白酒酿造中适产高级醇酿酒酵母菌株选育研究进展

随着时代的发展,白酒的品质成了大众日益关注的话题,这就要求酒既有优质的风味口感,又不对人体造成伤害。高级醇是白酒中最重要的风味物质之一,主要由酿酒酵母生成。适量的高级醇可赋予酒体醇香、柔和的口感,但当高级醇含量超过一定限度时,不但会降低酒体的口感,还会有损饮用者的身体健康。因此,白酒中高级醇种类及含量的调控对改善酒体品质有着重要意义。文章介绍了酿酒酵母中高级醇的形成机制,重点总结了高级醇代谢调控的关键基因以及白酒酿造中适产高级醇酿酒酵母菌株选育研究进展,以期为白酒中高级醇的精细化调控及适产高级醇酿酒酵母菌株的选育提供参考。     

控制上面发酵小麦啤酒中高级醇含量的研究进展

高级醇是啤酒中主要的风味物质,适量的高级醇能赋予啤酒丰满的口感,增加酒体的协调性,高级醇过量则会给啤酒带来异杂味并引起人体某些疾病。该文对高级醇的性质,测定方法,在啤酒中的代谢途径,影响其含量的因素以及降低上面发酵小麦啤酒中高级醇含量的研究情况进行了综述。     

黄酒中高级醇含量控制与检测研究进展

高级醇是黄酒中主要的风味物质,适量的高级醇能赋予黄酒丰满的口感,增加酒体的协调性。但高级醇过量则会给黄酒带来异杂味并引起较强的致醉性。该文在综述国内外相关研究成果的基础上,对黄酒中高级醇含量的影响因素以及高级醇的检测方法进行了阐述,以期为黄酒生产过程中控制高级醇的含量提供参考。     

影响啤酒中高级醇的因素

高级醇是酵母发酵过程中的副产物,啤酒中高级醇的含量一般约为60～120mg/L,优质淡爽型啤酒的高级醇含量一般控制在50～90mg/L。若高级醇含量过低,则使口感显得寡淡;如果高级醇含量过高将会给人以苦涩味,引起头晕,甚至会影响到人体的健康。降低高级醇含量,可以提高啤酒口味纯净性。由于影响高级醇的因素很多,不能逐一去尝试验证,最后我们根据试验的可行性,以14.4°P 酒源为试     

黄酒中高级醇含量控制的研究进展

高级醇是黄酒中主要的风味物质,适量的高级醇能赋予黄酒丰满的口感,增加酒体的协调性.但高级醇过量则会给黄酒带来异杂味并引起较强的致醉性,俗称“上头”,控制黄酒中高级醇含量对提高黄酒的质量显得十分重要.该文在简要论述黄酒发酵过程中高级醇形成途径的基础上,对近年来关于黄酒生产原料、糖化剂、酵母和发酵温度等工艺因素对高级醇含量影响的研究现状作了概述.     

添加谷氨酸对荔枝酒中高级醇生成的影响

荔枝酒中的高级醇类物质是构成酒的芳香物质的重要组成成分。高级醇在果酒中的含量过高会严重影响酒的品质,并引起易醉、头痛、头晕、口干等副作用。研究了在荔枝汁发酵过程中添加谷氨酸作为氮源物质对荔枝酒中高级醇生成量的影响。结果表明,在荔枝汁发酵过程中添加100 mg/L的谷氨酸可以明显抑制高级醇的生成量、提高乙醇产率。     

啤酒酵母高级醇的代谢与调控研究进展

高级醇是啤酒酵母在啤酒酿造过程中代谢产生的,是啤酒风味物质的重要组成部分。适量的高级醇能赋予啤酒独特的香味,但其含量过高或者过低都会影响啤酒的质量。该文重点综述啤酒酵母中高级醇的生成途径、关键基因、代谢调控机理及选育低产高级醇优良菌株的主要方法,为适当降低啤酒中高级醇含量,进而推动啤酒行业的健康发展提供理论基础。     

白酒酿造过程中高级醇的产生及控制技术研究进展

白酒作为中国的国酒之一,是极具中国特色和中国文化的典型代表.高级醇是中国白酒中呈香呈味的重要组成部分之一,其含量将直接影响白酒的品质和人体的健康.高级醇含量适中时,可以使白酒酒体丰厚,提高白酒品质;然而高级醇含量过高时,会使酒体后味带有微量苦涩味,并且它也是引起酒后"上头"、难醒酒的罪魁祸首.结合高级醇的产生机理,对降...     

影响啤酒上头的因素及控制措施

啤酒上头是啤酒饮用后使人感到头痛、头晕、迷糊等感觉。啤酒上头一直是消费者反映的主要质量问题。引起啤酒饮后上头的主要物质是正丙醇、异丁醇、异戊醇、β-苯乙醇、色醇等高级醇。啤酒中高级醇含量一般在60～100mg/L，适量的高级醇能赋予酒体口感的饱满与醇厚，过高的高级醇，减少啤酒适口性。本文通过试验和大生产工艺的调整，探讨影响啤酒高级醇形成的主要因素及影响程度，     

糖诱导型启动子调控ALD6基因表达降低黄酒中的高级醇生成量

高级醇是影响中国黄酒风味和饮用品质的重要因素之一,适量高级醇可赋予黄酒醇柔、协调的口感,但高级醇过高会导致酒体产生杂醇味,且有强烈的致醉性。在酿酒酵母中,过表达ALD6基因可以显著降低高级醇的生成量,但是过多乙酸的生成会抑制细胞的生长和代谢。由于黄酒发酵是双边发酵,可以通过筛选合适的糖诱导型启动子调控ALD6的表达,在降低高级醇生成量的同时减弱其对细胞生长的抑制作用。该研究选取了6个HXT系列的糖诱导型启动子P_hxt1、P_hxt2、P_hxt3、P_hxt4、P_hxt5和P_hxt7调控乙醛脱氢酶基因ALD6的表达,黄酒发酵结果显示,相较于出发菌株a17,各诱导型重组菌株总高级醇生成量分别下降22.29%、19.26%、42.56%、37.84%、16.72%和30.74%。对比组成型重组菌株a-P_pgk1-A和诱导型重组菌株a-P_hxt3-A发现,二者相较于出发菌株a17均可显著降低总高级醇的生成,但与a-P     

Changes in smoking prevalence in Ukraine in 2001-5

Objectives

To analyse trends in smoking prevalence in Ukraine from three surveys conducted in 2001–5, and to explore correlates of observed changes, in order to estimate the stage of tobacco epidemic in Ukraine.

Design

Repeated national interview surveys in Ukraine in 2001, 2002 and 2005.

Main outcome measure

Prevalence of current smoking among the population aged ⩾15 years.

Results

The age‐standardised prevalence of current smoking in Ukrainian men was 54.8% in 2001 and 66.8% in 2005. Among Ukrainian women, prevalence increased from 11.5% in 2001 to 20.0% in 2005. ORs for yearly increase in prevalence were estimated as 1.164 (95% CI 1.111 to 1.220) for men and 1.187 (1.124 to 1.253) for women, which implies that, on average, 3–4% of men and 1.5–2% of women living in Ukraine join the smoking population each year.

Conclusions

In Ukraine, smoking prevalence is increasing in most population groups. Among men, the medium deprivation group with secondary education has the highest smoking prevalence. Among women, while the most educated, young and those living in larger cities are the leading group for tobacco use, other groups are also increasing their tobacco use. Tobacco promotion efforts appear to have been significantly more effective in Ukraine than smoking control efforts. The decrease in real cigarette prices in Ukraine in 2001–5 could be the main factor explaining the recent growth in smoking prevalence.Ukraine is a large eastern European country with high smoking prevalence. Tobacco products are widely available at very low prices, and the transnational tobacco industry is extremely successful in promoting its products and lobbying for its interests in the legislative field. Advocacy of tobacco control has only recently achieved some success in the legislative field, with the first tobacco control law being adopted in late 2005. Ukraine ratified the Framework Convention on Tobacco Control in 2006, but there is still much cause for concern regarding the enforcement and effectiveness of the adopted legislative measures. Unfortunately, the government is not yet involved in nationwide surveillance of the tobacco problem, and the available data have mostly been gathered with funding from foreign donors. Several attempts have been made to measure the extent of the tobacco epidemic in the countries of the former Soviet Union (FSU).^{1,2,3,4,5,6,7} Most of these studies have shown rather high smoking prevalence among men (50–70%) and comparatively low prevalence among women (5–20%). Most countries in the FSU have similar smoking rates, while certain trends are shown to be related to the differences in how the transnational tobacco industry succeeds in every national tobacco market.⁶ Unfortunately, few studies have been published showing trends in smoking prevalence in the FSU.⁷ In Ukraine, two studies^3,4 provided point estimates of smoking prevalence.The aim of this study was to analyse trends in smoking prevalence in Ukraine, on the basis of three surveys conducted in 2001–5, and to explore correlates of observed changes in order to estimate the stage of the tobacco epidemic in Ukraine.     

2010年河南省部分食品中重金属污染状况分析

了解河南省部分食品中重金属污染的现状。方法 在河南省18个省辖市采集8大类3 657份食品样品,按照国家标准检测食品中铅、镉和汞的含量,检测结果按照GB 2762—2012《食品安全国家标准食品中污染物限量》进行评价。结果 河南省部分食品中铅含量的平均值为0.34 mg/kg,总体超标率为8.8%(320/3 656),其中粮食、肉类和蔬菜中超标率较高,分别为17.2%(95/552)、14.5%(85/587)和10.7%(57/534);部分食品中镉含量的平均值为0.054 mg/kg,总体超标率为3.9%(143/3 657),其中食用菌和蛋类中超标率较高,分别为9.6%(49/508)和8.1%(42/518);部分食品中汞含量的平均值为0.077 mg/kg,总体超标率为8.3%(303/3 657),其中蔬菜和粮食中超标率较高,分别为25.3%(135/534)和12.3%(68/551)。结论 河南省部分食品中铅、汞污染情况较为严重,其中粮食、蔬菜和肉类食品中污染情况尤为突出,需要加强监管。     

Moulds and mycotoxins in sorghum stored in traditional containers in India

Various traditional containers have been used in India for storage of sorghum grains. Sorghum is susceptible to fungal infestation and toxin elaboration. The present study relates to the mould and mycotoxin contamination (aflatoxin B₁ and T-2 toxin) in stored sorghum in different storage containers viz. “Kotlu” (Storage rooms), earthenware pots, gunny bags and reed baskets. Aspergillus sp. and Fusarium sp. were the prominent genera and the “Kotlu” form of storage was most susceptible to fungal attack. Storage treatment had little effect on fungal contamination, but despite the fungal infestation, the mycotoxin contamination was found to be very low.     

中国固态发酵白酒中功能细菌研究进展

细菌是白酒酿造3大类微生物之一,其在白酒生产中有着重要的作用,如:芽孢杆菌、乳酸菌、放线菌和梭菌等,它们能产生酯类、有机酸、吡嗪、萜烯等微量成分,从而影响白酒的风味与品质。基于细菌在白酒中的重要功能以及微生物分离培养技术和分析检测技术的进步,近年来相关研究越来越深入。该文综述了近年来白酒功能细菌的研究进展,介绍了酿酒各个环节中主要功能细菌及其在白酒中的作用,旨在为白酒功能细菌的研究提供参考。     

Heavy metals in vegetables sold in the local market in Jordan

Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009–0.275 mg kg^?1 wet weight, 0.004–0.060 mg kg^?1, 0.003–0.401 mg kg^?1, 0.105–3.51 mg kg^?1, 0.15–1.15 mg kg^?1, 0.93–14.39 mg kg^?1, 0.044–0.702 mg kg^?1, 0.072–0.289 mg kg^?1 and 2.23–6.65 mg kg^?1, respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.