Impact of drying techniques on the physicochemical and quality properties of sprouted quinoa powder

This study investigated the effects of various drying methods including convective, infrared, and microwave drying on the moisture content, pH, acidity, color indices, total phenolic content (TPC), and antioxidant capacity (AC) of sprouted quinoa powder. Initially, the quinoa seeds were soaked in magnetized water for ۱ h. Then the quinoa seeds were incubated in a magnetic field at ۲۵°C for ۷۲ h for sprouting. To increase the phenolic compounds of the powders, the sprouts were treated by ultrasound for ۵ min. The sprouts were dried in three ways and the powder prepared from them was analyzed. The infrared radiation facilitated removal of moisture from the quinoa sprouts, increased the effective moisture diffusivity coefficient, and shortened the dehydration duration. The moisture content and pH of the sprouted quinoa powders were in the range of ۲.۶۱ % to ۷.۰۳ %, and ۵.۹۵ to ۶.۰۸, respectively. The acidity of convective, infrared, and microwave dried sprouted quinoa powders was ۱.۲۴ %, ۱.۱۹ %, and ۰.۸۱ %, respectively. Among the sprouted quinoa powders, the sample dried using microwave treatment exhibited the lowest lightness value (۶۷.۷۸) and the highest redness (۹.۸۹) and yellowness (۲۱.۰۹) indices. The infrared-dried powders had the maximum TPC and AC. The TPC of convective, infrared, and microwave dried powders were ۹۱۶.۹۸, ۱۲۶۸.۴۸, and ۱۲۶۲.۴۶ μg gallic acid/g dry, respectively. In summary, using infrared was chosen as the best way to dry quinoa sprouts because it dries them faster, keeps the right color parameters, and results in the highest levels of beneficial compounds.

کلیدواژه ها:

Antioxidant capacity ، Color indices ، Infrared ، Microwave ، Sprouted quinoa