Effects of high hydrostatic pressure on enzymes, phenolic compounds, anthocyanins, polymeric color and color of strawberry pulps.
Ключові слова
Анотація
BACKGROUND
Changes in activity of polyphenol oxidase (PPO), peroxidase (POD) and β-glucosidase, individual phenolic compounds other than anthocyanins, total phenols, monomeric anthocyanins, polymeric color and instrumental color of strawberry pulps were assessed after high hydrostatic pressure (HHP) (400-600 MPa 5-25 min(-1)) at room temperature.
RESULTS
β-Glucosidase was activated by 4.7-16.6% at 400 MPa 5-25 min(-1) and inactivated by 8.0-41.4% at 500 or 600 MPa. PPO and POD were inactivated at all pressures, the largest reduction in activity being 41.4%, 51.5% and 74.6%, respectively. The individual phenolic compounds and total phenols decreased at 400 MPa, but total phenols increased at 500 or 600 MPa. However, the monomeric anthocyanins, polymeric color and redness (a*) exhibited no change. HHP induced a decrease in lightness (L*) and an increase in yellowness (b*) at 400 MPa, but no significant alteration in L* value and b* value at 500 or 600 MPa was observed; this was attributed to higher residual activity of PPO, POD and β-glucosidase at 400 MPa. Total color difference (ΔE) was ≥5 at 400 MPa and ≤3 at 500 or 600 MPa.
CONCLUSIONS
HHP effectively retained anthocyanins, phenolic compounds and color of strawberry pulps, and partly inactivated enzymes.
