Phenolic Composition and Antioxidant Activity of Purple Sweet Potato ( Ipomoea batatas (L.) Lam.): Varietal Comparisons and Physical Distribution.
Level 5 - mechanism / opinion, no new human data
In vitro analytical food chemistry study without human or animal models.
PubMed 33809444 · doi:10.3390/antiox10030462
What was done
Researchers analyzed the phenolic profile and antioxidant activity in the inner and outer layers of five purple sweet potato cultivars ('Sinjami', 'Jami', 'Danjami', 'Yeonjami', and 'Borami') harvested in Korea. Anthocyanins were identified by UHPLC-(ESI)-qTOF-MS and UHPLC-Ion trap-MS and quantified using HPLC-DAD. Non-anthocyanin phenolics (phenolic acids and flavonols) were quantified using UHPLC-(ESI)-QqQ mass spectrometry.
What was found
A total of 20 anthocyanins, 12 phenolic acids, and 6 flavonols (quercetin derivatives) were identified. Peonidin 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside was the major anthocyanin, reaching highest concentrations in 'Sinjami' (outer: 12,366 mg/kg DW, inner: 14,832 mg/kg DW). Outer layers across all cultivars had higher total phenolic acids and flavonols than inner layers. 'Sinjami' and 'Jami' had significantly higher phenolic acid and quercetin derivative contents and antioxidant activity compared to the other three cultivars (p < 0.05).
Why it matters
The outer layer of purple sweet potatoes, which is frequently discarded as waste during industrial processing, contains high concentrations of bioactive phenolics. Cultivars like 'Sinjami' and 'Jami' represent viable sources for natural antioxidant extraction and functional food applications.
Limits
This was an in vitro compositional study limited to five Korean cultivars. It did not assess compound bioavailability, in vivo biological activity, human health outcomes, or the effect of industrial thermal processing on phenolic stability.
Cited by
- supports Purple sweet potatoes contain anthocyanins, which are polyphenols.