Journal of Food Processing & Technology

Effect of different somatic cell levels on rheological properties of probiotic set yoghurt

11^th Global Summit on Food & Beverages

September 22-24, 2016 Las Vegas, USA

Anita Bavarian

Islamic Azad University Shahreza Branch, Iran

Posters & Accepted Abstracts: J Food Process Technol

Abstract:

In the present work, oscillatory rheological tests were carried out to investigate the effect of milk SCC on the viscoelastic properties of probiotic set yoghurt. The starter culture used to produce probiotic yoghurt was ABY1. Results of strain sweep test showed that by increasing SC levels in samples, structural strength, yield stress and flow point were decreased. Duration of storage time increased storage modulus but had no significant effect on damping factor. Frequency sweep test results revealed decreasing complex modulus and viscosity with the increasing SC levels. These 2 parameters had not changed during storage time (p�?�0.05). Power law model was fitted on experimental data. The consistency index of yoghurt samples decreased about 2 times (p<0.05) by increasing SC levels, however flow behaviour index increased. Increasing flow behaviour index of yoghurt with high SC level showed a weaker gel structure. Storage time had a significant effect on consistency index between first and day 7, while no significant differences on flow behaviour index observed during 21 days of storage. Therefore, increasing SC levels had a more pronounced effect on the parameters of viscoelastic and flow behaviour than duration of the storage of the probiotic yoghurts. Based on these results and adverse effect of increasing SC levels on milk proteins particularly caseins as well as lactose and minerals, raw milk used to produce probiotic yoghurt should not contain more than 200,000 somatic cells.

Biography :

Email: anita.bavarian@gmail.com