Foam mat drying of taro (Colocasia esculenta): The effect of ultrasonic pretreatment and drying techniques on the drying behavior, flow, and reconstitution properties of taro flour

ÇALIŞKAN KOÇ G., Yüksel A. N., Baş E., Erdoğan S. L.

Journal of Food Process Engineering, cilt.43, sa.11, 2020 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 43 Sayı: 11
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1111/jfpe.13516
  • Dergi Adı: Journal of Food Process Engineering
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Aquatic Science & Fisheries Abstracts (ASFA), Biotechnology Research Abstracts, Business Source Elite, Business Source Premier, CAB Abstracts, Compendex, Food Science & Technology Abstracts, INSPEC, Veterinary Science Database
  • Uşak Üniversitesi Adresli: Hayır

Özet

In this study, the effect of ultrasound pretreatment (UP) and drying methods (convective hot air [CHAD] and microwave oven [MOD]-assisted foam mat drying [FMD]) on the drying time, behavior and rate, diffusion coefficient, moisture content, color, bulk and tapped densities, flow properties, and reconstitution behavior of taro (Colocasia esculenta) flour were assessed. For this purpose, the taro foams with and without ultrasonic pretreatment (35 kHz, 80°C for 25 min) were dried in a convective oven (70°C, 20% ventilation rate) and microwave oven (460 W). The UP resulted in a higher drying rate, diffusion coefficient, moisture content, Hausner ratio (HR), and wettability time, and a lower drying time compared to the nontreated samples. Combined CHAD and MOD-assisted FMD improved the disadvantages of the CHAD method for example: long drying time (decreased around 63.33% for CHAD and 59.16% for UP + CHAD), low drying and diffusion rates, high moisture content, low brightness (L*) values, high Carr index (CI), HR, and times of wettability and solubility. Additionally, the CI and HR of the taro flours ranged between 4.29–13.96 and 1.04–1.16 which can also be classified as very good and low levels, respectively. Practical Applications: Taro flour is an important alternative flour source in baby food, cake, chips, noodle, and so forth due to its pasting, functional, and nutritional properties. In order to obtain taro flour, the taro corm (root) is washed, peeled, and sliced then generally blanched with distilled water, dried, and ground. The quality of taro flour depends on the preparation method such as the drying method and conditions. Foam mat drying (FMD) is an alternative technique and it has several advantages like low drying time and energy consumption, a high drying rate, increased drying surface area, porous structure, and the desired instant properties of the obtained powders. Ultrasound pretreatment (UP) has also some advantages such as increasing the mass transfer rate, reducing drying time, and energy consumption. In this study, the advantages of these techniques (FMD and UP) were combined and the effects on the drying behavior, time, effective moisture diffusivity, and the physical and powder properties were observed.