漂烫处理和速冻处理对白芦笋营养成分的影响

研究了不同漂烫条件和速冻处理对芦笋过氧化物酶(POD)活性及营养成分的影响。结果表明:漂烫处理和速冻处理造成一定量的蛋白质和氨基酸的损失。95℃条件下,漂烫2.5 min能显著抑制POD活性,较好地保存芦笋的外观品质,较长时间保持速冻芦笋的营养成分。     

速冻芦笋的热烫工艺条件研究

对速冻芦笋的热烫工艺条件进行了研究。结果显示,热烫因子笋径(A)、热烫温度(B)和热烫时间(C)对芦笋热烫效果影响的主次顺序为A>B>C;笋径对多酚氧化酶(PPO)和过氧化物酶(POD)活性有极显著的影响,对芦笋烫后的感官品质有显著影响;热烫温度和时间对POD活性有显著影响。芦笋热烫的适宜条件范围为茎粗0.8～1.4 cm,热烫温度88～95℃,热烫时间为2～3 min,热烫最佳处理组合为A_2B_3C_1。     

烤后烟叶挂灰的原因与防止烟叶挂灰的途径

从土壤酸度、重金属离子毒害、营养失调、生态因素、烟叶采收、烘烤技术等方面分析了烤后烟叶挂灰的原因,在此基础上,综述了防止或减轻烟叶挂灰的技术措施,以期为生产上采取措施降低烤后挂灰烟比例,提高橘黄烟比例,提高烟叶品质和可用性,增加烟农经济效益提供参考.     

Transmission of pathogenic respiratory bacteria to specific pathogen free pigs at slaughter

The purpose of this study was to evaluate the transmission of pathogenic respiratory bacteria to thirteen 5-month-old specific pathogen free (SPF) pigs, during the slaughtering process in a commercial slaughterhouse. Before transportation, the SPF pigs and the lorry were checked to confirm the absence of pathogenic respiratory bacteria.

Nine SPF pigs (group 1) were in contact in a conventional slaughterhouse with finishing pigs, during 4 h before slaughtering. Four SPF pigs (group 2) were slaughtered immediately at arrival in the slaughterhouse.

Five bacterial pathogens (Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Pasteurella multocida, Haemophilus parasuis and Streptococcus suis) were detected by PCR, after slaughtering, from nasal cavities, tonsils and trachea in the two groups of pigs. Lung samples were PCR negative. Three and four bacterial species were isolated from the pigs of group 2 and group 1, respectively. Cultures were negative from the lungs.

All the bacterial species present in the SPF pigs were detected by PCR. P. multocida was isolated, from three samples of scalding water before the onset of slaughtering.

Our results suggest that the SPF pigs became contaminated mainly by the slaughterhouse environment and the scalding water. Histological examinations revealed that during scalding, contaminated water could reach the trachea and the lungs of pigs. Checks conducted at slaughter for respiratory disorders have to be carried on, but nasal cavities and tonsils are not appropriate for bacteriological investigations. Moreover, bacteriological results obtained from the lungs of slaughtered pigs have to be used with carefulness.     

烫漂工艺对脱水菠菜品质影响的研究

本文主要对影响脱水菠菜成品的颜色及组织状态的烫漂工艺条件进行了试验研究，其研究结果表明，最佳条件是：烫漂液小苏打浓度是0．5％，烫漂温度为60℃，烫漂时间为1．5min。