Abstract
Concentrations of total, free, and combined acids (hereinafter referred to as total acidity, free acidity, and combined acidity, respectively) of juice in four citrus species were determined to clarify the relationships among them.
A high correlation coefficient was found in each species, between total acidity (T) and free acidity (F).
Linear regressions between T and F were:
T=0.967F+6.606 (r=0.954) for Satsuma mandarin
T=0.981F+6.779 (r=0.996) for Natsudaidai
T=1.199F+3.699 (r=0.990) for Hyuganatsu
T=0.964F+7.849 (r=0.988) for Eureka Lemon
where acids were expressed as me/100ml.
For these four species, it may be possible by using these linear regression lines, to make an estimation of total acidity of juice within an allowable error, if only free acidity is available.
