Woo
et al. (2011) further reiterated that betacyanin favours acidic
pH region and are stable between pH 3 to 7 whilst beyond this
range, it would be readily degraded. In the current study,
betacyanin content was significantly higher at pH 5 compared
to pH 7 (p≤0.05) (Table 2), in accordance to that of Woo et al.
(2011). No significant difference was observed at pH 3, 4 and
6 (p>0.05) (Table 2). Since there are limited types of yeasts,
molds and bacteria that are able to grow in low pH juices of
pH 3.3–4.0 (Bull et al. 2004), pH 4 was selected for subse-
quent studies for preservation purposes. Under acidic condi-
tions, decarboxylation of betanin was observed especially
when heated at approximately pH 3–4 (Huang and von Elbe
1987). Dehydrogenation to the yellow neobetanin was also