In a study published in the Journal of Dairy Science, researchers at the Mississippi State Universityfound that the system, called MicroFoss, was able to give a good indication of the shelf life ofpasteurised milk within thirty eight hours.
By comparison, the main microbiological method in use today, the Moseley test, requires at leasteight to nine days to indicate shelf life. The study was led by Charles White, a researcher at theuniversity's department of food science, nutrition, and health promotion.
A fast and convenient estimation of shelf life could provide dairy processors with a moreaccurate way to make decisions about the use of their milk. Reduced analysis time helps processors spot contaminations earlier and avoid product recalls.They can also release products for sale more quickly - reducing storage costs and extending product shelf-life.
In an abstract of paper, White says the study revealed that MicroFoss can be used with preliminary incubation toindicate fluid milk shelf-life through estimating total numbers of microorganisms and potential spoilageproblems due to gram-negative, psychrotrophic bacteria.
"This method is more effective at indicating shelf-life than the standard Moseley Keeping Quality Test and can estimate shelf-life within 38 h ofpasteurization," the authors stated. "The MicroFoss is similar to other methods in its ability to estimate shelf-life but has anadvantage over these methods because it can be used to identify problem samples by combining information ongram-negative counts with total viable counts to pinpoint potential shelf-life problems."
The study also showed the MicroFoss to be superior to the Moseley test in indicating shelf lifewith a better correlation to sensory evaluation, Foss stated in a press release announcing theresults of the study. The sensory test is normally performed by a panel of three experts using ascorecard system.
"It is still considered to be the most accurate way of predicting shelf life,"Foss stated. "However it is time-consuming taking between ten and twenty days."
MicroFoss product manager, Nicoline Baek said that the system gives processors microbiologicalindications in the hand about five days earlier than with current methods. MicroFoss also gives aresult for a number of different micro organisms. This helps to give a fuller picture aboutinherently complex microbiological activity.
By comparison the plate count method employed in tests such as the Moseley method gives only aone dimensional view based on bacteria colony forming units, he said.
"It is in general imperative for the industry to know the potential shelf life before theproducts is shipped," he said.
The MicroFoss system provides measurements such as TVC (Total Viable Count) of Coliform, E.coli, Enterobacteriaceae, and Yeast, in both raw materials and finished products.
"With screening times as low as a few hours, the MicroFoss system requires less labour inputs than any other products on the market today, thus allowing food companies to improve their surveillance programs without additionalstaff," the company claims.
