Influence of combined pretreatments on color parameters during convective drying of Mirabelle plum (Prunus domestica subsp. syriaca)

Heat and Mass Transfer - Tập 53 - Trang 2425-2433 - 2017
Jalal Dehghannya1, Rasoul Gorbani1, Babak Ghanbarzadeh1
1Department of Food Science and Technology, University of Tabriz, Tabriz, Iran

Tóm tắt

Discoloration and browning are caused primarily by various reactions, including Maillard condensation of hexoses and amino components, phenol polymerization and pigment destruction. Convective drying can be combined with various pretreatments to help reduce undesired color changes and improve color parameters of dried products. In this study, effects of ultrasound-assisted osmotic dehydration as a pretreatment before convective drying on color parameters of Mirabelle plum were investigated. Variations of L* (lightness), a* (redness/greenness), b* (yellowness/blueness), total color change (ΔE), chroma, hue angle and browning index values were presented versus drying time during convective drying of control and pretreated Mirabelle plums as influenced by ultrasonication time, osmotic solution concentration and immersion time in osmotic solution. Samples pretreated with ultrasound for 30 min and osmotic solution concentration of 70% had a more desirable color among all other pretreated samples, with the closest L*, a* and b* values to the fresh one, showing that ultrasound and osmotic dehydration are beneficial to the color of final products after drying.

Tài liệu tham khảo

Zhao D, Zhao C, Tao H, An K, Ding S, Wang Z (2013) The effect of osmosis pretreatment on hot-air drying and microwave drying characteristics of chili (Capsicum annuum L.) flesh. Int J Food Sci Technol 48:1589–1595