Davinder Pal Singh Oberoi

Effect of extraction conditions on lycopene extractions from tomato processing waste skin using response surface methodology.

Skin, rich in lycopene, is an important component of waste originating from tomato paste manufacturing plants. A central composite design with five independent variables, namely solvent/meal ratio (20:1, 30:1, 40:1, 50:1, and 60:1v/w); number of extractions (1, 2, 3, 4 and 5); temperature (20, 30, 40, 50 and 60°C); particle size (0.05, 0.15, 0.25, 0.35 and 0.43mm); extraction time (4, 8, 12, 16 and 20min) was used to study their effects on lycopene extraction. The experimental values of lycopene ranged between 0.639 and 1.98mg/100g. The second order model obtained for extracted lycopene revealed a coefficient of determination (R(2)) of 0.99 and a standard error of 0.03. Maximum lycopene (1.98mg/100g) was extracted when the solvent/meal ratio, number of extractions, temperature, particle size and extraction time were 30:1v/w, 4, 50°C, 0.15mm and 8min, respectively.

Physicochemical, morphological and pasting properties of acid treated starches from different botanical sources

Effect of acid modification on physico-chemical, morphological and pasting properties of banana, sweet potato, lotus stem and wheat starches were studied. Results revealed that swelling power, solubility and water binding capacity of all starches decreased by acid modification. By acid modification starch granules from different varieties tended to appear fused and less smooth than the native starch granules. The pasting properties of native starches of all different varieties have significantly decreased following acid modification. Acid modified starches showed higher syneresis as compared to native starches.

Thermal Degradation Kinetics of Pigments and Visual Color in Watermelon Juice

Thermal degradation of total carotenoids, lycopene and visual colour of watermelon juice was studied at 50–90°C up to 5 h. Total carotenoids content in fresh watermelon juice was reduced from 4.568 to 0.929 mg/100 g, lycopene from 4.403 to 0.82 mg/100 g and Hunter ‘a × b’ value from 251.66 to 89.59 when heated at 90°C for 5 h. First order model explained the degradation behaviour of total carotenoids, lycopene and Hunter ‘a × b’ value evident from correlation coefficient (R2) higher than 0.93. The dependence of degradation rate constant of total carotenoids, lycopene and Hunter ‘a × b’ value on temperature was adequately explained by Arrhenius equation. The activation energies for total carotenoids, lycopene and Hunter ‘a × b’ value were 24.19, 26.46, and 55.47 kJ/mol, respectively. Total carotenoids and lycopene were correlated with Hunter ‘a × b’ value with R2 > 0.99 indicating that visual colour may be used to predict lycopene and total carotenoids contents in watermelon juice.

Effect of extraction parameters on curcumin yield from turmeric

Effect of 4 independent variables — temperature (50–90°C), particle size (0.42–0.85 mm), mixing time (10–50 min) and solvent (ethanol) to meal ratio (10–50) on curcumin yield from turmeric (Curcuma longa L) was studied using central composite rotatable design. The experimental value of curcumin yield ranged between 4.49 and 12.89%. The second order model obtained for curcumin yield revealed a coefficient of determination (R2) of 0.78 and standard error of 0.72. The linear, square and interaction terms were significant at p <0.05 while lack of fit was non-significant at p >0.05. Surface graphs were plotted to optimize the curcumin extraction. The maximum curcumin yield was obtained when temperature, particle size, mixing time and solvent to meal ratio were 60°C, 0.42 mm, 30 min and 50, respectively.

Drying Characteristics, Sorption Isotherms, and Lycopene Retention of Tomato Pulp

Tomato pulp separated by centrifugation of crushed tomatoes was dried in cabinet, tray, fluidized-bed, and freeze dryers at 50–70°C using 4–12 kgm−2 tray loads. Drying behavior was well described by the Pages model with coefficient of determination greater than 0.99 and standard error of 0.004–0.019. A fluidized-bed dryer was more efficient to dry tomato pulp than tray, freeze, and cabinet dryers. Retention of lycopene in tomato pulp was maximum in a freeze dryer (72.483–78.093 mg 100 g−1) followed by fluidized-bed (42.273–57.926 mg 100 g−1), cabinet (35.532–49.271 mg 100 g−1) and tray dryer (24.454–45.842 mg 100 g−1) under experimental conditions (tray load 4–12 kgm−2, temperature 50–70°C). The moisture sorption isotherms of tomato pulp obtained by equilibrating saturated salts solution of known water activity (0.113–0.92) at 30–60°C were sigmoid. A modified Henderson model was the best model for the tomato pulp with coefficient of determination more than 0.99 and standard error less than 0.270. The net isosteric heat of sorption, estimated using the Clausius-Clapeyron equation, was 21.451–5.541 Jmol−1 at 25–5% moisture content (dry basis).

Utilization of watermelon pulp for lycopene extraction by response surface methodology

Lycopene extraction was optimized from watermelon pulp using response surface methodology using independent variables:solvent/meal ratio (4:1-12:1v/w), number of extractions (1-5), temperature (20-60°C) and extraction time (4-20min). Watermelon pulp had 59.95mglycopene/100g on fresh weight basis. The experimental values of lycopene with selected combinations of independent variables were 8.20-59.17mg/100g on fresh weight basis. The second order model obtained revealed a coefficient of determination (R2) of 0.986, the standard error of 0.04, the root mean square error of 0.02 and a scattered plot between experimental and predicted values. The optimum solvent/meal ratio, number of extractions, temperature and extraction time were 10:1v/w, four, 50°C and 16min respectively. The optimum conditions of lycopene extraction were confirmed experimentally.

Moisture Diffusivity During Drying of Pineapple and Mango Leather as Affected by Sucrose, Pectin, and Maltodextrin

The effect of the addition of sucrose (0, 5, 10%), pectin (0, 1, 2%), and maltodextrin (0, 2.5, 5%) on the moisture diffusion from pineapple and mango pulp during the making of fruit leather was studied in a cabinet drier. The drying rate of both pineapple and mango leather was reduced by the addition of sucrose, pectin, and maltodextrin. Drying rate constant of both pineapple and mango leather was most significantly affected by sucrose followed by maltodextrin and pectin. The drying rate constant (k) of 0.214 and 0.116 1/h was lowest in the pineapple and mango pulp containing 10, 2, and 5% of sucrose, pectin, and maltodextrin, respectively. The experimental moisture effective diffusivity varied from 6.64–12.93 × 10−7 m2/sec and 1.65–4.03 × 10−7 m2/sec for pineapple and mango leather, respectively, and the coefficient of determination (R2) of regression coefficients for effective moisture diffusivity was 0.82 and 0.96, respectively. The effect of addition of pectin was most significant on moisture diffusivity both in pineapple and mango leather.

Effect of Particle Size, Temperature, and Total Soluble Solids on The Rheological Properties of Watermelon Juice: A Response Surface Approach

Central composite design was used to analyze the effect of particle size (0.075, 0.15, 0.25, 0.355, 0.425 mm), temperature (1.6, 5, 10, 15, 18.4°C) and total soluble solids (14.77, 25, 40, 50, 65.23°Brix) on the rheological properties of watermelon juice. Experimental values of consistency coefficient k, varied from 0.178–0.628 Pa sn and flow behavior index n from 0.281 to 0.949. Regression equation was computed and used to predict the values of k and n. Results revealed that coefficient of determination (R2) and standard error for consistency coefficient k were 0.84 and 0.043 and for flow behavior index n were 0.42 and 0.102 respectively. Surface graphs showed that k value increased with increase in total soluble solids and particle size while decreased with temperature.