Selection and characterisation of the predominant Lactobacillus species as a starter culture in the preparation of kocho, fermented food from enset

Abstract

Enset (Ensete ventricosum (Welw.) Cheesman) (false banana) plant is a multipurpose traditional crop widely cultivated in the south and southwestern Ethiopia. A study was conducted to determine the predominant microbes from kocho for subsequent use as a starter culture. Accordingly, a total of 40 lactic acid bacteria associated with kocho were characterized both at the phenotypic and genotypic level. Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus paracasei/casei and Lactobacillus fermentum were the isolated strains during kocho fermentation. Most L. plantarum showed rapid acidification and the higher growth rate than L. brevis. Based on these results L. plantarum (n = 10) and L. brevis (n = 3) were selected as possible starter strains and applied to enset pulp in laboratory scale. These starter strains showed fast pH reduction, increased microbial load than control sample and the possibility of a single strain in the fermentation of enset pulps for the production of kocho.

Microbial and Physicochemical Dynamics of Kocho, Fermented Food from Enset

“…Fermentation starts after kocho is stored in an earthen pit, which may range from three months to one year for completion [ 20 , 35 , 37 ]. It depends on the climatic conditions of that environment [ 15 ].…”

“…Through a long period of fermentation, AAB isolated from the LAB selective media, which may increase the number of metabolites and sensory attributes, maintain hygiene, and promote wholesome kocho fermentation [ 7 , 42 ]. Concomitantly, higher counts of AAB were isolated from fermenting kocho after inoculating the LAB starter culture at the onset of fermentation [ 19 , 20 ]. Aeration causes the enhancement of AAB in fermenting kocho mass, which may affect the sensory quality of fermented mass [ 7 , 9 , 42 ].…”

“…The findings of Karssa and Papini [ 63 ] also revealed similar results: an increment in LAB counts allows for a reduction in pH value and an increase in titratable acidity. Strains of LAB starter culture are responsible for the development of kocho quality [ 20 ]. The mutual interaction of L. plantarum and L. mesenteroides during kocho fermentation causes the degradation of starch content, reduction of pH value, and increase in titratable acidity that inhibit pathogenic microbes and improve the desirable organoleptic characteristics of kocho [ 42 ].…”

“…Studies by Hunduma [ 16 ] and Elifu [ 17 ] showed LAB as a dominant microbial group in the entire enset fermentation process. This is due to their tolerance to an acidic environment [ 18 , 19 ], and hence lactic acid-producing bacteria are suggested to be the potential starter culture organisms for enset fermentation [ 17 , 19 , 20 ]. However, reviews of related literature on physicochemical parameters and microbial dynamics of fermenting enset mass are not analyzed in depth or well organised at all.…”

Purdue improved crop storage bag for kocho fermentation; Ethiopian traditional fermented food from Enset (Ensete ventricosum)

“…Despite enset being the primary food security crop in Ethiopia, enset plant processing for the preparation of food is time-consuming, pit preparation is labor intensive, unhygienic, extended fermentation period and pungent odors are considered the main reasons for limited cultivation of the enset plant [ 7 , 21 ]. Furthermore, the sensory quality of fermented enset is very variable and generally poor, which leads to a lower market price for kocho compared to other crops consumed in the country [ 14 , 22 ].…”