Effects of heat and shallot ( L.) supplementation on nutritional quality and enzymatic browning of apple juice.

This study investigated the effects of shallot ( L.) supplementation on improved nutritional quality and browning index of apple juice, specifically by comparing between heated (96 °C, 30 min) and unheated apple juice. The results showed that total soluble solid, phenolic content, flavonoid content, as well as antioxidant activities of heated and unheated apple juice, significantly (< 0.05) increased with the increase in shallot supplementation (0.5%, 1.0%, 1.5%, and 2.0%). The outcomes indicated that the nutritional parameters values for heated apple juice supplemented with shallot were greater than those of unheated apple juice. The unheated and heated apple juice supplemented with shallot showed inhibition of browning, while shallot supplementation exhibited higher functionality upon being heated. The heated apple juice appeared to be an efficient way to reduce browning and to increase antioxidant activities, irrespective of shallot supplementation. Shallot supplementation inhibited browning and improved the nutritional quality of unheated apple juice. These results proved that heated apple juice supplemented with shallot exhibited maximum inhibition of browning and increased nutritional quality. Therefore, heating and shallot supplementation can massively improve the quality of apple juice.