Formulation challenges in encapsulation and delivery of citral for improved food quality

Citral, one of the most important natural flavouring compound having intense lemon aroma and flavour, is widely used as an additive in foods, beverages and cosmetics with high consumer acceptance. Citral is chemically unstable and degrades over time in aqueous solutions due to acid catalysed and oxidative reactions leading to loss of desirable flavour and formation of off-flavours. Therefore, incorporation of citral into foods and beverages is a major challenge for the food industry because their chemical deterioration needs to be inhibited to minimize loss of product quality. The task to find the appropriate delivery system is most challenging for food industry. In the present review, the encapsulation and delivery techniques of citral mostly based on colloidal systems have been reviewed in detail. Moreover, the remaining technical challenges of such delivery systems like insignificant stabilization of citral, use of non-biocompatible constituents, instability to the environmental stress and difficulty of their preparation are discussed for prospective development of such formulations.