Rheological Characteristics of Carob Pekmez

Abstract

This study investigated the physicochemical properties and rheological behavior of carob pekmez. Rheological measurements were undertaken at 30, 40, 50, 60, and 70°C using a rotational viscometer at the shear rate of 5, 10, 20, 50, and 100 1/s. The flow characteristics of carob pekmez were described by the power law and Herschel-Bulkley models. The Herschel-Bulkley model was found to be the best to describe the rheological property with the coefficient of determination higher than 0.998. Carob pekmez exhibited a time-independent shear thickening behavior. An Arrhenius equation was used to describe the effect of temperature on viscosity and E_a value of the carob pekmez was calculated as 103.86 kJ mol⁻¹.

Keywords:

• Carob
• Pekmez
• Chemical and rheological properties
• Concentrated fruit juices

Notes

4. Gökçen, J.; Ömeroglu, S.; Ceritoglu, A. Üzümlerden elde edilen pekmez bulama, jöle, cevizli sucuk gibi tipik Türk gıda maddelerinin yapim yöntemlerinin geliştirilmesi olanaklarının araştırılması. TÜBİTAK. 1982, Marmara Bilimsel ve Endüstriyel Araştırma Ens. Gebze Yay. No. 65. Tükiye.

25. TS. Üzüm Pekmezi Standardi. TS 3792. Türk Standartlari Enstitüsü. Necatibey Caddesi, 112, Bakanliklar, Ankara, 1989.

37. Gürses, A. Bayrakçeken, S. Deneysel Fizikokimya. Atatürk Üniversitesi Yayın No: 807. K. K. Egitim Fak. Yayın No: 62. Ders Kitapları Serisi No: 48. Erzurum, Turkey, 1996.