The Effects of Herbal Plants on Quality and Microbial Safety of Cow Milk Produced by Smallholder Dairy Farmers in Northern Ethiopia

Abstract

Cow milk is a perishable commodity that spoils easily. Its low acidity and high nutrient content makes to be a medium for bacteria growth. The study was conducted to evaluate the effect of five herbal plants (Olea europaea L, Vernonia amygdalina, Solanum schimperianum hochst, Acacia etbaica schweinf, Aoe elegans) on improving the quality and microbial safety of cow milk. Milk samples were collected and poured in to 6 calabash and 6 plastic containers each with 200 ml. Non-fumigated plastic and calabash containers were used as control group. Bacterial load was estimated using standard plate and coliform counts. Effects of herbal plants were assessed on the basis of selected organoleptic (odor and taste) and physical attributes (temperature and pH) parameters. The lowest standard plate (7.8x10⁵) and coliform (4.5x10⁵) bacterial count was obtained from milk samples fumigated by Vernonia amygdalina. The highest bacterial count was recorded from milk samples of non-fumigated containers. Vernonia amygdalina was identified as the best herbal plant in improving the quality of milk. Milk stored in plastic and calabash containers had an excellent taste and odour but did not significantly decreased bacterial load. There is a need to investigate the active ingredients contained in the herbal plants.

Keywords: Calabash, Coliform count, Plastic, Fumigation, Standard plat count