不同类型病斑粒、热损伤粒及胚部内霉粒对小麦中呕吐毒素含量的影响

通过对小麦病斑粒进行分类，将不同类型病斑粒、热损伤粒、胚部内霉粒以不同比例回掺入完善粒中，研究其对小麦中呕吐毒素的影响，旨在为小麦收购、储存及加工提供理论依据。结果表明，不同类型病斑粒对小麦中呕吐毒素的影响不同，其中赤霉病粒与呕吐毒素含量呈显著正相关，且相关性系数高达0.91,其他种类病斑粒与呕吐毒素积累之间无明显规律，但若含量超标也存在呕吐毒素含量较高的情况；热损伤粒及胚部内霉粒与呕吐毒素含量相关性不大，表明小麦中呕吐毒素的产生主要由赤霉病粒引起，其他不完善粒对呕吐毒素的积累无直接影响。     

小麦赤霉病粒含量与呕吐毒素含量关系研究

采用胶体金快速定量法,对不同梯度赤霉病粒含量的小麦样品进行呕吐毒素的检测,并绘制曲线。结果表明,当小麦赤霉病粒含量超过2.5%时,呕吐毒素存在一定的超标风险。本研究对基层粮库小麦入库,以及通过测定赤霉病麦粒含量来判断呕吐毒素超标程度提供了参考依据,有助于粮库提高呕吐毒素检测效率,提高收粮速度。     

小麦中呕吐毒素含量与不完善粒关系研究

批量采集小麦样品,检测不完善粒和呕吐毒素值,研究小麦中呕吐毒素与各不完善粒相关规律。研究结果发现,呕吐毒素与不完善粒之间存在正相关性,呕吐毒素与赤霉病粒存在显著线性关系,呕吐毒素与黑胚粒之间不存在相关性,呕吐毒素与发芽粒之间存在正相关性。对小麦中呕吐毒素含量初步判定,应以赤霉病粒含量为主,适当参考不完善粒总量和发芽粒,而黑胚粒参考价值不高,粮食种植、购销主体可以此实现小麦质量初步控制。     

小麦分选过程中赤霉病粒与呕吐毒素含量关系探讨

基层粮库小麦收购入库工作量大,小麦的呕吐毒素含量检测成本高、时间长,不能满足收购现场的需要。基层粮库小麦收购入库,可以通过赤霉病粒含量的检测来辅助判断呕吐毒素是否超标,对赤霉病粒严重的小麦在清杂后通过籽粒比重的差异实施分选处理,大大降低小麦赤霉病粒含量、呕吐毒素含量,这种处理方法对实际应用有极强的意义。     

呕吐毒素在小麦正常粒和赤霉病粒中的分布情况研究

选用不同梯度呕吐毒素含量的小麦样品10份,通过测定样品赤霉病粒去除前后的呕吐毒素含量,以确定呕吐毒素在正常小麦和赤霉病粒中的分布比例情况。结果表明:小麦中的呕吐毒素60%左右分布在赤霉病粒中,在正常麦粒中也有一定分布。     

小麦赤霉病与DON含量的检测研究

赤霉病是小麦成长中比较常见的病菌感染,在经过一系列生理分化以后,会产生呕吐毒素,影响到小麦品质和安全性。为此,必需要对收购的小麦进行赤霉病含量检测,确保其呕吐毒素含量≤1 000 μg/kg。通过试验验证,当小麦赤霉病含量≤3%时,小麦呕吐毒素的含量处于规定安全范围内。     

小麦中呕吐毒素的分布规律及加工影响

采用自然污染不同程度呕吐毒素的小麦为材料,通过检测制粉工艺过程中不同产物如麸皮、细麸、皮粉、心粉中呕吐毒素含量,探索小麦不同部位呕吐毒素的含量分布及制粉工艺中去除DON的效果。结果表明:呕吐毒素在小麦中的污染程度从外到内逐步递减;经过小麦制粉加工工艺后,存留在面粉中的DON浓度仅为原来小麦中DON浓度的49.17%～77.68%,而粗麸及细麸中DON浓度为原来小麦中DON浓度的132.00%～185.96%。另外,小麦中呕吐毒素的含量跟赤霉病粒的含量不存在完全的一一对应的线性关系,赤霉病粒含量的多少不能完全反应小麦中呕吐毒素的含量。     

小麦呕吐毒素含量与赤霉病粒含量的相关性研究

该文通过大量数据的积累与分析,建立了小麦呕吐毒素含量与赤霉病粒含量的相关性曲线y=297.6x+135.96,并通过数十组实验数据加以验证曲线的正确性。所建立的相关性曲线在辅助仓库进仓小麦呕吐毒素定性筛查上具有较好的应用价值。     

小麦赤霉病及呕吐毒素的分析检测

采集赤霉病含量不同的小麦样品为检验组,用赤霉病粒小麦配制成不同病粒含量的梯度小麦样品为对照组,用酶联免疫法测定感染赤霉病后的小麦中呕吐毒素含量,结果显示,控制小麦赤霉病含量≤3%,可确保小麦呕吐毒素含量符合国家粮食卫生指标规定,由此指导基层粮库小麦的收购工作。     

赤霉病对小麦品质影响的研究

选取2012年江苏产硬质白小麦,制备不同赤霉病含量的小麦样品,探讨不同赤霉病含量对小麦籽粒品质、小麦粉品质影响程度,以及由小麦赤霉病病原菌分泌产生的脱氧雪腐镰刀菌烯醇(DON毒素)在小麦籽粒中积累分布情况。实验结果表明,随着小麦样品中赤霉病麦含量的升高,涉及小麦籽粒品质、小麦粉品质的主要指标明显下降;同时DON毒素在小麦籽粒中积累分布,皮层中含量明显高于胚乳(小麦粉)中的含量。     

Population growth of the khapra beetle,Trogoderma granarium Everts (Coleoptera: Dermestidae) on different commodities

We evaluated the population growth of the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) on different grains, cracked wheat containment categories and amylaceous materials by conducting three series of laboratory bioassays. In the first series, peeled barley, whole (raw) barley, peeled oats, whole (raw) oats, peeled rice, rough rice, rye, triticale and hard wheat were tested. In the second series, six cracked wheat containment categories were tested: wheat containing intact kernels only (0% cracked kernels), wheat containing 5% cracked kernels and 95% intact kernels, wheat containing 10% cracked kernels and 90% intact kernels, wheat containing 25% cracked kernels and 75% intact kernels, wheat containing 50% cracked kernels and 50% intact kernels and wheat containing 100% cracked kernels. In the third series, the following amylaceous commodities were tested: hard wheat (intact kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour and semolina. Significantly more dead adults were found on wheat than on peeled barley, maize, whole oats, rough rice and rye. Significantly more larvae alive were found on wheat and triticale, than on the other grains, with the exception of oats, both whole and peeled. The increase of the percentage of cracked wheat kernels increased population growth, except in the case of 10% cracked wheat kernels. In vials that contained 100% cracked wheat kernels, 584.1 individuals per vial were found, which was 3.7 times more than the respective number of larvae alive in vials with intact wheat kernels only. Significantly more dead adults were found on whole barley flour than on the other commodities. More than 1213 larvae per vial were recorded on whole barley flour, which was 1.3–15 times higher than the other commodities. The lowest number of larvae alive was found on pasta, followed by the white soft wheat flour. The findings of the present work show that some commodities are more prone to spread T. granarium than others, a fact which should be seriously taken into account in international trade of grains and related amylaceous products.     

不同杂粮对面粉品质特性的影响研究

本文以谷物杂粮为研究对象,通过将不同质量的红豆粉、绿豆粉、玉米粉和燕麦粉混合于小麦粉中,观测其对面粉的品质特性和面包质量的影响。试验结果表明：除玉米粉外,随着其他杂粮添加量的增加,其蛋白质、面筋和灰分含量呈增加趋势;而混合粉的峰值黏度、最低黏度、衰减值、最终黏度和回生值均有所下降;添加绿豆粉和红豆粉的小麦粉在添加量12%时其峰值黏度最低,而添加12%燕麦粉的小麦粉峰值黏度突然增大;峰值时间和糊化温度明显降低。杂粮的添加改变了面团的品质特性。综合评价后认为最佳添加比为不超过12%。     

免疫磁珠高通量自动净化-超高效液相色谱法测定粮食中玉米赤霉烯酮

基于免疫磁珠高通量自动净化的前处理方法,使用超高效液相色谱仪对粮食中玉米赤霉烯酮的含量进行测定。首先将免疫磁珠与玉米赤霉烯酮的反应时间、样品提取液和不同粮食基质的净化效果进行优化。经方法验证,超高效液相色谱的检出限和定量限分别为3.5 μg/kg和12.0 μg/kg。在优化条件下,全麦粉和玉米全粉阴性样品的3 个添加水平的加标回收率在99.04%～109.26%之间,变异系数不大于6.88%。玉米全粉、全麦粉、糙米粉、小麦粉等粮食基质中玉米赤霉烯酮成分的国家有证标准物质或质控样品的测定结果在标准值及其扩展不确定度范围内,变异系数不大于3.54%,测定结果较为满意。采用Bland-Altman法对免疫磁珠净化法和免疫亲和柱净化法之间的差异进行分析,结果显示这2 种净化方法的差异在可接受范围内,因此,这2 种方法在净化和富集粮食中玉米赤霉烯酮时可互相代替使用。免疫磁珠净化方法配套使用的真菌毒素全自动净化仪可同时净化10～24 个样品,平均每个样品的净化时间约为2～3 min,实现粮食中玉米赤霉烯酮的高通量自动净化。超高效液相色谱分析速度快、灵敏度高、准确性高,可用于检测粮食中玉米赤霉烯酮的含量。     

小麦赤霉病情与麦粒中DON含量关系的分析

为分析小麦赤霉病田间病情、病粒率与麦粒中脱氧雪腐镰刀菌烯醇(DON)含量的关系,以感染赤霉病不同病情的小麦样品为材料,用高效液相色谱法(HPLC)检测了麦粒中DON的含量。结果表明:麦粒中DON含量随田间病情级别或病粒率的提高而增加,呈极显著相关。依据病粒率推算DON含量,具有一定的实用性,但在小麦品种间以及不同病情条件下的理论值误差较大。     

Comparison of lipid content and fatty acid composition and their distribution within seeds of 5 small grain species

Barley, oats, rice, sorghum, and wheat, each with two genotypes, were sequentially abraded by an electric seed scarifier. The pearling fines (PF) and pearled kernels (PK) at each cycle were analyzed for lipid (mostly nonpolar) content and fatty acid (FA) composition. The oil content in whole or dehulled grains ranged from 2.18% of a wheat variety to 6.38% of an oat line. Compared with barley and wheat, rice, oat, and sorghum had higher relative % of C18:1 (31.60 to 36.64 compared with 12.15 to 15.61) and lower % of C18:2 (35.69 to 45.44 compared with 50.79 to 61.50). The relationship between oil content in PF and the cumulative level of surface removal essentially describes the distribution pattern of oil content within a seed. Barley, rice, and sorghum had a similar distribution pattern, characterized by a rapid rate of decreasing for the first few outer layers and then by gradual decrease to a flat value toward the inner core. In contrast, distribution within oats was characterized by a gradual reduction in oil content across the seed. The distribution of oil within wheat fell between the former 2 types. For all 10 grains, from seed surface to inner core, C16:0 and C18:0 increased, C18:1 and C18:3 decreased, and C18:2 changed slightly, providing a new reason for improved oxidative stability for pearled kernels. The differences in the changing intensity of FA composition among grain species correspond to those in oil distribution within a seed, while varietal difference in distribution patterns of content and FA composition of lipids within a species was insignificant. PRACTICAL APPLICATION: This study was the first to document fatty acid distribution across a grain seed. Results provide 2 major reasons for improved oxidative stability of pearled grains: reduced oil content and shift of fatty acids toward more saturated and less unsaturated composition.     

平菇-650液态发酵啤酒糟获取膳食纤维的培养基优化

以啤酒糟为主要原料,以麸皮、玉米粉、豆渣为辅料,对平菇-650液态发酵麦糟制取膳食纤维进行培养基优化。以可溶性膳食纤维（SDF）得率为评价指标,通过单因素试验和正交试验,考察麸皮、豆渣和玉米粉添加比例对发酵膳食纤维品质的影响,优化培养基组成并分析因素影响的显著性。结果表明,在培养基中添加4%麸皮、2%豆渣、2%玉米粉发酵制取膳食纤维品质最好,在该培养基组成下发酵生产膳食纤维,其SDF得率可达15.71%。     

Influence of commodity on the population growth of the larger grain borer,Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae)

In this study, we compared different amylaceous commodities for their suitability for population growth of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), which is an important pest of stored maize in the tropics. In this context, we conducted three different series of tests. In the first test, we compared whole grains: whole barley, peeled barley, maize, whole oats, peeled oats, peeled rice, rough rice, rye, triticale, and wheat. Only maize was found suitable for P. trunctatus to reproduce and significantly increase its population, but there were certain commodities where surviving adults were found. In the second series of tests, we evaluated the percentage of cracked maize kernels on P. truncatus population growth. In this test, we found that the numbers of alive P. truncatus adults in the vials that contained 100% cracked kernels was higher than these with lower percentages of cracked kernels (5–50%) or no cracked kernels (0%). Finally, in the third series of tests, we compared eleven different types of amylaceous commodities with maize. These commodities were: whole maize (whole kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour, and semolina. The results indicated that only whole maize and maize flour were suitable for P. truncatus population growth. Nevertheless, in some of the other commodities tested, there was a low number of adults and immatures that were able to survive 60 days after the incorporation of the parental adults. The results of the present study indicate that from the commodity range tested here, only maize was suitable for P. truncatus population growth. Nevertheless, the marginal numbers of surviving individuals in the non-maize commodities and the role of these substrates as potential “non-preferred food vehicles” that may contribute to further spread of this species should be tested in more detail.     

Properties of extruded whole grain cereals and pseudocereals flours

Common cereals such as wheat are widely used worldwide in extruded products. Nevertheless, other locally available grains would be beneficial for local consumers regarding taste preference, nutritional needs and sustainability. Locally available cereals, that is millet, teff, sorghum and pseudocereals, that is quinoa and amaranth flours were extruded at the same processing conditions, and the resulting properties were compared to those of extruded refined wheat flour. Amaranth flour contained the highest protein content (16%). Sorghum was the highest in calories because of its high lipid content (10%). The extrusion process greatly increased a water solubility index (WSI) of amaranth from 11% to 61%, while the WSI level of quinoa was almost not affected (WSI of 4%). The expansion properties varied differently among grain types. These grains had a sectional expansion index (SEI) ranging between 11 and 13, which could not achieve the performance of the refined wheat (SEI of 22). The lowest expansion was observed for amaranth flour which contained the lowest starch content. Sorghum extrudates, interestingly, provided comparable stress at rupture value to that of wheat. For the mechanical properties, none of these local grains could fully replace refined wheat at the employed extrusion conditions.     

真菌毒素在赤霉病小麦研磨及其湿法加工中的分布研究

小麦赤霉病不仅会导致粮食减产,更会引起多种真菌毒素的高污染风险。将染病小麦进行实验室制粉并湿法分离统粉中的粗淀粉、谷朊粉,采用酶联免疫吸附测定法(Enzyme-Linked Immuno Sorbent Assay,ELISA)测定各系统的呕吐毒素(Deoxynivalenol,DON)、黄曲霉毒素B1(Aflatoxin B1,AFB1)、玉米赤霉烯酮(Zearalenone,ZEN)以及赭曲霉毒素A(Ochratoxin A,OTA)的含量,以探究赤霉病小麦在制粉及其湿法加工中四种常见真菌毒素的分布变化规律。结果显示:研磨制粉及湿法加工对真菌毒素的分布影响显著。制粉加工后,皮磨和心磨系统粉的DON、AFB1、ZEN和OTA含量比原粮显著降低,降低率分别为1.38~16.24%、20.47~71.77%及26.71~69.51%;湿法加工产物中,DON消减为相应统粉的4.88~12.11%,AFB1与OTA浓缩富集,富集率分别可达统粉的2.55、3.65倍,粗淀粉中ZEN消减为统粉的12.70~15.83%,谷朊粉则富集为统粉的4.11倍。研究表明,在工业生产中,可根据赤霉病小麦的感染类型及程度,适当选用研磨或湿法加工等合适的方法加工处理。     

Differences in content and composition of free lipids and carotenoids in flour of spring and winter wheat cultivated in Poland

The work presents the content and composition of free lipids and carotenoids in spring and winter classes of wheat flour. It discusses genetical and physiological aspects of their synthesis and accumulation in wheat kernels and also indicates how methodological differences explain differences in results presented in the literature. It has been reported that spring wheat flours are richer in free lipids, especially in the non-polar fraction. The content of glycolipids ranged from 134 to 215 mg/100 g flour and was more stable within the winter wheat class. The percentages of the two main fractions, namely DGDG and MGDG, were similar in both wheat classes and reached ca. 77%. Phospholipids constituted the smallest fraction of the flour free lipids in both wheat classes; however, spring wheat flours were richer in these compounds, which is likely associated with a greater content of spherosomes in the endosperm of this wheat class. The free lipids of spring wheat flour contained more oleic and slightly less linoleic and linolenic acids. Spring wheat flour was also richer in carotenoids, although there were varieties in both classes that deviated from this. The main carotenoid was lutein, whose total percentage in the form of different isomers ranged from 71.3% to 83.3% and was slightly lower for spring wheat flour. Lutein, in the form of a trans-isomer, constituted about 62% and 70% of all carotenoids in spring and winter wheat flours, respectively.