Abstract #M130

# M130
Whey acerola-flavored drink processed by ohmic heating: Effect on ascorbic acid degradation and color parameters.
L. Cappato1, M. V. Ferreira*1, G. Mercali2, L. Marczak2, A. Cruz3, 1Universidade Federal Rural of Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil, 2Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil, 3Instituto Federal de Ciência e Tecnologia do Rio de Janeiro (IFRJ), Rio de Janeiro, RJ, Brazil.

Ohmic heating (OH) consists of the passage of electric current in the food itself, which promotes a fast and homogeneous heating, due to the conversion of the electric energy into thermal by the joule effect, thus resulting in a greater retention of bioactive compounds. The aim of the present work is to evaluate the OH effect and determine the best processing parameters (10, 100, 1000 Hz at 25 V, 45, 60, 80 V at 60 Hz) compared with conventional processing (pasteurization – 64°C/30 min) of acerola-flavored whey beverage (35% pasteurized milk + 65% whey, 30% acerola pulp wt/wt) regards the impact on color parameters and ascorbic acid degradation. Samples were collected at the following pre-determined interval times (0, 15, 30, 45, 60, 80, 100 min) to determine the AA degradation kinetics to obtain the D value (time to degrade 90% of the initial concentration). The data were adjusted by the first-order model [C = C0 × exp (-K)]. For colorimetric analysis the parameters hue angle (°h), the chromaticity (C*) and the color variation (ΔE*) were calculated. The OH performed at 1000 Hz - 25 V (D = 675 min) and 60 V - 60 Hz (D = 759 min) presented a lower D value (P < 0.05), whereas for the other treatments there were no significant difference in relation to the conventional (D = 864.8 min). In relation to the color degradation after the pasteurization, a significant difference (P < 0.05) in hue and color values was observed. Color parameters changes were observed just for the OH processing parameters (80V – 60 Hz) in relation to the conventional processing (°h = 2.15 and 1.13 and ΔE* = 4.58 and 1.31, respectively, P < 0.05). Regarding the Chroma values, no OH effect was observed (P > 0.05). The findings suggests that OH is presented as a promising technology for the production of whey dairy drinks, which in this context, the knowledge of the best process parameters is a crucial point to guarantee the best retention capacity of AA, without influencing the color aspects.

Key Words: ohmic heating, acerola-flavored whey drink, ascorbic acid degradation