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Journals / Turkish Journal of Agriculture and Forestry / 2014 / Cilt: 38 - Sayı: 3

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
Pages
377–387
Publication Date
2014-05-18
DOI
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

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.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:Boza is a beverage produced by lactic acid bacteria (LAB) and yeast, which affects rheological properties.
📊
Key Findings & Data: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.
💡
Conclusion & Impact: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.
🔬Design:Modeling & Simulation
📍Scope:Comprehensive Sample
⚙️Variables:Key words: Arrhenius · boza · Cox-Merz rule

Abstract

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.

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.

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Cite This Article

ARICI, M., TATLISU, N. B. E., TOKER, Ö. S., YILMAZ, M. T. (2014). Microbiological, steady, and dynamic rheological characterization of boza samples: temperature sweep tests and applicability of the Cox-Merz rule. Turkish Journal of Agriculture and Forestry, Cilt: 38 - Sayı: 3, 377–387. https://ajindex.com/articles/180062

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References (15)

  1. Ahmed Z, Wang Y, Anjum N, Ahmad A, Khan ST (2013). Characterization of exopolysaccharide produced by Lactobacillus kefiranofaciens ZW3 isolated from Tibet kefirPart II. Food Hydrocolloid 30: 343–350.
  2. Altay F, Karbancıoglu-Güler F, Daskaya-Dikmen C, Heperkan D (2013). A review on traditional Turkish fermented nonalcoholic beverages: microbiota, fermentation process and quality characteristics. Int J Food Microbiol 167: 44–56.
  3. Alvarez MD, Fernández C, Canet W (2011). Effect of cryoprotectant mixtures on rheological properties of fresh and frozen/thawed mashed potatoes. J Food Process Eng 34: 224–250.
  4. Arici M, Daglioglu O (2002). Boza: a lactic acid fermented cereal beverage as a traditional Turkish food. Food Res Int 18: 39–48.
  5. Arslan E, Yener ME, Esin A (2005). Rheological characterization of tahin/pekmez (sesame paste/concentrated grape juice) blends. J Food Eng 69: 167–172.
  6. Augusto PED, Falguera V, Cristianini M, Ibarz A (2013). Viscoelastic properties of tomato juice: applicability of the Cox–Merz rule. Food Bioprocess Tech 6: 839–843.
  7. Bahnassey YA, Breene WM (1994). Rapid visco-analyzer (RVA) pasting profiles wheat, corn, waxy corn, tapioca and amaranth starches (A. hypochondriacs and A. cruentus) in the presence of konjac flour, gellan, guar, xanthan and locust bean gum. Starch 46: 134–141.
  8. Blandino A, Al-Aseeri ME, Pandiella SS, Cantero D, Webb C (2003). Cereal based fermented foods and beverages. Food Res Int 36: 527–543.
  9. Botes A, Todorov SD, von Mollendorff JW, Botha A, Dicks LMT (2007). Identification of lactic acid bacteria and yeast from boza. Process Biochem 42: 267–270.
  10. Bourne MC (1982) Food Texture and Viscosity: Concept and Measurement. New York, NY, USA: Academic Press.
  11. Bourne MC (2002). Physics and texture. In: Bourne MC, editor. Food Texture and Viscosity. London, UK: Academic Press, pp. 59–106.
  12. Chun SY, Yoo B (2004). Rheological behavior of cooked rice flour dispersions in steady and dynamic shear. J Food Eng 65: 363– 3 Cox W, Merz E (1958). Correlation of dynamic and steady flow viscosities. J Polym Sci 28: 619–622.
  13. Da Silva JAL, Rao M (1992). Viscoelastic properties of food hydrocolloid dispersions. In: Rao MA, Steffe JF, editors. Viscoelastic Properties of Foods. London, UK: Elsevier, pp. 285–315.
  14. Deegan LH, Cotter PD, Hill C, Ross P (2006). Bacteriocins: biological tools for bio-preservation and shelf-life extension. Int Dairy J 16: 1058–1071.
  15. De Vuyst L, Vandamme EJ (1994). Bacteriocins of Lactic Acid Bacteria: Microbiology, Genetics a