Hardness of high protein nutrition bars based on milk protein concentrates:a review

High protein nutrition (HPN) bars are gaining increased global popularity as convenient and high nutritious food products. Proteins of different origins have been used singly or in combinations in HPN but milk proteins (whey protein products, casein and caseinates) remain the favorable proteins used in HPN formulations. Milk protein concentrates (MPC) of different protein contents are new milk protein ingredients of multifunctional properties for diversified food applications. They contain both casein and whey protein in their native form and ratio found in milk. The use of high protein MPCs in nutrition bars is one of the promising applications for these products. HPN based on different protein sources develops hardness during storage particularly at high temperatures but more pronounced hardness develops on the use of MPCs. Several approaches have been suggested to overcome this problem through modification of MPCs. This review presents an overview ofthe HPN bar hardness mechanisms and MPC modifications to combat this problem.