Comparative study on the microbiology and shelf life stability of palm wine from <i>Elaeis guineensis</i> and <i>Raphia hookeri</i> obtained from Okigwe, Nigeria

Abstract

The microbiological and biochemical changes and shelf life stability of Elaeis guineensis and Raphia hookeri brands of palm wine were determined. R. hookeri brands were found to habour more heterotrophic and coliform population than the E. guineensis, whereas the later haboured more yeast species. Identification tests revealed the isolation of Bacillus, Lactobacillus, Brevibacterium and Staphylococcus from E. guineensis while Escherichia coli and Micrococcus species with the exception of Brevibacterium sp. was additionally isolated from R. hookeri. Furthermore heterotrophic count and pH were observed to decrease with increased fermentation days. The effect of the preservatives on the sensory properties of palm wine was dependent on the type of preservation used. The level of CO₂ as well as the effect of extracts from the plant preservatives on the isolates from the palm wine samples was also carried out. Percentage loss of CO₂ for each successive fermentation day was observed and there was significant difference in the effect of the plant preservatives used.