Carlton & United Breweries Ltd., Melbourne, Australia.
IDENTIFICATION AND QUANTITATION OF SEVERAL NONVOLATILE ORGANIC ACIDS OF COCOA BEANS
Version of Record online: 25 AUG 2006
Journal of Food Science
Volume 36, Issue 6, pages 877–879, September 1971
How to Cite
WEISSBERGER, W., KAVANAGH, T. E. and KEENEY, P. G. (1971), IDENTIFICATION AND QUANTITATION OF SEVERAL NONVOLATILE ORGANIC ACIDS OF COCOA BEANS. Journal of Food Science, 36: 877–879. doi: 10.1111/j.1365-2621.1971.tb15550.x
Published as paper No. 3931 on February 22, 1971, in the journal series of the Pennsylvania Agricultural Experiment Station. Supported in part by funds provided by the Chocolate Manufacturers Association of the U.S.A.
- Issue online: 25 AUG 2006
- Version of Record online: 25 AUG 2006
- Ms received 4/10/71; revised 6/21/71; accepted 7/2/71
SUMMARY— Organic acids precipitated as lead salts from water extracts of cocoa beans were converted to trimethylsilyl ethers. TMS ethers were then separated and identified using a combined gas chromatograph-mass spectrometer. Citric, phosphoric, lactic, oxalic, malic, tartaric, succinic and gluconic acids were present in every sample examined, irrespective of geographic origin. Five of the acids were quantitated using a GLC procedure which involved the preparation of methyl esters from freeze-dehydrated, water extracts. Concentration ranges found, g/100g beans, were: lactic, 0.11–0.71; oxalic, 0.24–0.43; succinic, 0.02–0.07; malic, 0.02–0.10; citric, 0.56–1.32. Concentrations of lactic acid were lowest and citric acid levels tended to be highest in commercial samples from countries where cocoa beans usually are not subjected to a planned fermentation. These trends were confirmed in an experiment involving beans from Trinidad which had undergone a carefully controlled fermentation. Only minor differences were found in organic acid concentrations between roasted and unroasted cocoa beans.