凉果中二氧化硫的快速高效检测方法探究

本文利用凯氏定氮仪对凉果及其制品进行蒸馏处理,并利用电位滴定仪中的电位突跃替代淀粉指示剂对滴定终点进行判定,建立了自动电位滴定仪滴定二氧化硫含量的快速高效检测方法。     

KDN型定氮仪测定粮食中粗蛋白质含量的相关问题探讨

目前测定蛋白质的方法和仪器很多,为了提高蛋白质含量检测结果的准确性和检测效率,依据GB/T 5511-2008《谷物和豆类氮含量测定和粗蛋白质含量计算凯氏法》要求,常用定氮仪来测定粮食中粗蛋白质含量。对此方法中化学试剂硫酸的选择及实际操作进行了探讨。     

粗脂肪自动测定仪与残余法快速测定菜籽含油量

比较索氏抽提法、残余法、粗脂肪自动测定仪法、近红外法与粗脂肪自动测定仪残余法5种测定方法,检测油菜籽含油量的准确性与效率。研究不同条件下,粗脂肪自动测定仪残余法测定油菜籽含油的最佳条件,以达到简化操作、节省时间提高效率的目的。对2014年全国208份油菜籽样品测定,粗脂肪自动测定仪残余法检测油菜籽含油量结果与标准方法测定结果一致。粗脂肪测定仪残余法仪器条件为:加热功率90%、每个抽提管放入5个样品包、抽提时间5 h、淋洗时间0.5 h、溶剂回收15 min。完成一批样品处理,能达到单个样品提取时间11.5 min与国标法相比,为索氏抽提法时间的18.2%,残余法的54.5%,能极大地提高工作效率,自动化程度高,具有较大的适用性。     

200袖珍式谷物水分测定仪

美国马里兰州Ｔｒｅｂｅｒ工业公司研制出一种袖珍谷物水分快速测定仪 ,其精确度为±０．５% ,达合于测定大豆、玉米和其它谷物。因在测定过程中采用了绝缘措施 ,故能保证其测值的精确性。所测含水量范围为 :大豆１０%～３０ % ,玉米为１０%～２４%。测出的数字在数字显示器上即可读出。这种谷物水分测定仪操作简单 ,只要将测试样装入仪器上部的样品室 ,并按一下按钮即可。该仪器由４节“ＡＡ”型电池供电 ,仅需定期更换电池 ,不需要任何其它的维护和保养。译自 :美国《ＦｏｏｄＥｎｇｉｎｅｅｒｉｎｇ》200袖珍式谷物水分测定仪…     

YN型土壤肥料养分测定仪(简介)

农业部全国农技推广中心“统测统配流动测试服务”特指定、中国农业生产资料集团公司推广使用产品ＹＮ型集成式土壤肥料养分测定仪 ,可快速测定土壤、肥料、植株中的氮、磷、钾及有机质等养分含量。该仪器测试成本低、精度高、操作简便、稳定可靠 ,已在全国各省市建有服务网站。研制开发单位 :河南农大机电技术开发中心联系方式 :0 3 71- 3 84562　 43 852 497　Ｅｍａｉｌ:ｈｎｊｄｚｘ @ｐｕｂｌｉｃ2 .ｚｚ .ｈａ .ｃｎ详细情况请访问本中心网址 :ｈｔｔｐ ://ｗｗｗ .ｈｎｂｘ .ｃｏｍ .ｃｎ/ｈｎｊｄｚｘ .YN型土壤肥料养分测定仪(简…     

凯氏定氮法测定粮食蛋白质含量方法研究

对凯氏定氮法测定粮食蛋白质含量的3个国家标准检验方法进行了对比,研究了蛋白质测定的消化、蒸馏、结果计算等主要操作步骤对测定结果的影响,并对蛋白质含量的国家标准检验方法及质量控制回收率测定提出了建议,对保证蛋白质检测结果的真实可靠具有重要意义.     

LDS谷物水分测定仪测玉米水分的影响因素分析

玉米水分的快速测定是玉米出入库过程中非常重要的一个环节,本文试验不同因素对LDS-1F谷物水分测定仪检测玉米水分的影响,并分析可能的原因。试验结果表明:样品质量、容重对LDS谷物水分测定仪测玉米水分有影响,一定范围内高、中、低水分段及样品温度对LDS谷物水分测定仪测玉米水分影响不大。样品质量在148g-152g范围内时,快测法与定温定时法误差≤0.3%。一定范围内,容重越大,快测法与定温定时法偏差越大。     

食品中脱氢乙酸的测定

目的:用液相色谱法对不同食品中脱氢乙酸的测定进行验证。方法:经50 g·L-1氢氧化钠溶液调样品pH提取脱氢乙酸,经离心、过柱净化、洗脱、过膜,用紫外检测器测定样品中的脱氢乙酸。结果:标准曲线有良好的线性关系(R2=1),最低检出浓度为0.44μg·mL-1,测定样品的相对标准偏差为2.65%~8.36%,加标回收率为79.2%~111.2%。结论:该方法操作简单,检测灵敏度高,干扰少,结果准确。     

水发食品中甲醛测定的方法比较

目的:对高效液相色谱法(High Performance Liquid Chromatography,HPLC)和紫外可见分光光度法(Ultraviolet Visible,UV)测定水发食品腐竹中的甲醛进行比较,寻找一种较准确、简单的测定水发产品中甲醛的方法.结论:两种测定方法测定结果无明显差别,液相色谱法和紫外法均可作为水发食品腐竹中甲醛含量的测定方法,但液相色谱法比紫外法准确度和回收率高、精密度好,更适合作为水发产品腐竹的甲醛含量测定方法.     

电感耦合等离子体质谱法测定食品中硒方法的优化

目的:通过改变电感耦合等离子体质谱仪(ICP-MS)的测定模式和前处理方法,优化电感耦合等离子体质谱仪(ICP-MS)测试食品中硒的方法。方法:样品经过微波消解仪消解后添加4%异丙醇后再定容,电感耦合等离子体质谱仪(ICP-MS)设定为高能氦气模式(HE He)测试样品中硒的含量。结果:优化后的方法在检测硒的过程中,仪器灵敏度从12.69增加到842.6,灵敏度提高了66倍。标准样品中硒多平行检测结果的相对偏差从3.5%降低到0.9%。结论:电感耦合等离子体质谱仪(ICP-MS)在高能氦气模式(HE He)下,样品消解后加入4%的异丙醇上机测试的方法有效、灵敏、精确。     

2018-2020年榆阳区食品中铝元素残留量调查

目的:了解榆阳区食品中铝含量超标的状况,为加强食品化学污染物的监督和控制管理提供科学依据。方法:分析汇总2018—2020年榆林市榆阳区食品安全监督抽检结果,对铝残留量不合格项目等信息进行分析。按GB 5009.182—2017的方法检测,按GB 2762—2017、GB 2760—2014和《国家卫生计生委关于批准β-半乳糖苷酶为食品添加剂新品种等的公告》(2015年第1号)进行评价。结果:从3年总体抽检情况来看,铝残留量不合格问题主要集中在淀粉及淀粉制品(粉丝、粉条类、凉粉)、油炸面制品、其他粮食加工品(包子、馒头类)以及糕点。从不合格项目来看,主要是含铝食品添加剂的“两超”(超范围、超限量)。结论:榆阳区粉类制中的铝残留量较高,主要与传统工艺中使用含铝食品添加剂有关,当地监管部门需重视,加强高风险食品靶向性抽检。     

The effects of food sales taxes on household food spending: An application of a censored cluster model

This study proposes a model of household food spending that accounts for zero censoring and can be applied to data collected through a clustered survey design to investigate the impact of food sales taxes on three groups: households who are eligible for and participate in the Supplemental Nutrition Assistance Program (SNAP), households who are eligible but do not participate in the program, and households who are not eligible for the program. We find that SNAP participating households are largely insensitive to grocery taxes and respond to restaurant taxes by shifting more of their food dollars towards at-home foods. Among households who are eligible for SNAP but do not participate in the program, grocery taxes reduce spending on foods purchased for at-home consumption, and thereby increase the amount of the total food budget allocated to away from home foods. This is concerning from a nutrition and health standpoint since away from home foods tend to be more calorie dense and nutritionally poorer than at home foods.     

Consumption Trends of Edible Mushrooms in Developing Countries

Abstract

Mushrooms are an important commodity worldwide. However, a thorough understanding of consumption trends is not yet available. In developing countries, the importance of edible mushrooms within consumer preferences and perceptions has not been studied. We carried out a study (2000-2003) to understand the patterns of mushroom consumption in central Mexico, where most wild/cultivated mushrooms are produced and/or marketed. About one-half (49.4%) of urban consumers bought mushrooms, independently of their social level [fresh or canned: white button mushroom (Agaricus), oyster mushroom (Pleurotus), shiitake (Lentinula). Preferences and perceptions from Mexican consumers depended on the social level. Mushroom prices were considered very or moderately expensive. Mushrooms were markedly more expensive than foods widely consumed. The variation of mushroom prices was a major factor influencing consumption. Basic data to carry out further marketing research are discussed, as well as an integral strategy considering social levels and regions to increase mushroom consumption.     

Dietary Globalization in Chinese Breakfasts

Demand for nontraditional foods is on the rise in China. Data from household surveys and consumer food diaries in Beijing, Nanjing, and Chengdu are examined to measure the effects of demographics on consumption of nontraditional food products. We focus on bakery and dairy products, two categories of foods that are rarely consumed in traditional Chinese breakfasts. We find that income, time constraints, and education positively affect the inclusion of nontraditional foods in the breakfast meal. Our results suggest that younger consumers are leading the transition to new global consumption patterns that integrate nontraditional foods into urban Chinese breakfasts. The implications of these findings for wheat and milk production and processing industries are discussed.     

动物源性食品中抗生素残留的快速检测方法研究

畜牧业养殖中存在滥用抗生素的情况,导致动物源性食品内的抗生素残留严重超标,对人体健康产生威胁.分析抗生素残留种类,科学采用前处理技术,开发出关于动物源性食品抗生素残留检测的有效方法,有助于保障食品质量安全.本文对抗生素残留的危害进行详细分析,介绍了动物源性食品中抗生素残留的种类及检测方法,为相关研究提供参考.     

Food Consumption Trends in the Pacific Rim

The growing affluence of the Pacific Rim countries has changed food consumption patterns. Diets in the region have become more diverse and well-balanced nutritionally. Western-style foods are becoming increasingly popular and available to people in the region. The rapid growth of fast-food chains and supermarkets present U.S. agricultural exporters with a myriad of opportunities for exporting food products to the Pacific Rim. Food producers who are willing to modify their products to the tastes of Pacific Rim consumers will have the most success. By reformulating food products and developing new packaging technologies more high-value foods can be sold in the Pacific Rim. U.S. food processors must also develop improved methods of processing traditional foods eaten by people in the region into more convenient forms. Finally, it is important for U.S. agricultural exporters to keep a close watch on the changing trends in food consumption in the region in order to stay competitive and increase their opportunities for entering new markets.     

Food Consumption Patterns and Nutrition in Urban Java Households: The Discriminatory Power of some Socioeconomic Variables

Food consumption patterns are undergoing substantial change in many countries as economic development proceeds. The trend is a move away from traditional cereals towards higher-value and higher-protein foods. Explaining such changes only in terms of traditional economic variables can lead to biased estimates of income effects and perhaps biased projections of food demand. Household survey data from Indonesia are used to measure the importance of several socioeconomic variables in explaining differences in household food consumption patterns and nutrition. Household expenditure and the level of women's education are shown to be the most influential in this explanation.     

超高效液相色谱-串联质谱法在食品安全检测中的应用

目的:探究超高效相色谱-串联质谱法在动物源性食品检测中的应用。方法:样品采用乙酸乙酯提取、氮气吹干,经ACQUITYUPLC BEH C18柱超高效液相色谱分离后电喷雾串联质谱法检测,采用负离子方式多反应模式监测,内标法定量。结果:目标化合物在1.0~100 ng·m L^-1呈现良好的线性关系,相关系数r≥0.9929;氯霉素类药物检出值为0.3μg·kg^-1,低于标准方法检测低限、检测限;精密度测定,相对标准偏差为0.4%~2.3%,说明方法精密度良好。结论:超高效相色谱-串联质谱法简单、快捷、灵敏度高,满足食品及保健食品市场监管及检验需求。     

食用菌种植户的生存策略研究——以山东省为例

作为农业循环经济的代表性产业,中国食用菌产业近年来发展迅速,产业结构出现了新变化,工厂化大规模集中生产方式发展较快。但近三年的产量数据表明,我国食用菌产业的生产主体仍是以家庭为生产单位的种植户。通过实地调研与对比观察法,文章分析了山东省食用菌种植户的相对优势、自身缺陷及生存战略,并提出了对策建议。文章首先指出,食用菌种植户的竞争优势在于低生产成本与高生产灵活性。继而分析了影响种植户生存能力的负面因素,即:议价能力低、技术与操作水平低、外部交易成本高、销售渠道有限、抵御市场风险能力差。并指出为了提高生存能力,种植户采取了差异竞争、合作化及多元经营的生存策略。最后,从进一步降低成本与优化合作模式的角度提出了加强种植户生存能力的对策建议:指出循环利用工厂化企业废弃菌棒与杂菌污染菌棒可以有效降低生产成本;并提出在合作社发展基础薄弱的地区率先发展"农户+议价合作社+公司"的合作模式,在基础较好的地区大力推行"农户+合作社+超市"的合作模式。