Saudi Journal of Pathology and Microbiology (SJPM)
Volume-1 | Issue-02 | 42-49
Original Research Article
Yoghurt Production from Powdered Milk using Mixed Lactic Acid Bacteria Starter Cultures
Obi CN, Olugbue VU, Mpamugo CP
Published : July 30, 2016
Abstract
Lactobacillus bulgaricus, Streptococcus thermophilus and Lactobacillus fermentum isolated from fermented
foods: yoghurt, “ugba” and “kunu-zaki” using MRS agar and a commercially acquired lactic acid bacteria (LAB) were
used to produce yoghurts samples A-H from Milksi Powered milk in a 5 hour fermentation process. The three LAB
isolates were used singly and in combinations as starter cultures. There was a maximum drop in pH (4-4.8) between the
second and third hour of fermentation while the yoghurt produced using S. thermophilus had the lowest pH (5.2) at the
temperature of 40oC. The optimum pH for the yoghurt production was 5.5 while the optimum temperature was 40oC.
Yoghurt samples B and F had the highest moisture level (P<0.05) while Samples C, E and G had the highest dry matter
content. The highest ash content (0.8 ±0.01; P<0.05) was from sample F while Samples D and E had the highest crude
fibre content. Sample A had the highest crude fat value (3.95a±0.01; P<0.05), Sample F the highest crude protein content
(3.95a±0.01; P<0.05) while the highest carbohydrate content was from Samples C, E, G and H (control). The control
Sample (H) had the highest and Hedonic test for sensory properties of the eight yoghurt samples showed that the eight
yoghurt samples were acceptable to the panelist indicating that the samples would compete favourably in the market with
commercially sold yoghurts.