Changes in acrylamide content and quality characteristics of red pepper oil by cooking method and conditions

Red pepper oil is a flavored oil produced at home and in restaurants. Most red pepper oil is manufactured by extraction at a high temperature, which can produce harmful substances, such as acrylamide. Acrylamide, a toxic substance classified as a probable human carcinogen, is formed when foods are cooked at high temperatures above 120 °C. In this study, we aimed to propose the optimal method to produce red pepper oil with a decreased amount of acrylamide while maintaining quality characteristics. The conventional cooking (CC) method (160, 180, and 200 °C) and microwave cooking (MC) method were used to make red pepper oil. The acrylamide, carotenoids, and capsaicinoids contents increased with temperature and time. The maximum and minimum acrylamide content of red pepper oil was 3,494.00 ± 147.81 ppb after CC at 200 °C for 5 min and 131.78 ± 2.93 ppb after CC at 160 °C for 1 min, respectively. The total carotenoid contents of the CC samples ranged from 3.74 ± 0.01 to 4.47 ± 0.04 mg/g. Capsaicin and dihydrocapsaicin contents of CC samples ranged from 3.03 to 4.44 and from 1.33 to 1.92 mg/g, respectively. The total carotenoid and capsaicinoid contents of the MC sample were significantly higher than that of CC samples (p < 0.05). In the results of sensory evaluation for 4 samples (CC at 160, 180, and 200 °C, and MC), the sample with the highest score for all attributes was the MC sample. Based on the results of this study, the MC method is considered as an optimal condition for producing red pepper oil with a low acrylamide content and desirable quality characteristics.