Dynamics of ammonia levels during long-term storage of canned meats

Ammonia content in relation with sensory changes was studied in four kinds of meat cans (Pork in Natural Juice, Beef with Bacon, Luncheon Meat, and Liver Paté), stored for 36 months under constant conditions (average temperature 21 degrees C. average relative humidity 73%). Four groups of final products were prepared from each kind of these cans; the final products differed from one another in the ammonia contents, depending on the freshness of the food. After sterilization and cooling, i.e. after the termination of the technological process of production, the produced meat cans were subjected to sensory evaluation and their ammonia contents were determined. These values were used as initial data for the start of long-term storage. In the course of long-term storage the selected parameters were measured in regular intervals. It was concluded from the experimental results that the content of ammonia slightly increased with the time of storage of the tested kinds of meat cans without any significant influence on their sensory characteristics that would affect their use for human consumption.     

Dynamics of chlorinated pesticide residues in long-term storage of canned food

Meat tins denoted as pork in natural juice, beef with bacon, luncheon meat and liver paté, all produced in a food-processing plant, were stored under definite conditions (temperature 21 degrees C, relative humidity 73%) for three years. Before the long-term storage and then in half-year intervals, the contents of the residues of chlorinated pesticides, including HCB (hexachlorobenzene), gamma-HCH (gamma isomer of hexachlorocyclohexane) and pp'DDE (1,1-dichloro-2,2-bis/p-chlorofenyl/-ethylene), were determined in the above-mentioned final products by the method of gas chromatography. As suggested by the records of the changes in the pesticide residue contents in the meat tins during their long-term storage, the average contents of all chlorinated carbohydrates gradually decrease with the length of storage and the "reduction" of residues varies with the kind of final product and with the pesticides. In HCB the reduction ranged from 18.4 to 34.4%, in gamma-HCH from 36.2 to 80.4% and in pp'DDE from 23.9 to 48.9%.     

Dynamics of ammonia and pH in meat stored under various conditions

The changes in ammonia content and pH values in beef and pork stored at different temperatures were studied in relation with sensory changes. Samples were taken from the stored meat at a temperature of +3 degrees C in the 0th, 12th, 36th, 60th, 84th, 108th and 132nd hour and at a temperature of +10 degrees C in the 0th, 6th, 24th, 36th, 54th, 72nd and 84th hour. The quantity of ammonia in the samples was determined by means of an ion-selective electrode. The pH value was determined potentiometrically. The kinds of meat (pork, beef) differed in the development of ammonia content. Ammonia content was found to be directly dependent on storage temperature. A similar relation was observed in the development of pH values. The sensory changes of stored meat were parallel to the changes in ammonia levels and pH values. The results can be used for an evaluation of the degree of biochemical changes in the meat and of the fitness of the raw material to the production of tins for long storage. Advantageous points are seen in the rapid and objective determination of ammonia content by the ion-selective electrode and the determination of the pH value by means of the combined glass electrode with the aid of the same apparatus.     

放心肉生产加工企业名单公布

5月24日,北京市政府食品安全办、市商务局向全社会公布了10家放心鲜猪肉生产企业和9家熟肉制品放心企业名单。据北京市政府食品安全办的有关负责人介绍,今年全市计划关闭18家生猪定点屠宰厂,同时建成4到5家大型屠宰场。到2008年,单班屠宰量在1500头以下的屠宰企业将全部退出首都市场,本市只保留10家左右大型现代化屠宰厂。10家放心鲜猪肉生产企业分别是:北京顺鑫农业股份有限公司鹏程食品分公司,北京市第二肉类联合加工厂,北京市第五肉类联合加工厂,北京市怀柔区肉类联合加工厂,北京资源亚太食品有限公司,北京中瑞食品有限公司,北京华都肉食…     

世界3大产肉国主要肉类生产情况对比

中国、美国和巴西是世界上3大产肉国．也是世界肉类贸易中占重要地位的国家,对这3个国家的肉类生产进行分析可折射出世界肉类生产的现状与趋势。以下根据FAO公布的统计数据,对3国主要肉类品种的总产量、平均单产、人均占有量和进出13情况作一简要分析。     

不同杂交组合肉用牛生长发育及产肉性能试验

通过引进优秀肉牛品种夏洛莱、皮埃蒙特和利木辛，对本市西本牛进行大面积杂交改良，推动了本市肉牛产业的发展，取得了显著的经济效益。结果表明：三元杂交牛生长发育迅速，增重快，屠宰率、净肉率、眼肌面积等产肉性能指标均高于西本牛；在农户和全舍饲二种条件下，夏西本F1、皮西本F1和利西本F1三个杂交组合均生长发育迅速，增重快，其中：夏西本F1最好。试验进一步证明，良好的饲养方式和科学管理，以及合理组装配套“五良”养牛技术，才能发挥良种优势，从而进一步提高生产性能。     

近期我国肉类生产与价格分析

2003年第一季度我国肉类产量稳定增加。据全国30个省、自治区、直辖市畜牧行业部门统计,1～3月份我国肉类总产量为2201.58万吨,比去年同期增加4.49%。肉类结构进一步改善,猪肉占我国肉类的比重下降到66.86%,牛肉和羊肉的比重分别达到8.73%和4.68%,禽肉的比重提高到18.54%。1.1生猪存栏和出栏稳步增长,能繁母猪比重与上年持平2003年第一季度末我国生猪存栏数为43816.0万头,比去年同期上升了1.85%,其中,能繁母猪存栏3988.1万头,与去年同期持平,仅提高0.88%。能繁母猪存栏占生猪存栏的比重为9.10%,比去年同期略有下降。第一季度我国生猪出栏196…     

Beef breed bulls versus selected dual purpose bulls in producing calves for meat production

The mating of small beef type bulls (Angus, Eringer) to reduce difficulties at first calvings is increasingly applied in Switzerland. In contrast to this, calf producers refuse to use large type beef bulls on their cows because of direct and indirect damages due to increased calving problems. It proved to be an attractive alternative to use specially selected dual purpose bulls tested for ease of calving and high growth rate but low dairy performance, so called M-bulls (Meat bulls), out of the regular AI testing programme for Braunvieh and Simmentals.From 1974 to 1976, Charolais, Limousin and Piemontese bulls were included in the AI testing programme and compared with Braunvieh- and Simmental-M-bulls. Data included progeny from 47 bulls, 7936 calvings, 1137 animals with carcass gains, and 130 dissected carcasses. If calving performance and net gains are considered, the M-bulls compete well with the foreign breeds. If, in addition, the amount of meat in the carcass is taken into account, then Charolais and Piemontese crosses are superior. The problem is one of distributing gains and losses among calf producers, feeders and butchers. It needs specially tested bulls with emphasis on ease of calving out of the specialized beef breeds or sire lines to persuade the dairy farmer to cross his cows.     

Change in ribose levels in the meat of stored carp]

To study the changes in ribose levels in carp meat during storage, total ribose soluble in acids was determined, ribose precipitating by barium hydroxide (free ribose), the ratio of these two values, and determination from the alkaline extract of zinc sulphate was also used. Already in freshly suffocated carp relatively high levels of acid-soluble ribose were found as well as free ribose. The even increase of pentose in the alkaline extract of zinc sulphate allows to use the procedure for the evaluation of carp meat loss of freshness during storage; the limiting value for inedible carp meat is the content greater than 10 mumol per kg.     

不同杂交组合杂种羊产肉性能的研究

5个杂交组合中，以德本F1和德细F1最好，周岁体重比本地羊高10.5kg的10.4kg（P＜0.05）。寒本F1较差，周岁生与本地羊相近，这是由于小尾寒羊放牧采食性较差之故。产肉性能、羊肉品质及经济效益等项指标亦以德本F1和德细F1组合最好，值得在生产中推广。而小尾寒羊应在改善饲养管理和效放牧为舍饲的基础上积极引进行利用。     

Differential protein profiles in duck meat during the early postmortem storage period

The present study was designed to investigate proteomic differences in duck breast muscle during the early postmortem storage period. The meat quality was evaluated at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, black Muscovy ducks and Mule ducks. Differentially expressed proteins were detected by two‐dimensional gel electrophoresis (2‐DE) and matrix‐assisted laser desorption ionization‐time‐of‐flight mass spectrometry (MALDI‐TOF/TOF MS) at 0 hr and 24 hr postmortem in the three duck breeds. The results showed that 53 proteins spots were differentially expressed at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, 75 spots in black Muscovy ducks, and 72 spots in Mule ducks. A total of 30 (10 spots for each breed) were selected for identification by mass spectrometry. Seven proteins were identified in Pekin ducks, eight in black Muscovy ducks and seven in Mule ducks. Moreover, the above results obtained by 2‐DE and MALDI‐TOF/TOF MS were confirmed by western blotting. To our knowledge, this study is the first to provide insights into the protein profiles of ducks during postmortem storage and provides a better understanding of the biochemical processes that contribute to duck meat quality.     

正交试验法优选大黄超微粉生产工艺研究

目的：优化大黄超微粉的生产工艺。方法：本研究采用正交试验法对大黄超微粉生产工艺过程进行优化,考察了不同生产工艺对大黄超微粉过筛率的影响。结果：正交试验优选出大黄超微粉碎生产工艺的最佳条件,生产时水分含量为3%,研磨时间为20 min,棒料比为20∶1。结论：以优化工艺所得大黄超微粉的过筛率高,有利于工业生产。     

长期储运对输液软袋的质量影响

目的 :模拟纸箱储存和运输过程,在确保纸箱质量的前提下,对输液软袋进行抗叠压和跌落试验,观察试验中是否出现质量问题,以便规范储存和物流运输行为,保证药品质量。方法:模拟纸箱储存和运输过程,对输液软袋进行抗叠压和跌落试验,采用外观目检和显微镜检方法并记录结果。结果:输液软袋的纸箱叠压超过7层或搬运摔碰均可出现漏液,同时焊接层开裂而造成的拉丝,在遇到剧烈运动或震动可导致脱离的部分进入药液中形成异物。纸箱叠加也会出现因底部纸箱变形无法支撑上面重物而造成倒垛、上部软袋产品因重摔而漏液的情况。结论:应对物流运输公司、临床药房、抽检的储运提出防磕碰及过高码放箱体的运输要求,以保证长期储运的药品质量。     

抗生素工业化生产中一级种子罐染菌原因及解决方法

抗生素工业化生产中,菌种往往需要扩大繁殖到一定的数量后再进入发酵罐.在一级种子制备过程中,引起染菌的因素很多,极大地影响了抗生素生产的产量和质量.解决一级种子罐染菌的方法,除制定科学的岗位SOP并不断提高操作者的技能外,更重要的是要加强工艺管理,树立以预防为主的思想,根据微生物特性,强化环境清洁,加强设备清洁、维修,操作时实行定人、定操作.