Microbiological, steady, and dynamic rheological characterization of boza samples: temperature sweep tests and applicability of the Cox-Merz rule

Muhammet ARICI; Nevruz Berna ERSÖZ TATLISU; Ömer Said TOKER; Mustafa Tahsin YILMAZ

doi:https://doi.org/10.3906/sag-1308-35

Makale detayları

Microbiological, steady, and dynamic rheological characterization of boza samples: temperature sweep tests and applicability of the Cox-Merz rule

Yazarlar:

Muhammet ARICI | Nevruz Berna ERSÖZ TATLISU | Ömer Said TOKER | Mustafa Tahsin YILMAZ

Yayıncı:

TUBITAK

Ana Başlıklar:

Tarım

Dergi:

Turkish Journal of Agriculture and Forestry 2014 Vol.38 Issue 3, pp.377-387

Belge Tipi:

Makale

Yayın Tarihi:

5/2014

Belge Dili:

İngilizce

Document ID (Org No.):

2000807396

Sıklık:

İki Aylık

eISSN:

1303-6173

pISSN:

1300-011X

DOI:

https://doi.org/10.3906/sag-1308-35

Anahtar kelimeler:

Özet:

 

Boza is a beverage produced by lactic acid bacteria (LAB) and yeast, which affects rheological properties. In the present study, boza samples collected from a local market were characterized with reference to microbiological and rheological approaches. The boza samples were characterized with respect to their microbiological population, i.e. the numbers of LAB and yeast. The numbers of LAB and yeast were found to range from 2.88 × 106 to 2.06 × 1010 CFU/mL and from 3.71 × 103 to 9.40 × 105 CFU/mL, respectively. Their steady and dynamic rheological properties were investigated within the temperature range of 0-50 °C. Apparent viscosity values (h) of the boza samples decreased with shear rate, indicating that the samples behaved as a pseudoplastic fluid. The Ostwald-de Waele model satisfactorily described (R2 > 0.99) the flow behavior of the samples at 5 and 20 °C. Storage modulus (G') values were higher than loss modulus (G''), indicating that boza samples had a solid-like structure. Temperature had a remarkable effect on the steady and dynamic properties of the samples; therefore, temperature sweep tests were also conducted to determine temperature dependency of the samples. The h50, G', and G'' values decreased with increase in temperature. The Arrhenius equation could be satisfactorily used to describe changes in these parameters depending on temperature. A modified Cox-Merz rule with shift factors ranging from 1.0 to 2.2 was successfully applied to put forward a relationship between steady shear and dynamic shear viscosity data.

 

Boza is a beverage produced by lactic acid bacteria (LAB) and yeast, which affects rheological properties. In the present study, boza samples collected from a local market were characterized with reference to microbiological and rheological approaches. The boza samples were characterized with respect to their microbiological population, i.e. the numbers of LAB and yeast. The numbers of LAB and yeast were found to range from 2.88 × 106 to 2.06 × 1010 CFU/mL and from 3.71 × 103 to 9.40 × 105 CFU/mL, respectively. Their steady and dynamic rheological properties were investigated within the temperature range of 0-50 °C. Apparent viscosity values (h) of the boza samples decreased with shear rate, indicating that the samples behaved as a pseudoplastic fluid. The Ostwald-de Waele model satisfactorily described (R2 > 0.99) the flow behavior of the samples at 5 and 20 °C. Storage modulus (G') values were higher than loss modulus (G''), indicating that boza samples had a solid-like structure. Temperature had a remarkable effect on the steady and dynamic properties of the samples; therefore, temperature sweep tests were also conducted to determine temperature dependency of the samples. The h50, G', and G'' values decreased with increase in temperature. The Arrhenius equation could be satisfactorily used to describe changes in these parameters depending on temperature. A modified Cox-Merz rule with shift factors ranging from 1.0 to 2.2 was successfully applied to put forward a relationship between steady shear and dynamic shear viscosity data.

Makale detayları

Microbiological, steady, and dynamic rheological characterization of boza samples: temperature sweep tests and applicability of the Cox-Merz rule

Yazarlar:

Muhammet ARICI | Nevruz Berna ERSÖZ TATLISU | Ömer Said TOKER | Mustafa Tahsin YILMAZ

Yayıncı:

TUBITAK

Ana Başlıklar:

Tarım

Dergi:

Turkish Journal of Agriculture and Forestry 2014 Vol.38 Issue 3, pp.377-387

Belge Tipi:

Makale

Yayın Tarihi:

5/2014

Belge Dili:

İngilizce

Document ID (Org No.):

2000807396

Sıklık:

İki Aylık

eISSN:

1303-6173

pISSN:

1300-011X

DOI:

https://doi.org/10.3906/sag-1308-35

Key words: Arrhenius

boza

Cox-Merz rule

dynamic and steady shear

temperature sweep

Sayı

Makale detayları

Microbiological, steady, and dynamic rheological characterization of boza samples: temperature sweep tests and applicability of the Cox-Merz rule

Yazarlar: Muhammet ARICI | Nevruz Berna ERSÖZ TATLISU | Ömer Said TOKER | Mustafa Tahsin YILMAZ

Yayıncı: TUBITAK

Ana Başlıklar: Tarım

Dergi: Turkish Journal of Agriculture and Forestry 2014 Vol.38 Issue 3, pp.377-387

Belge Tipi: Makale

Yayın Tarihi: 5/2014

Belge Dili: İngilizce

Document ID (Org No.): 2000807396

Sıklık: İki Aylık

eISSN: 1303-6173

pISSN: 1300-011X

DOI: https://doi.org/10.3906/sag-1308-35

Key words: Arrhenius

boza

Cox-Merz rule

dynamic and steady shear

temperature sweep

Sayı

Yazarlar:

Muhammet ARICI | Nevruz Berna ERSÖZ TATLISU | Ömer Said TOKER | Mustafa Tahsin YILMAZ

Yayıncı:

TUBITAK

Ana Başlıklar:

Tarım

Dergi:

Turkish Journal of Agriculture and Forestry 2014 Vol.38 Issue 3, pp.377-387

Belge Tipi:

Makale

Yayın Tarihi:

5/2014

Belge Dili:

İngilizce

Document ID (Org No.):

2000807396

Sıklık:

İki Aylık

eISSN:

1303-6173

pISSN:

1300-011X

DOI:

https://doi.org/10.3906/sag-1308-35