Application of Ultrasound and Curing Agent during Osmotic Dehydration to Improve the Quality Properties of Freeze-Dried Yellow Peach (Amygdalus persica) Slices

Abstract

This study aimed to improve the quality of freeze-dried yellow peaches (Amygdalus persica). Yellow peaches were pretreated with osmotic dehydration for 15 min prior to vacuum-freeze drying and supplemented with different ultrasonic power levels (180 W, 240 W, 300 W) and a curing agent (calcium lactobionate, CaLa) to investigate the effects on the quality of freeze-dried yellow peach slices. After vacuum freeze-drying the yellow peach slices for 48 h, their moisture, color, texture, microstructure, total phenol (TP) content and oligomeric proantho-cyanidin (OPC) content were determined. It was found that the auxiliary ultrasonic power with various levels, especially powered at 240 W, produced very favorable effects on the quality characteristics of freeze-dried yellow peaches. The average pore size of USOD-240 W samples was reduced by 57.07% compared with that of the FD samples. In terms of nutrient maintenance, USOD-240 W can also prevent nutrient loss to the greatest extent. The TP content (5.40 mg/g) and OPC content (14.42 mg/g) were always highest in each pretreatment. The addition of CaLa can further improve the quality of yellow peach slices. Overall, the application of ultrasound and CaLa to improve the quality of freeze-dried yellow peach slices along with osmotic dehydration before freeze-drying is a method worth considering.

Mass transfer kinetics (soluble solids gain and water loss) of ultrasound-assisted osmotic dehydration of apple slices

“…The average rehydration ratio of apple slices decreased from 237.7 to 177.5%, by increasing osmotic solution concentration from 30 to 50%. The use of ultrasound and curing agents during OD for enhancing the quality characteristics of freeze-dried yellow peach slices was examined by Chu et al 24 . The authors reported that with increasing ultrasound treatment time, the drying time and shrinkage of the product would reduce.…”

Recent Progress and Application of Freeze Dryers for Agricultural Product Drying

“…The use of ultrasonic waves and curing agents during osmosis dehydration to enhance the quality attributes of freeze-dried yellow peach pieces was studied by Chu et al [22]. The authors indicated that product drying time and shrinkage decreased as the sonication time increased.…”

“…Recently, various combination techniques have been examined to improve dehydration speed and save energy when freeze-drying fruits and vegetables. These include the combination of the FD technique with other techniques, as assisted or pretreatment, such as ultrasound [20][21][22][23][24], microwaves [18,[25][26][27], vacuum [28], pulse-spouted microwave vacuum [26], CO 2 laser perforation [29][30][31], pulsed electric field (PEF) [32][33][34][35], and infrared radiation [1,[36][37][38]. As a result, these techniques reduce the processing time and cost, and improve the quality of the final products.…”

Ultrasound applications in drying of fruits from a sustainable development goals perspective

“…In the face of the advantages and disadvantages of each main ultrasound technology, most applications rely on ultrasound pre-treatments in ultrasonic baths followed by traditional drying techniques, such as oven [20] , [107] , forced convective [27] , [28] , [37] , [143] , [144] , fluidized bed [145] , [146] , microwave [147] , [148] , [149] , infrared [92] , [93] , [102] , [118] , vacuum-assisted [150] , [151] , and freeze-drying [152] , [153] , [154] .…”