天然色素的开发

<正>论述了国内外天然食用色素的发展状况,介绍了天然色素的三大系列,并就我国具体情况提出了开发天然食用色素的建议。前言 色、香、味是食品的三大要素。然而,在食品加工、贮藏期间,往往     

湖相生油岩中四吡咯色素的分布及演化

陆相沉积物中,目前已找到了三类有机色素;类绿素色素——叶绿素、绿素及卟啉;类叶红素色素——橙色素、叶红素及叶黄素;黄素阮、黄色素及有关的N—杂环物质,还有少量其它的天然有机色素存在于水生生物中。 类绿素色素都有四吡咯结构,故又称为四吡咯色素。植物化学的研究发现,叶绿素的四吡咯主体结构排列在类囊体脂肪层的表面。      

克拉玛依油田七中区内源微生物驱矿场试验生化指标跟踪与评价

为揭示油井产出液中各项生化指标的变化规律与增产效果之间的关系,在克拉玛依油田七中区克上组砾岩油藏4口注入井和11口采油井开展了内源微生物驱矿场试验,对试验井各项生化指标进行了跟踪监测,包括油井产出液中总活菌数、烃氧化菌(HOB)数,硫酸盐还原菌(SRB)数、营养物质(总糖、总氮)、乙酸根离子浓度、水质及水相表面张力等。现场跟踪监测结果表明,实施微生物驱措施后,试验井内源微生物总活菌数可提高1数2个数量级,有益菌HOB数可提高2个数量级,SRB得到抑制,总活菌数和HOB菌数越高增产效果越明显;内源微生物在好氧环境中被大量激活,产生乙酸根离子,每口井的乙酸根离子浓度平均可达8.0 mg/L左右;对激活剂的利用率较高,总糖、总氮含量小于注入营养剂含糖量和含氮量的10%,监测期间的变化较小,与增产效果的关系不明显;水相表面张力、水质矿化度及pH值变化较小,对增产效果的影响较小。     

微波辅助提取紫背天葵食品色素的研究

研究了微波辅助提取紫背天葵食品色素的新工艺,最佳工艺条件为:紫背天葵干花2g,提取剂为60%乙醇,提取剂用量为60g/mL,微波功率648W,提取时间200s,提取次数2次。在此条件下,色素提取率为96.8%,产率为9.98%,色价(1%,526nm)为10.5,pH值为6.5。     

含丙烯酰基可聚合色素中间体的合成

采用N,N-二羟乙基苯胺(BHEA)与丙烯酸直接酯化法,合成了一类可聚合色素的重要中间体。考察了催化剂种类及用量、反应温度、物料配比等反应参数对酯化反应的影响。对酯化产物分别采用TLC和GC/MS法进行了分析和鉴定。     

海洋丝状真菌转化石油烃的研究

研究从湄洲湾海域分离的4株丝状真菌MF1，MF2，MF3，MF4的生长特性及去除油污的过程，观察在温度26℃，初始油浓度在3g/l,培养12d的过程中培养液的变化，分析培养液的pH值及原油的去除率与时间的关系，结果表明，丝状真菌去除原油的[过程是生物吸附与生物降解相结合的生物转化过程，比较革兰氏阴性细菌与丝状真菌细胞壁组成，结构，得出海洋微生物的脱油作用与其细胞壁有直接的关系。     

工艺技术管理系统的建设

大庆石化分公司投产40多年来,对企业生产的工艺技术管理经验不断积累与总结,在工艺管理上有着丰富的历史经验。许多管理条例是经验和教训积累的结果,是生产工艺技术管理的宝贵财富。近年来随着各企业注重加强管理,走内涵发展的道路来提高企业的综合竞争能力,大庆石化公司在工艺技术管理上也不断创新与发展。但是,     

平湖凝析气藏放一断块产水动态特征研究

针对平湖凝析气藏气井出水问题,依据气井动态测试资料,将出水气井划分为明确出水层位和不明确出水层位两类气井,分别分析了其出水机理和产水动态规律:明确出水层位气井的产出水来自其他断块的水层,其带水生产能力与产水气层的产气比例具有良好的相关关系,出水气层的产气比例越小,气井的带水生产能力越高,反之则带水生产能力越低;不明确出水层位气井的产出水是异常高温高压边水凝析气藏的地层水在生产过程中转成水蒸气后的凝析水。随着开发的进行在边水水体与生产井之间形成3个不同的凝析水饱和流动区,根据凝析气藏地层水气化饱和模式和饱和凝析水生产水气比与压力关系曲线,可以进行气井产水类型的判断和地层水出水风险的预报。      

螺杆泵优选软件的开发与应用

利用计算机对油井的地质资料及生产数据综合处理,作出相应变量间的函数关系曲线,通过曲线模拟,找出相应变量间的函数关系,由此计算螺杆泵地面驱动总扭矩、举升产液总压降及所需螺杆泵的公称排量,并对现有螺杆泵各项参数综合分析,优选出螺杆果最优泵型。现场应用证明:螺杆泵优选软件对提高螺杆泵井作业一次成功率、延长螺杆泵运转周期、提高油井产能及节能降耗等方面都具有重大意义。     

油库平面与悭向关系浅析

油库的总平面设计是一项复杂的工作，要考虑的内容和因素很多。因此，在进行油库总平面设计之前，要对影响平面布局的各种因素进行深入的分析和研究，主要包括用地范围、地形地貌、风向、交通运输、防洪排涝、安全距离等。通过分析研究总平面设计与竖向设计的关系，即与地形地貌的关系，在进行平面设计时，必须要考虑竖向关系，才能使平面满足生产、交通运输、安全的要求，以及与周边环境、地貌等相吻合，以达到油库设计既经济又实用的目的。     

Bacterial dynamics during the spontaneous fermentation of cassava dough in gari production

The microbial dynamics and diversity during solid substrate fermentation of cassava, a case study of gari production in West Africa, was investigated. The 16S rDNA gene sequence analysis of the PCR-Denaturing Gradient Gel Electrophoresis (PCR–DGGE) analysis of microbial community DNA and Pulsed Field Gel Electrophoresis (PFGE) of selected isolates as well as culturing techniques using different selective media were used to monitor the bacterial dynamics during cassava fermentation. The V3 variable region of the 16S gene was analyzed and the closest relatives of Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus pentosus, Lactobacillus acidophilus and Lactobacillus casei were identified by sequencing of the DGGE band amplimers. The DGGE amplimers also revealed the succession and dynamics of LAB; there was a progressive increase in their population proportional to the fermentation period. The analysis of the PFGE band patterns showed that five diverse species of LAB were involved in the fermentation. The representative isolate of each of the PFGE clusters was phenotypicaly identified as L. plantarum, L. fermentum and Leuconostoc mesenteroides by the API 50 CHL sugar fermentation profile. These combinations of parameters identified heterofermentative LAB as bacteria that initiated the fermentation, reduced the pH below four and increased the acidity of the fermentation mash. Information such as this is relevant for the development of starter cultures and predictability of the process for traditional fermented foods and to aid their intermediate and large scale production.     

Effect of sulfur dioxide and ethanol concentration on fungal profile and ochratoxin a production by Aspergillus carbonarius during wine making

Fungal profiles and ochratoxin A (OTA) accumulation during wine making were investigated using five different wine grape cultivars, Cabernet Sauvignon, Pinot Noir, Merlot, Syrah and Petit Verdot and the intrinsic influences caused by sulfur dioxide, ethanol and combine effect of ethanol and reducing sugar were analyzed using Cabernet Sauvignon and inoculation of Aspergillus carbonarius. Aspergillus spp. and Penicillium spp. were found as the major fungi in all winemaking processes and were highly correlated with OTA accumulation in wine. Most fungi died and OTA production decreased after 48 h of alcoholic fermentation, being consistent with the period when ethanol accumulation increased. The addition of SO₂ significantly inhibited the growth and OTA production of A. carbonarius with complete inhibition at 500 mg/L. When the ethanol concentration in the must increased to the range of 2–4%, growth and OTA production of A. carbonarius were significantly inhibited. Reducing sugar concentration had no significant effect on the growth and OTA production of A. carbonarius within the levels changing during the winemaking. Therefore, the increase of ethanol concentration played an important role in causing the decrease of fungal contamination and OTA accumulation during winemaking.     

Sequencing-based screening of functional microorganism to decrease the formation of biogenic amines in Chinese rice wine

As a traditional alcoholic beverage, Chinese rice wine with a unique flavor and high nutritional value has been popular in China for thousands of years. The biogenic amines in Chinese rice wine and other fermented food are attracting much more attention than ever. There are numerous microorganisms accompanying the fermentation of Chinese rice wine. Based on the next-generation sequencing technology, an in vivo screening process was carried out to find the strains without biogenic amines formation, and then these strains were screened and back-added into the fermentation mash. It was found that the Lactobacillus might not produce biogenic amines by the correlation analysis of bacteria community succession and biogenic amines change. After that, three Lactobacillus strains without biogenic amines formation were screened and identified as Lactobacillus plantarum and L. hilgardii. The L. plantarum JN01 showed high lactic acid production, low acetic acid production, and high ethanol tolerance which was preferable for Chinese rice wine brewing. When 0.001 gDCW/t of L. plantarum JN01 was used to inoculate the fermentation mash, the biogenic amines concentration was significantly decreased 24%. Although the formation of biogenic amines was further inhibited by increasing the dose of L. plantarum JN01, the total acid and the residue sugar would increase resulting an incomplete fermentation. In this paper, we firstly developed an effective method to decrease the formation of biogenic amines in traditional fermentation foods based on the next-generation sequencing technology. This research provided new strategy to decrease biogenic amines in fermentation food.     

Selected Saccharomyces cerevisiae yeast strains and accurate separation of distillate fractions reduce the ethyl carbamate levels in alembic cachaças

Ethyl carbamate (EC) is a potentially toxic compound that may be present at concentrations above maximum limits established in alcoholic beverages, such as cachaça. Most traditional alembic cachaça is produced on a small scale using empirical knowledge. The fermentation step is conducted using yeasts that are endogenous to the sugar cane, and the distillation process is relatively uncontrolled. In this study, gas chromatography coupled with mass spectrometry was used to determine the EC levels in distillate musts and fractions produced by spontaneous or selected Saccharomyces cerevisiae strains. The aim was to verify the influence of selected strains as starters for fermentation compared with spontaneous fermentation on EC formation. The distillate fractions from these two production processes were also analysed. Our results demonstrated higher levels of EC (which surpass the limits defined by Brazilian law) in cachaças produced by spontaneous fermentation (50%) compared with the selected strains (30%); and the distillation step showed great contribution for the reduction of the compound. From must to distillate fractions we found an average decrease on EC levels of 62% using selected strains and 44% for the spontaneous fermentation. In addition, careful separation of the distillation fractions was crucial for producing high-quality and safe beverages.     

Monitoring of fermentation process parameters of Chinese rice wine using attenuated total reflectance mid-infrared spectroscopy

There is a growing need for the effective fermentation monitoring during the manufacture of wine due to the rapid pace of change in the industry. In this study, the potential of attenuated total reflectance mid-infrared (ATR-MIR) spectroscopy to monitor time-related changes during Chinese rice wine (CRW) fermentation was investigated. Interval partial least-squares (i-PLS) and support vector machine (SVM) were used to improve the performances of partial least-squares (PLS) models. In total, four different calibration models, namely PLS, i-PLS, SVM and interval support vector machine (i-SVM), were established. It was observed that the performances of models based on the efficient spectra intervals selected by i-PLS were much better than those based on the full spectrum. In addition, nonlinear models outperformed linear models in predicting fermentation parameters. After systemically comparison and discussion, it was found that i-SVM model gave the best result with excellent prediction accuracy. The correlation coefficients (R² (pre)), root mean square error (RMSEP (%)) and the residual predictive deviation (RPD) for the prediction set were 0.96, 6.92 and 14.34 for total sugar, 0.97, 3.32 and 12.64 for ethanol, 0.93, 3.24 and 9.3 for total acid and 0.95, 6.33 and 8.46 for amino nitrogen, respectively. The results demonstrated that ATR-MIR combined with efficient variable selection algorithm and nonlinear regression tool as a rapid method to monitor and control CRW fermentation process was feasible.     

Iron,copper and zinc in white sugar from Serbian sugar beet refineries

Small amounts of soluble and insoluble impurities such as iron, copper and zinc in refined white sugar determine the usefulness of sugar for various industrial applications. The content of iron, copper and zinc was evaluated in 166 white sugar samples from four Serbian beet sugar refineries during the campaign of 2003. The production of the chosen sugar factories is accounted for about 70% of the total national sugar origin and the taken samples were representative of their production. Wet digestion was applied and the content of studied microelements was determined by flame atomic absorption spectrometry. The mean content of iron, copper and zinc (0.37, 0.06 and 0.02 mg/kg, respectively) was low in all the white sugar samples from the Serbian sugar refineries, but statistically it was significantly different from the content of the investigated elements in the sugar samples from European sugar factories. The iron content was significantly higher in Serbian sugar, while the content of copper and zinc found in sugar from Serbian refineries were significantly lower than the ones from some European beet refineries. The origin of these impurities was discussed as far as known.     

Microbiological and biochemical changes during processing of the traditional chinese food douzhi

The microbiological and biochemical changes during douzhi processing were studied. The sedimentation process was shown to follow a lactic fermentation course. The main fermenting bacteria were identified to be Lactococcus lactis and Leuconostoc citreum; the former played the main role in producing acids, and the latter ensured a better flavor of douzhi. Yeasts thrived during the late part of fermentation were believe to account for the decrease in acidity. Tracing the change of chemical compounds suggested that active metabolic activity was induced when beans were steeped in water, in which significant reduction in crude protein and sugars were observed, but levels of soluble proteins, free amino acids increased. Fermentation by lactic acid bacteria caused a rapid reduction of soluble proteins, soluble sugars and reducing sugars, but significant accumulation of free amino acids and slight changes in crude protein. Mung bean endogenous protease and amylase activity dropped significantly during fermentation.     

Effects of starch damage and yeast fermentation on acrylamide formation in bread

The effects of starch damage and yeast fermentation on the formation of acrylamide in wheat bread were studied. Four wheat cultivars were milled separately by three laboratory mills to obtain wheat flours with damaged starch content ranging from 1.7 to 6.6%. Reducing sugar contents increased with increasing damaged starch content in flour. Yeast fermentation decreased greatly the content of asparagine by 40–60% in the dough, but increased substantially the content of reducing sugar. Compared with the unleavened bread, dough fermentation significantly decreased the content of acrylamide in leavened bread. The content of acrylamide in bread increased with increasing damaged starch content in wheat flours from the same cultivar. This study clearly showed that damaged starch content in wheat flour and dough fermentation are two major determinants of the formation of acrylamide in bread. The mitigation of acrylamide formation in bread can be achieved by reducing damaged starch in flour and by fermentation of the dough.     

Study of Saccharomyces cerevisiae W13 as a functional starter for the removal of ochratoxin A

In this paper, a wild strain of Saccharomyces cerevisiae (W13) was studied for its OTA-removal ability, growth pattern and alcoholic fermentation profile at two different temperatures (25 and 30 °C) and two different sugar levels (200 and 250 g l⁻¹), with or without supplementation of medium with diammonium phosphate (DAP). A commercial strain (Lallemand EC1118) and a collection isolate (DBVPG 6500) of S. cerevisiae were also studied. All the strains were able to conclude fermentation, with S. cerevisiae W13 producing higher ethanol and glycerol contents; moreover, the wild strain was able to remove OTA (reduction of 6–57.21%), with the highest removing effect observed at 30 °C with 250 g l⁻¹ sugar and after 3 days.In addition, S. cerevisiae W13 was studied for its technological and qualitative traits, as it showed a high tolerance to single and combined stress conditions, β-d-glucosidase, pectolytic and xylanase activities, a low level of hydrogen sulphide production, a low-to-medium parietal interaction with phenolic compounds and no biogenic amines formation.The findings of this work have an applicative value for the potentiality of using S. cerevisiae W13 as functional starter for the production of wines with improved qualitative and food safety characteristics.     

气井开井瞬间井筒积液液面变化规律研究

井筒积液是产水气井不可避免的现实问题,深入了解其开井生产过程中液面的变化规律,对选择合理的排水采气工艺是非常必要的。在前人理论研究的基础上,主要对产水气井开井后液面的变化规律进行了研究,得出了开井瞬间井筒液面距井口高度随开井时间的变化关系,采用油田现场数据对该变化关系进行了计算验证。计算发现,该变化关系能够比较真实地反映现场生产实际情况,在该前提下对影响气井开井瞬间井筒液面变化的各因素（操作因素、气藏因素和流体因素等）分别进行了敏感性分析,为含水气井在实际生产中制定合理的工作制度提供了理论依据,对现场应用具有一定的指导作用。