Occurrence of Alicyclobacillus in the fruit processing environment--a review

Concentrated fruit products have a significant place in modern consumption markets and are valuable semi-prepared food components to the bakery, dairy, confectionary, canning, baby food, frozen food, distilling and beverage industries. There is continuous pressure on the beverage industry to improve the quality of concentrated fruit products in order for reconstituted fruit beverages to compete with beverages that are made from fresh fruits. In recent years, Alicyclobacillus spp. have become a major concern to the beverage industry worldwide as many high-acid, concentrated fruit products have been found to be contaminated with these spoilage microbes. The thermo-acidophilic nature of alicyclobacilli and highly resistant endospores allows for their survival during the production of concentrated fruit products. Under favourable conditions, endospores can germinate and multiply to numbers high enough to cause spoilage and product deterioration through the production of chemical taint compounds. It is imperative to understand the nature of Alicyclobacillus within the fruit concentrate processing environment so as to develop effective control strategies and to prevent spoilage in juice and beverage products that are reconstituted from fruit concentrates. This paper reviews the occurrence of alicyclobacilli in the fruit processing environment, control measures, as well as detection, identification and standardised test methods that are currently used for Alicyclobacillus in concentrated fruit products.