Impact of Thermal Pasteurization and Thermosonication Treatments on Black Grape Juice (Vitis Vinifera L): CP-OES, GC–MS/MS and HPLC Analyses

Abstract

Grape juice is a fruit juice that is widely consumed due to the bioactive compounds, minerals and aroma components it contains. When processing of black grape juice, the aim is to enrich its bioactive compounds using the thermosonication process. Surface response methodology (RSM) and artificial neural network (ANN) models were used for optimization of enrichment. ANN showed superior predictive values (>99%) to RSM. Optimal combinations were obtained at 40 °C, 12 minutes and 65% amplitude for thermosonication. Under these conditions, phenolic, flavonoid, antioxidant, and anthocyanin values were 822.80 mg GAE/L, 97. 50 mg CE/L, 24.51 mmol Trolox/L, and 368, 81 mg of mv-3-glu/L, respectively. Thermosonicated grape juice (TT-BGJ) was tested against black grape juice (P-BGJ) produced with conventional thermal methods. In this study, the effects of thermal pasteurization and thermosonication on bioactive compounds in black grape juice and on mineral, aroma profile and sensory evaluation were investigated. Thermosonication affected the aroma profile less, which was 329.98 μg/kg and 495.31 μg/kg in P-BGJ and TT-BGJ samples, respectively. TT-BGJ was detected to contain 7 different mineral elements (Mn, K, Fe, Mg, Cu, Zn and Na). Thermosonication caused an increase in Fe, Zn, Mn and K minerals. Panelists generally liked the TT-BGJ sample. These results suggest that the thermosonication process may have the potential to replace the traditional thermal process for black grape juice processing.

Keywords: black grape juice, thermosonication, artificial neural network, mineral, aroma profile