Storage studies on a sous vide spaghetti and meat sauce product

Shelf-life studies were done on a minimally processed sous vide spaghetti and meat sauce product subjected to a heat processing at 65°C and 75°C equivalent to a 5D and 13D reduction of Streptococcus faecium and subsequently stored at refrigeration (5°C) or under mild temperature abuse storage conditions (15°C). Products stored at 5°C had a shelf-life of ≥35 days irrespective of the processing treatment. However, for products stored at 15°C, packages were visibly swollen due to additional carbon dioxide production after 14 to 21 days, depending on the severity of the heat processing treatment, and the product had a distinct fruity odor when opened. Initial spoilage micro-organisms consisted predominantly of Bacillus species. However, after 7-12 days at 15°C, the spoilage pattern changed, with lactic acid bacteria accounting for almost all of the spoilage micro-organisms. As lactic acid bacteria increased in numbers, there was a concomitant increase in carbon dioxide and lactic acid production and a drop in pH of the product. This study has shown that physical, chemical and microbiological changes can be useful indicators to demonstrate temperature abuse of a minimally processed pasta product.