Sorption of citrus flavour compounds on XAD-7HP resin during the debittering of grapefruit juice

Abstract

Grapefruit juice made from concentrate was debittered using a laboratory-scale downflow column packed with XAD-7HP adsorbent resin. Sorption of the bitter principle naringin was analysed by high-performance liquid chromatography. In addition, the influence of the debittering process on the flavour of the juice was investigated using headspace gas chromatography for the volatile flavour compounds a-pinene, b-myrcene, d-limonene, a-terpineol and b-caryophyllene. Kinetic constants were determined for all substances using the Lagergren adsorption model. The debittered juices showed a selective shift in their reduced flavour profile. Reduction of naringin to 51.28% of its initial value led to a decrease in a-terpineol to 43.05%, whereas the other flavour compounds ranged from 76.27% (b-myrcene) to 92.76% (b-caryophyllene). The column flow rate influenced the adsorption of a-terpineol and naringin. The highest affinity for adsorption was consistently observed for the off-flavour a-terpineol, which indicates a promising option for its selective removal from processed juices during debittering.

Effect of treatment with adsorbent resin on the volatile profile and physicochemical characteristics of clarified cashew apple juice

“…This adsorbent removed the compounds with a positive impact on the odor of the cashew apple juice (cashew odor) and also with a negative impact (offflavors), which leads to a weaker fruity aroma (Kranz, Adler and Kunz (2011) also observed a flavor loss during adsorptive debittering of grapefruit juice using XAD-7HP resin. Although FPX66 resin removed most of the compoounds (15.72% of the control), some odor active volatiles such as ethyl propanoate and ethyl 3-methyl butanoate were still present, which imparted…”

Industrial orange juice debittering: effect on volatile compounds and overall quality attributes

“…These results are in accordance to those reported by Kranz et al . () in grapefruit juice, who reported that the DP has a strong impact on volatile flavour compounds. Moreover, they also reported that the off‐flavour compound α‐terpineol had the higher adsorption affinity for the adsorption resin.…”

“…The most commonly used method to reduce the bitterness in processed citrus juices is the use of polymeric adsorbents to selectively remove limonoids (Konno et al, 1982;Johnson & Candler, 1986). Other compounds rather than limonoids may be reduced by the debittering process (DP) such as vitamin C, hesperidin and naringin or total phenolic compounds (Kimball & Norman, 1990;Lee & Kim, 2003;Kranz et al, 2011).…”

Enzymatic Debittering on Antioxidant Capacity of Grapefruit Juice

“…Among the various techniques that are used to reduce bitterness, adsorption on macroporous resin is the process that is applied most frequently in the citrus industry (Kranz et al, 2011). This and other techniques for debittering routinely remove bioactive compounds, such as ascorbic acid, phenolics, flavonoids, isoflavonoids, isoflavones, and terpenes from fruit juices (Puri et al, 2008;Lee and Kim, 2003).…”

“…As in all citrus fruits, the grapefruit also contains the bitter triterpenoid, limonin (Hasegawa et al, 1985a). However, these techniques involve not only the removal of the bitter compounds, but also nutrients/flavor/color from the juice (Kranz et al, 2011;Puri et al, 2008;Lee and Kim, 2003). A number of physico-chemical methods and materials (macroporus resins, affinity columns, cyclodextrin polymer, activated diatomaceous earths,…) have been applied to minimize the flavonoid and limonoid bitterness problem Ribeiro et al, 2002).…”