The microbiology of Kocho: An Ethiopian Traditionally Fermented Food from Enset (Ensete ventricosum)

Abstract

Kocho is starchy food product obtained from a mixture of the scraped pulp of pseudo stem and pulverized corm of enset plant (Ensete ventricosum). Ensete ventricosum is a drought resistant plant and can be cultivated as an alternative food source for food security problem around the globe. This study was conducted to examine the fermentation process, the microbial dynamics and the physicochemical changes that occur during traditional fermentation of kocho. Survey on kocho fermentation was carried out at three localities in the vicinity of Hawassa city, Southern Ethiopia. Matured enset plants were purchased and processed and fermented following the traditional methods practiced by the Sidama (local people living in and around Hawasa City) women. Kocho samples were taken for microbiological and physicochemical analysis. The fermentation process was conducted in two Phases: Phase I (surface fermentation or without burring) and Phase II (pit fermentation or buried in pit) under five treatment conditions (kocho dough with traditional starter culture in bucket at surface or not buried in the pit, Kocho dough without traditional starter in bucket at surface or not buried, kocho dough with traditional starter culture in bucket buried in the pit, kocho dough without traditional starter culture in bucket buried in the pit and traditional kocho fermentation in pit). At Phase I, Aerobic mesophilic counts (AMC) were varied between 3.8 and 7.8 log CFU/g in all treatments. Correspondingly lactic acid bacteria (LAB) and yeasts were varied between 2.3 to 9.5 and 2.1 to 8.3 log CFU/g respectively. The pH value ranged from 6.12 to 4.50. At Phase II, AMC showed decreasing trend and enterobacteriaceae were totally inhibited towards the end as pH value lowered. Inconsistent variation was observed on LAB and yeast counts. Results suggested that LAB and yeasts were identified as the major microorganisms responsible for the fermentation of kocho. The isolates need further investigation to identify to species and/or strain level and use in starter culture development. DOI: http://dx.doi.org/10.3126/ijls.v8i1.8716

Effect of fermentation system on the physicochemical and microbial community dynamics during enset (Ensete ventricosum ) fermentation

“…Lactic acid bacteria are considered to be the main contributor for the increase in titratable acidity and the consequent drop in pH during enset fermentation (Gashe ; Karssa et al . ; Bosha et al . ; Andeta et al .…”

“…The decrease in pH and the increase in titratable acidity during fermentation can mainly be attributed to the activity of acid producing micro-organisms. Lactic acid bacteria are considered to be the main contributor for the increase in titratable acidity and the consequent drop in pH during enset fermentation (Gashe 1987;Karssa et al 2014;Bosha et al 2016;Andeta et al 2018). Similarly, lactic acid bacteria were reported as the main acid producing micro-organisms during sauerkraut and cassava fermentation (Oguntoyinbo and Dodd 2010; Xiong et al 2012).…”

“…However, some information exists on the succession of diverse microbial groups during fermentation of enset, mainly based on classical microbial counts (Karssa et al . ; Bosha et al . ; Andeta et al .…”

“…Fermentation of kocho takes several months and it is traditionally carried out in an underground pit or in a bamboo basket, also known as 'erosa' (Gashe 1987;Andeta et al 2018). However, some information exists on the succession of diverse microbial groups during fermentation of enset, mainly based on classical microbial counts (Karssa et al 2014;Bosha et al 2016;Andeta et al 2018), so far there is no in-depth study that compares the whole microbiome for the two major fermentation systems by a culture-independent technique (hence also including the viable but not culturable organisms). The first aim of this study was therefore to provide baseline data of the pit and the erosa system with respect to the evolution of intrinsic parameters, classical microbial counts and the bacterial population, based on high-throughput sequencing of the 16S rRNA gene using the Illumina Miseq platform.…”

Review on contribution of indigenous food preparation and preservation techniques to attainment of food security in Ethiopian

“…Records suggest that Enset has been grown in Ethiopia for more than 10,000 years (Jacob, 2004). It is ranked as the first in its importance as cultivated staple food crop in the highlands of central, south, and southwestern Ethiopia (Karssa, Ali, & Gobena, 2014;Tsegaye, 2002 Enset is a crop that tolerates harsh environmental conditions including prolonged drought periods, flooding, and many diseases. It is ranked as the first in its importance as cultivated staple food crop in the highlands of central, south, and southwestern Ethiopia (Karssa, Ali, & Gobena, 2014;Tsegaye, 2002 Enset is a crop that tolerates harsh environmental conditions including prolonged drought periods, flooding, and many diseases.…”