Multivariate evaluation of extraction solvent employing in carotenoids extraction of cashew apple

The peduncle constitutes with nut the cashew apple, fruit of cashew tree (Anacardium occidentale L.) occurring naturally in three colors: orange, yellow and red1. The pseudo fruit has nutrients such as polyphenols (flavonoids, carotenoids, anarcadic acid and tannins). Especially carotenoids, the focus of this study, correspond for isoprenoids with forty atoms of carbon that can be synthetized by plants among others autotrophies organisms2,3. Although already has works involving carotenoids of cashew apple, but it do not explore the extraction methodology of these analytes. Therefore, this study aims to develop a method for carotenoids extraction from cashew apple through multivariate approach. The samples were acquired in the city of Valença-PI, then, freeze dried and pulverized in cryogenic mill. The composition of the extraction solution was optimized applying the simplex centroid design for the pure solvents, acetone, ethanol, petroleum ether, methanol and its respective binary, ternary, and quaternary mixture. The carotenoids extraction was carried out in these steps: ca. 90 mg of powdered cashew peduncle received addition of 6.0 mL solution or extraction mixture in coated Falcon® tube to avoid light incidence. After this, the mixture was kept under stirring for 20 min at 290 rpm on a mechanical shaker. The extract was centrifuged at 3500 rpm during 10 min. The supernatant was collected and stored at -4 °C for the spectrophotometer analyses. Aiming to find the better extraction solution, the multivariate approach was using the simplex centroid design to evaluate four solvents acetone (a), ethanol, petroleum ether (p) and methanol (m). Their combination in binary, ternary, quaternary were evaluated resulting in 15 experiments in duplicate. The total carotenoids content found in extracts using solvent mixture was higher than those with pure solvents. The mixture among acetone/ethanol/petroleum ether presented ca. 140.03 µg g-1. From all these observations, it is important to notice that extraction solution containing solvent mixtures resulted in effective increases in total carotenoid content when compared to pure solvents. The performance of a special linear, quadratic and cubic model was evaluated by analysis of variance (ANOVA). The special cubic model presented the best fit for the experimental domain of the proposed extraction methodology and the ANOVA for the applied model indicated that it did not present a significant lack of fit at the 95% confidence level. It is noticed that a ternary mixture containing 38% acetone, 30% ethanol and 32% petroleum ether was the optimal solution.

References:
[1] SCHWEIGGERT, R. M.; VARGAS, E.; CONRAD, J.; HEMPEL, J.; GRAS, C. C.; ZIEGLER, J. U.; MAYER, A.; JIMÉNEZ, V.; ESQUIVEL, P.; CARLE, R. Carotenoids, carotenoid esters, and anthocyanins of yellow-, orange-, and red-peeled cashew apples (Anacardium occidentale L.). Food Chemistry, v. 200, p. 274–282, 2016.
[2] DEY, S.; RATHOD, V. K. Ultrasound assisted extraction of β-carotene from Spirulina platensis. Ultrasonics Sonochemistry, v. 20, n. 1, p. 271–276, 2013.
[3] ORDÓÑEZ-SANTOS, L. E.; PINZÓN-ZARATE, L. X.; GONZÁLEZ-SALCEDO, L. O. Optimization of ultrasonic-assisted extraction of total carotenoids from peach palm fruit (Bactris gasipaes) by-products with sunflower oil using response surface methodology. Ultrasonics Sonochemistry, v. 27, p. 560–566, 2015.