Abstract:

Ultra high pressure (100–500 MPa) (UHP) was used for the treatment of sweet orange pulp. The results showed
that the chromatic aberration of fruit flesh in each group before and after UHP treatment was not significant (ΔE* < 2).
There were no obvious differences in the composition of volatile components of orange pulp treated with UHP for 10 min
compared to control samples based on the results of electronic nose, while significant effects were found when the pressure
was higher than 400 MPa for 20 min. The content of vitamin C (VC) was reduced gradually with increasing pressure
and holding time, and under UHP with 500 MPa for 10 min and 20 min, the retention rate reached 95.27% and 85.92%,
respectively. The contents of total carotenoids, total phenols, flavonoids, hesperidin and naringin showed different increasing
trends with increasing pressure and holding time, which reached their highest increase rate of 66.53%, 36.04%, 32.74%,
25.61% and 8.74%, respectively. It is concluded that UHP treatment has little effects on the sensory quality of orange pulp
but could reduce the loss of VC. Furthermore, it could increase total carotenoids yield and the contents of total phenols,
flavonoids, hesperidin and naringin.

Key words: orange pulp, ultra high pressure, quality