Emerging technique for healthier frying for production of reduced-fat beetroot (Beta vulgaris) chips

Abstract

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 (Y 1 ) B 15.7, breaking force (Y 2 ) B 11.53, L* value (Y 3 ) C 27.94, a* value (Y 4 ) B 17.87, b* value (Y 5 ) C 6.46, betalain content (Y 6 ) C 13.05 (mg/l) and overall acceptability (Y 7 ) C 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.

Effect of vacuum frying on quality attributes of pear ( Pyrus communis L) chips and blended oil

“…After the product is taken out, during the cooling period, the residual vapor entrapped in the pores gets released to the atmosphere because of pressure difference. After the release of vapor from the pores, the empty space left behind will be filled by the oil present on the surface of the product thereby increasing the oil uptake (Diamante et al., 2011; Juvvi et al., 2016). In comparison to the conventionally fried (175°C ± 5°C) product, the vacuum‐fried pear chips showed reduced oil uptake (Table 3), in turn, iterating the advantage of vacuum frying over conventional frying.…”

“…The response surface graph obtained by plotting the independent variables temperature versus time (with constant vacuum pressure 110 mbar), the maximum color a * (redness) was found to be in the positive section of the temperature and time axis (Figure 3a (vi)). An increase in redness is associated due to Maillard and caramelization (non‐enzymatic browning) reactions during frying (Juvvi et al., 2016; Marquez & Añon, 1986). Besides, pear fruit is one among the high carbohydrate‐containing fruit and hence gets degraded at higher temperatures and prolonged frying.…”

“…During this period, the residual vapor entrapped in the pores gets released to the atmosphere because of the pressure difference leaving empty space or void in the pores. After the release of residual vapor from the pores, the empty space left behind will be filled by the residual oil present on the surface of the product thereby increasing the oil uptake (Diamante et al., 2011; Juvvi et al., 2016).…”

“…In recent times, the consumer trends are observed toward the consumption of low‐fat snacks food, and hence the research is oriented toward the processing of snacks with low or no oil absorption during frying (Juvvi, Chakkaravarthi, & Debnath, 2016; Liberty, Dehghannya, & Ngadi, 2019; Sun, Zhang, & Fan, 2019;). Fried snacks are the favorite of the consumers, mainly because of its taste.…”

“…These results in the lowering of the boiling point of moisture and frying temperature of oil (Ayustaningwarno, Dekker, Fogliano, & Verkerk, 2018; Deng, Chen, Tian, Miao, & Zheng, 2019; Shen, Zhang, Bhandari, & Guo, 2018). The absence of oxygen during frying and temperature of frying well below than traditional deep‐fat frying results in the least damage to the frying medium (Juvvi et al., 2016 ) .…”