Abstract

Zoom-koom is a popular non-alcoholic beverage in Burkina Faso, which is based on cereals and mainly produced by women with important socio-economic implications. This study aimed to evaluate the effect of controlled fermentation using two selected isolates of lactic acid bacteria (LAB) as starter cultures, on the rheological and hygienic quality of zoom-koom. The starter cultures were used singly in monoculture and both in mixed culture. Microorganisms dynamic during the controlled fermentation were followed and enumerated using pour plate methods. The titratable acidity, pH, viscosity, water, ash, crude protein (N×6.25), crude fat and total carbohydrates contents were determined on the final zoom-koom by using standards methods. Sensory analyses of zoom-koom samples were performed by a panel of 30 tasters. The enterobacteria counts of all the controlled fermented zoom-koom samples using starters cultures decreased totally and significantly (pË‚0.05) from 6.4 (LAB 1), 5.5 log CFU/g (LAB 5) and 3.8 (LAB 1 and 5 in mixed culture) to Ë‚ 1 log CFU/g after 24 h of fermentation. However, those of natural fermentation without inoculum decreased significantly (pË‚0.05) but not totally (1.4 log CFU/g after 24 h of fermentation). The zoom-koom from LAB 5 presented the best production of exopolysaccharides and was more viscous and homogenous than the others. All the zoom-koom samples presented a low fat (4.74, 5.21, 5.36 and 5.55%/DM) and ash (0.32, 0.53, 0.49 and 0.69%/DM) contents with a high total carbohydrate (74.18, 76.24, 68.86 and 76.09%/DM) and protein (20.75, 18.02, 25.30 and 17.66%/DM) contents. The most appreciated zoom-koom by the tasters was the controlled fermented zoom-koom from mixed culture (LAB 1 and 5).

Key words: Zoom-koom, starter cultures, fermentation, exopolysaccharides (EPS), hygienic quality.