Re: What acids account for the acidity of tomatoes?

Dear Mr. Owens:

The acids that account for the acidity of tomatoes are citric, malic, 
lactic, ascorbic (Vitamin C)and polycarboxylic. Their concentrations vary 
from several parts per million (ppms) to 1-20 mg/100 g of fresh tomato. The 
concentrations will also vary depending on the variety, cultural practices 
and the environmental conditions during the growing season.

I hope this answers your question.

Al Bushway
Professor of Food Science