Acidified or “pickled” foods is a category of food products that is very popular with food entrepreneurs and farmers interested in value added opportunities. Many products are traditionally processed this way, including pickles (cucumbers) and pickled vegetables, meat and eggs. The variety of products and flavors is limited only by the creativity of food processors as new formulations and presentations continuously debut in food stores to meet consumer’s new expectations and ethnic preferences.
Definition
It is important to understand the regulatory meaning of an acidified food. From the regulatory point of view, foods are classed as acid, low acid or acidified depending on the natural acidity of each product. A product’s acidity is measured based on a pH scale. If the raw or initial product has a pH above 4.6 it is considered a low acid food. If the pH is below 4.6 then the food is classified as an acid food. Acidified foods are low acid foods to which acid or acid ingredients are added to produce a final equilibrium pH of 4.6 or below. Equilibrium pH means the final pH measured in the acidified food after all the components of the food have achieved the same acidity.
The pH value of 4.6 is important because it is the limiting factor for the growth of an extremely dangerous microorganism called Clostridium botulinum, which produces a potent toxin that causes the lethal disease botulism. The regulations concerning acidified foods were established to assure the control and inhibition of the growth of Clostridium botulinum by proper acidification and pH control, as this microorganism is very heat resistant and therefore it is not destroyed by pasteurization or cooking temperatures below 212°F.
We all relate to the word pickled as a food item being treated with an acid liquid, typically vinegar or lemon/lime juice. In doing this procedure we extend the shelf-life of the product due to the preservative effect of the acid as well as develop or produce a sour or pickled taste in the product. In a way, we are imitating a traditional fermentation process by directly adding the acid component to the product. Any food grade acid can be used such as vinegar (acetic acid), citric acid, lactic acid, malic acid or phosphoric acid.