探究食品微生物检验的质量控制

随着食品安全领域的不断发展,对食品检验要求也不断提高。在食品微生物检验工作不断进步的过程中,对食品微生物检验过程中的质量控制,确保提高食品及微生物检验结果的准确程度,以进一步保障食品的安全卫生。本文从微生物检验过程的特殊性和食品微生物检测质量控制两方面进行了分析。     

FD香葱生产中的危害分析与关键环节控制

将HACCCP体系引入FD(真空冷冻干燥)香葱生产过程中,经危害分析找出关键控制点,通过过程控制提高产品合格率,降低危害发生的风险,形成一套行之有效的食品安全管理体系.     

高效液相色谱法与微生物法测定食品中烟酸的比较

目前,测定食品中烟酸含量所采用的高效液相色谱法（ＨＰＬＣ）大多用单柱法［５］,不能得到完整的峰,我们采用柱开关,可达到良好分离效果［２,４］。１实验部分１．１仪器：高效液相色谱仪（具有可变波长ＵＶ检测器,数据处理系统或记录仪）一台;机械化六通阀、柱开...     

啤酒生产过程中厌氧菌的危害与控制

过去,国内一些啤酒厂普遍不太重视厌氧菌对啤酒的危害,并且很少对啤酒酵母和发酵液以及成品啤酒进行厌氧菌数目的检测,只是基于食品卫生的要求对于啤酒生产过程中的冷麦汁、压缩空气、无菌水、发酵液、成品啤酒进行细菌总数和大肠菌群的检测,其实一些厌氧菌对啤酒有很大的危害,它不仅可以影响啤酒口味的纯正,还可以使啤酒异常发酵,酒液严重混浊、酸败、难以入口。因此,必须加强对啤酒有害菌的控制工作。啤酒有害菌是指厌氧条件下生长,革兰氏阳性,过氧化氢酶阴性的细菌,一般在麦汁发酵初期,由于氧的存在,厌氧菌在此时还不能生成…     

食品中常见有毒物质及危害概述

众多食品中有毒危害物质对人身体健康产生危害。     

浅谈食品微生物检验中无菌操作技术

随着生活水平的提高,人们对于食品安全卫生标准的需求越来越高。为了能够准确、客观的反应食品的安全卫生质量,必须在食品采样、食品取样以及检验等环节进行全面的食品微生物无菌检验,否者就是去的食品检验的根本意义。接下来,本文将结合笔者多年相关工作经验,简要论述食品微生物检验中无菌操作技术。     

食品的微生物区系

微生物的活动对食品的影响，主要包括食品腐败，食品制造，单细胞蛋白质。     

冷冻食品中低温微生物的研究

目的：研究冷冻食品中的低温微生物。方法：采用传统法对30份样品进行菌属鉴定,同时探讨了低温微生物的最适温度和时间。结果：得出5类菌属,并确定15℃ 48h为低温微生物快速、适用的检超温度和时间。     

冷冻水产品生产过程中微生物的监控

水产品的种类及其丰富,而水产品携带的微生物也同样丰富。在我国70%以上的不合格冷冻水产品都是由于微生物超标造成的。微生物的超标不但带来了资源浪费,还严重影响了人们的健康和生命。本文从水产品的微生物携带种类及防控等方面论述冷冻水产品生产过程中的微生物监控,希望把更营养、更丰富、更健康的冷冻水产品带上人们的餐桌。     

蝉的变音调复合声和发声机制的分析

蛙鸣蝉(Meimuna opalifera (Walk).ab.punctata Kato)的自然鸣声为“ji…guái”的重复单变调复合声.“ji”为主音频约4800Hz的准单音;“guái”的波形和主音频呈明显的演变,优势主频约2100Hz和2800Hz的变音调声.鸟鸣蝉(Meimuna opalifera (Walk)var.formosana Kato)的自然鸣声由重复的“jiū…ruǎ”和“jiū…gū…”合成的双变调复合声.“jiū”为基频和主频分别约625Hz和2100—2300Hz的准单音;“ruǎ”的波形和主音频呈明显的演变,基音和优势主频分别约575—625Hz和1550—1750Hz的变音调声.“gū”为优势主频约625Hz的准单音.变音调复合声不仅与腹部运动有关,而主要取决于发声肌的收缩特性和发声膜肋结构的振动特性.     

FAECAL PRODUCTION AND AN ESTIMATE OF FOOD INTAKE IN THE WILD OF THE ANTARCTIC LIMPET NACELLA CONCINNA (STREBEL)

The Antarctic limpet Nacella concinna is common in shallow watersaround the Antarctic Peninsula, and has a mean density of 125individuals/m² at Signy Island (Picken, 1980). In the australsummer 1986/87 ammonia excretion and faecal egestion were measuredas part of a programme to develop a detailed individual energybudget for this species. Ammonia production was measured in 102 individuals ranging from3 to 720 mg dry weight. For a standard limpet of 200 mg dryweight, ammonia excretion was 0.13 µg-at/hr. Comparedwith previous measures of oxygen uptake these data suggest anO:N atomic ratio of between 15 and 25. The relationship betweenammonia excretion and dry weight could be expressed by a powercurve with a weight exponent of 0.82 (SE 0.042). Faecal production was measured in limpets freshly sampled fromthe field, and placed in dean seawater for 4 days. During thistime faecal production decreased (since the limpets were notfeeding), although only data from the first 24 hours were used.Again the relationship between faecal egestion and dry weightcould be expressed by a power curve, although this time theweight exponent was 0.94 (SE 0.101). The ash content of thefaecal strings increased significantly with the size of thelimpet, possibly because larger limpets were ingesting a greaterproportion of substrate during feeding. If this is so, thenthis would also explain the weight exponent dose to 1.0, ratherthan the value of about 0.8 to be expected from metabolic measures(since larger limpets would be passing relatively more faecalmaterial). If assimilation efficiency is known, then food intake in thewild may be estimated from a measurement of faecal egestionand faecal organic content (Clarke et at., 1988). Applying typicalvalues of assimilation efficiency for limpets (40 to 60%) suggestsa daily food intake in Nacella of 2 to 3% body weight per day.This is a quite typical figure for a grazing limpet, and suggeststhere is no resource limitation for Nacella at Signy in summer.     

GRAPHICAL APPLICATIONS IN THE ANALYSIS OF CROSSOVER DESIGNS IN FOOD SENSORY STUDIES

Graphs useful in exploratory data analysis for checking assumptions and evaluating treatment, sequence, and period effects in a linear model from a crossover design are discussed. In particular, a two-period, two-treatment crossover design of a food sensory study is used to illustrate the applications of these graphs.