Effect of Jerusalem artichoke (Helianthus tuberosus) extract as an alternative to fat on the quality of low fat Yoghurt

Abstract

The effect of adding different concentrations of Jerusalem artichoke (Helianthus tuberosus) extract on the quality of low-fat yoghurt was studied. 10, 15, 20 ml of the Jerusalem artichoke (Helianthus tuberosus) extract was added to the pasteurized liquid milk contain 0.1% milk fat to purpose of giving different levels of inulin/ µg (each milliliter from Jerusalem artichoke (Helianthus tuberosus) extract contains 21 µg of inulin). The yoghurt samples were compared with the control sample produced from whole fat milk. The content of total solids in milk was adjusted to 14% by adding skim milk powder. After storage periods 1, 7, and 15 days, the chemical-physical composition of the yoghurt samples, such as pH, titratable acidity, syneresis (whey separation), the amount of acetaldehyde, and volatile fatty acids. The sensory characteristics of the samples were also evaluated during the same storage periods. It was found that the addition of Jerusalem artichoke extract containing more than 210 µg caused in increased separation of whey and consistency. The values of acetaldehyde, PH and titratable acidity were not affected by adding the Jerusalem artichoke extract. volatile fatty acid levels were affected negative. In the case of sensory evaluation of yogurt. The addition of Jerusalem artichoke extract resulted in the retention of the sensory quality grades, where the treatment control was highest, and the lowest grade was obtained in the yoghurt samples containing 420 μg of inulin. Overall, the quality characteristics of the yoghurt containing 210 μg inulin was similar to the quality characteristics of the control like yoghurt made from whole milk.