THE EFFECT OF FRYING AND STEAMING ON β-carotene CONTENT IN ORANGE AND YELLOW SWEET POTATO (Ipomoea batatas (L) Lam.)

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1 THE EFFECT OF FRYING AND STEAMING ON β-carotene CONTENT IN ORANGE AND YELLOW SWEET POTATO (Ipomoea batatas (L) Lam.) Yudha Amandangi S 1., Yunahara Farida 1 Faculty of Pharmacy, Pancasila University 1 Abstract The aim of this study was to investigate the effect of frying and steaming on β-carotene content in orange and yellow sweet potato. In this study, sweet potato was extracted using acetone n-hexane (40:60) solvents. After filtering, the n-hexane phase was separated using water, then n-hexane phase was measured its absorption by spectrophotometrically method at the maximum wavelength of 450 nm. Based on the test results, β-carotene content in fresh, fried, and steamed orange sweet potato are 5.57 mg/100g; 3.13 mg/100g and 4.07 mg/100g respectively, while in yellow sweet potato are 1.55 mg/100g; 0.76 mg/100g and 0.86 mg/100g respectively, with a relative standard deviation of orange and yellow sweet potato are 2.91% and 1.99%, respectively. The recovery of β-carotene showed that it was in the range of 96.4%-97.44%. The results of statistical analysis using t-test value showed that β- carotene content in fried sweet potato were significantly different from that of steamed sweet potato. β- carotene content in steamed sweetpotato is higher than that of in fried sweetpotato. Keyword : β-carotene, sweet potato, Ipomoea batatas (L) Lam, UV-Vis Spectrophotometry INTRODUCTION Sweet potato (Ipomoea batatas (L) Lam is a plant that belongs to the family Convolvulaceae contains high in vitamins, minerals, dietary fibre and antioxidants, including anthocyanins, phenolic acids, β- carotene and tocopherol (Bengtssona et.al., 2008; Kim et al., 2007; Van Jaarsveld et al., 2006; Yildirim et.al., 2011). β-carotene has received a lot of attention as potential anticancer and a powerful antioxidant, protecting the cells of the body from damage caused by free radicals. Most vegetables are commonly cooked before being consumed. Many studies have shown that various cooking methods affected content of phytochemicals, in particular, antioxidants present in the vegetables (Turkmen et al.,2005; Zhang and Hamauzu, 2004; Ishiguro et al., 2010)). Beside that, losses of β-carotene were higher after frying and vitamin C losses were smaller after frying, but higher after roasting (Inocent. et al., 2011). Steaming was then the best method which preserves the above nutrient contents in sweetpotato (Inocent et al., 2011) The aim of the study was to determine the effect of cooking on the β-carotene content of sweet potato using spectrophotometry. The study of β-carotene content in orange and yellow sweet potato (Ipomoea batatas Lam.) have been done using extracted in aceton-petroleum eter (5:1) by HPLC method, yield β-carotene 8,0 mg/100 g (K osambo et al., 1999). According to the AOAC International, β-carotene analysis in fresh plant formerly by extraction using acetone-n-hexane (40:60), the absorbance is measured by spectrophotometry (Horwitz W 2005). MATERIALS AND METHODS Materials and Chemicals. β-carotene RS (SIGMA), orange and yellow sweet potato, n-hexane, acetone, magnesium carbonate. All other reagents and solvents for analytical.

2 Instruments. UV-Vis Spectrophotometer (Shimadzu 1700), Analytical balance (AND GR-200), Micro balance (Mettler MT5). All other instruments for analysis. METHODS. Sample Preparation Sweet potatoes were obtained from Ballitro, Bogor. Sweet potato were washed with tap water, dried, then cut into small pieces. One portion was retined raw, while others were fried in hot oil (170 o C) for 2 minutes, or was boiled in boiling water (100 o C). The samples were drained and cooled before extraction process. Preparation of reference standard Accurately weigh 2.0 mg of β-carotene into 100 ml volumetric flask, added n- hexane until 100 ml (20 ppm). Add n- hexane to 1 ml filtrate in 10 ml conical flask (2 ppm), this filtrate was stock solution. Preparation of sample Accurately weigh 5 g of sample in high speed blender using 40 ml acetone, 60 ml n-hexane and 0.1 g magnesium carbonate for 5 min. and filtered. Wash residue with two 25 ml portions acetone, then with 25 ml n-hexane and combine extracts. Wash acetone from extract with five 100 ml distillate water in 250 ml separatory funnel, then transfer upper layer to 100 ml volumetric flask containing 9 ml acetone, and dilute to volume with n- hexane. The filtrate was used sample solution. Preparation of calibration curve Accurately weigh 0.5 mg of β-carotene into 100 ml volumetric flask, was dissolved with 10.0 ml acetone, then with n-hexane until ml (5 ppm). From the filtrate, was prepared into 100,0 ml volumetric flask, diluted with 10,0 ml of acetone, diluted with n-hexane 95 ppm). Into 25 ml volumetric flasks place 0.76, 1.15, 1.53, 1.91, 2.30, 2.68 and 3.07 ppm respectively. To each flask dilute to volume with n-hexane. Determine absorbance of solution as soon as possible with spectrophotometer at maximum wavelength using n-hexane as blank. Create calibration curve, absorbance as the ordinate and concentration as abscissa. Determination of β-carotene in orange and yellow sweetpotato Determine absorbance of sample solution as soon as possible with spectrophotometer at 450 nm. Sample solution obtained from the extraction process was measured at the wavelength of maximum absorption predetermined. Content of β-carotene in sample (g/100g) where C sample = sample concentration(µg/ml), W= sample weigh (g), V a = final volume (ml) Method validation and recovery study To study the accuracy and precision of the proposed method, recovery experiment was carried out. Add reference standard by 10 and 20% in the sample of known levels and total amount of standard were determined. Percent recovery was calculated from the amount of β-carotene was added by the formula: Recovery (%) = x 100% where Cf = concentration of total samples obtained from measurements (mg), Ca = concentration of the actual sample (mg), C*a=concentration of analyte is added (mg)

3 RESULTS AND DISCUSSION The calibration curve. Table 2. β- carotene content from orange sweet potato Table 1. The result of β-carotene calibration curve Concentration Absor (ppm) bance Regression linear equation y = 0,0398x + 0, r = 0, x = Concentration y = absorbance Based on table, yield the regression linear equation y = x and coefficient correlation (r ) The regression linear equation was used to count the content of β-carotene in orange and yellow sweet potato. Table 3. β- carotene content from yellow sweet potato Figure 1. Curve relationship between the absorbance and concentration of β-carotene standard Determination of β-carotene content in orange and yellow sweet potato Determination of β-carotene was conducted in orange and yellow sweet potato. The results showed in Table 2 and Table 3. Figure 2. Bar chart of β-carotene content in orange and yellow sweetpotato

4 The result showed that β-carotene content in raw, fried and steamed an orange sweetpotato is larger than the yellow. The average level are 5.57, 3.13 and 4.07 mg/100 g with Relative Standard Deviation (SBR) 2.91, 6.04 and 3.49% respectively, which meets the requirements of the analyte concentration of 10 mg / kg is equal to 7%, while the average level of raw, fried and steamed yellow sweet potato are 1.55, 0.76 and 0.86 mg/100g with Relative Standard Deviation (SBR) each respectively 1.99, 3.0 and 1.49% respectively, which meets the requirements of the analyte concentration of 10 mg / kg and 1 mg / kg is equal to 7.3 and 11%.. RSD values that meets requirements indicates that visible light spectrophotometric method in the determination of β- carotene content in orange and yellow sweet potato either fresh or cooked method with a precision or accuracy are eligible. The recovery of β-carotene showed that it was in the range of 96-97%. The mean recovery was close to 100% which indicates the accuracy of the method. The results of statistical analysis using t-test value showed that β-carotene content in fried sweet potato were significantly different from that of steamed sweet potato. β-carotene content in steamed sweetpotato is higher than that of in fried sweetpotato CONCLUSION The content of β-carotene in the orange sweetpotato is larger than the yellow. The content of raw sweetpotato is larger than fries sweetpotato. REFERENCES 1. Bengtssona, A., Namutebib, A., Larsson, A.M., Svanberg, U Effects of various traditional processing methods on the all-trans b-carotene content of orangefleshed sweetpotato. J.of Food Composition and Analysis. 21, Horwitz W Official method of analysis of AOAC International. 18 th edition. Vol II; Chapter 45, p Inocent G. et al., Impact of three cooking methods (steaming, roasting on charcoal and frying) on the β-carotene, vitamin C contents of plantain and sweetpotato, American J. of Food Technol. 6(11): Ishiguro K, Yoshinaga M, Kai Y, Maoka T, Yoshimoto M Composition, content and antioxidative activity of the carotenoids in yellow-fleshed sweetpotato (Ipomoea batatas L.). Breeding Sci., 60: K osambo LMK, Carey EE, Misra AK, Wilkes J, Hagenimana V Influence of age, farming site, and boiling on pro-vitamin a content in sweet potato (Ipomoea batatas (L) Lam) storage roots. J. of Food Tech. in Africa. Vol.4(3): Kim, Y., Giraud, D.W. & Driskell, J.A Tocopherol and carotenoid contents of selected Korean fruits and vegetables. Journal of Food Composition and Analysis, 20, Ozlem T., Zihin Y Effects of cooking methods on the anthocyanin levels and antioxidant activity of a local turkish sweet potato (Ipomoea batatas (L) Lam) cultivar hatay kirmizi: boiling, steaming and frying effects. Turkish Journal of Field Crops. vol.17(1):87-90.

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