散料抽样调查方法在粮食卫生抽检中的应用

探讨了散料抽样方法在粮食卫生抽检中的应用,并举例比较了散料调查方法与传统抽样方法,包括两种抽样方法的实施成本、风险和检验结果置信度,分析了散料抽检方法的优势,并对该方法的拓展应用作了展望和思考。     

新型散料输送技术

<正> 随着食品加工商对单一供应商能提供生产整线设备的日益需求,为满足市场需要,设备供应商便开发出各种新技术。Key Technology公司新近推出了振动输送带系列,为解决各种散料输送的难题提供了有效的方案,保证产品质量恒定。 这种系列的振动输送带应用广泛,适合不同的食品加工使用。其特点是运作流畅、温和、产率高,避免产品与活动机件接触,同时具有良好的卫生消毒效果,维修保养少,有助于提高食品产品的质量和产量。此     

计数抽样检验在桶装饮用水生产企业桶的验收中的应用探讨

本文以GB/T 2828.1—2003为依据,系统地介绍了桶装水原料桶质量验收中的计数抽样方案的理论方法,详细地介绍了抽样方案检索实施步骤,并结合实例进行了说明,可供桶装水生产企业在实践中使用。     

超高压技术在低过敏大米中的应用

对大米过敏原进行了简介,阐述了超高压消除大米过敏原的机理,最后论述了超高压消除大米过敏原的影响因素和处理条件.     

酶在大米深加工中的应用

酶是具有生物催化功能的生物大分子,在大米深加工领域得到了广泛的应用。介绍了酶在大米蛋白提取,大米淀粉提纯,大米蛋白发泡粉、大米肽和大米多孔淀粉的制备以及大米发酵制备酒精等方面的应用情况。     

蛋白酶在大米深加工中应用

蛋白酶是食品工业最重要一类酶,在大米深加工领域得到广泛应用;该文介绍蛋白酶在大米蛋白提取、大米肽和大米蛋白发泡粉制备、大米淀粉提纯及大米发酵制备酒精等方面应用情况。     

大米蛋白在面包中的应用研究

研究醒发时间、大米蛋白添加量及不同蛋白含量大米蛋白的添加对面包品质的影响。结果表明,添加58．4％的大米蛋白量为2％,发酵时间2h,对面包的品质无不良影响。     

大米胚芽钦料的研究

大米胚芽是一种没有被很好利用的食品原料.本文通过研究得到了大米胚芽饮料的最佳制作工艺,并且对其稳定性进行了研究.     

散料连续累加秤

由哈尔滨杰曼机电设备有限公司生产的GM301—10-Q1型散料连续累加秤适用于粮食仓储、粮食加工、饲料加工、港口码头等原料的计量。每个型号均有固定式和移动式两种结构。     

腈纶散纤湿料装缸染色法

腈纶散纤在干料装染色加工过程中易结块,易产生色花,针对这一问题,中提出了湿料装缸染色法,通过小样实验和小大生产实践,有效地解决了以上问题。     

Short communication: influence of sampling interval on the accuracy of predicting bulk milk somatic cell count

Although bulk milk somatic cell count (BMSCC) is, in most instances, not a good proxy for actual average herd somatic cell count (SCC), BMSCC is the only SCC parameter available to monitor trends in udder health for a large number of farms worldwide. The frequency of sampling BMSCC varies considerably between countries, and it is unknown to what extent the sampling interval of BMSCC or variation in BMSCC data itself influences the accuracy. The aim of this study was to assess the effect of sampling interval and variation of the BMSCC data on the accuracy to predict BMSCC. Because BMSCC is measured at regular time intervals, an artificial neural network (ANN) was used to determine both the effect of sampling interval and variation of the BMSCC data. The intervals examined in this study ranged from 4 to 14 d and were compared with the baseline of a standard 2-d sampling interval. The BMSCC data were collected every other day for a 24-mo period on 949 farms, and all series were created by exclusion of BMSCC data in between the original 2-d sampling interval series. The effect of variation of BMSCC was determined by comparing the error of the ANN model in 2 subsets of farms, those with the lowest SD (n = 239) and those with a high SD of BMSCC data (n = 236). No significant differences were found in any of the sampling intervals between the 2 cohorts of low and high SD in BMSCC. Overall, compared with the 2-d sampling interval, on average the error of the ANN model was 32,600 cells/mL for all farms included, ranging from 15,000 cells/mL (4-d interval) to 41,000 cells/mL (14-d sampling interval). Therefore, the length of the sampling interval greatly influences the usefulness of BMSCC data to monitor trends in udder health at the herd level.     

A review of international standards and the scientific literature on farm milk bulk-tank sampling protocols

Adequate agitation is required to ensure homogeneity before sampling from on-farm bulk tanks, but excessive agitation may cause churning with a resulting loss of milk quality. Homogeneity can be assured by thorough mixing before a sample is taken and can also be combined with intermittent agitation of the bulk tank. There is general but qualified agreement among various countries and agencies, such as the IDF, that 5 min of agitation for small, and 10 min for large, quiescent farm-milk bulk tanks is required to ensure sample homogeneity. However, no empirical studies are cited to support these standards. The few studies that examined bulk-tank mixing estimate required agitation times of 8 to 10 min or longer, depending on the size of the tank. If intermittent agitation is practiced, mixing for 1 to 2 min before sampling is considered acceptable in some jurisdictions but, once again, empirical supporting evidence is absent. Automatic samplers decrease the amount of time needed to obtain a sample from the bulk tank, but both intermittent agitation and agitation during milk transfer are still recommended to minimize fat residue accumulation in the bulk tank. Systematic studies are needed to establish mixing protocols that assure accurate sampling for all tanks in a given jurisdiction.     

Towards an optimum mixing protocol for on-farm bulk milk sampling

This paper describes the application of a bottom-sampling technique to dynamically monitor creaming and mixing in bulk milk tanks and determine optimum mixing protocols for milk sampling. Creaming onset in field experiments occurred between 40 and 50 min. Bottom-sampling data determined after 3 h of creaming indicate that the mean mixing time required to ensure a homogenous sample for composition testing is 57 s, and there is a less than 1% probability that an individual tank would require more than 2 min of agitation. Bottom and top-sampling statistics determined after 1 h of creaming indicate mean mixing times of 20 and 34 s, respectively, and predict that individual tank mixing times will exceed 46 and 64 s, respectively, less than 1% of the time. Bacterial cell counts were directly correlated with fat content, but somatic cell counts were independent of fat content. Based on these results, it is recommended that hourly agitation of bulk tanks as currently prescribed in many jurisdictions should be maintained, but the duration of intermittent agitation should be reduced from 5 to 2 min to reduce the impact of agitation on fat globule stability. If hourly agitation is effected during milk storage, agitation time before sampling can be reduced from 5 to 2 min. This will save time for drivers and trucks and reduce the potential impact of agitation on fat globule stability.     

Contagious agalactia monitoring in caprine herds through regular bulk tank milk sampling

Surveillance and control of Mycoplasma spp. responsible for contagious agalactia (CA) in caprine herds are important challenges in countries with a large small-ruminant dairy industry. In the absence of any clinical signs, being able to determine the potential circulation of mycoplasmas within a herd could help to prevent biosecurity issues during animal exchanges between farms and improve health management practices. The objective of this study was to determine whether regular sampling of bulk tank milk was suitable for such surveillance. Twenty farms were sampled once a month for 2 yr and CA-responsible mycoplasmas were detected by real-time PCR on DNA extracted from milk, using 3 different DNA extraction methods. The pattern of mycoplasma excretion in bulk tank milk was assessed over time and several herd characteristics were recorded together with any event occurring within the herds. In general, the results obtained with the different detection methods were comparable and mainly agreed with the culture results. Several patterns of excretion were observed but were not related to herd characteristics (size, breed, and so on). Recurrence of the same (sub)species and same pulsed-field gel electrophoresis subtype during the 2-yr period is indicative of the considerable persistence of mycoplasmas. This persistence was associated with intermittent excretion. In conclusion, bulk tank milk sampling could be valuable for controlling CA in caprine herds provided it is repeated several times, yet to be defined, per year and analyzed using an appropriate methodology and the right cut-off for interpretation.     

稀酸温和提取直接进样快速测定大米中镉含量的研究

建立了常温条件下利用稀酸温和提取直接进样石墨炉原子吸收光谱法快速测定大米中镉的方法。考察了粉碎粒径、硝酸浓度、提取时间、固液比例等因素的影响,优化了灰化温度和原子化温度等仪器条件,确定了大米中镉元素测定的最佳条件。结果表明,常温条件下采用稀硝酸提取大米中的镉元素,浸提率在98.5%~100%之间,加标回收率达到93.0%~100%之间,精密度小于5%,方法的检出限和定量限分别为0.016μg/L和0.048μg/L,样品处理时间可缩短至20 min内,与经典的微波消解原子吸收光谱法和微波消解ICP-MS法比较,各类大米中镉元素的测定值无显著性差异(P>0.05)。     

农产品中转基因检测抽样研究-第1部分: 转基因农产品抽样标准国际现状及理论研究

针对目前没有国际范围内可接受的转基因产品(genetically modified organism,GMO)抽样标准的现状,分析世界各国家和国际组织的GMO相关抽样标准,并对国际标准关于GMO抽样的适用性进行分析;同时对适用于农产品中GMO抽样的理论进行了总结,依次对GMO检测中涉及的4个过程,包括分析试料、从分析样品中采取试料的过程、从实验室样品到分析样品以及从批到实验室样品的过程,对各步骤所产生的方差进行分析,并对总方差进行合成计算,以期指导本系列文章的其余部分抽样研究实践,并期望能推动相应国际标准的制定。     

滤筒除尘器在散粮卸船机上的应用

散粮卸船机装卸过程中会产生大量粉尘并向周围环境逸散,其中呼吸性粉尘占比也相对较高,严重危害相关作业人员身体健康,影响工作视线,而传统的袋式除尘技术不能有效降低粉尘浓度。因此,提出了用于卸船机散粮装卸作业的滤筒除尘技术,并研发了相关装置,在埋刮板卸船机上进行了现场应用及相关测试。测试结果表明:在水平刮板输送机末端转载产尘点处以及离心式风机出口1 m处,总粉尘平均浓度由89.5 mg/m^3降低到4.2 mg/m^3,呼吸性粉尘平均浓度从8.9 mg/m^3降至0.6 mg/m^3,除尘效率分别为95.19%和93.26%,粉尘排放浓度符合国家相关职业卫生标准,周围环境明显改善。滤筒除尘器有效提高了对卸船机散粮装卸过程中粉尘的除尘效率,具有广阔的应用前景。