As shown in Fig. 2, the activity of

As shown in Fig. 2, the activity of PAL in raspberry fruits treated
with Aloe vera gel increased when compared with the control
(p < 0.05), showing that Aloe vera gel treatment triggered the key
enzymes of the secondary metabolites biosynthetic pathways in
raspberry fruits. Biosynthesis of phenols and flavonoids in plants
perform via the shikimate-phenylpropanoid-flavonoids pathways
(Tsai, Harding, Tschaplinshi, Lindroth, & Yuan, 2006). PAL as a key
enzyme in the phenylpropanoid pathway, catalyzes conversion of
phenylalanine to trans-cinnamic acid. P
erez-Balibrea, Moreno, and
García-Viguera (2011) suggested that the activity of PAL, a key
regulatory enzyme responsible for the phenylpropanoid metabolism,
induced by SA treatment, could favor the phenols biosynthesis
gene expression (Jahangir, Abdel-Farid, Kim, Choi, &
Verpoorte, 2009), triggering the accumulation of these secondary
metabolites in broccoli sprouts. The results showed that Aloe vera
gel treatment significantly enhanced PAL activity in raspberry
fruits.