Flavour And Fragrance Journal, vol.37, no.1, pp.52-62, 2022 (SCI-Expanded)
The aim of this study was to remove bitterness from cold-press
produced grapefruit
seed oil by adsorption principle. The 14 different materials and 5 different metal–organic
frameworks (MOFs) were tested for this purpose. Best performing adsorbents
were selected based on the analyses of sensory bitterness measurements, as well as
oil loss, free fatty acidity (FFA), peroxide value (PV), and color measurements. The
silica gel 60 and MIL-101
MOF were selected as the best performing adsorbents and
tested against control oil. There were some changes in oil color. Oil FFA and unsaponifiable
matter values were decreased, and PV and turbidities were enhanced after the
treatments. Similarly, unsaturated fatty acid content and tocopherols were decreased
expectedly. Although MIL-101
caused great sterol losses, it was in fewer quantities
with silica gel 60 treatment. Silica gel 60 treatment resulted in the complete removal
of the bitter-tasting
flavonoids: naringin and neohesperidin. The non-bitter
flavonoids
were also decreased after both treatments. Most importantly, sensory descriptive
analysis proved that after silica gel 60 treatment, the bitter taste was totally removed,
and the astringent, menthol, and raw vegetable attributes significantly reduced compared
with the control sample. Overall, the silica gel 60 treatment provided total success
in removing bitterness from the oil. Further studies for the reusability of the silica
gel 60 and possibly other similar adsorbents for the same purpose were suggested.