Influence of Carbon Dioxide and Nitrogen on Microbial Populations and Shelf Life of Cottage Cheese and Sour Cream

Abstract

Creamed Cottage cheese sealed in commercial thermoplastic containers following air evacuation and carbon dioxide or nitrogen-flushing, and stored at 4C, showed greatly repressed growth of spoilage organisms, including yeast and mold and psychrophiles, for up to 112 days. Excellent flavor and texture were maintained in gassed cheese to 45 days. Slight bitterness was apparent in Cottage cheese held under carbon dioxide for 73 and 120 days, and slight to medium bitterness in cheese held under nitrogen for a similar period. Creamed Cottage cheese stored in waxed cartons and replaceable lids, without evacuation or gassing deteriorated in flavor after 11 to 18 days and in texture after 32 to 45 days.Carbon dioxide gassing maintained the basic fresh flavor of cheese for 73 days at 4C, but gave the Cottage cheese a pleasant, slight, fizzy character.Excellent quality sour cream packaged and stored under identical experimental conditions showed no growth of spoilage organisms even in control containers for 112 days at 4C and pH 4.5. Flavor of the sour cream stored under carbon dioxide was excellent for 120 days, but some body and texture destabilization occurred in 25 days. The body and texture of sour cream stored under nitrogen was excellent for 73 days at 4C.