Cold plasma pre-treatment as a promising technique to improve oil yield and its effect on Camellia seed oil quality

Camellia (Camellia oleifera Abel.) seeds are considerably nutritious and extensively used for edible oil extraction. This study aimed to enhance the extraction process and quality of camellia seed oil by investigating the impact of cold plasma (CP) pre-treatment, specifically dielectric barrier discharge (DBD) and plasma-activated water (PAW), on camellia seed quality. The results revealed that CP pre-treatment induced structural modifications in camellia seeds, leading to increased oil yield, higher carotenoid content, and facilitated water loss during drying. Specifically, DBD and PAW pre-treatments increased oil yield by 20.16% and 12.61%, respectively. Additionally, after DBD and PAW pre-treatments, the carotenoid content increased by 11.8% and 7.9%, respectively. However, CP pre-treatment was observed to exert a slight influence on the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. After DBD treatment, the DPPH radical scavenging rate decreased by 11.7%; nonetheless, other antioxidant indicators, such as the total phenolic content, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity, and the tocopherol content, were not affected. Moreover, CP pre-treatment was found to have a certain impact on the stability of oil quality, leading to an increase in the peroxide value, while the acid value remained unaffected. Specifically, DBD treatment increased the peroxide value by 17.6%. In conclusion, CP pre-treatment holds promise in enhancing the yield and quality of camellia seed oil.