Processamento de bebida láctea de framboesa por aquecimento ôhmico

Abstract

Ohmic Heating (OH) is an emerging technology that presents as an excellent alternative to the conventional heating (CH), as the heat is dissipated within the food in a homogenous way (electric current through the food matrix) and not by convection and conduction. Among the advantages it can be listed: the reduction in color change, thermosensitive compounds preservation, including the bioactive, and other rheological factors that interferes in the product characteristics. Additionally, the presence of the non-thermal effect in the OH (electroporation) confers to it great potential in a better microorganism inactivation compared to the conventional treatment. Thus, OH was used to pasteurize raspberry flavored whey-drink in the following parameters (45, 60 and 80 at 60 Hz) and frequency (10, 100, 1000 Hz – 25 V), maintaining the same time-temperature profile (65°C-30min), in the evaluation physical-chemical and Rheological effect compared to the CH in the whey-drink. All the treated beverages showed an increase in the antioxidant capacity for the (DPPH, FRAP, and TPC). Likewise, it was observed an increase for ACE and 10% of increase for antihyperglycemic activity. The OH treated samples showed better preservation of anthocyanins and a change in the fatty acids profile. The treatment 10Hz-25V and 1000Hz-25V showed the best characteristic regarding color, rheological behavior, while the others (treated varying voltage) showed less viscosity and higher color alteration in a negative way. The results highlighted the importance to establish the adequate parameters to the ohmic equipment. However, in general, the OH showed an interesting potential to the raspberry-flavored whey-drink.