Experimental study of physical and rheological properties of grape juice using different temperatures and concentrations. Part II: Merlot

Maurício Bonatto Machado de Castilhos; Lilian Fachin Leonardo Betiol; Gisandro Reis de Carvalho; Javier Telis-Romero

doi:10.1016/j.foodres.2017.12.026

Experimental study of physical and rheological properties of grape juice using different temperatures and concentrations. Part II: Merlot

Food Res Int. 2018 Mar:105:905-912. doi: 10.1016/j.foodres.2017.12.026. Epub 2017 Dec 13.

Authors

Maurício Bonatto Machado de Castilhos¹, Lilian Fachin Leonardo Betiol², Gisandro Reis de Carvalho², Javier Telis-Romero²

Affiliations

¹ São Paulo State University - UNESP, Institute of Biosciences, Humanities and Exact Sciences - IBILCE, Campus São José do Rio Preto, Food Engineering and Technology Department - DETA, Cristóvão Colombo St. 2265, 15054-000 São José do Rio Preto, Brazil. Electronic address: mbonattosp@yahoo.com.br.
² São Paulo State University - UNESP, Institute of Biosciences, Humanities and Exact Sciences - IBILCE, Campus São José do Rio Preto, Food Engineering and Technology Department - DETA, Cristóvão Colombo St. 2265, 15054-000 São José do Rio Preto, Brazil.

PMID: 29433287
DOI: 10.1016/j.foodres.2017.12.026

Abstract

The effect of the temperature and concentration on rheological behavior of Merlot juice concentrates was assessed using a rheometer over a wide range of temperature (1-66°C) and concentrations (13.6-45.0Brix) at shear rates of 0.84-212.1 1/s. The Ostwald-De Waele was the best rheological model fitted the data (R²=0.99967 and relative error=7.99%). The consistency levels were significantly reduced with the increase of temperature and increased with the increase of the concentrations, ranging from 0.1766 (13.6Brix at 66°C) to 19.1140Pa·sⁿ (45.0Brix at 1°C). The flow behavior index presented no up or downward pattern when the temperatures were compared. The flow activation energy ranged from 13.95 (45.0Brix) to 24.88KJ/mol (21.0Brix) with a R²=0.9822 and 0.9812, respectively. Density and specific heat were influenced by both temperature and concentration; however, thermal conductivity was only influenced by concentration and temperature in two cases (13.6 and 29.0Brix). The data showed the potential use of Merlot juice concentrates as wine chaptalization agent in winemaking.

Keywords: Activation energy; Grape juice; Merlot; Physical properties; Rheology.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Food Analysis / methods*
Food Handling / methods*
Fruit / chemistry*
Fruit / classification
Models, Chemical
Rheology
Temperature*
Thermal Conductivity
Vitis / chemistry*
Vitis / classification
Wine / analysis*