Optimization of trans-resveratrol concentration and sensory properties of peanut kernels by slicing and ultrasound treatment, using response surface methodology.

Effect of postharvest stress application by slicing at 0.2, 0.4, and 0.6 cm, exposure to ultrasound (power density of 39.2 mW/cm3) for 4 min at 25 degrees C and subsequent incubation for 24, 36, 42, and 48 h on trans-resveratrol concentrations, and sensory attributes were evaluated using response surface methodology. Peanuts sliced 0.4 and 0.6 cm, exposed to ultrasound, and incubated for 42 h had trans-resveratrol concentrations above 1.0 microg/g, as did all samples incubated for 48 h. The optimized area was bound by peanut size of 0.89, 0.72, and 0.64 and incubation time of 48, 41.5, and 48 h, respectively. Combinations of treatments that fall within the optimized area were predicted to result in a peanut with a trans-resveratrol > or = 1.0 microg/g; slightly lower roasted peanut aroma (> 24) and flavor (> 43); peanut butter aroma (> 14), and flavor (> 31) compared to controls with attribute ratings of 33, 78, 38, and 51, respectively; and slightly higher oxidized aroma (< 6), and painty (< 0.5), fishy (< 6), and cardboard flavor (> 4) compared to controls rated 0 for all attributes.