Quality characteristics of a red chili oil product processed via oil infusion: effects of pre-heated oil temperature

The increased availability of infused red chili oil in the Northwest China market can be attributed to cultural practices, culinary preferences, and environmental factors. However, despite its popularity, there is a lack of systematic investigation into the formulation and production processes of authentic red chili oil. Therefore, this study aimed to evaluate the impact of pre-heating oil temperature on the quality attributes of red chili oil products. The results revealed that higher pre-heating oil temperatures in the range of 100–200 °C led to a darker color of red chili oil. Concurrently, the pungency of the oil decreased as the pre-heating temperatures increased, with the total capsaicinoid content significantly reduced from 0.29 g/kg to 0.12 g/kg. Besides, over 80 volatile components were identified in the oil, with aldehydes, alcohols, ketones, and esters being the predominant compounds. The total volatile levels notably increased with higher pre-heating oil temperatures, specifically with significant elevations in aldehydes, alcohols, and ketones, while the levels of ketones, hydrocarbons, and nitriles decreased. Based on these findings, it was concluded that the optimal quality attributes, characterized by moderate spiciness, robust flavor, and vivid color, were observed in oils pre-heated between 140 °C and 160 °C. These insights provide valuable guidance for optimizing the production of red chili oil to meet consumer preferences.