The Behavior of Yeast Populations in Stracchino Cheese Packaged under Various Conditions.

The growth of yeasts, lactic acid bacteria, pseudomonads, and enterobacteria during the refrigerated storage of an Italian soft cheese (Stracchino) in various packaging conditions (under air, under vacuum, and in the presence of ethanol) was studied. Yeasts were found to play a significant role in cheese spoilage, producing unplesant flavors and odors and causing significant reductions in the shelf life of the paper-wrapped cheeses. Packaging under vacuum decreased the yeast growth rates and reduced the populations attained at the end of the exponential phase of growth, resulting in a shelf-life extension of the Stracchino cheese of over 28 days.

Effect of Essential Oils on Aeromonas hydrophila in a Culture Medium and in Cooked Pork.

The inhibitory effects of essential oils of coriander, clove, nutmeg, and pepper towards Aeromonas hydrophila were studied in tryptic soy agar. Essential oils of clove, coriander, and nutmeg at concentrations of 500, 1,250, and 10,000 μg/ml, respectively, were effective in inhibiting the growth of A. hydrophila on tryptic soy agar.