Ultrasound-assisted drying of orange peel in atmospheric freeze-dryer and convective dryer operated at moderate temperature

Abstract

Atmospheric freeze-drying (AFD) at -10 °C and moderate temperature convective drying (MTD) at 50 °C without and with ultrasound application (20.5kW/m ) were carried out. Alcohol insoluble residue (AIR) and its swelling capacity (SC), water retention capacity (WRC) and fat retention capacity (FRC) were measured in the dried product. Ultrasound significantly shortened the drying time in both processes, the intensification effect being more significant in atmospheric freeze-drying (57 % and 27 % reduction in atmospheric freeze-drying and convective drying, respectively). As regards AIR and WRC, no effect was observed of either the drying temperature or ultrasound application. On the contrary, SC was significantly lower in AFD samples. The FRC of MTD samples was similar to that of the fresh ones and higher than the values obtained for atmospheric freeze-dried samples. Therefore, convective drying at moderate temperature preserved the AIR properties better than atmospheric freeze-drying.

Cider apple pomace as a source of nutrients: Evaluation of the polyphenolic profile, antioxidant and fiber properties after drying process at different temperatures

“…A similar value of 67.2 % was reported by Kosmala et al (2011) . This value was lower than that obtained by Borsini et al (2021) for artichoke bracts (85 %), but higher than that of artichoke stems (63 %) or orange peel (53 %) ( Mello et al, 2020 ).

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Ultrases Ön İşleminin Elma Dilimlerinin Kurutma ve Rehidrasyon Karakteristikleri ile Mikroyapısına Etkisinin Araştırılması

“…Therefore, diffusion is the major physical mechanism of mass transfer in the apple samples. The same result was reported in hot air drying of Granny Smith apple (Andres et al, 2004) and ultrasound assisted convective drying of orange peel (Mello et al, 2020). Contreras et al (2008) indicated that the Page and Modified Page models were represented the drying kinetics of apple products better than the other models like our study.…”

Ultrasonically assited atmospheric freeze-drying of orange peel: comparison between plate and tubular transducer arrangement

“…As for β parameter, it significantly decreased when ultrasound was applied, which means an increase in the drying kinetics. This fact has been previously observed applying ultrasound in AFD of orange peel [8].…”