Optimization of Ultrasound-Assisted Extraction of Phloretin and Other Phenolic Compounds from Apple Tree Leaves (Malus domestica Borkh.) and Comparison of Different Cultivars from Estonia
Laen...
Kuupäev
2021
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
MDPI
Abstrakt
Polyphenolic compounds, plant secondary metabolites essential for plant survival, are
known for their high antioxidant and anti-inflammatory activity. In addition, several polyphenols,
such as phloretin, also have potential antiviral effects, making these compounds potential ingredients
of biofunctional foods. A promising source for the extraction of phloretin is a by-product of apple
production—apple tree leaves. Focusing on green technologies, the first aim of the present study
was to optimize the direct ultrasound-assisted extraction conditions to gain the maximum yield
of phloretin from air-dried apple leaves. For the optimization of process parameters, we applied
the response surface method with Box–Behnken design. The optimal extraction conditions were
extraction time 14.4 min, sonication amplitude 10% and 10 g of sample per 100 mL solvent (70%
ethanol, w/w). Using these conditions, we assessed the content of individual and total polyphenolic
compounds along with antioxidant activity in the leaves of different autumn and winter apple
cultivars grown in Estonia. The analyses were carried out with chromatographic (HPLC-DADMS/
MS) and spectrophotometric methods. The phloretin concentration ranged from 292 to 726 g/g
and antioxidant activity from 6.06 to 11.42 mg GA eq./g, these being the highest in the local winter
cultivars ‘Paide taliõun’ and ‘Tellissaare’, respectively.
Kirjeldus
Received: 6 January 2021,
Accepted: 25 January 2021,
Published: 28 January 2021
Märksõnad
malus domestica, leaves, agri-food waste valorisation, polyphenols, phloretin, antioxidant activity, ultrasound-assisted extraction, optimization, articles
Viide
Ben-Othman, S.; Kaldmäe, H.; Rätsep, R.; Bleive, U.; Aluvee, A.; Rinken, T. Optimization of Ultrasound-Assisted Extraction of Phloretin and Other Phenolic Compounds from Apple Tree Leaves (Malus domestica Borkh.) and Comparison of Different Cultivars from Estonia. Antioxidants 2021, 10, 189. https://doi.org/10.3390/ antiox10020189