精白保胚发芽米淀粉理化性质

研究发芽对精白保胚米淀粉理化性质的影响。测定精白保胚发芽米淀粉的溶解度、膨胀度、透光率、冻融稳定性等理化性质;采用快速黏度分析仪和流变仪研究精白保胚发芽米淀粉RVA 特征值的变化和流变学特性;并与糙米、发芽糙米和精白保胚米淀粉的理化性质做比较。结果表明,精白保胚米发芽之后直链淀粉含量降低,溶解度、膨胀度和透光率增加,冻融稳定性得到改善;RVA 特征值表现为精白保胚发芽米的峰值黏度降低,最终黏度升高,崩解值降低,消减值和回升值升高;动态流变学表现为加热过程中精白保胚发芽米的储能模量(G')降低。     

发芽对不同品种糙米碳水化合物组成及其相关酶活性的影响

4个不同品种的糙米样品在35℃下发芽60 h,每间隔12 h取样分析其碳水化合物组成及相关酶活性的变化。结果表明,发芽使不同品种糙米的淀粉、直链淀粉及支链淀粉含量降低;还原糖和可溶性糖含量先增加、后降低;总淀粉酶活力和α-淀粉酶活力先上升、后下降。其中,籼稻糙米发芽36 h时,还原糖和可溶性糖含量以及总淀粉酶和α-淀粉酶活力达到高峰;而粳稻糙米和糯稻糙米的高峰值则出现在发芽48 h时。     

燕麦发芽过程中淀粉及其相关酶活性的动态变化

研究了裸燕麦发芽过程中淀粉及其相关酶活性的动态变化。结果表明,发芽过程中,燕麦还原糖和可溶性糖含量及α-淀粉酶、β-淀粉酶和总淀粉酶活力明显地先增加后降低;直链淀粉、支链淀粉和总淀粉的含量均随着发芽的进行呈下降趋势,发芽72 h分别降低了25.86%、11.08%和17.31%。相关性分析表明,燕麦发芽期间还原糖、可溶性糖含量分别与α-淀粉酶、β-淀粉酶及总淀粉酶活力呈显著正相关,而直链淀粉、支链淀粉及总淀粉含量均与淀粉酶活力呈显著负相关。     

发芽对精白保胚米淀粉分子结构的影响

目的：研究发芽对精白保胚米淀粉分子结构的影响。方法：采用扫描电子显微镜、高效液相色谱、X射线衍射仪及傅里叶红外光谱(FT-IR)分析精白保胚发芽米淀粉颗粒的表面结构、相对分子质量分布、结晶度和特征结构的变化。结果： 精白保胚米发芽之后淀粉颗粒表面结构变化不明显,但淀粉的相对分子质量、结晶度降低;发芽后精白保胚米淀粉的红外透光率降低,O－H键、C－H键和C－O键的伸缩振动均增强。结论：发芽过程中直链淀粉和支链淀粉降解,使精白保胚米淀粉分子结构发生明显变化。     

精白保胚米发芽过程中米谷蛋白及其氨基酸的变化

研究精白保胚米发芽过程中米谷蛋白及其氨基酸组成的变化。精白保胚米在发芽过程中,淀粉含量呈下降趋势,蛋白质的含量略有上升;十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和体积排阻色谱的结果显示：发芽后米谷蛋白中含量较高的各亚基分子质量没有太大差别,但其含量有所变化,高分子质量亚基含量减少,低分子质量亚基含量增多。米谷蛋白氨基酸分析结果发现：发芽可以增加精白保胚米总氨基酸和必需氨基酸的含量,必需氨基酸组成模式更加合理。分析结果表明发芽可以提高精白保胚米的食用品质和营养价值。     

不同玉米品种发芽过程中碳水化合物代谢变化的初步研究

以普通玉米(苏玉24号,SY-24)、糯玉米(紫花糯玉米,ZY)和甜玉米(京晶3号,TY)为试材,研究了不同玉米品种的组分差异及不同发芽阶段生理生化和碳水化合物组成的变化.结果表明:不同品种玉米之间存在组分差异,SY-24的千粒重和直链淀粉含量最高,ZY中未检测到直链淀粉;ZY的水分、还原糖、可溶性糖、Mg、Na和Ca的含量最高;TY中的类胡萝卜素、可溶性蛋白、游离氨基酸、灰分、粗脂肪、Zn和K含量最高.SY-24中未检出Ca;TY和SY-24中Fe含量没有显著差异(P＞0.05),但均显著高于ZY(P＜0.05),分别是ZY中铁含量的4.69和1.04倍.在发芽过程中,芽长、发芽率、呼吸强度逐渐升高,干物质含量逐渐降低;淀粉酶活力而逐渐增加,β-淀粉酶活力显著高于α-淀粉酶活力(P＜0.05);在淀粉酶作用下,淀粉含量逐渐降低,淀粉颗粒逐渐变小,ZY中没有检测到直链淀粉,SY-24和TY直链淀粉含量随发芽时间延长呈先增加后降低,并分别在第24h和第36h达到最大值,分别是未发芽的3.10倍和1.46倍;可溶性糖在发芽过程中呈现波动变化;ZY和SY-24中还原糖含量逐渐增加;TY中还原糖含量呈现先降低后增加的趋势,在发芽地12h达到最低,与未发芽相比降低了15.44％.     

发芽糙米制备工艺研究

以“粳稻9516”为试材,研究了其糙米经Ca2 /GA3处理发芽后,其淀粉酶活力和主要成分变化。结果表明,发芽糙米中淀粉酶活力、还原糖、游离氨基酸、淀粉和水溶性蛋白质等含量高于糙米,制备发芽糙米的最适工艺条件是:GA3浓度为0.2mg/L、发芽温度16℃和发芽时间5d。     

温度处理对发芽糙米中淀粉酶活力的影响

研究了温度处理对发芽糙米中淀粉酶活力的影响。结果表明 :在 1 6～ 2 8℃温度范围内 ,较低的温度能提高发芽糙米中α 淀粉酶和总淀粉酶活力 ,较高的温度使酶活力高峰提前出现 ,糙米最适发芽温度为 2 2℃。发芽糙米中 β 淀粉酶活力受发芽温度的影响较小。在发芽期间 ,糙米中淀粉含量随淀粉酶活力升高而降低 ,还原糖含量先升后降。     

精白保胚发芽米食用品质

以糙米、发芽糙米、精白保胚米及精白保胚发芽米为研究对象,对其食用品质的主要方面,即炊饭方法、蒸煮特性、糊化特性、质构特性及感官分析进行对比评价。结果表明：精白保胚发芽米的吸水率和膨胀率均低于其他3 种大米,而米汤固体溶出物和碘蓝值均高于糙米和发芽糙米;糊化特性分析中,精白保胚发芽米与大米食用品质相关的崩解值降低,消减值升高;质构分析表明精白保胚发芽米具有最低的硬度;感官分析结果表明,精白保胚发芽米在色泽、香气、口感、滋味方面都优于未发芽米。     

糙米发芽过程中主要营养成分变化的研究

探究糙米的主要营养成分在发芽过程中的变化。对糙米中各营养成分发芽前后含量进行测定。淀粉含量72 h时比发芽前下降28.8%,且淀粉含量随着α-淀粉酶活力的升高而下降;还原糖含量相比发芽前增加了6.46倍;可溶性蛋白先增加后减少;谷胱甘肽含量由3.74 mg/100 g上升到9.58 mg/100 g;游离氨基酸72 h时含量最高达881.45μg/g;γ-氨基丁酸含量呈现急剧增长趋势;主要内源酶活力均呈现逐渐上升趋势;VB6不断增加;VC24 h时含量达最高3.25 mg/100 g;植酸含量呈现持续降低趋势。糙米发芽24 h~48 h的营养价值最高。     

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。     

Content of selenium in fishes,caught in lakes in Buriatia

Study of selenium accumulation by fish of Buryatia shows relatively high accumulation level for the Baikal lake (213-513 mcg/kg) contrary to the lakes of Baunt and Selenginsk regions of the republic (84-227 mcg/kg). Selenium deficiency in Baunt region is also confirmed by low selenium levels in meat of native origin (39-95 mcg/kg). Among different tissues and organs the lowest selenium levels are typical for muscles, the value increasing in the row: muscle < skin < air bladder < scales < fin < liver < roe.     

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。