However at higher temperatures like 50–
70 °C, the AA loss was significant (p b 0.05) after the HPP (Fig. 4). The
AA loss was 7.3, 12.5 and 23.5% at 50, 60 and 70 °C, respectively for
the pulse treatment at 200 MPa. An increased AA loss was obtained at
pulse treatment at the higher pressure levels for a fixed temperature
with a maximum at 600 MPa. The maximum AA loss was 24% at
600 MPa/70 °C/20 min. At 60 °C, AA retention ranged between 84.7
and 90.6%; whereas the figures were 86.2–92.7% and 76.4–78.2% at 50
and 70 °C, respectively. The overall trend of AA loss in the sample was
quantified by a quadratic model (Table 2) and it has been graphically
represented in Fig. 3b. Themodel was fitted well with a high correlation
coefficient (R2 N 0.95). The difference between temperature and pressure
sensitivities of AA can be clearly seen. It can be visualized that temperature
had a major deterioration effect on AA stability than pressure.