The use of carbon dioxide in the processing and packaging of milk and dairy products: A review

The upswing in consumer demand for fresh and high quality preservative-free foods has led to the development of modified atmosphere packaging (MAP). Increasingly, MAP is being used with high carbon dioxide (CO2) concentration as well as CO2/N2 gas mixes. Modified atmosphere packaging or 'gas flushing' as it is also known is an increasingly popular technique used to extend the shelf life (both quality and safety) of a number of dairy products. Carbon dioxide is an active constituent of MAP, naturally present in freshly drawn raw milk. Addition of CO2 to raw milk or flushing the package headspace has proved to be a simple and cost-effective method, depending upon the initial microbiological quality of the food product. Carbon dioxide addition through MAP or direct injection as an economically affordable shelf life extension strategy is used commercially worldwide for some dairy products. The development of food packaging machines with integrated gas flushing capabilities and the supply of 'food grade' gases allow dairy foods manufacturers to enhance the quality of their products. This review presents a broad spectrum of current research and the current trends with respect to CO2 as a natural microbial hurdle with special focus on its precise mechanism and its role in quality improvement of dairy products.