Debittering of cold pressed grapefruit seed oil by metal‐organic framework adsorbents

Abstract

The aim of this study was to remove bitterness from cold pressed grapefruit seed oil. Seven different metal-organic frameworks and three natural clays (commercial bleaching earth, zeolite, and sepiolite) were used as adsorbents. In addition, water washing and solvent extraction treatments were done. After the treatments, oil physicochemical properties, fatty acid, sterol, tocopherol and flavonoid compositions, sensory flavor profile analysis, and consumer tests were completed. Results indicated that adsorbent treatments were better for oil color, turbidity, free fatty acidity, and p-anisidine values than those of the washing and extraction treatments. Although there was no significant change in oil fatty acid and sterol composition, some loss in tocopherol content was observed after the treatments. Sensory descriptive analysis indicated that oil bitterness, spicy, and throatcatching scores decreased by 62.79%, 42.42%, and 58.97% by chromium metal-organic framework (Cr-MOF) treatment. In conclusion, Cr-MOF treatment successfully removed the bitterness from cold pressed grapefruit seed oil. Practical applications The bitter taste of cold pressed grapefruit seed oil was almost totally removed by adsorbent treatment with the laboratory synthesized chromium metal-organic frameworks. Sensory flavor profile analysis and consumer test indicated that the treated oil can be directly consumed as edible oil. This method could have practical importance for those who interested to produce and use cold pressed grapefruit seed oils for edible purposes.