测定猪肉中土霉素及金霉素残留的HPLC法建立

文章建立了测定猪肉组织中土霉素及金霉素残留量的HPLC法.该方法按照国家检测标准采用了5％高氯酸50 mL为样品提取液;乙腈+0.01 mol·L-1磷酸二氢钠溶液(用30％硝酸调节pH2.5)=35:65为流动相;检测波长为355nm,进行测定.在此色谱条件下,土霉素、金霉素标准品浓度在0.1～1.0 μg· mL-...     

The Effects of Sodium Alginate on Quality of Rainbow Trout (Oncorhynchus mykiss) Fillets Stored at 4 ± 2°C

Edible coating is a novel food packaging technology for controlling the growth of spoilage bacteria and chemical changes in ready-to-eat food products. Fresh fish are highly perishable foodstuffs and are very susceptible to spoilage. A sodium alginate coating was used to maintain the quality of rainbow trout fillets in chilled storage over a period of 20 days. Fillet samples were coated with an aqueous solution of 3% sodium alginate and then stored at chilled temperature (4 ± 2°C). The control and coated samples were analyzed periodically (every 5 days) for microbial (aerobic plate count and psychrotrophic count), chemical (total volatile basic nitrogen, thiobarbituric acid, peroxide value), and sensory characteristics. The results indicated that the sodium alginate coating helped protect the quality characteristics of treated fresh fish fillets and prolonged the shelf life during chilled storage of rainbow trout fillets.     

Quality and Shelf Life of Liver of Farmed Cod (Gadus morhua)

ABSTRACT

Livers of Atlantic cod (Gadus morhua) are traditionally used in cod liver oil production or consumed cooked or canned. The farming of cod is a relatively new industry in Norway. The aim of this study was to determine quality and shelf life of fresh liver from farmed cod during chilled storage on ice by hydrolysis and oxidation state and sensory quality and the influence on canned liver. In two experiments, livers from farmed cod were stored chilled and sampled from Days 0 to 13, respectively. Quality, measured as hydrolytic and oxidation degradation, was reduced after 7 days of storage, while sensory quality was reduced after 4 days. Free fatty acids increased from Day 7 in both experiments, while peroxide value and anisidine value showed no change when the livers were single wrapped. Rancid odor was the first sign of oxidation and was registered after three to four days of storage. Canning within 2 days of storage prevented leakage of oil from the canned livers. Sensory analyses of oxidation are recommended as a sensitive and rapid method to detect oxidation of chilled cod liver.     

漯河市猪肉弓形虫病的流行病学调查

用弓形虫529 bp重复序列（Toxo-529）作为猪肉中弓形虫的检测靶分子,对河南省漯河地区来自6个不同规模的菜市场上200份猪后腿瘦肉样进行猪肉弓形虫分子流行病学调查,结果发现猪肉弓形虫总阳性率为4.0％（8/200）,且阳性病例均出现在乡镇菜市场3和6。菜市场的管理不规范导致了该地区市售猪肉的弓形虫的污染现象出现,此结果可为指导居民建立健康的饮食习惯提供重要的参考价值。     

鲜猪肉在室温贮藏过程中品质的变化研究

对市售新鲜猪肉在室温贮藏条件下品质的变化进行研究,检测项目包括微生物指标、理化指标和感官指标,具体对样品进行细菌总数、大肠菌群数、 pH值、酸价和色泽、组织状态、滋味和气味以及煮沸试验的检测,得出鲜猪肉在无包装贮藏过程各项指标的变化。证实常温贮藏鲜猪肉的最佳食用时间为36 h内。     

花椒籽粗蛋白酶解物对冷鲜猪肉的保鲜应用初探

为探究花椒籽粗蛋白酶解产物对冷鲜猪肉的保鲜效果,配制0.5%、1.5%、2.5%的粗蛋白酶解液,以0.04%的乳酸链球菌素(Nisin)溶液和无菌超纯水分别作为阳性对照和阴性对照组,测定各组在不同时间的菌落总数、感官评价值、p H值、挥发性盐基氮值(TVB-N)、硫代巴比妥酸值(TBA)和汁液流失率等指标。结果表明,花椒籽粗蛋白酶解产物能有效抑制微生物的增长,延缓p H值、TVB-N值和汁液流失率的上升,降低脂质氧化速度,各指标均显著优于阴性对照,保鲜效果与阳性对照相近。综合各指标发现,采用2.5%的粗蛋白酶解液处理冷鲜猪肉,贮藏至第9天,菌落总数为5.48 lg(cfu·g-1),pH值为6.71,TVB-N值为19.8 mg·100g~(-1),其保质期比阴性对照延长6d。本研究表明花椒籽粗蛋白酶解物是一种成本低廉、效果明显、具有开发价值的新型天然保鲜剂。     

发酵床饲养方式对育肥猪血清免疫指标和肉品质的影响

 试验选择23 d 断奶三元杂交（杜洛克猪×长白猪×大约克猪）仔猪60 头,公母各半,随机分成试验组和对照组。试验组以发酵床饲养方式,对照组采用常规饲养方式,试验期为137 d,每组设2 个重复,每个重复15头。试验过程观察试验猪发病率和死亡率,测定肉猪的生产性能。试验结束时,提前12 h 禁食,称重,每组随机抽样6 头猪血样,离心分离血清,采用全自动生化分析测试仪测定血液生化指标。每组随机抽样6 头猪屠宰,用原子吸收分光光度计测定猪肉中部分重金属含量。结果表明,在保育期,试验组发病率比对照组降低26.47%,在生长期和育肥期,试验组发病率比对照组分别提高了42.29%和39.50%,各组死亡率没有变化;试验组平均日增重比对照组增加了6.76%,差异显著 (P<0.05),料重比降低了5.13%, 差异不显著 (P>0.05);试验组血清中尿素含量明显降低（P<0.05）,其他各项指标均与对照组无明显差异;试验组猪血清IgA、IgG含量提明显高（P<0.05）,但对血清IgM无影响。各组猪肉肉质感官和部分重金属含量均符合标准,说明发酵床饲养方式对猪是安全性的,可以明显提高肉猪的生长性能,但后期发病率有所提高。     

家庭冰箱冷藏猪肉的微生物变化

了解居民家庭冰箱冷藏猪肉的微生物变化,为居民安全冷藏食品提供参考,以购自北京市海淀区大型超市和农贸市场的50份鲜猪肉为样品,采用微生物测试片法检测家庭冰箱冷藏18~24h猪肉的菌落总数、大肠菌群及金黄色葡萄球菌、沙门氏菌和单增李斯特氏菌变化。结果表明:猪肉经家庭冰箱冷藏后的菌落总数和大肠菌群数量均增加。冷藏前和冷藏后的平均菌落总数分别为(19.95±4.08)10~3cfu/g和(68.57±14.23)10~3cfu/g,大肠菌群数量分别为(1.34±0.14)10~2cfu/g和(6.87±1.15)10~2cfu/g,冷藏前和冷藏后菌落总数和大肠菌群数量的差异均达显著水平(P0.05)。猪肉在家庭冰箱冷藏前后的金黄色葡萄球菌阳性样品数分别为2份和9份,单增李斯特氏菌阳性样品数分别为1份和3份,差异达显著水平(P0.05);沙门氏菌阳性样品数分别为0和1份。家庭冰箱冷藏猪肉存在微生物污染隐患。     

电化水在猪肉加工灭菌中的应用

为保障猪肉产品卫生安全,探讨了电化水在猪肉加工灭菌中的应用效果、参数和作用机制。结果表明,电化水通过有效氯、O3、H2O2和氧化还原电位等多种因素协同灭菌,应用于猪肉加工冲淋环节的最佳参数为：有效氯浓度140.5 mg/L、O3浓度1.12 mg/L、H2O2浓度3.44 mg/L、pH 8.13和氧化还原电位（ORP）1 072.7 mV,冲淋时间16 s。该参数下对猪肉表面菌落总数、大肠菌群的杀灭对数值分别为1.89 lg(CFU/25 cm2)、1.33 lg(MPN/25 cm2),相对自来水分别提高1.43 lg(CFU/25 cm2)、0.88 lg(MPN/25 cm2),并保持4 h内持续抑菌;同样对器具的消毒效果显著优于次氯酸钠。     

Effect of storage on quality traits of the semimembranosus muscle of farmed fallow deer (Dama dama) bucks and does

A total of 12 farmed fallow deer bucks and 12 does aged 31–32 months were included in a study on the effect of storage in vacuum packaging on the functionality of venison of the Semimembranosus muscle. All the analyzed meat quality traits were not affected by sex. The storage of meat in vacuum led to: an increase of pH (by 0.13 units; P = 0.001), L* (by 1.85 units; P = 0.002), a* (by 1.15 units; P = 0.013) and chroma (by 1.16 units; P = 0.016), a decrease of free water (by 6.62 percentage points (p.p.); P = 0.001) and water‐holding capacity (cm²) (by 29.61%; P = 0.001), and the increase of dry matter content (by 0.67 p.p.; P = 0.001). The results indicate that the chilled storage of venison caused the stabilization of pH and color, improvement of water‐holding capacity, with no negative effect on the proximate chemical composition. The quality of deer meat obtained from does and bucks was similar.