The pH and/or acidity of a food is generally used to determine the safe home canning methods and conditions. The term "pH" is a measure of acidity; the lower its value, the more acid the food. The equipment used for determining pH was generally pH meters. Canning methods are described on this page. Some liquids, like lemon juice, lime juice and vinegar, are used as acidifiers, to help lower the pH of foods to increase safety. See this page for an explanation.
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