Microbiological Testing of Unwashed Salad-like Vegetables
J. Tregenza, G. Hale and R. Premier
Program and Abstract. Australasian Postharvest Horticulture Conference. Royal Lakeside Novote., Rotorua, New Zealand. 27-30 September 2005. July 5-10, 2005. Page 56
2005
บทคัดย่อ
Microbiological Testing of Unwashed Salad-like Vegetables
The issue of microbiological contamination of salad and salad-like vegetables is routinely raised as more and more overseas cases of food poisoning outbreaks are reported. A lot of these cases have been linked with on farm practices such as the use of animal manure, low quality irrigationwater and infections contamination from workers. In Australia, samples of these products are routinely tested as part of the requirements for "on farm" quality assurance plans. Three microbial parameters tested for include; Total aerobic plate count (often used as a measure of quality), Faecal coliforms (an indicator of recent faecal contamination) and E. coli (a more specific indicator of faecal contamination). These parameters assist in determining the quality of the produce. In this study, we looked at the microbiological results over the past seven years of a number of salad-like vegetables from farms around Melbourne: These products were considered high risk because they are not washed or processed further after harvest. Almost all of the samples tested show high levels of Total aerobic bacteria. This microbial parameter serves as a measure of quality because low quality produce tends to show higher levels (maybe duo to damage or poor temperature management). The level of Faecal colifoms varied and were present at higher levels in a number of samples. on the other hand, E. coli was detected in only a few samples but was present at relatively low levels. The Australian guidelines specify levels below 20 cfu/g. The acceptable levels were adequately met by most or the samples tested. This poster will discuss these results, especially the interpretation of the Faecal coliform count and it's relevance to fresh produce testing.