Anhydrouronic acid (AUA): The content of AUA indicates the purity of the extracted pectin and is suggested to be not less than 65%. From figure-6, only in extraction using citric acid did it give pure pectin for both type of peel. Extraction using nitric
acid did not give pure pectin. Result indicates that the extract may not be sufficiently pure due to presence of sugars in the precipitated pectins.