After 8 days of storage, 50% Aloe vera gel had the highest GSSG and
GSH activities on raspberry fruits (Fig. 5). The important function of
GSH enzyme is the maintenance of cellular redox status
(Rennenberg, 1980). The primary oxidation product of GSH is its
disulfide, GSSG, which can be reduced back to GSH by glutathione
reductase at the expense of NADPH (Ric de Vos, Kraak, & Bino,
1994). The result showed that 50% Aloe vera gel enhanced the increase
of GSH enzyme in raspberry fruits during storage. This
reduced form of glutathione serves as a substrate for DHAR and
reacts directly with free radicals, including hydroxyl, to prevent the
deactivation of enzymes by oxidation of the essential thiol group