Acid invertase was extracted from mango nectars using 4% (w/v)
NaCl solution as reported by Hasegawa and Smolensky (1970). Invertase
assay was performed using sucrose as a substrate as described earlier
(Bhatti, Asgher, Abbas, Nawaz, & Sheikh, 2006) with some
modifications. An appropriate amount (0.5 mL) of the enzyme solution
was mixed with 5 mL of pH 4.0 sodium phosphate–citric acid buffer
(contained 2% sucrose, w/v) and shaken in a water bath at 55 °C for
6 h. The reaction was quenched by placing tubes in boiling water for
10 min, and immediately cooling in an ice bath. The released glucose