Effect of the Addition of Blueberries on Selected Physicochemical and Sensory Properties of Yoghurts

Asuman Cinbas and Fehmi Yazici*

Food Engineering Department, Engineering College, Ondokuz Mayis University, TR-55139 Samsun, Turkey

Article history:
Received May 10, 2007
Accepted September 24, 2007

Key words:
blueberry, sugar, yoghurt, syneresis, storage time

Summary:
In this research, physicochemical and sensory properties of blueberries and sugar added to yoghurts have been investigated on the first, 10th and 20th day of storage in refrigerator. Samples were analyzed for pH, total solids, protein, fat, ash, viscosity, syneresis, Hunter's L, a, and b values, flavour, body, texture, appearance and colour. Blueberry and sugar mass fractions and storage time had a significant effect on the physicochemical and sensory properties of yoghurts. The addition of blueberries to yoghurt formula resulted in an increase in the syneresis and a decrease in the pH, fat, protein, ash, viscosity and whiteness values. The addition of sugar improved only the flavour of yoghurts. Panelists favoured samples with 25 % blueberries and 4 % sugar in terms of flavour, body, texture, appearance and colour.

*Corresponding author:           fyazici@omu.edu.tr
                                               ++90 362 312 1919/1517
                                               ++90 362 457 6035