Lactic acid bacteria and yeasts involved in the fermentation of amabere amaruranu, a Kenyan fermented milk

Abstract

Indigenous fermented milk products contain microbiota composed of technologically important species and strains which are gradually getting lost with new technologies. We investigated the microbial diversity inamabere amaruranu, a traditionally fermented milk product from Kenya. Sixteen samples of the product from different containers were obtained. One hundred and twenty isolates of lactic acid bacteria (LAB) and 67 strains of yeasts were identified using API 50 CH and API 20 C AUX identification kits, respectively. The average pH of all the traditional fermented samples was 4.00 ± 0.93. Lactobacilli, yeasts, and molds as well asEnterobacteriaceae counts from the plastic containers were significantly higher (P < 0.05) than those from gourd.Enterobacteriaceae were below 1.00 ± 1.11 log10 cfu/mL in products from the gourds and 2.17 ± 1.92 log10 cfu/mL from the plastic containers. The LAB species were identified asStreptococcus thermophilus (25%),Lactobacillus plantarum (20%), andLeuconostoc mesenteroides (20%). The predominant yeasts wereSaccharomyces cerevisiae (25%),Trichosporum mucoides (15%),Candida famata (10%), andCandida albicans (10%). The type of vessel used for fermentation had no significant influence on the type of isolated and identified species. The diverse mixture of LAB and yeasts microflora forms a potential consortium for further product innovation inamabere amaruranu and other fermented milk products.

Spontaneously fermented kenyan milk products: A review of the current state and future perspectives

“…Mostly, the milk to be fermented is boiled, cooled and added to the gourd (ekerandi) for fermentation. The fermentation is spontaneous, however normally back-sloping is used where a small batch of previous successfully fermented milk (enduranerio) is added to fresh milk to initiate the fermentation (Nyambane et al, 2014). The milk is valued for provision of nutrition to children and the elderly.…”

“…However, in a pioneering study of Amabere amaruranu, Nyambane, Thari, Wangoh & Njage (2014) analyzed the microbiological composition of the product. The total viable counts were high (log 10 8.06 ± 0.59 -8.24 ±0.40 cfu/ml).…”

“…Some of these products including fermented cereals, tubers, and roots are dietary staples in Africa hence; they are important for food security (Marshall and Mejia, 2012). In Kenya, fermented foods and beverages are produced at household/ village level using traditional fermentation technology from various raw materials such as cereals, milk, honey, sugarcane, bananas, and coconut sap, among others (Nout, 1981;Mathara et al, 2004;Kunyanga et al, 2009;Nyambane et al, 2014). Milk fermentation is a common method for preserving milk and many communities ferment milk to produce desired products.…”

“…In some communities, fermented milk plays a crucial role in the nutrition of vulnerable groups of population such as infants, pregnant women, young children, and the elderly (Chilton et al, 2015). Examples of fermented milk in Kenya include the Mursik from the Kalenjin community (Muigei et al, 2013), Amabere amaruranu from the Kisii community (Nyambane et al, 2014), Kule naoto from the Maasai community (Mathara, 1999), and Suusa from the North Eastern pastoralist communities (Lore et al, 2005). The fermentation processes for the production of these fermented products are typically uncontrolled and are dependent on microorganisms from the environment.…”

“…Fermented foods and the microorganisms that contribute to the fermentation process have also been associated with many beneficial effects on human health and food preservation, however they are underexploited. Although there have been studies characterizing the microorganisms in some of the Kenyan spontaneously fermented products (Lore et al, 2005;Mathara et al, 2004;Nieminen et al, 2013;Nyambane et al, 2014), there has been no technology in Kenya that has been developed to modernize the production of the traditional fermented products using starter cultures under controlled conditions or exploiting their probiotic and antimicrobial potential (FAO, 2010;Reid et al, 2014). This is partly because most studies intended to characterize traditional fermentations employs the classical microbiological culturing techniques, which are inadequate in identifying and characterizing microbial consortia.…”