SOME TRADITIONAL FERMENTED FOOD FROM AFRICAN LOCUST BEANS (PARKIA BIGLOBOSA): PRODUCTION AND VOLATILE COMPOUNDS

Abstract

African locust bean is used for both medicinal and domestical purposes in West Africa. The seeds are processed to nutritive and flavoring fermented condiments such as netetu, iru, sonru, afitin, soumbala, and dawadawa. The production process and the volatile compounds of these fermented condiments were investigated in the present study. The findings showed that dried and cleaned seeds were used to be produced traditional condiments. The processing operations implying mainly and successively a first long boiling (6-24h), dehulling, a second short cooking (1-2h) and fermentation (24-72h). The variations of the operations involving in the production affect physicochemical, biochemical and microbiological characteristics of the final products. More than 160 volatile compounds namely pyrazines, ketones, aldehydes, alcohols, esters, alkanes, alkenes, benzene derivatives, pyridines, furan, volatile phenols, sulfur compounds, and terpenes have been reported in fermented African locust beans. Among these, pyrazines, ketones, aldehydes, and alcohols were found to be the most abundant groups with 2,5-Dimethyl pyrazine, tetramethyl pyrazine, trimethyl pyrazine, 3-methyl butanal, benzene acetaldehyde, 2-nonadecanone, 2-decanone, 3,5-Dimethyl phenylmethanol and 3-methyl-1-butanol as the most important aroma compounds found in the condiments. Production steps mainly fermentation (type and duration), boiling and use of additives conferred to each fermented seed its unique aroma characteristics. Use of pure starter culture enhances overall aroma profile of the finished products.