文摘
In the present work, the processing variables were optimized to retain betalain compound and their effect on quality attributes (oil content, breaking force and color) of fried beetroot chips. The beetroot slices were fried in lab scale vacuum fryer. Experimental design with temperature (86–153 °C), absolute pressure (1.3–9.7 kPa) and frying time (2.6–9.4 min) as independent variables which produced 20 different combinations, were studied using response surface methodology to study the effect of these variables on product responses. Multiple regression equations were obtained to describe the effects of each variable on product responses. Results predicted that optimum frying conditions namely temperature ranging from 101 to 110 °C, pressure ranging from 2.9 to 4.4 kPa and time 6.0 min required for preparing beetroot chips with oil content (Y1) ≤ 15.7, breaking force (Y2) ≤ 11.53, L* value (Y3) ≥ 27.94, a* value (Y4) ≤ 17.87, b* value (Y5) ≥ 6.46, betalain content (Y6) ≥ 13.05 (mg/l) and overall acceptability (Y7) ≥ 7.5. Further results showed that traditionally fried beetroot chips contain 2.6 mg/l betalain, 19.68 N breaking force, 21.1 L*, 15.18 a*, 2.38 b*, overall acceptability 6.0 and 38.41 % oil content.
