Raw milk from vending machines: Effects of boiling, microwave treatment, and refrigeration on microbiological quality.
Raw milk from vending machines: Effects of boiling, microwave treatment, and refrigeration on microbiological quality.
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自动售货机中的生奶：煮沸、微波处理和冷藏对微生物质量的影响。
DOI：
10.3168/jds.2013-7744
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发表时间：
2014
影响因子：
3.5
通讯作者：
E. Sorrentino
中科院分区：
文献类型：
--
作者：
P. Tremonte;Luca Tipaldi;M. Succi;G. Pannella;L. Falasca;V. Capilongo;R. Coppola;E. Sorrentino
在意大利，自2004年以来，允许自动售货机销售生奶。消费者必须在使用前进行煮沸处理，因为生奶可能是食源性病原体的重要来源。本研究符合这一背景，旨在评价从位于意大利南部地区莫利塞的3台自动售货机定期采集（2013年3月至2013年7月）的30份原料奶样品的微生物质量。牛奶样品在4 °C下储存72小时，然后进行不同的处理，如煮沸和微波，以模拟家庭处理。结果表明，所有采集后立即检测的原料奶样品都受到高微生物负荷的影响，其数值非常接近甚至高于意大利法律可接受的数值。在冷藏期间微生物种群增加，对于假单胞菌属，在72小时后达到约8.0 log cfu/mL的值，6.5 log cfu/mL（酵母菌）和高达4.0 log cfu/mL（肠杆菌科）。煮沸处理，72小时后施加到冷藏牛奶样品，造成完全去污，但负面影响的牛奶的营养质量，如乳清蛋白的急剧减少所示。微波处理在900 W为75 s产生类似于煮沸的微生物去污，保留牛奶中乳清蛋白的含量。这项研究所观察到的生奶的微生物学特性充分证明，在食用前必须将自动售货机出售的生奶煮沸。然而，这项研究也表明，家庭煮沸会导致牛奶的营养价值急剧下降。微波处理可以代表一个很好的替代煮沸，条件是过程变量标准化的安全国内应用。
In Italy, the sale of raw milk from vending machines has been allowed since 2004. Boiling treatment before its use is mandatory for the consumer, because the raw milk could be an important source of foodborne pathogens. This study fits into this context with the aim to evaluate the microbiological quality of 30 raw milk samples periodically collected (March 2013 to July 2013) from 3 vending machines located in Molise, a region of southern Italy. Milk samples were stored for 72 h at 4 °C and then subjected to different treatments, such as boiling and microwaving, to simulate domestic handling. The results show that all the raw milk samples examined immediately after their collection were affected by high microbial loads, with values very close to or even greater than those acceptable by Italian law. The microbial populations increased during refrigeration, reaching after 72 h values of about 8.0 log cfu/mL for Pseudomonas spp., 6.5 log cfu/mL for yeasts, and up to 4.0 log cfu/mL for Enterobacteriaceae. Boiling treatment, applied after 72 h to refrigerated milk samples, caused complete decontamination, but negatively affected the nutritional quality of the milk, as demonstrated by a drastic reduction of whey proteins. The microwave treatment at 900 W for 75 s produced microbiological decontamination similar to that of boiling, preserving the content in whey proteins of milk. The microbiological characteristics of raw milk observed in this study fully justify the obligation to boil the raw milk from vending machines before consumption. However, this study also showed that domestic boiling causes a drastic reduction in the nutritional value of milk. Microwave treatment could represent a good alternative to boiling, on the condition that the process variables are standardized for safe domestic application.