微波技术在食品和农产品加工中应用研究进展

微波加热技术具有速度快、可控性高等特点,在食品和农产品的热加工过程中具有较强的应用潜力。该文在分析微波加热原理的基础上,从技术应用、设备研制和仿真研究等方面介绍微波加热应用现状,如在农产品干燥、杀菌、萃取和膨化等方面进行深入研究和应用。指出微波加热在机理解析、工艺局限性、加热不均匀性和能量利用低等问题,尤其是微波场对物料内极性成分作用机制的研究深度、微波加热时在物料内温度和水分分布的不均匀性规律定量表征等方面,严重影响产品质量稳定性和能量充分利用。从揭示微波在加热腔体内传递和物料内吸收的机理,提高微波加热均匀性和改善加工质量,以及研制智能化工业用微波加工设备等方面,指出微波加热技术在食品和农产品加工中应用热点研究方向。针对微波加热技术在农产品和食品加工中科学问题、技术需求和设备现状,为发挥技术优势、拓展应用领域,该文提出微波加热理论研究与技术应用的发展趋势,以期提高微波热加工技术工业化应用适用性、保证产品质量和能量利用率。

食品委托检验及质量控制措施研究

食品委托检验是指由企业或机构委托具有相应资质的第三方检验机构,对其产品进行全面或特定的检验以确保产品质量和安全的一种方法。本文分析了食品委托检验的发展现状,并探讨了其存在的风险及优化措施,以供参考。

高效液相色谱-串联质谱法测定植物性食品中多种有机锡化合物

样品分别经甲酸乙腈(甲酸1%)和甲酸甲醇(甲酸1%)提取,上清提取液经混合盐析试剂除水分层,上清液与水按2∶3(体积比)混合,过膜后上机检测。以0.2 g·L^(-1)乙酸铵水溶液(含0.1%甲酸)-0.1%甲酸乙腈为流动相,在0.3 mL·min^(-1)流速下梯度洗脱,采用苯基色谱柱进行液相分离,正离子模式检测,外标法定量。结果表明,在草莓、苹果、柑橘、葡萄、黄瓜5种基质中,7种有机锡化合物线性关系良好,相关系数均≥0.995;方法检出限为0.2~4μg·kg^(-1),定量下限为0.5~10μg·kg^(-1);在3个浓度添加水平下,7种有机锡化合物的平均回收率为68.1%~103.1%,相对标准偏差为1.00%~11.36%。该方法准确、灵敏、快捷,适用于植物源性食品中多种有机锡化合物的定量分析。

Determination of Rotenone Residues in Foodstuffs by Solid-Phase Extraction (SPE) and Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS)

We developed a novel approach to determine rotenone residues in foodstuffs, by integrating solid-phase extraction （SPE） and liquid chromatography/tandem mass spectrometry （LC-MS/MS） technologies, to achieve high sensitivity and selectivity. In our method, the solvent extraction with n-hexane-dichloromethane （50：50, v/v） and cleanup with florisil SPE cartridges using ethyl acetate-ethyl ether （25：75, v/v） as eluents provided adequate recovery of rotenone. The detection of rotenone was then carried out by LC-MS/MS using acetonitrile-water with the 0.1% formic acid （w/v） as the mobile phase. The multiple reaction monitoring （MRM） scheme employed in the approach involved the transitions of the precursor ion to three selected product ions, in which one pair for quantification was m/z 395.3 〉 213.2 and the other two pairs for identification were m/z 395.3 〉 192.2 and 395.3 〉 367.0. The limits of quantification （LOQs） of the method ranged from 0.001 to 0.005 mg kg-1 depending on the matrix. Intra- and inter-day precisions （relative standard deviations, RSDs） for rotenone were less than 7.1 and 14.8%, respectively. Results from repetitive analysis suggested good reproducibility of the method for rotenone residue detection. The recoveries at three concentrations （LOQ, 10LOQ and 100LOQ） ranged from 79.3-118.3% in cabbage, potato, onion, carrot, apple, orange, banana, lichee, tea, and Shiitake mushroom. The proposed procedure was then applied to the analysis of 129 real samples collected from Xiamen, Fujian Province, China. The existence of rotenone was found in two tea products with concentrations of 0.012 and 0.016 mg kg-1, respectively. The method has great potential for routine analysis of monitoring rotenone residue in foodstuffs.

Determination of Indoxacarb Residue in Foodstuffs of Plant and Animal Origin by GC-ECD and LC-MS/MS

An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.

Actuality and Influencing Factors of Integrated Production Capacity of Foodstuff in Heilongjiang Province

Heilongjiang Province is an important marketable grain depot in China. Since the reform and opening up, Heilongjiang Province production capacity of foodstuff is increasingly growing into a new level. This paper started with the actuality of Heilongjiang Province integrated production capacity of foodstuff, and analyzed its major factors empirically through the mathematical model, then proposed some measures to enhance Heilongjiang Province production capacity of foodstuff which ensured China foodstuff security

Model of Combined Transport of Perishable Foodstuffs and Safety Inspection Based on Data Mining

There is still no effective means to analyze in depth and utilize domestic mass data about agricultural product quality safety tests in china now. The neural network algorithm, the classification regression tree algorithm, the Bayesian network algorithm were selected according to the principle of selecting combination model and were used to build models respectively and then combined, innovatively establishing a combination model which has relatively high precision, strong robustness and better explanatory to predict the results of perishable food transportation meta-morphism monitoring. The relative optimal prediction model of the perishable food transportation metamorphism monitoring system could be got. The relative perfect prediction model can guide the actual sampling work about food quality and safety by prognosticating the occurrence of unqualified food to select the typical and effective samples for test, thus improving the efficiency and effectiveness of sampling work effectively, so as to avoid deteriorated perishable food’s approaching the market to ensure the quality and safety of perishable food transportation. A solid protective wall was built in the protection of general perishable food consumers’ health.

Contamination of Fungi and Mycotoxins in Foodstuffs in High Risk Area of Esophageal Cancer

Fungal and mycotoxin contamination has been found in fordstuffs from Cixian County, an area with a high incidence of esophageal carcinoma (Eca). To set a scientific foundation for the prevention of Eca at the etiological level, fungal and mycotoxin contaminations of local foodstuffs in Cixian County were analyzed using classical fungal culture methods and HPLC. From 1990 to 1994, 220 corn/wheat samples and 34 corn samples were studied. As a control, 26 corn samples collected from a relatively low incidence area of Eca in Zanhuang County were analyzed for mycotoxins in 1990. The results showed that fungal contamination in corn and wheat was severe and that several of the predominant contaminating fungi such as Furasium moniliforme, etc. were carcinogenic. HPLC results showed that the detection rate and mean content of the mycotoxin sterigmatocystin (ST) in the mountainous area (5/8; 9. 14 μg/kg) were significantly higher than those in the hilly (0; 0) and plain areas (1/18; 1. 29 μg/kg) as well as in low risk area control samples (3/26; 0. 76 μg/kg). Detection rates of deoxynivalenol (DON) in mountainous and hilly areas (5/8, 4/8 respectively) were slightly higher than that in plain area (8/18), while the mean content of DON in the plain area was significantly higher (90. 45-170. 22 vs 50. 56 and 46. 45 μg/kg).Among the different aflatoxins, AFB1 was detected in samples from the two villages in the plain area for the subsequent two years. The mean content of AFB1 was 0. 0183μg/kg, and the highest level was 0. 0497 μg/kg. No AFB1 was detected in the samples from mountainous and hilly areas. AFG1 was detected in more than half of all the samples, and its concentration ranged from 8. 77 to 46. 51 ng/kg. No AFG2 was found in the samples. Thus, the results suggest that at present, fungal and mycotoxin contamination of foodstuffs in Cixian County are quite common.

Level of natural radionuclides in foodstuffs and resultant annual ingestion radiation dose

The natural radioactivities in three major groups of foodstuff widely consumed in Upper Egypt were de- termined. The specific activities of 226Ra, 232Th, and 40K in cereals, leguminosae, and flour were measured using γ-ray spectroscopy. Another group of hay, water, and soil samples from the same location were also analyzed. Hay samples were found to contain the highest radioactivity concentration among all the samples that were investigated. This in- crement could be due to the high water content in the shoots which tends to accumulate soluble radionuclides. The average calculated concentrations of soil samples in the present study exhibits the lowest values with respect to those from different countries. In the case of water samples, the average activities of both 232Th and 40K were similar to those for soil while 226Ra was twice that of water sample. The annual ingestion dose from each radionuclide was cal- culated. The computed annual dose owing to daily intake of radium, thorium, and potassium via wheat flour, lentils, and bean in the present study (214.8 μSv) is ten times lower than the global average annual radiation dose (2400 μSv) from the natural radiation sources as proposed by UNSCEAR. The obtained results show that the dose values are quite low and carry insignificant radiation dose to the public.

Standardizing Foodstuff Processing & Its Improvement in Guangzhou

Based on a survey carried out on all fully certificated foodstuff manufacturers in Guangzhou, an analysis of the status quo of Foodstuff Processing Standardization in Guangzhou is made to identify the major problems and measures to be adopted for improvement.

Zhejiang Provincial Cereals,Oils and Foodstuffs I/E Co.Ltd.

Zhejiang, situated in the Yangtze delta and neighbouring Shanghai, is widely known for fish and rice production. The Zhejiang Provincial Cereals, Oils and Foodstuffs I/E Co. Ltd. formerly Zhejiang provincial Cereals, Oils and Foodstuffs I/E Company, is one of the largest foreign trade shareholding enterprises in Zhejiang Province. It

三重冲击下农业企业如何实现供应链韧性提升?--以温氏为例

面对环境规制、非洲猪瘟疫情与新冠疫情的三重叠加冲击,维护生猪供应链稳定运行、培育生猪供应链韧性是推动生猪产业持续健康发展的重要基础。在引导养殖户衔接农业现代化发展的进程中,温氏立足“公司+农户”模式的存续与创新,实现了三重冲击下生猪供应链韧性的提升。本文基于纵向时序嵌入式单案例研究法,分析温氏生猪供应链的调整过程,揭示温氏生猪供应链韧性策略的形成机制,以及不同冲击发生期韧性策略间的互动过程。研究发现:温氏基于“准备、反应、恢复、适应”四个阶段,构建了生猪供应链韧性策略;强化“公司+农户”模式合作紧密性以提升供应链整合强度,是供应链延伸发展后经济产出提升的基础;多重冲击的叠加能够促进温氏生猪供应链双元性能力的形成,前一冲击发生期“适应阶段”的生猪供应链韧性策略,在延续至下一冲击发生期的同时,也为下一冲击发生期“恢复阶段”韧性策略的实施奠定基础;同时,特定制度因素会促进或阻碍关键资源向生猪供应链韧性的转变,也会促进或阻碍供应链韧性对生猪供给分布与供给总量的作用过程。据此,本文提出缓解生猪供应链韧性重要约束,基于“公司+农户”模式继续推动生猪供应链持续健康发展的政策建议。

Amino acid nutrition and metabolism in domestic cats and dogs

Domestic cats and dogs are carnivores that have evolved differentially in the nutrition and metabolism of amino acids.This article highlights both proteinogenic and nonproteinogenic amino acids.Dogs inadequately synthesize citrulline(the precursor of arginine)from glutamine,glutamate,and proline in the small intestine.Although most breeds of dogs have potential for adequately converting cysteine into taurine in the liver,a small proportion(1.3%-2.5%)of the Newfoundland dogs fed commercially available balanced diets exhibit a deficiency of taurine possibly due to gene mutations.Certain breeds of dogs(e.g.,golden retrievers)are more prone to taurine deficiency possibly due to lower hepatic activities of cysteine dioxygenase and cysteine sulfinate decarboxylase.De novo synthesis of arginine and taurine is very limited in cats.Thus,concentrations of both taurine and arginine in feline milk are the greatest among domestic mammals.Compared with dogs,cats have greater endogenous nitrogen losses and higher dietary requirements for many amino acids(e.g.,arginine,taurine,cysteine,and tyrosine),and are less sensitive to amino acid imbalances and antagonisms.Throughout adulthood,cats and dogs may lose 34%and 21%of their lean body mass,respectively.Adequate intakes of high-quality protein(i.e.,32%and 40%animal protein in diets of aging dogs and cats,respectively;dry matter basis)are recommended to alleviate aging-associated reductions in the mass and function of skeletal muscles and bones.Pet-food grade animal-sourced foodstuffs are excellent sources of both proteinogenic amino acids and taurine for cats and dogs,and can help to optimize their growth,development,and health.

粮油食品质量检测中气相色谱技术的应用

气相色谱技术在食品、环境以及化工等领域都得到了广泛应用,在粮油食品质量检测方面表现尤为突出。在实际应用过程中,相关人员应当结合实际情况,充分发挥气相色谱技术优势,对粮油食品中农药残留、微生物以及有害物质进行检测和分析,保障粮油食品质量安全。本文主要对气相色谱技术在粮油食品质量检测中的应用进行了分析。

某货船伙食冷库的设计

船舶伙食冷库是船舶重要的辅助设备,保证了船上食品的新鲜程度,为船员的生活质量提供了保障。文章根据冷库设计的基本原则、程序步骤与方法,介绍了船舶伙食冷库工作特性和常规的工艺设计方案,以及设计技术参数和冷量的选定等,最后确定了某货船伙食冷库的设计以及设备布置。

闽西革命根据地粮食工作探析

中国共产党人在农村革命根据地建设实践中逐步认识到根据地创建与巩固离不开一个基础条件,即经济上保障革命力量发展和巩固。从社会功能看,农村是农业生产的主要场域,粮食的供给是最基础也是最重要的战略支撑。闽西革命根据地建立在地瘠民穷、农业水平落后的偏僻山区,在严酷斗争的环境下,中国共产党领导下的闽西苏维埃政府立足政治优势、遵循自然和市场规律,在促进粮食生产、流通、保障和贸易方面进行了许多开创性的实践,为提高群众生活,巩固武装革命和苏维埃政权积累了治国安民的宝贵经验。

食品生产加工环节中的质量安全控制研究

随着人们生活水平的提升,食品种类也日趋丰富,食品生产加工规模也不断扩大。但是,近些年食品安全问题屡见不鲜,对人们的身体健康产生了影响,这对食品生产加工环节的质量安全控制提出了新的要求。本文通过分析食品生产加工环节的质量安全控制,认识到食品生产加工中质量安全控制的重要性,深入分析食品生产加工中质量安全控制工作存在的问题,并提出针对性的措施,为食品的安全生产与加工提供借鉴和参考。