A microbiological study of sobia: A fermented beverage in the Western province of Saudi Arabia

Abstract

Sobia is a traditional fermented beverage prepared from wheat and malt flours in the Western province of Saudi Arabia. Fourteen samples of sobia were collected from Makkah Al-Mukarrmah (Western province) and from Riyadh (Central province). Samples were examined microbiologically for total bacterial counts, lactic acid bacteria, yeasts and moulds as well as coliforms. Titratable acidity and pH were also analysed. The results revealed that sobia samples had high total bacterial and lactic acid bacteria counts that ranged from 4.17 to 8.09 log c.f.u./ml and from 4.01 to 8.19 log c.f.u./ml respectively. Yeasts and moulds counts ranged from 3.96 to 5.87 log c.f.u./ml. The coliform count was from 0.67 to 3.84 log c.f.u./ml. Acidity expressed as percent lactic acid ranged from 0.04 to 0.30%, while the pH of the samples ranged from 3.37 to 5.53. Identification of microorganisms in sobia revealed the presence of lactic acid bacteria, coliforms, yeasts and moulds. Lactic acid bacteria consisted of Lactobacillus cellobiosus (26.8%), L. buchneri (17.9%), L. plantarum (8.9%), L. brevis (23.2%), L. delbrueckii, delbrueckii (8.9%), Leuconostoc lactis (8.9%), and Pediococcus pentosaceus (5.4%). Coliforms consisted of Klebsiella pneumoniae (25.8%), Enterobacter aerogenes (6.1%), E. sakazakii (33.3%), E. cloacae (19.7%), and Serratia liquefaciens (3%). Yeasts comprised Saccharomyces cerevisiae (27.6%), Candida tropicalis (26.3%), C. ciferrii (13.1%), C. guilliermondii (13.1%), C. lipolytica (6.58%), Kloeckera japonica (13.1%), and Rhodotorula rubra (1.3%). All moulds were Penicillium spp.