Effect of carotenoids, extracted from dry tomato waste, on the stability and characteristics of various vegetable oils

In this study, various vegetable oils were enriched with carotenoids originating from dry tomato waste using ultrasound-assisted extraction, microwave-assisted extraction and maceration. Analyses of total carotenoids, color and oxidative stability (determined by free radical scavenger activity, peroxide value, Rancimat method and DSC analysis) were carried out. Commercial oils without enrichment were used for comparison. The results showed that the carotenoid contents of the oils increased significantly by increasing incorporation of dry tomato waste. Also, maceration proved to extract significantly higher amounts of these compounds. In some oils the extraction of dry tomato waste improved their oxidative and thermal stability while in others it caused an increase in the peroxide value and a decrease in induction time. Finally, the color parameters of the oils were significantly influenced. Enriched oils could be a potential source of bioactive compounds and might have significant antioxidant activity when ingested as part of a dietary regime.