Rheological properties of sour‐cherry juice and concentrate

Abstract

Rheological properties of sour cherry juice were determined by a Controlled Stress Rheometer. Sour cherry juice with different solid contents (40, 45, 50, 55, 60, 65, 68.5 and 70 Brix) was prepared using a rotary evaporator after squeezing and filtration of sour cherries. The rheological behavior of these concentrates was studied in the temperature range of 5, 10, 20, 30, 40, and 50°C. Sour cherry juice was found to exhibit Newtonian behavior. The effect of temperature on viscosity can be described by means of an Arrhenius equation. Activation energies appeared in the range of 22.44-73.49 kJ/mol with increasing concentration. To study effect of concentration on the viscosity, power-law and exponential equations were used. Finally, two equation describing the combined effect of temperature and soluble solids content on the viscosity of concentrated sour cherry juice were obtained.

Rheological Models of Kiwifruit Juice for Processing Applications

“…According to Telis-Romero et al [32], high values of activation energy mean that there is a large effect of temperature on the considered property. Akbulut et al [20], who used a similar to Equation (14) model for the viscosity of Juniperus drupacea fruit juice with a total soluble solids concentration varying from 62.8 to 75.2%, reported an activation energy value of 70.37 kJ/mol, whereas [14,17]. In addition, once the structure responsible for thixotropy was destroyed, there was also a lower effect of solids concentration on the viscosity than that in forward and backward measurements.…”

“…On the contrary, Belibagli and Dalgic [17], Altan and Maskan [14], Nindo et al [15], Khalil, Ramakrishna, Nanjundaswamy and Patwardhan [34], and Rao, Cooley, and Vitali [35] reported that clarified sour-cherry, pomegranate, blueberry, raspberry, and banana juices and depectinized clarified apple juice exhibit Newtonian behavior at all concentrations and temperatures. According to Zuritz et al [16], the clarified juice concentrates have a Newtonian behavior, although Ibarz et al [21] have found a small pseudoplasticity in the flow of various fruit concentrates due to the presence of some soluble solids, mostly pectins and tartrates.…”

“…There is a number of research works published about rheological properties of fruit juices [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. However, the scientific literature lacks information on the rheological characteristics of kiwifruit juice.…”

Rheological evaluation of Prunus mume pulp

“…Preliminary experiments showed no significant dependence or slight thixotropy for mume pulp (BELIBAGLI and DALGIC, 2007). Table 1 showed that the yield stress (τ 0 ) did not show consistent behaviour with regards to the variation in temperature between 15 and 75 °C for mume pulp from 6 to 9 °Brix.…”

“…The Arrhenius equation is commonly used for rheological studies reported in the literature, and the effect of temperature on the viscosity can be determined in juices and pulps (ARSLAN et al, 2005;BELIBAGLI and DALGIC, 2007;FALGUERA and IBARZ, 2010;VANDRESEN et al, 2009):…”