运用TTI法恢复地层原始沉积厚度——以华北晋西、中原地区为例

岩石中有机质的成熟度是它在埋藏史中热演化效应的累积,这种累积效应可用时间-温度指数(TTI值)或镜煤反射率(R°)表示。在取得某地区研究层的TTI(或R°)值及埋藏史后,就可反演出其最大埋深,恢复地层原始沉积厚度。此法的精度取决于地温、厚度及TTI或R°等参数,当研究区地质历史上发生多次降升和沉降时,必须进行深度校正和时间-温度的热校正。     

Mortality and some biochemical changes in mink (Mustela vison) given sublethal doses of aflatoxin each day

Two feeding trials were done to study the susceptibility of mink (Mustela vison) to multiple sublethal doses of aflatoxins. In the 1st trial, twenty 3-month-old male mink were divided equally among groups. Each mink in groups 1, 2, 3, and 4 was given a meatball daily that contained 15, 30, 45, or 0 mug of aflatoxins (B1:G1, 40:60), respectively. All mink in group 3 died between the 25th and the 30th days of the feeding trial. Each mink had ingested 1,035 to 1,480 mug of aflatoxins. Four of the mink in group 2 died almost as soon as did mink in group 3. Four mink in group 1 died between 40 and 59 days after the start of the feeding trial. Generally, a marked increase in plasma cholesterol and alkaline phosphatase activity appeared before mink died. The liver from animals that died of aflatoxicosis showed prominent pathologic changes which included hemorrhages and appearance of pink yellow spots. Histopathologic examination of liver from dead mink revealed fatty infiltration, bile duct proliferation, bile stasis, pseudotubular formation, congestion, and fibrosis. The feeding trial was repeated with 20 mink (8 males and 12 females) that were 1.5 to 2 years old. In this instance, 0, 20, 40, and 60 mug of aflatoxins were administered each day. All treated animals, except 1, were dead within 37 days after the experiment started. The survivor was given the lowest dosage of toxins and died after 52 days by which time 960 mug of aflatoxins were consumed. Plasma cholesterol content and alkaline phosphatase activity generally were similar to those observed in younger mink of the 1st feeding trial.     

Alginate‐Based Emulsion Template Containing High Oil Loading Stabilized by Nonionic Surfactants

Oil‐in‐water (O/W) emulsion‐gel systems containing high oil payloads are of increasing interest for food applications because of the reduction in encapsulation cost, consumption frequency or volume of food products. This study shows a facile approach to prepare stable alginate‐based O/W emulsions at high oil loading using a mixture of nonionic surfactants (Tween 80 and Span 20) as a template to form gelled‐emulsions. The synergistic effects of alginate and surfactants on the O/W emulsion properties were evaluated in terms of oil droplet size and emulsion stability. At 2% (w/v) of alginate and 1% (w/v) of surfactants, the size distribution of oil droplets was narrow and monomodal, even at an oil loading of 70% (v/v). The emulsions formed were stable against phase separation. The oil droplet size could be further reduced to below 1 μm using a high‐shear homogenizer. The emulsions formed could be easily molded and gelled into solids of different shapes via ionic gelation. The findings of this study create possible avenues for applications in food industries.     

盐分对广式高盐稀态酱油发酵微生物菌群结构的影响

随着健康中国计划的推进,酱油的减盐成为一种趋势,然而广式高盐稀态酱油发酵过程中盐分对不同发酵阶段的群落结构影响的基础研究仍较薄弱,难以支撑减盐酱油产品的普及。该研究基于Illumina HiSeq高通量基因序列分析及理化指标监测,研究不同盐分条件下不同发酵阶段微生物群落结构及理化指标变化规律。结果表明,低盐组(120 g/L)pH值最低,发酵后快速积累总酸、氨基酸态氮和还原糖;在细菌菌群结构方面,随着盐浓度降低,葡萄球菌属(Staphylococcus)、乳球菌属(Lactococcus)、乳杆菌属(Lactobacillus)均在低盐酱醪中持续增长;在真菌群落构成方面,假丝酵母属(Candida)和米勒氏酵母属(Millerozyma)含量在低盐组酱醪中明显较高。低盐(120 g/L)酱醪发酵中乳酸菌含量及总酸明显比中盐(150 g/L)及高盐(170 g/L)组较高,并在发酵初期快速形成了更加适合酵母菌目生长的酸性环境,促进酵母菌目在发酵中期形成了明显的优势菌群。该研究结果为减盐发酵提供了理论基础,为进一步开发酱油低盐发酵微生物调控技术提供参考依据。     

Antrodia camphorata ameliorates high-fat-diet induced hepatic steatosis via improving lipid metabolism and antioxidative status

Nonalcoholic fatty liver disease (NAFLD) commonly results from excessive dietary fat intake which characterized by obesity and insulin resistance. Wild fruiting body of Antrodia camphorata (AC) was assayed for alleviative effects on NAFLD. An NAFLD animal model was successfully established in male 7-week-old C57BL/6 mice fed with high-fat diet (HFD) for 36 weeks. The HFD mice exhibited obese and impaired glucose metabolism. After an induction of NAFLD syndrome, AC was given for one week via gavage. Mice with AC treatment showed lowered (p < 0.05) serum TG and TC, lowered (p < 0.05) liver TG content, improved (p < 0.05) oxidative status (TBARS values and GSH levels), and ameliorated (p < 0.05) liver damage (AST, ALT, and LDH values). In addition, AC activated (p < 0.05) gene expressions of PPAR-α with its downstream genes in the liver and caused higher (p < 0.05) rectal temperature, which showed AC attenuates hepatic lipid accumulation by promoting lipid oxidation and further suggests the role of AC in energy expenditure. Overall, our findings revealed that AC possesses alleviative effect on NAFLD.     

Volatile components of the enzyme-ripened sufu, a Chinese traditional fermented product of soy bean

In the present study, sufu, a soft cheese-like oriental fermented food, was prepared by ripening the salted-tofu cubes in Aspergillus oryzae-fermented soybean-rice koji at 37°C for 16 days (16-day sufu). Sufu was further held at room temperature for another 30 days (46-day sufu). The volatile components of the non-fermented tofu cubes and the sufu products were identified and quantified by GC and GC-MS. A total of 70 volatile compounds including 20 aldehydes, 18 alcohols, 16 esters, 5 ketones, 5 acids and 6 other compounds were identified. Sufu products contained more volatile compounds than non-fermented tofu cubes qualitatively and quantitatively. After 16-days of ripening, fatty acid, aldehyde and ester were noted to be the dominant volatile fractions. In contrast, the 46-day sufu contained ester, and alcohol as the major volatile fractions. They comprise approximately 63.9% of the total volatile components.     

Transformation of bisphenol A and alkylphenols by ammonia-oxidizing bacteria through nitration

Transformation of bisphenol A (BPA) by ammonia-oxidizing bacteria (AOB) Nitrosomonas europaea ATCC 19718 was investigated. On the basis of the ultraperformance liquid chromatography (UPLC) coupled to quadrupole time-of-flight mass spectrometry (Q-TOF MS) and nuclear magnetic resonance analysis, we found N. europaea could transform BPA into nitro- and dinitro-BPA, suggesting that abiotic nitration between the biogenic nitrite and BPA played a major role in the transformation of BPA in the batch AOB system. Nitrite concentrations, temperature, and pH values were the major factors to influence the reaction rate. Furthermore, the yeast estrogenic screening assay showed that the formed nitro- and dinitro-BPA had much less estrogenic activity as compared with its parent compound BPA. Similar reactions of abiotic nitration were considered for 4-n-nonylphenol (nNP) and 4-n-octylphenol (nOP) since nitro-nNP and nitro-nOP were detected by UPLC-Q-TOF MS. In addition, results from the local wastewater treatment plant (WWTP) showed the occurrence of nitro-BPA and dinitro-BPA during the biological treatment process and in the effluent, indicating that nitration of BPA is also a pathway for removal of BPA. Results of this study provided implication that AOB in the WWTPs might contribute to removal of selected endocrine-disrupting compounds (EDCs) through abiotic nitritation.     

低聚糖和多酚结合偏最小二乘判别分析鉴别油菜蜜产地

采用气相色谱-串联质谱技术测定油菜蜜中6 种低聚糖成分,高效液相色谱-串联质谱技术测定油菜蜜中18 种酚酸物质,并结合偏最小二乘判别分析（partial least square-discrimination analysis,PLS-DA）对来自湖北钟祥市、江苏盐城市、青海刚察县3 个具有显著地理、气候、环境差异的51 个油菜蜜样本进行产地鉴别。方差分析结果显示：3 个产地油菜蜜中松二糖含量具有显著性差异,且青海刚察油菜蜜低聚糖含量相对偏高;油菜蜜的18 种多酚类物质中大多数具有显著的地理差异性且湖北钟祥的油菜蜜中多酚含量相对偏高。多元统计分析结果显示多酚具有显著的地理特征性。油菜蜜中低聚糖和多酚的含量结合PLS-DA产地鉴别的预测精度可达到97%。