A review on processes, mechanisms, and quality influencing parameters for puffing and popping of grains

Ready to eat expanded food grains are gaining popularity in modern days due to their ease to digest, lightness, crispiness and most importantly their ready to eat in nature. The demand for these products is increasing gradually, which tempts researchers to develop products with enhanced quality more diversifications in product and taste. An integrated study on food grain expansion helps to understand these processes. Puffing and popping process expands the grain by many folds. The expansion of grains depends upon heat and mass transfer rates, which take place in the counter direction. Therefore, optimal heat and mass transfer conditions affect the final quality and play an important role. Processing methods and grain characteristics influence these processes. Processing parameter levels and grain characteristics are interrelated. Optimum levels of processing parameters differ with changes in processing methods. This review article explains the effect of processing parameters on product quality and influencing mechanisms. Novelty impact statement This review covers the varietal effect of grains, their conditioning processes, heating methods for expansion, and the effect of these such parameters on the quality of the final product. Quality characteristics such as texture, nutrition, and other organoleptic properties play an essential role in selecting puffing or popping methods and preconditioning parameters for enhancing consumer acceptability. This review summarizes optimal processing conditions and the various quality parameters description to evaluate the quality of the final product.