| Popis: |
An infrared (IR) rotary dryer was designed and fabricated to sterilize flaxseeds under different experimental treatments. The investigations were conducted under varying IR intensities (882, 964, 1050, and 1140 W/m2) and exposure times (6, 9, 12, and 15 min). Data analysis showed the minimum amount of specific energy consumed at 882 W/m2 and 6 min for the studied varieties Sakha 3 and Sakha 6. The highest thermal efficiency belonged to the highest radiation intensity and the lowest exposure time, with values of 77.26 % and 86.17 % for Sakha 3 and Sakha 6, respectively. Different IR intensities caused an increase in oil yield (OY), acid value (AV), and peroxide value (PV). For example, 1050 W/m2 for 15 min showed the highest OY for Sakha 3 (37.37 %), whereas 964 and 1050 W/m2 for 12 min reported the highest activity for Sakha 6 (43.20 and 43.43 %, respectively); 1140 W/m2 was the intensity that recorded the highest content of AV (range of 2.67–3.93 mg KOH/g for Sakha 3 and 3.19–4.22 mg KOH/g for Sakha 6) and PV (range of 4.05–6.91 meq. O2/kg for Sakha 3 and 5.21–5.92 meq. O2/kg for Sakha 6). Moreover, increasing IR intensity caused an increase in total phenolic content. The maximum amount was obtained at 1140 W/m2 for 12 min (153.27 and 154.59 mg GAE/100 g sample for Sakha 3 and 6, respectively) without significant changes at 1050 W/m2 and 12 min. For radical scavenging activity, 1050 W/m2 at 9, 12, and 15 min represented the highest activity for Sakha 3 (range of 30.27%–32.64 %) and Sakha 6 (range of 36.58%–37.37 %). Thus, IR pretreatment at 1050 W/m2 and duration between 12 and 15 min is recommended for Sakha 3 and 6. After the oil extraction and storage period (4 weeks), PV increased in all the investigated oil samples. In general, the heat-treated seeds’ oil will stay stable and maintain quality as long as the seeds are stored before the oil is extracted. |
