The first commercial pressure treated food was a fruit jam, launched in Japan in
1990. Since then a wide variety of HPP fruit and vegetable products have been available in the USA and
Europe.
Higher quality and longer shelf-life fruit products
High
pressure can easily kill many of the microorganisms that typically spoil fruit products such as juices,
sauces, jams and purees. However, the main advantage this technology has over other treatments, such
as heat, is that flavour, colour and vitamin content are not adversely affected. Fruit juices, for example,
retain their fresh, “just-squeezed” properties with a shelf-life extended for several weeks when held
at refrigeration temperatures. The technology also has potential advantages for producing high quality
fruit smoothies, salads and sauces and vegetable products such as carrot juice and garlic puree.
The
guacamole story
One of the most successful HPP products available in
the USA is guacamole. The fresh product normally spoils rapidly, mainly due to enzyme activity that
discolours the avocado pulp. Traditional preservation treatments such as heating, flash freezing or
modified atmosphere packaging all result in a product of inferior quality compared to fresh. However,
HPP can be used to retain the natural fresh flavour and texture. HPP guacamole, which requires refrigeration,
is now available in an ever-increasing number of US states. The leading manufacturer now also produces
a range of vegetable salsas, and refrigerated Mexican fajita meal kits containing onion, peppers, cooked
meats, guacamole and salsa, all treated with high pressure to ensure additional safety and shelf-life.
Selected
referencesPatterson, M.F. (2005) Microbiology of pressure treated foods.
Journal of Applied Microbiology 98, (4) 541-548.
Baxter, I.A., Easton, K.,
Schneebeli, K. and Whitfield, F. B. (2005) High pressure processing of Australian navel oranges juices:
Sensory analysis and flavor profiling. Innovative Food Science and Emerging Technologies 6, 372-387.
Bull,
M.K., Szabo, E.A., Cole, M.B. and Stewart, C.M. (2005) Toward validation of process criteria for high-pressure
processing of orange juice with predictive models. Journal of Food Protection 68, 949-954.
Linton,
M., McClements, J.M.J. & Patterson, M.F. (1999). Survival of E. coli O157: H7 during storage in
pressure-treated orange juice. Journal of Food Protection 62, 1038- 1040
