Jerusalem Artichoke Paste as a Fat Replacer in the Manufacture of Low-Fat Yoghurt

The influence of different levels of Jerusalem Artichoke (Helianthus tuberosus) paste (JAP) on the quality of low-fat yoghurt was investigated. The JAP was added to low fat milk ( 0.1% fat) to give solids of paste levels of 1, 2, 3 and 4 %. The experimental yoghurt samples were compared with control yoghurt produced from full fat milk (3.1% fat). Acetaldehyde, soluble tyrosine contents, total solids, pH, titratable acidity, synersis, firmness, organoleptic properties and microbiological analysis were determined in the yoghurt after 1, 3, 5, 7 and 14 days. Addition of JAPat more than 1% increased synersis and decreased firmness. Acetaldehyde, pH and titratable acidity were not influenced by addition of JAP. Soluble tyrosine levels were negatively affected by JAP addition. With respect to the organoleptic quality of yoghurt, the parameters studied for all the different treatments were significantly accepted by the panelists. Overall, the yoghurt samples containing 1% of JAP were similar in quality characteristics and not different from the control yoghurt made with whole milk. On the other hand, It seems that 1% JAP affected positively like a prebiotic on the lactic acid bacteria growth .