Khoa and khoa based traditional dairy products: preparation, spoilage and shelf life extension.

Khoa and khoa based products ( burfi , peda , kalakand , milk cake , etc.) are a category of traditional dairy products of Indian subcontinent. They are prepared by open pan desiccation along with stirring and scraping of milk to the desired consistency, followed by addition of sugar and / or colour and flavoring ingredients. The peculiar sensory attributes developed during their course of preparation makes them unique, but their short shelf-life is a major challenge faced by the dairy industries. They are spoiled mainly because of yeast and mold growth along with detrimental changes in the sensory attributes. This review describes various preservation techniques explored in the last two decades such as packaging interventions, modified atmospheric and active packaging, chemical preservation, water activity modification, natural preservation, thermal treatments, bio-preservation, etc. which can be used either singly or in combination (hurdle technology), to enhance the shelf life of these milk products.