Food Preservation and Processing Methods
• Food Preservation involves the actions taken to maintain foods with the
• Desired properties or nature for a desired time frame
• For example, a fresh sandwich has a shelf-life of about 1 day, whereas canned vegetables have a shelf-life of at least 1year.
• First it is important to identify the properties or characteristics one wants to preserve
• A property may be important in one product but detrimental in others.
• For example, collapse and pore formation occurs during the drying of foods,
• And this can be desirable or undesirable depending on the desired quality of the dried product.
• Two illustrations will suffice:
• Firstly, crust formation is desirable for long bowl life in the case of breakfast cereal ingredients, whereas quick rehydration is necessary (i.e. no crust and open pores) for instant soup ingredients
• Secondly, consumers expect apple juice to be clear whereas orange juice can be cloudy.
• In the case of preservation and safety we want to eliminate pathogenic and spoilage bacteria,
• Whereas in the case of yoghurt we want to preserve the beneficial lactic acid bacteria
• New preservation techniques are being developed to satisfy
• The current demands of economic preservation and consumer satisfaction with regard to nutritional and sensory aspects, convenience, safety, absence of chemical preservatives, low price, and environmental safety
• The factors that should be considered before selection a preservation process include