Guaiacol formation in apple juice, effect of selected additives on Alicyclobacillus growth

Abstract

Disinfectant or card-board off-flavour formation was observed in the batch of pasteurised reconstituted apple juice. Aroma profile of products was analysed using SPME and GC/MS, guaiacol was detected in the apple juice sample as well as apple concentrate. Sporulating bacteria Alicyclobacillus acidoterrestris, which are able to growth in acidic conditions were isolated and identified as the cause of the off flavour formation. The possibilities of flavour formation inhibition using various additives were evaluated. The inhibitory effect of nisin, sulphur dioxide, benzoic acid and EDTA was followed. The best way of prevention is the sufficient washing and disinfection of apples prior the processing e.g. using chlorine dioxide. But when the treatment is insufficient and contaminated apples are to be processed the tested additives can prolong the lag phase and increase product stability. The inhibitory effect of the tested additives decreased in the order: benzoic acid, EDTA, nisin and sulphur dioxide.

Keywords

• alicyclobacillus
• acid foods
• apple juice
• off flavour formation
• inhibition