Fruit maturity is an important factor associated with final product quality, and it may have an effect on the level of browning in peaches that are high pressure processed (HPP). Peaches from three different maturities, as determined by firmness (M1 = 50-55 N, M2 = 35-40 N, and M3 = 15-20 N), were subjected to pressure levels at 0.1, 200, and 400 MPa for 10 min. The damage from HPP treatment results in loss of fruit integrity and the development of browning during storage. Increasing pressure levels of HPP treatment resulted in greater damage, particularly in the more mature peaches, as determined by shifts in transverse relaxation time (T2) of the vacuolar component and by light microscopy. The discoloration of peach slices of different maturities processed at the same pressure was comparable, indicating that the effect of pressure level is greater than that of maturity in the development of browning.
Keywords: 1H NMR; enzymatic browning; high pressure; maturity; peaches.