Thermal processing of raspberry pulp: effect on the color and bioactive compounds

BADIN, E.E.; ROSSI, Y.E.; MONTENEGRO, M.A.; IBARZ, A.; RIBOTTA, P.D.; LESPINARD, A.R.

FOOD AND BIOPRODUCTS PROCESSING

INST CHEMICAL ENGINEERS

Año: 2020 vol. 124 p. 469 - 477

0960-3085

The effect of heating on color degradation and the bioactive compounds, such as totalmonomeric anthocyanins (TMA), L-ascorbic acid (AA) and total polyphenols (TP), ofraspberry pulp were investigated at 70, 80, 90 and 100 ºC for 2 h. The changes in a*(redness-greenness), chroma (C*) and browning index (BI) color parameters followed afirst-order reaction with activation energies of 39.39, 35.60 and 51.17 kJ mol-1,respectively. The degradation of TMA and AA also followed first order kinetics while TPdid not show significant variations with thermal treatment. The activation energies of theTMA and AA changes were 28.36 and 29.47 kJ mol-1, respectively. In addition, theactivation energies revealed that BI was the most sensitive parameter towards temperaturechanges, while the reaction rate constants (k) showed that AA had the highest degradation rate in comparison with the other parameters studied. The degradation of TMA showed astrong positive correlation with a*. The results obtained in this study may be useful tofood processors for designing and optimizing thermal treatment conditions in order toobtain high quality raspberry pulp products.