Impact of tiger nut flour as a prebiotic and thickener agent on bio-yoghurt drink

Document Type : Original research paper

Authors

1 Department of Food Science and Technology, Faculty of Agriculture, Tanta University, Tanta 31527, Egypt

2 Department of Food Science and Technology, Faculty of Agriculture, Tanta University, Egypt

3 Dokki, Giza

Abstract

Bio- yoghurt drinks were prepared by mixing water (15%) with cow’s milk yoghurt (85%) and sugar 6% . 0.15% of stabilizer (Unicream 300) was added only to the control treatment, while tiger nut flour was added to the other four treatments at levels of 0.5, 1, 1.5, and 2% (T1, T2, T3, and T4, respectively). The final bio-yoghurt drinks were stored in the refrigerator (4±1 °C) for 15 days and analyzed chemically, physically, microbiologically, and organoleptically when fresh and after 7 and 15 days of cold storage. Results showed that the addition of tiger nut flour increased the total solids, protein, fat, and acidity but decreased the pH value. An inverse relationship was observed between wheying off, viscosity, and the amount of tiger nut added, this mean that as the amount of tiger nut increased the previous parameters decreased. The addition of tiger nut flour also increased the counts of total viable bacteria, Lactic acid bacteria, and Lactobacillus rhamnosus (probiotic bacteria) during the storage period compared with the control treatment. All yoghurt drinks (including control treatment) had more than 1× 106 cfu / ml of probiotic bacteria after 15 days of cold storage. The sensory properties were improved by adding tiger nut flour to the yoghurt drink , especially body and texture and flavor.

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