Soluble solids were evaluated as Brix at 20 C using an ABBE-3L
Refractometer (Milton Roy Inc., Rochester, NY, USA). The pH was
measured by direct reading at 20 C in an Orion Benchtop pH/ISEmeter Model 420A (Orion Research Inc., Boston, MA, USA). Acidity
was measured by titrating with 0.1 N NaOH to a pH end-point of 8.2,
the result being expressed as mg malic acid/mL of sample