NIRS prediction of total acidity has been difficult to achieve, due to the relatively low levels of organic acids in fruit.

Organic acids contribute to the SSC to an extent of 10% in citrus fruit, yet NIRS prediction of total acidity has been difficult to achieve, due to the relatively low levels of organic acids in fruit.

P.75 in Cayuela (2008) Vis/NIR soluble solids prediction in intact oranges cv. Valencia late by reflectance, Post Biol and Tech, 47, 75-80.