食源性致病菌快速检测仪器现场评价分析

目的加快快速检测技术和装备的推广,规范其在食品安全监管中的应用,组织食品安全快速检测技术现场验证评价活动。方法以准确率、假阴性率、假阳性率、时效性被作为检测结果的考量指标,考察14家企业的仪器检测食源性致病菌情况,主要考核的项目为沙门氏菌和金黄色葡萄球菌,每家企业考核样为4个,每个考核样均需检验沙门氏菌和金黄色葡萄球菌。结果各参试企业的表现差距较大,大部分快检仪器灵敏度在103~104 CFU/m L之间。14家企业中,4家企业准确率为100%,有71.42%的企业出现了假阴性。结论恒温实时荧光PCR技术在食源性致病菌快检中发挥比较明显的优势。准确率、假阴性率、假阳性率、时效性这4个参数能科学有效地评价食源性致病菌快检仪器。     

生物发光快速测定生乳菌落总数的方法

为消除利用ATP生物发光法测定生乳菌落总数时非细菌ATP对测定结果的干扰,建立了一种样品前处理方法。利用ATP生物发光法对经过前处理的生乳样品进行检测,结果表明,生乳菌落总数对数值与生乳细菌ATP发光对数值呈现较好的线性关系(R2=0.982),相关程度为显著相关(P<0.01),说明该前处理方法能够有效排除非细菌ATP的干扰,有利于提高ATP生物发光法定量测定生乳菌落总数准确性。     

Screening utility of a rapid non-invasive dry eye assessment algorithm

PurposeTo evaluate the discriminative ability of a rapid non-invasive dry eye assessment algorithm (global evaluation component: SANDE questionnaire, and non-invasive tear film breakup time; subtype classification testing component: tear film lipid layer grade, and tear meniscus height) in detecting dry eye disease, as defined by the TFOS DEWS II diagnostic criteria.MethodsTwo hundred and thirty-five participants (77 male, 158 female), with a mean ± SD age of 43 ± 17 years, were recruited into a prospective diagnostic accuracy study. OSDI, DEQ-5, and SANDE dry eye symptomology scores; non-invasive tear film breakup time; absolute and inter-ocular differences in tear osmolarity; corneal, conjunctival, and lid margin staining scores; tear film lipid layer, meibum expressibility, meibomian gland orifice plugging, and eyelid margin telangiectasia grades; and tear meniscus height were evaluated in a single clinical session.ResultsThe areas under the ROC curves exceeded 0.80 for all individual components of the rapid non-invasive dry eye assessment algorithm, and the discriminative abilities were significantly greater than chance (all p < 0.001). At the Youden optimal diagnostic thresholds for the global evaluation component of the rapid non-invasive assessment algorithm (SANDE score ≥30, non-invasive tear film break-up time <10 s), the overall sensitivity was 86%, specificity 94%, positive likelihood ratio 15.0, and negative likelihood ratio 0.15.ConclusionsThe abridged non-invasive dry eye assessment algorithm may be a useful rapid screening instrument for the full TFOS DEWS II diagnostic test battery, of particular benefit in resource or time-constrained settings.     

Simple tests for rapid assessment of the quality of raw milk.

Simple and inexpensive tests are described for rapid qualitative assessment of the microbiological quality of raw milk. These tests included the monitoring of dissolved oxygen levels and changes in the color of raw milk with time in a slightly modified methylene blue test using 16 ppm of dye concentration. The initial bacterial population in raw milk determined by standard plate count could be estimated with coefficients of determination (r2) of about 0.697 and 0.613 from the respective normalized voltage outputs of the dissolved oxygen probe and light-sensing probes at selected time intervals in less than 1 h. However, a comparison of experimental and estimated initial bacterial populations in raw milk showed correlation coefficients (r) of about 0.754 and 0.616 for the dissolved oxygen probe and light-sensing probe, respectively. These results clearly indicated the potential and need for improving such empirical models for grading raw milk with both types of probes.     

电子鼻技术在肉类品质应用中快速分析初探

电子鼻技术是近年发展起来的一种新型仿生嗅觉检测技术,因其具备快速、无损等优点被广泛应用于食品品质检测领域。电子鼻通常包括两部分:硬件部分——多个性能彼此重叠的气体传感器;软件部分——恰当的模式识别技术对采集信号的分析、处理。本文主要综述了近年来国内外电子鼻技术在肉类品质分析中的应用。首先阐述了电子鼻技术工作原理、数据处理方法,随后重点讨论了电子鼻技术在肉类新鲜度评定、肉与肉制品品质区分、肉类有害成分监测、肉类掺假检测等4个方面的应用进展,最后对电子鼻技术目前存在的问题及未来发展趋势进行了简要探讨。     

Critical assessment of voltammetry for rapid screening of antioxidants in marine algae

Voltammetric methods of analysis represent an attractive option for rapid screening of large numbers of plant samples in the search for novel antioxidants. However, the technique has not found widespread use as compared to established methods such as the DPPH and Folin–Ciocalteu assays. In this study we provide a critical assessment of voltammetric methods compared to the DPPH and Folin–Ciocalteu assay by conducting antioxidant assays using these methods in a study of 99 crude samples of marine algae. Thirty samples showed the presence of antioxidants via the voltammetric assay compared with 20 samples for the DPPH assay and 16 via the FC assay. Through a detailed interpretation of the results the study suggests that voltammetric methods can identify potential antioxidants in crude samples with a higher degree of confidence than DPPH or the FC method alone and represents a viable screening method for marine algal samples.     

A chromametric method for the rapid assessment of deep frying oil quality

A rapid chromametric method was developed for the assessment of deep frying oil quality based on the strong correlation between colour index and total polar compounds in deep frying oil. Colour indices of frying oil samples, measured by chromameter, decreased significantly during frying and were strongly correlated with frying time (r ≥ 0.95, p < 0.001). Colour indices of a set of oil samples taken from 0 to 80 h of deep frying were also significantly correlated with total polar compounds of the same samples determined using the official method of the American Oil Chemists' Society (r = 0.96, p < 0.001). The equation for conversion of the colour index (x) to the content of total polar compounds (y) in an oil sample is y = 0.0174x² ? 2.9506x + 124.34. In addition, colour indices of 10 different types of frying oils were strongly correlated with the corresponding contents of total polar compounds in the oils with samples taken from 0 to 80 h of deep frying in duplicate (r = 0.95, p < 0.001, n = 220). The results of colour index analyses agreed well with the results of chemical and sensory analyses of the frying oils tested. This chromametric method is rapid, convenient and reliable. Copyright © 2003 Society of Chemical Industry     

大豆肽免疫调节作用的研究

目的:研究大豆肽对正常及免疫低下小鼠免疫功能的影响。方法:腹腔注射环磷酰胺以引起小鼠免疫功能低下,观察大豆肽对正常及免疫功能低下小鼠胸腺指数、脾脏指数、脾淋巴细胞对ConA的刺激指数(SI)、抗体生成细胞含量(PFC)和血清溶血素(HC50)等指标的影响。结果:大豆肽不仅能增强正常小鼠免疫功能,而且能显著提高环磷酰胺致免疫功能低下小鼠的胸腺指数、脾脏指数、脾淋巴细胞对ConA的刺激指数、抗体生成细胞含量和血清溶血素的含量。结论:大豆肽对机体的免疫功能有一定的增强作用。     

食用油中黄曲霉毒素B1快速检测试剂盒的质量评价

依据食药监办科\[2017\]43号《食品快速检测方法评价技术规范》和KJ 201708《食用油中黄曲霉毒素B1的快速检测 胶体金免疫层析法》制定评价方案,对目前福建省内应用较广的4种食用油中黄曲霉毒素B1快速检测胶体金试剂盒产品进行质量评价。结果表明： 4个品牌产品中,只有2个品牌产品符合要求,不同品牌产品的黄曲霉毒素B1检测效果存在差异。为确保食用油中黄曲霉毒素B1的快检监管效果,结合试剂盒评价结果和市场调研情况,建议快检试剂盒产品须经质量评价合格再投入使用,并不定期对产品进行跟踪评价。     

Ranking experts' preferences regarding measures and methods of assessment of welfare in dairy herds using Adaptive Conjoint Analysis

Welfare in dairy herds can be addressed using different concepts. The difficulty is to extract which measures are the most important to practically address welfare at the herd level and the methods to assess traits considered most important. Therefore, the preferences of 24 acknowledged European welfare experts were ranked regarding 70 measures suitable to assess dairy cattle welfare at herd level using the Adaptive Conjoint Analysis (ACA; Sawtooth Software, Inc., Sequim, WA) technique. The experts were selected on the basis of 3 criteria: at least 5 yr experience in animal welfare research; recent scientific publications in the field of animal welfare; and, at the most, 3 animal species including dairy cattle as their field of expertise. The 70 traits were ranked by using the median ACA questionnaire utility scores and the range between the answers of the 24 experts. A high utility score with a low range between the answers of the experts was considered as suitable to assess welfare at farm level. Measures meeting these criteria were prevalence of lameness cases (107.3 ± 11.7), competition for feed and water (96.4 ± 13.9), and number of freestalls per 10 cows (84.8 ± 13.3). Based on the utility score alone, these former measures were replaced by stereotypic behavior (111.7 ± 17.1), prevalence of lameness cases (107.3 ± 11.7), body condition score (108.0 ± 18.9), and hock lesions (104.7 ± 16.1). Subsequently, to demonstrate that the ACA technique can be used to rank either well-known or inconclusive methods of assessment, the methods for the traits lameness cases and the hygiene of the calving pen were ranked using another 2 ACA questionnaires. The results are based on the opinions of selected, internationally acknowledged dairy cattle welfare experts within the European Union. In the future, other parties like dairy farmers and farmers’ organization should be included to achieve consensus about the most suitable traits applicable in practice. The currently investigated traits do not always apply to all dairy husbandry systems across the world, but are based on a system that includes indoor housing during winter. It is concluded that ACA is a useful technique to rank the different scientific opinions of experts regarding suitable traits and methods of assessment of dairy cattle at the herd level.     

High-power gradient diffusion NMR spectroscopy for the rapid assessment of extra-virgin olive oil adulteration

A high gradient diffusion NMR spectroscopy was applied to measure diffusion coefficients (D) of a number of extra-virgin olive, seed, and nut oils in order to ascertain the suitability of this rapid and direct method for discrimination of adulterated olive oils. Minimum adulteration levels that could be detected by changes in D were 10% for sunflower (SuO) and soybean oil (SoO), and 30% for hazelnut (HO) and peanut oil (PO). Qualitative and quantitative prediction of adulteration was achieved by discriminant analysis (DA). The highest prediction accuracy (98–100%) was observed only when two DA models were concomitantly used for sample classification. The first DA model provided recognition of high adulterated EVOO with more than 20% of SuO or SoO, and 30% with PO, whilst the second model could differentiate EVOO adulterated with 10% of SuO or SoO, and more than 30% of HO. The validation test performed with an independent set of randomly adulterated EVOO samples gave 100% classification success. The high accuracy levels together with minimal requirements of sample preparation, and short analyses time, prove the high-power gradient diffusion NMR spectroscopy as an ideal method for rapid screening of adulteration in valuable olive oils.     

全媒体出版的概念理解与前瞻

从<非诚勿扰>在全国的全媒体出版,到<贫民窟的百万富翁>在全球的全媒体出版,随着数字出版的发展,跨越印刷媒体、网络媒体及无线通信平台的全媒体出版方式日渐升温.全媒体出版这个概念成为热词,不仅在印刷出版界,而且在相关领域也引起了广泛的关注.本人对此概念的理解和认识尚为浅薄,愿求教于大家.     

Rain damaged wheat tester: An instrument for the rapid assessment of sprouted grain at silos

A small unit for the rapid assessment of sprouted grain in cereal samples has been developed. The technique is based on the use of a β-amylase-resistant α-amylase chromogenic starch substrate, and is therefore specific for α-amylase. Extraction time for α-amylase from the grain is 30 s using a blender. Incubation time with the substrate in the unit is 3 min. Results are expressed as the percentage of sprouted grain in the sample. The small size of the unit, and the rapid warm-up time, enable the unit to be readily moved between grain receival points. The unit is electrically mains operated.     

几块羽绒面料的服用性能评价

本文通过对几种不同的羽绒布试样服用性能的对比分析，测试了它们的强力仲长性、透气性，抗皱性，抗弯性，抗起毛起球性等几项性能指标，在此基础上获得了客观的科学评价，即羽绒布的高支高密是织造的关键，而织物组织，原材料采用的情况等因素能够极大地影响它们的服用性能。     

浅谈制革厂的品质管理

做好制革厂品质管理工作的几个要点：品质检查、品质记录、品质分析和统计、品质改善、部门间良好沟通。