Physical, sensory and flow properties of wheat starch-dairy by-product spray-dried pekmez mixtures

Sert D., YILMAZ M. T., Karakaya M.

JOURNAL OF TEXTURE STUDIES, vol.39, no.2, pp.150-168, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 39 Issue: 2
  • Publication Date: 2008
  • Doi Number: 10.1111/j.1745-4603.2008.00135.x
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.150-168
  • Yıldız Technical University Affiliated: No


Pekmez, also known as a concentrated grape juice, was spray dried in a laboratory-type pilot drying unit to obtain pekmez powder (PP). The flow characteristics of PP, wheat starch (WS) and some dairy by-products (whey powder, skim milk powder, calcium caseinate and sodium caseinate) systems as binary and ternary mixtures were studied. The empirical power law model fitted the apparent viscosity-rotational speed data. PP-dairy by-product and WS-dairy by-product mixed solutions exhibited a shear-thinning behavior at 21C with flow behavior index (n) values of 0.86 <= n <= 0.92 and 0.06 <= n <= 0.27, respectively. WS-dairy by-product mixed solutions showed high shear-thinning behavior with the highest consistency index (k = 25,425-180,599 mPa.s(n)). However, PP-WS and PP-WS-dairy by-product mixed solutions at the same temperature exhibited the shear-thickening behavior with flow behavior index (n) values of 1.05 <= n <= 1.18.