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

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.

Jilebi 3: Effect of frying conditions on physical characteristics.

The process of jilebi making includes the frying of specially shaped batter strands to obtain a crisp texture followed by absorption of sugar syrup. The effects of frying temperature (150-180 °C) and time (15-300 s) on the physical characteristics have been investigated; these are moisture and fat contents, density, colour, textural attributes and microstructure. Among the textural parameters obtained by shearing the jilebi strands, shear failure force and the number of minor fractures increase markedly with an increase in time of frying. The brightness of the sample is lower when fried at higher temperatures like 180 °C compared to that of 150 °C; the hue or dominant wavelength of batter prior to frying is 578.0 nm, and after frying, it is between 564.8 and 591.3 nm indicating an overall shift towards yellow colouration during frying. The density of the jilebi strands decreases along with moisture content, while fat content increases gradually with an increase in frying time. The microstructure and image analysis of the fried products indicate the creation of porous structure consisting of several pores that are separated by thin cell walls of thickness between 10 and 15 µm. The eccentricity of pores/vacuoles in jilebi is between 0 and 0.92 indicating a close resemblance to elliptical shapes. The samples fried at 160 °C for 180-240 s have been judged as the best sample both as fried and fried-sugar syrup soaked products.

Jilebi 2: Flowability, pourability and pH of batter as affected by fermentation.

Fermentation of batter is an integral part of the preparation of jilebi, a traditional ready-to-eat sweet product of Indian sub-continent. The flowability and pourability of batter are crucial for forming jilebi strands during frying. Flowability and pourability have been determined from simulation studies based on the movement of batter on an inclined surface and the exit from an orifice, respectively; simple gadgets have been designed to determine these two characteristics along with providing the definitions. Response surface experimental design consisting of moisture content (50-65%), amount of added curd (0-10%) and time of fermentation (0-24 h) has been employed. The response functions are pH, flowability and pourability. Strong interaction effects of added curd and time of fermentation on the response functions have been observed. An increase in added curd and time of fermentation decreases pH in a curvilinear manner as both linear and quadratic effects are significant (p ≤ 0.01). Moisture content has a non-significant effect on pH but markedly affects the flowability and pourability of batter. Flowability and pourability decreases when there is an increase in consistency index or apparent viscosity.

Frying of the Dispersion Droplets with Varying Contents of Chickpea Flour and Gum Arabic: Product Characterization and Modeling.

Dispersions having chickpea (37%, 40%, and 43%, w/w) and gum arabic (0%, 1%, 2%, 3%, 4%, and 5%, w/w) solids were prepared. These dispersion droplets were fried, and the physical, sensory, and microstructural characteristics of the fried products were determined. The oil content in the fried snack decreased up to 20.3% when the level of chickpea and/or gum in the dispersions was increased. The compression curve for fried snack showed 5 major zones and exhibited the failure phenomenon. Failure force (6.5 to 11.4 N) increased with chickpea flour in the dispersions. Fracture strain (12.0% to 19.5%) indicated that all the fried samples were soft-crisp products. An increase in chickpea flour concentration offered an ovoid/oblong shape of dispersion droplets while falling to oil, and changed the spherical shape of the fried snack. The near-spherical product could be obtained by using 37% chickpea flour containing 0 to 2% of gum arabic, or with the 40% and 0 to 1% combinations. The hue or dominant wavelength increased from 578.5 nm (flour) to 581.0 to 582.7 nm (product) indicating a shift toward red coloration. A porous microstructure with scattered small cavities and large vacuoles of the fried snack were observed; big vacuoles were located in the inner portion of the fried product. The cells were divided into closed and open cells and were characterized by image analysis. The air cells usually had an elliptical shape with varying sizes; the cell wall thickness was between 12 and 80 µm. An artificial neural network (ANN) structure of 2-9-2 was developed for the prediction of sensory overall acceptability and oil content of the fried snack. PRACTICAL APPLICATION: Chickpea flour is used in several food preparations. The addition of gum arabic affects the textural and structural characteristics, and the sensory acceptance; the fried dispersion droplets have a lower fat content when gum arabic is used compared to samples fried without the addition of gum arabic. The fried dispersion droplets change their shape with the level of the ingredients used in the dispersion.