Properties of ascorbic acid and its applications in food processing: a critical appraisal

L – ascorbic acid (vitamin C) plays important roles in human nutrition as well as in food processing. L – ascorbic acid occurs naturally in fruits and vegetables and citrus fruits are rich sources of this vitamin. The west Indian cherry is reported to be the richest source of L -ascorbic acid. It exists in a variety of tautomeric forms. Its chemical properties show reducing behaviour and it can form derivatives. Titrimetric and spectrophotometric methods can be used for the analytical determination of L -ascorbic acid. Commercially, L -ascorbic acid is manufactured either by enzymatic method or by a direct fermentation process. Ascorbic acid finds several applications In food processing. It acts as a preservative to prevent enzymatic browning during processing, as an antioxidant and it promotes clarity as well as preservation of taste and flavour during beer and wine fermentation as well as many other food processing operations. This paper critically reviews the various aspects of L-ascorbic acid such as its occurrence, chemistry, analytical methods for its determination, commercial synthesis and its role In food processing vis-a-vis human nutrition.