Determination of ascorbic acid
The spectrophotometric method (Pepkowitz, 1943;
Robinson & Stotz, 1945) for determination of ascorbic
acid was performed by using Unicam UV–VIS (UV-2)
spectrophotometer at a wavelength of 500 nm against
xylene. The loss of ascorbic acid in citrus juice concentrates
was calculated by using the standard equation
for a first-order reaction given below