Flow chart presentation
Jams

The manufacture of jams is based on a technological strategy that combines four operations to ensure the long-lasting, independent preservation of the fruit. The first involves the partial evaporation of the water contained in the fruit, either at atmospheric pressure by simple cooking in a pot, or under vacuum (reduced partial pressure) in an evapo-concentrator. The second is the addition of sugars to the fruit base. These first two operations result in a reduction in the Aw (water activity) of the finished product, generally between 0.75 and 0.80, which inhibits the proliferation of microbial bacteria, but not fungi. Thirdly, the pH of the mixture is lowered by the addition of organic acids such as citric acid (E300), in varying doses depending on the original acidity of the fruit. Lastly, pasteurization-type heat treatment, combined with packaging at a temperature of 75/80°C, will stabilize...