Aims: Little information exists regarding the microbiology of two traditional Maori food preparation processes which may involve fermentations. Preliminary microbiological and chemical analyses were carried out on these two foods in order to identify the fermentations involved (if any).
Methods and results: Testing was carried out on freshly-prepared foods and on those that had been processed and stored. Kina (sea urchins, Evechinus chloroticus) are harvested and then stored either under fresh water or buried underground. The most frequently-occurring process appeared to be an alkaline fermentation. Large numbers of Clostridium perfringens were detected in one set of samples prepared outside of the traditional season, but this was the only pathogen detected. In Kina stored in buried plastic bottles during the traditionally-accepted time of the year, bacterial numbers decreased. Tiroi is prepared from mussels and Puha (sow thistle, Sonchos asper) that have been cooked to some degree, combined and stored. Of three methods used to prepare and store Tiroi, the results for one indicated the possible involvement of a lactic acid fermentation, but the other two methods were effectively only cooking and bottling processes.
Conclusions: In the case of Kina, the use of an alkaline fermentation to prepare a seafood for consumption is unusual. One method of Tiroi production is a lactic acid fermentation.
Significance and impact of the study: If these foods are produced as described and are not either eaten immediately or cooked before consumption, then growth, and intoxication by, Clostridium botulinum might occur.