How cooking techniques influence the bioaccessibility and antioxidant activity of Carotenoids from Pereskia Aculeata

Pereskia aculeata is an unconventional food plant - PANC, its leaves are considered an excellent alternative to be implemented in meals because they are rich in minerals, fiber, phenolic compounds and carotenoids. It is well known that the cooking techniques can influence the bioactive compounds content, and therefore directly change the nutritional benefits of the food. In this work, an integrated study regarding the bioaccessibility and antioxidant activity of carotenoids was performed relating the carotenoid content when submitted to different food techniques, namely steaming, stir-frying and microwave. The carotenoids were exhaustively extracted by acetone and determined and quantified by HPLC-PDA-MS/MS. The antioxidant activity was evaluated by Peroxyl Radical Scavenging, expressed as μmol α-tocopherol. The bioaccessibility of carotenoids was evaluated using an adapted INFOGEST protocol. The carotenoid profile was not influenced by the different preparation techniques, being the all-trans-lutein and all-trans-β-carotene the major carotenoids. However, considering the quantitative profile, the microwave technique led to higher extraction yield (55.56 µg/g) compared to steaming (35.52 µg/g) and stir-frying techniques (23.76 µg/g), besides being also higher than the raw (46,47 µg/g). Moreover, the microwave technique led to the highest antioxidant activity (7.28 μmol α-tocopherol); 2.5-fold higher than the raw sample. Regarding bioaccessibility, the stir-frying technique was more bioaccessible (28.81%) than the other techniques, followed by microwave (12.99%), steaming (11.96%) and raw (6.79%).The use of oil during the stir-frying preparation helps to increase the micellarization, protecting the carotenoids against degradation, while the microwave technique involves the application of high temperatures in a short period, reducing the cooking time and, consequently, reducing the carotenoid losses. Considering this, it is extremely important to know the effects of cooking techniques in order to improve carotenoid food intake recommendation.