Résumé:
The experimental study is devoted to the evaluation on the one hand of the inhibitory effects of the aqueous extract of Foeniculum vulgare on the growth of specific yoghurt germs, and on the other hand of the impact of the addition of this extract. At different doses as a natural additive on the evolution of the physico-chemical, microbiological and organoleptic parameters of a fermented milk (of the parboiled yogurt type) during the periods of fermentation and post-acidification. The extract of the plant under study was obtained by macerating a prose of plant material from the fennel seed in a hydroethanolic solution. The recovered extract was then incorporated at 0, 2 and 4% in the preparation of a fermented milk such as stewed yogurt. The various measurements and controls were carried out in triple tests periodically on the 1st, 7th, 14th and 21st day of storage of the experimental fermented milks in the cold at 4 ° C and related to: pH, acidity, viscosity, enumeration germs specific to yogurt, and organoleptic tests including (taste, adhesiveness, cohesiveness, freshness, color, etc. The results have undergone an analysis of variance and a comparison of means in pairs according to the Newman and Keuls test.
The addition of hydroethanolic extract of Foeniculum vulgare in fermented milk even at a severe dose of 4% did not affect the acidity, pH, viscosity and even the growth of the bacteria Streptococcus thermophilus and Lactobacillus bulgaricus.In addition, the fermented milk with the addition of 2% and 4% aqueous fennel extract was very well appreciated by the tasting panel, as was the control yogurt.
