pH, peroxide values, TVB-N, and TCA-soluble peptides The change in pH value of each treatment is illustrated in Fig. 3A. On day 0, the pH of the control and TM was 6.68 ± 0.01 and 5.71 ± 0.25, respectively. This result indicated that the pH value of TM was lower than that of the control (P < 0.05) due to the low pH condition of C. aurantium juice. No significant differences (P > 0.05) were then indicated in the pH values between the control treatment and TM during storage on days 14 and 21.