Impact of drying on techno-functional and nutritional properties of food proteins and carbohydrates - A comprehensive review

Foods comprise of many macromolecules that have varying techno-functional and nutritional properties. The isolated proteins and carbohydrates from them are increasingly being used as potential ingredients in the food industries. Numerous processes like drying for food processing and preservation cause variations in functional and nutritional attributes of proteins and carbohydrates in different degrees in the food products that can ultimately affect their possible applications. This article explores different drying technologies being used in the food industries, including freeze-drying, microwave-assisted drying, infrared drying, vacuum drying, spray drying, and oven drying. Based on the evaluation of multiple studies, it can be inferred that these drying methods have the potential to contribute to low drying performance, high operational costs, and strong environmental impact. Moreover, they can affect the nutritional value of macronutrients such as proteins, starches, gums, and dietary fibers present in foods, the integrity of the food structures, and their functional properties. Understanding the correlation between the drying technique used and the functional and nutritional attributes of macromolecules will help to provide better insight into the importance of the different drying methods. Optimization of the operational parameters of the different drying methods could be vital and needs to be evaluated to avoid the degradation of the proteins and carbohydrates and the loss of their properties.