Physicochemical evaluation and microbiological properties of artisanal Yoghurt sold in Maroua-Cameroon

Abstract

Malnutrition remains a real health problem in the Far North Region of Cameroon despite the presence of many food commodities. The objective of this work was to evaluate physicochemical and microbiological properties of ten artisanal yoghurt (kossam) sold in Maroua-Cameroun. Proximate composition, viscosity and titratable acidity were determined by standard Association of Official Analytical Chemists (AOAC) methods. Mineral contents: calcium, magnesium, sodium, potassium, iron, zinc and manganese were determined by atomic absorption spectrophotometry and phosphorus by Murphy Riley reagent. The microbiological analyses were carried out following the standard protocols. Analysis of variance revealed a significant difference in the levels of the parameters analysed in the different yoghurt samples (p<0.05). The results of this study revealed for all the samples an acid pH (3.20 - 4.37); titratable acidity (2.01-2.74% ); viscosity (1.32-1.51). Other contents per 100g fresh matter are as fellow: Moisture (87.29- 92.45%); Protein (2.02-3.72g); Carbohydrate (4% for all the samples); ashes (0.28-0.49g); calcium (74-113mg); magnesium (4-20mg); zinc (0,117-0,333mg); potassium (60.4-165mg); sodium (10- 17,25mg); iron (0.034-0.088mg) and phosphorus (51-80mg). The microbiological analyses revealed that fungal flora were only detected in few samples (1.2-4.47 log10cfu/ml); Total aerobic mesophilic flora (4.36 -9 log10cfu/ml); Staphylococcus (1.30-5.31 log10cfu/ml) and total coliforms (1- 3 log10cfu/ml). These yoghurts could therefore contribute nutrients for human nutrition and for the management of some nutritional diseases.