg/L]。根据定量结果,采用正交偏最小二乘判别分析,可成功区分不同产地的酱香型白酒;苯并噻唑、吡嗪、2,3,5,6-四甲基吡嗪、2,6-二甲基吡嗪等11种变量投影值大于1的含氮化合物,可作为区分不同产地酱香型白酒的差异成分。研究可为酱香型白酒产地区分和溯源提供理论支持。     

一株芽孢杆菌的分离鉴定及其在发酵酱渣研究中的应用

从酱渣中筛选分离出一株芽孢菌株,通过生理生化实验以及16SrDNA鉴定其为地衣芽孢杆菌,将该菌种应用于发酵酱渣研究,表明用液态发酵方式较好,当酱渣与玉米淀粉比例为1∶1时,获得的活菌数较多。对添加辅料元素进行正交实验优化结果表明,当培养基中MgSO₄为3g/L,MnSO₄为2g/L,CaCO₃为3g/L时,培养基中的活菌数最多,为6.55×10⁹cfu/mL。     

酱油熟料消化中蛋白质热变性的研究

综述了酱油生产过程中蛋白质热变性机理及蛋白质热变性的变性种类及相关观点，通过蒸煮压力、时间、加水量、对酱油熟料消化中蛋白质的消化率、二级蛋白衍生物等的影响进行检测，研究蛋白质热变性对酱油生产的影响。     

pH值对酱油中呈味肽种类和呈味特性的影响

利用固相萃取技术结合超高效液相色谱-串联质谱法对不同pH值发酵酱油的酸性组分进行分离、鉴定和呈味特性分析.结果表明,从调控pH值发酵的酱油中鉴定出14 种呈味肽,从自然pH值发酵的酱油中鉴定出12 种呈味肽,其中8 种呈味肽在两种酱油中均鉴定出来.调控pH值发酵的酱油中含有较多良好呈味效果的小分子肽,其中ED、EE、E...     

一株产2-苯乙醇酵母的鉴定及其在酱油酿造中的应用

2-苯乙醇是酱油的特征香气成分,为研究其合成代谢途径并提高其在酱油发酵醪中的含量,从酱油发酵醪分离筛选到1株产2-苯乙醇酵母菌株30-2;通过形态观察、生理生化试验、转录间隔区（ITS）序列测序和系统进化树分析鉴定菌株30-2为接合酵母（Zygosaccharomyces sp.）;菌株30-2可以在高含盐（18% NaCl）培养基中生长,采用唯一氮源实验证明了菌株30-2主要通过艾氏途径,以苯丙氨酸为底物合成2-苯乙醇。菌株30-2添加至酱油发酵醪可一定程度降低发酵液还原糖含量,2-苯乙醇合成量达到40.95 mg/L,并可以抑制发酵醪产酸,对酱油其他理化指标影响不显著（P＞0.05）;外加苯丙氨酸后2-苯乙醇含量进一步提高到对照组的14.7倍;显示出菌株30-2在高盐发酵调味品风味改善方面的应用前景。