氮气及温度、湿度条件对锈赤扁谷盗卵发育的影响

在3种氮气浓度(78.8%、83.0%、88.0%)、3种相对湿度(69.6%RH、75.1%RH、83.7%RH)及5种温度(19.9、25.0、29.3、34.7、39.8℃)组合条件下,研究了锈赤扁谷盗卵的孵化情况。结果表明:发育历期为2.2~18.9 d,发育起点温度为13.8~14.3℃,最高临界发育温度为40.4~43.0℃,有效积温为61.6~115.6日度。发育历期、发育速率与温度之间分别是"指数"型及"S"型曲线关系。氮气及温度、湿度因素相互作用影响了卵的孵化,88.0%的氮气对孵化有显著的抑制效应,温度(30.0℃)及湿度(69.6%RH)强化了氮气对孵化的抑制效应。     

不同储粮温湿度普通肉食螨的生长发育研究

普通肉食螨(Cheyletus eruditus(Schrank))是粮库中广泛存在的一种害虫的捕食性天敌。研究了粮仓常见的不同温湿度环境下(16、20、24、28℃和57%、75%、93%RH)普通肉食螨的生长发育历期、发育起点温度和有效积温。结果表明:普通肉食螨的生长发育分别经历卵、幼螨、原若螨、后若螨和雌成螨5个发育阶段;在一定的温度范围内,温度越高,发育历期越短,各螨态发育历期最短分别达3.4、4.4、4.1、3.9、15 d,在28℃、75%RH下普通肉食螨的发育时间最短,为30.8 d,在16℃、75%RH下发育时间最长,为118.6 d;各螨态普通肉食螨几乎均是在75%相对湿度下的发育时间最短;普通肉食螨各螨态发育历期与温度呈logistics曲线回归关系;根据直接最优法计算发现普通肉食螨的一个世代、总历期的发育起点温度最低分别为10.39℃和11.64℃,有效积温最低分别是367.09日·度和543.72日·度。为普通肉食螨的大规模工厂化饲养以及应用奠定了基础。     

氮气气调胁迫对赤拟谷盗生长发育及种群动态的影响研究

为明确不同氮气体积分数对赤拟谷盗生长发育和种群动态的影响,本文研究了在27~29 ℃、70~80% RH,氮气体积分数分别为78%（对照组）、90%、95%、98%下赤拟谷盗的发育历期、存活率、产卵量及其他生命表参数。研究结果表明,不同氮气体积分数对赤拟谷盗生长发育和繁殖具有显著影响。在78%、90%氮气体积分数下,增加氮气体积分数对赤拟谷盗卵、幼虫、蛹的发育有明显的抑制作用。赤拟谷盗每雌产卵量随着氮气体积分数的增加而显著减少;赤拟谷盗世代平均周期（T）、种群加倍时间（Dt）随着氮气体积分数的增加而增加。种群净增值率（R0）、种群趋势指数（I）、内禀增长率（rm）、周限增长率（λ）均随着氮气体积分数的增加而降低。当氮气体积分数为95%、98%时,赤拟谷盗不能完成世代发育。在相同氮气体积分数下赤拟谷盗各虫态间的发育历期差异显著。氮气气调处理对赤拟谷盗卵的孵化率、1~5龄幼虫及蛹的存活率均有显著的抑制作用,对赤拟谷盗6龄、7龄幼虫和预蛹的存活率无显著影响。     

温度对高氮气调中米象各虫态致死和发育的影响

明确氮气气调中温度对隐蔽性害虫各虫态致死时间的延迟程度及差异,可为气调杀虫时间的科学掌控提供参考。研究了在98％氮气浓度和（75±5）% RH下18、23和28 ℃时米象Sitophilus oryzae（L.）成虫和隐蔽于粮粒内的卵、幼虫和蛹在不同时间的死亡率、致死时间以及羽化出成虫的时间。18 ℃温度下达到100%死亡率的时间为25 d,比23 ℃和28 ℃时相应延迟了6 d和12 d。18 ℃下气调致死虫卵、幼虫、蛹和成虫的LT50值（半数致死时间）分别为9、8、11和7 d,LT99值（99%个体致死所需时间）分别为24、21、26和17 d;23 ℃时相应LT50值为6、5、7和5 d,LT99值为19、16、21和11 d;28 ℃时LT50值为3、3、4和3 d,LT99值为11、10、12和7 d。98%氮气气调后残存米象隐蔽虫态均可发育,与正常气体环境相比18 ℃时从卵发育至成虫的历期最大可延迟27 d,温度降低可导致发育历期延长更为明显。米象不同虫态对氮气气调耐力由大到小为：蛹＞卵＞幼虫＞成虫,氮气气调杀除米象时应以完全杀死隐蔽发生的蛹为目标。     

温度对高氮气调中米象各虫态致死时间和发育的影响

明确氮气气调中温度对隐蔽性害虫各虫态致死时间的延迟程度及差异,可为气调杀虫时间的科学掌控提供参考。研究了在98%氮气浓度和(75±5)%RH下18、23和28℃时米象Sitophilus oryzae(L.)成虫和隐蔽于粮粒内的卵、幼虫和蛹在不同时间的死亡率、致死时间以及羽化出成虫的时间。18℃温度下达到100%死亡率的时间为25 d,比23℃和28℃时相应延迟了6 d和12 d。18℃下气调致死虫卵、幼虫、蛹和成虫的LT_(50)值(半数致死时间)分别为9、8、11和7 d,LT_(99)值(99%个体致死所需时间)分别为24、21、26和17 d;23℃时相应LT_(50)值为6、5、7和5 d,LT_(99)值为19、16、21和11 d;28℃时LT_(50)值为3、3、4和3 d,LT_(99)值为11、10、12和7 d。98%氮气气调后残存米象隐蔽虫态均可发育,与正常气体环境相比18℃时从卵发育至成虫的历期最大可延迟27 d,温度降低可导致发育历期延长更为明显。米象不同虫态对氮气气调耐力由大到小为:蛹卵幼虫成虫,氮气气调杀除米象时应以完全杀死隐蔽发生的蛹为目标。     

温度对大豆食心虫卵和幼虫生长发育的影响

在17～33℃条件下,研究了温度对大豆食心虫卵和幼虫生长发育的影响。结果表明：在试验温度范围内,卵的发育速率与温度呈正相关,模型为：Yegg=0.61/[1＋exp（3.19-0.08t）]（F=128.5976,p=0.0077,R=0.9961）,发育历期随温度升高而缩短;幼虫期发育速率模型为：Ylarva=0.10/[1＋exp（3.25-0.17t）]（F=21.7316,p=0.0440,R=0.9778）,其中2龄、3龄幼虫发育速率与温度呈正相关且明显高于其它龄期,33℃条件对1龄和4龄、5龄幼虫的生长发育有抑制作用。温度对大豆食心虫卵孵化率影响不明显,而对各龄幼虫存活率的影响较大,幼虫期对环境温度的适应性随龄期增加而增强。温度影响幼虫的营养积累,在25℃条件下老熟幼虫体重为17.26mg,显著高于其它温度。大豆食心虫卵的发育起点温度为7.24℃,有效积温为117.63d.℃;幼虫期发育起点温度为4.71℃,有效积温为285.33d.℃。     

谷蠹生态学特性的研究

本文对蛀食性储藏物害虫－谷囊（Ｒｈｉｚｏｐｅｒｔｈａｄｏｍｉｎｃｉｃａ（Ｆｂｒｉｃｉｕｓ）的生态学特性进行了试验研究，结果表明：（１）温度对谷蠹发育历期影响非常显著，１８～３６℃范围内，谷蠹能进行正常生长发育和繁殖，其发育起点温度为１７．６℃，有效积温为６９４日度，储粮采用通风低温仓（１５℃）能有效控制谷蠹种群。（２）湿度和粮食水分对谷蠹各发育历期影响非常显著，当小麦水分９％和相对湿度４０％时，谷     

温湿度对嗜卷书虱实验种群生长发育的影响

本文报道了不同温湿度组合条件对嗜卷书虱实验种群生长发育的影响,结果表明：温湿度对嗜卷书虱实验种群的生长发育影响极其显著。各虫态发育历期一般随着温湿度的升高而变短,温度的影响更显著;各期的存活率则随着温湿度的升高而升高,湿度的影响更大。把嗜卷书虱的世代历期与世代存活率与温度（X1）和湿度（X2）作回归得方程为：世代历期＝105．3252－3．9006X1＋0．0392X^21－0．0003X^22(R＝0．9822,P＜0．01）;世代存活率＝－330．1287＋8．7139X1＋6．7602X2－0．2290X^21－0．0497X^22＋0．0585X1X2（R＝0．9792,P＜0．01）。嗜卷书虱卵发育的起点温度为9．93℃,有效积温187．15日度;若虫发育的起点温度13．77℃,有效积温184．52日度;完成一个世代所需的有效积温为371．67日度。     

烟粉虱MED隐种对不同烟草品种的适合度比较

烟粉虱MED隐种是近年来烟草上的重要害虫,为明确不同烟草品种对烟粉虱的抗性水平,应用微虫笼研究了烟粉虱在6个烟草品种上的寿命、产卵量、卵-成虫存活率、发育历期等重要生物学参数,比较了烟粉虱对不同烟草品种的适合度差异。结果表明：除卵孵化率外,烟粉虱MED隐种在供试烟草品种上的寿命、产卵量、卵-成虫存活率、发育历期均存在显著差异。雌成虫寿命和产卵量均以在翠碧1号上最高（35.9 d,236.5粒）,在NC89上最低（9.6 d,27.8粒）;雄成虫寿命在K326上最长（7.2 d）,在云烟87上最短（1.8 d）;卵-成虫存活率在红花大金元上最高（91.6%）,在云烟87上最低（81.4%）;发育历期在红花大金元上最短（19.5 d）,在云烟99上最长（21.1 d）。烟粉虱MED隐种对不同烟草品种的适合度高低顺序为翠碧1号、K326 > 红花大金元 > 云烟99、云烟87 > NC89。     

不同贮存条件对鸡蛋呼吸强度的影响

贮存期鸡蛋呼吸强度随外界贮存条件的变化而变化,为了更进一步明确贮存条件对鸡蛋呼吸强度的影响,选取同一品种的鸡蛋作为实验样本,将其分为3组,分别置于湿度为65%RH和温度分别为4、25、35 ℃,温度为22 ℃和湿度分别为30%RH、60%RH、90%RH,温度为25 ℃、湿度为65%RH和CO_2浓度分别为1.5%、3.0%和4.5%的条件下贮存20 d,利用呼吸测定仪进行鸡蛋的呼吸强度测定,研究不同贮存条件下呼吸强度的变化情况。结果表明:在不同温度条件下,鸡蛋呼吸强度与贮存时间呈负相关关系,且受温度影响显著,随着温度的降低,呼吸强度变化幅度变小,当鸡蛋于4 ℃冷藏时,其呼吸强度趋于稳定,且数值较小。CO_2浓度对鸡蛋呼吸强度变化影响显著,增加CO_2浓度对鸡蛋呼吸强度具有抑制作用,当CO_2浓度高于3.0%时,其抑制效果不再明显增强。此外,鸡蛋的呼吸强度受湿度变化影响较小。     

Isolation,Composition, Structure,Properties, Modifications,and Uses of Yam Starch

Starch is the major carbohydrate in yam tubers and can amount up to 80% of the dry matter. The starch quality determines the quality of food and industrial products made from yam tubers. This review summarizes the present knowledge of the isolation, composition, structure, property, modifications, and uses of starches from diverse yam species. Compared with other tuber and root starches, there is a lack of systematic information on the yam starches. This hinders the further development of yams as sustainable crops as well as the value‐added processing of the starches. Therefore, suggestions on how to better understand and utilize these starches are provided.     

Mineral contents of some southern Italian wines. II. Determination of Li, Na, Mg, K, Ca, Co, As, Rb, Sr, Ag, Sb, Ba

Following our study of the mineral contents of some Southern Italian wines, this work reports on the detection of 12 elemental components. The elements were determined using ICP-AES, flame atomic emission or absorption spectroscopy. The values determined for Li, Na, Mg, K, Ca, Rb, Sr and Ba were within the usual ranges for wines (average values for these elements were: 0.010, 26.2; 94.4; 888; 94.0; 3.30, 0.82 and 0.11 mg/l respectively). All the wines contained low levels of As, the concentrations of which were always under 0.20 mg/l, the maximum level permitted by E.E.C. standards. The measuring of Co, Ag, and Sb led us to ascertain, in all the wines, concentrations lower than 0.01 mg/l for Co and Ag and below the instrumental detection level for Sb (0.06 mg/l). In a previous study wines from D.O.C. areas of Southern Italy were analysed by the technique of inductively coupled plasma atomic emission spectroscopy (ICP-AES), for 14 minerals. This paper deals with further investigation of the mineral composition of the same wines for different metal constituents, analysed by ICP-AES, flame atomic emission, or atomic-absorption spectroscopy (two techniques). The first technique was applied to the detection of Co, As, Sr, Ag, Sb, and Ba. The alkaline metals Li, Na, K, and Rb were determined by flame atomic emission, a technique which possesses better detection limits for these elements. For Mg and Ca the atomic absorption methods were applied.     

Survey of trace elements (Al,As, Cd,Cr, Co,Hg, Mn,Ni, Pb,Se, and Si) in retail samples of flavoured and bottled waters

Concentrations of eleven trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) were measured in 39 (natural and flavoured) water samples. Determinations were performed using graphite furnace electrothermetry for almost all elements (Al, As, Cd, Cr, Co, Mn, Ni, Pb, and Si). For Se determination hydride generation was used, and cold vapour generation for Hg. These techniques were coupled to atomic absorption spectrophotometry. The trace element content of still or sparkling natural waters changed from brand to brand. Significant differences between natural still and natural sparkling waters (p < 0.001) were only apparent for Mn. The Mann–Whitney U-test was used to search for significant differences between flavoured and natural waters. The concentration of each element was compared with the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. It was shown that flavoured waters generally increase the trace element content. The addition of preservatives and acidifying regulators had a significant influence on Mn, Co, As and Si contents (p < 0.05). Fruit juice can also be correlated to the increase of Co and As. Sweeteners did not provide any significant difference in Mn, Co, Se and Si content.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Varied Composition of Tocochromanols in Different Types of Bran: Rye,Wheat, Oat,Spelt, Buckwheat,Corn, and Rice

The profiles of tocopherol (T) and tocotrienol (T3) homologues in 37 samples of seven different types of bran (rye, wheat, oat, spelt, buckwheat, rice, and corn), available on the Polish market, were studied. Tocochromanols were identified and quantified by reverse phase-high-performance liquid chromatograph/fluorescence detector and reverse phase-ultra performance liquid chromatography-electrospray ionization/mass spectrometry. Only rice bran contained all eight tocochromanol types. Corn bran lacked β-T3; rye, wheat, oat, and spelt bran lacked γ-T3 and δ-T3; and buckwheat bran lacked β-T3, γ-T3, and δ-T3. In buckwheat and corn bran tocopherols predominated (98 and 78%, respectively); whereas rye, wheat, oat, spelt, and rice bran were rich in tocotrienols (78, 76, 66, 87, and 66%, respectively). The average total tocochromanol contents in the oat, corn, spelt, buckwheat, wheat, rye, and rice bran were 5.5, 16.2, 15.8, 14.7, 12.8, 10.7, and 9.1 mg/100 g of dry weight, respectively. Tocochromanol concentrations in samples of the same type bran from different sources varied considerably. Better labeling of bran products to reflect this variation would assist with control of vitamin E daily dietary requirements.     

Optimization of extraction conditions of total phenolics, antioxidant activities, and anthocyanin of oregano, thyme, terebinth, and pomegranate

The purpose of this study was to evaluate the total phenolic extracts and antioxidant activity and anthocyanins of varieties of the investigated plants. These plants include oregano, thyme, terebinth, and pomegranate. The optimum extraction conditions including temperature and solvent of the extraction process itself were investigated. Total phenolic and anthocyanin extracts were examined according to Folin-Ciocalteu assay and Rabino and Mancinelli method, respectively. The effect of different extracting solvents and temperatures on extracts of phenolic compounds and anthocyanins were studied. Plant samples were evaluated for their antioxidant chemical activity by 2, 2-diphenyl-1-picrylhydrazl assay, to determine their potential as a source of natural antioxidant. Results showed that all tested plants exhibited appreciable amounts of phenolic compounds. The methanolic extract (60 °C) of sour pomegranate peel contained the highest phenolic extract (4952.4 mg/100 g of dry weight). Terebinth green seed had the lowest phenolic extract (599.4 mg/100 g of dry weight). Anthocyanins ranged between 3.5 (terebinth red seed) and 0.2 mg/100 g of dry material (thyme). Significant effect of different extracting solvents and temperatures on total phenolics and anthocyanin extracts were found. The methanol and 60 °C of extraction conditions found to be the best for extracting phenolic compounds. The distilled water and 60 °C extraction conditions found to be the best for extracting anthocyanin.     

Analysis of cheese for histamine, tyramine, tryptamine, histidine, tyrosine, and tryptophane

A method is described for determining the content of selected biologically active amines (histamine, tyramine, tryptamine) and amino acids (histidine, tyrosine, tryptophane) in cheeses by high performance liquid chromatography. The amines and amino acids were quantified by employing a counter ion-containing mobile phase and by comparing peak areas of high performance liquid chromatography charts for sample cheeses versus standard cheeses containing known amounts of added amines based on dual injections of samples and standards. Recovery of amines and amino acids varied from 87.5 to 111%. Histamine, which has been associated with food poisoning in concentrations of 185 mg/100 g in Swiss cheese and 180 to 500 mg/100 g in fish, was found in concentrations above 500 mg/100 g in Swiss cheese. The high performance liquid chromatography analytical method should be useful for screening to detect cheese samples containing toxic amounts of histamine and for research studies designed to determine the cause and effect relationships for histamine production in cheese.     

Physicochemical,morphological, thermal,pasting, and textural properties of starch acetates

Acetylated starches are a commercially important group of modified starch known for their reduced retrogradation tendency, high clarity, low viscosity, high swelling power, and lower gelatinization temperature and time. Due to these remarkable properties, acetylation is a commonly used chemical modification for preparing stabilized starches. This review summarizes the methods used for preparation of starch acetates and corresponding effects of acetylation on morphological, thermal, pasting, digestibility, textural, and other functional characteristics of starches isolated from various botanical sources. Starch acetates are also useful as packaging material, as wall material for encapsulating active ingredients, and to improve the storage stability of different products.     

鲁浙粤豫苏冀六省造纸工业近年发展特点之比较

对我国6省造纸工业具有不同地方特色的四种发展模式及前景进行了分析和预测。     

Risk assessment of antimony,barium, beryllium,boron, bromine,lithium, nickel,strontium, thallium and uranium concentrations in the New Zealand diet

ABSTRACT

Identifying and monitoring dietary toxicants is an important component of contemporary food safety systems. To characterise their potential dietary risks, analysis was undertaken of 10 elements: antimony, barium, beryllium, boron, bromine, lithium, nickel, strontium, thallium and uranium in 132 different food types. All 10 elements were reported as quantified in aportion of the analysed foods, with prevalence ranging from less than 1% for antimony to 98% for barium. Dietary exposure assessment was undertaken for 10 New Zealand population cohorts using apublished simulated diet, and proportionality of food groups to total exposure identified. Characterisation against health-based guidance values identified no dietary risk from exposures to beryllium, boron, bromine, lithium, strontium and uranium to any of the population cohorts. For antimony and thallium, the exposure range for infants was calculated to exceed the health-based guidance value, and for barium and nickel, all mean exposures were above the health-based guidance value for younger population cohorts. Although some conservatism in applying upper-bound mean exposures reduces the likelihood of asignificant dietary risk, further laboratory method development and analysis of these elements in the New Zealand diet would be beneficial to ensure protection of New Zealand public health.