Extraction yield with great concentration of sweet pepper has improved by using green technology that reduce environmental cost, and short duration. Results suggested that sweet pepper have higher content of radical scavenging activity and reducing power. Phenolic and flavonoids contents were (86.82 and 38.14 respectively) for Supercritical Fluid Extraction (SCF-CO2) extracts and increased to (90.14 and 45.11 in their nano-capsules, followed by Ethanol extract (EE) and Microwave-Assisted Extraction (MAE). In HPLC analysis, chlorogenic acid was the largest phenolic compounds in MAE 12275.31 µg/g and Gallic acid was 648.45, followed by SCF-CO2 extract being 342.11µg/g. SCF-CO2 nano-capsules recorded high total phenolic, total flavonoids contents, small nano-particles through TEM, more mortality for cancer cell lines under the study followed by MAE, and their stability were less than MAE. The result proved that encapsulation is a very important technique to protect the plant extract from any environmental conditions and aid in the release of these bioactive compounds in the target organs when incorporated in some functional foods. Functional foods produced in this work (ketchup) proved that the addition of 1% sweet pepper extracted by SCF-CO2 followed by microwave were the most acceptable products from the consumers since they retain their release of these bioactive compounds in the target organs when incorporated in some functional foods.