Physicochemical and microbiological study on tunjanee – a traditionally fermented Sudanese food from groundnut (Arachis hypogaea) seed cake

Abu ElGasim A. Yagoub ¹ and Thoria Abaker Ahmed²

¹Faculty of Agriculture, University of Zalingei, PO Box 6, Zalingei, Sudan.

²Ministry of Education and guidance, Nyala, Sudan

Corresponding author  Email:  gaschem2000@yahoo.com                                   

Accepted 25 March, 2012

Abstract

Tunjanee is traditionally prepared by fermenting groundnut (Arachis hypogaea L.) seed cake for 21 days. Physicochemical and microbiological properties of the seed cake and tunjanee were analyzed. Tunjanee fermentation resulted in significant changes in major nutrients of the seed cake. Mineral content, total polyphenols, phytic acid and in vitro protein digestibility of the cake were not affected. Mobilization of amino acids content was found. The significant increase in total acidity and fat acidity coupled with a decrease in pH suggests microbial hydrolysis of the major nutrients. Bacillus and Lactobacillus spp. are the main active organisms in tunjanee. The number of total bacteria and yeast increased significantly within 21 days of fermentation. Staphylococcus aureus was absent. Coliforms and faecal coliforms were detected in groundnut cake; however, they increased significantly in tunjanee. A significant lower viable cells count of total bacteria and coliforms after addition of combo salt was observed.

Keywords: Arachis hypogaeae; fermentation; tunjanee; in vitro protein digestibility; physicochemical and microbiological properties