Effects of high intensity pulsed electric fields or thermal treatments and refrigerated storage on antioxidant compounds of fruit juice-milk beverages. Part I: Phenolic acids and flavonoids

Abstract

The effects of high intensity pulsed electric fields (HIPEF) or thermal pasteurization (TP) over phenolic compounds in mixed beverages were evaluated after processing and during chilled storage, having untreated beverage as reference. Total phenolic (TPC, 57.0-58.8 mg of galic acid/100mL) and flavonoid (TFC, 4.14-4.33 mg of quercetin/100mL) contents remained constant in fruit juice‐skim milk (FJ‐SM) and ‐whole milk (FJ‐WM) beverages just after HIPEF or TP. Nonetheless, concentration of most individual phenolics augmented. TPC in HIPEF treated beverages remained constant through storage, while in thermally pasteurized beverages tended to decrease (5-15%). No significant changes were observed in TFC in untreated and treated beverages over time. The concentration of individual phenolics in fresh and treated beverages remained constant or decrease with time, except hesperidin, which significantly increased (19-61%) after 56 days. Hence, HIPEF is a feasible technology to obtain mixed beverages with antioxidant properties.

This study was supported by the Ministerio de Ciencia e Innovación (Spain) throughout the project AGL2006‐12758‐C02‐02. L. Salvia‐Trujillo and M. Morales‐de la Peña thanks the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR) (Catalonia, Spain), Consejo Nacional de Ciencia y Tecnología (CONACYT) (México) and Tecnologico de Monterrey (México) for the predoctoral and posdoctoral Research Funds. ICREA Academia Award is also acknowledged by Olga Martín‐Belloso.