Modeling the rheological properties of currant paste as a function of plasticizers concentration, storage temperature and time and process temperature. (February 2019)

• Record Type: Journal Article
• Authors: Nikolidaki, Eirini K.; Mandala, Ioanna; Zogzas, Nikolaos P.; Karathanos, Vaios T.
• Is Part Of: Food research international. Volume 116(2019)
• Page Start: 1357
• Page End: 1365
• Publication Date: 2019-02
• Subjects: Raisin paste -- Plasticizers -- Viscosity -- Viscoelastic properties -- Modeling; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2018.10.025
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: The steady and dynamic shear rheological properties of currant paste samples as a function of storage temperature (15, 25 and 35 °C) and time (180 days) and plasticizers content (water and/or glycerol) have been evaluated. Apparent viscosity (ηa ) has been found to be significantly increased with prolonged storage, implying possible structural changes, and decreased with the increase in storage temperature and the addition of water or/and glycerol. Flow behavior index and consistency index were determined by fitting the resulting experimental data to a power law equation with high values of correlation coefficients (R 2 ≥ 0.912). Furthermore, the combined effect of storage temperature, time and plasticizers concentration on the apparent viscosity was described adequately by a proposed empirical model, with low standard relative errors (SRE ≤ 0.011). Additionally, the viscoelastic properties were significantly affected by all evaluated parameters in the same way as in apparent viscosity while both moduli (G′ and G″) were modeled sufficiently (R 2 ≥ 0.884) as power functions of oscillatory frequency. The heat treatment (heating from 25 to 100 °C and cooling back with a rate of 10 °C/min) applied has proved sufficient to reverse the observed storage effects. Moreover, the modified Cox-Merz rule was satisfactorily applied to describe the correlation between the apparent viscosity and the complex viscosity. Graphical abstract: Unlabelled Image Highlights: The rheological properties of currant paste were modeled by power-law functions. A multi parameter model was proposed to predict storage viscosity changes. Heating could reverse the structural effects of samples observed during storage.