Effects of High Intensity Pulsed Electric Fields or Thermal Pasteurization and Refrigerated Storage on Antioxidant Compounds of Fruit Juice-Milk Beverages. Part I: Phenolic Acids and Flavonoids

abstract

© 2016 Wiley Periodicals, Inc.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. Practical Applications: Fruit juice-milk beverages can be considered as a great source of phenolic compounds with high antioxidant properties. Hence, these kind of beverages are attracting the attention of consumers to introduce healthy products in their diets. Currently, food scientists are focused on developing technologies able to preserve bioactive substances in foods. This study demonstrates that the concentration of phenolic acids and flavonoids in mixed beverages could be well preserved by the application of non-thermal technologies such as HIPEF. Although some fluctuation on phenolic compounds concentration in FJ-WM or FJ-SM beverages occur during the storage; at the end, HIPEF treated beverages had a higher content than those thermally treated. Hence, HIPEF processing might be considered as a potential alternative to TP for the preservation of mixed beverages with high content of antioxidant compounds.