Ultra-sonicated vacuum drying's effect on antioxidant activity, TPC, TFC and color of elephant apple slices. (August 2020)

• Record Type: Journal Article
• Authors: Krishnan, Kesavan Radha; Rayaguru, Kalpana; Nayak, Prakash Kumar
• Is Part Of: Food bioscience. Volume 36(2020)
• Publication Date: 2020-08
• Subjects: Dillenia indica -- Drying kinetics -- Ultrasound -- Vacuum -- Ultrasonic vacuum drying; Food -- Biotechnology -- Periodicals; Food -- Research -- Periodicals; Aliments -- Biotecnologia -- Revistes; Aliments -- Investigació -- Revistes; Food -- Biotechnology; Food -- Research; Revistes electròniques; Periodicals; 664.005
• DOI: 10.1016/j.fbio.2020.100629
• Languages: English
• ISSNs: 2212-4292

Abstract

Abstract: The use of ultrasound and vacuum to shorten the processing time and to improve the quality of elephant apple ( Dillenia indica ) slices during drying was investigated. Preliminary studies were done on the application of ultrasonic vacuum energy with elephant apple slices at different temperatures (40, 50, 60, 70 and 80 °C). The best results were obtained at 60 ± 12 °C. The values for DPPH radical scavenging activity, total phenolic content and total flavonoid content of dried samples were found as 50 ± 2 μ mol of TE/g, 31 ± 1 mg GAE/g and 12 ± 1 mg quercetin/g, respectively. The effect of ultrasonic vacuum drying (UVD) was compared with the slices dried using vacuum drying (VD) and tray drying (TD). The time required to dry elephant apple slices to final moisture content of ~8.5 ± 1% (db) was 930, 870 and 690 min for TD, VD and UVD, respectively. The drying kinetics of the elephant apple slices was tested using 9 thin-layer drying models. Among the mathematical models investigated, the two term exponential model satisfactorily described the drying behavior of elephant apple slices with high R 2 (0.9971–0.9989) and low χ 2 (0.00039–0.00056) values. UVD may be a useful non-thermal technology for drying elephant apple slices, which accelerates drying kinetics as well as improves the quality of the final product. Graphical abstract: Image 1