Nayely Leyva-López, Laura A. Contreras-Angulo, Gustavo A. Gonzalez-Aguilar, María D. Muy-Rangel, J. Basilio Heredia* Centro de Investigación en Alimentación y Desarrollo, A.C., Carretera a Eldorado Km5.5, Col. Campo El Diez, Culiacán, Sinaloa, México. *Corresponding autor: INTRODUCTION There is an increasing interest in carotenoids (CAR) in pharmaceutical and nutraceutical industry due to their antioxidant (AOX) and antimutagenic (AM) potential. Tomato peel residue from the processing industry represents an environmental problem. However, the peel still has a high content of CAR that can be used as functional ingredients in the development of new products 1,2. Due to CAR are inside the plant cell its recovery with solvents became difficult, so using cell wall degrading enzymes is proposed to overcome this situation 2,3. The aim of this study was to optimize the enzyme-aided CAR extraction from tomato peel and evaluate its AOX and AM activity. MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES A central composite design was used to optimize the enzyme-aided extraction of CAR from tomato peel. Peel was pretreated with a food-grade enzyme preparation (cellulolytic and pectinolytic activity) and then subjected to hexane:acetone:ethanol (50:25:25) extraction. The factors investigated were pretreatment time “PT” (1-6 h) and enzyme percentage “E%” ( %). Total CAR content was measured accordingly with previous report 4. The AOX and AM were determined by Trolox equivalent of antioxidant capacity (TEAC) 5 and Ames Test 6, respectively. RESULTS AND DISCUSSION It is possible to increase the CAR yield extraction from tomato peel using enzymes that degrade the cell wall, at the same time that the biological activity of the extracts is enhanced. The perspective of this research is the feasibility of scaling the use of enzymes in industrial extraction of plant pigments. This study provide an alternative to agribusiness to exploit residues in industrialization of tomato to extract CAR, which can be extend to the use of waste from other industries. [1]. Knoblich M, Anderson B, Latshaw D. (2005). J. Sci. Food Agric. 85: [2]. Rizk EM, El-Kady AT, El-Bialy AR. (2014). Ann. Agric. Sci. 59(1): [3]. Zuorro A, Lavecchia R. (2010). Biotechnol. Biotec. Eq. 24: [4]. Gross J. (1991). Pigments in vegetables: Chlorophylls and carotenoids. Van Nostrand Reinhold. New York. [5]. Thaipong K, Boonprakob U, Crosby K, Cisneros- Zevallos L, Byrne DH. (2006). J. Food Comp. Anal. 19, [6]. Kado NY, Langley D, Eisenstadt E. (1983). Mutat. Res. Lett. 121(1): [7]. Wall ME, Wani MC, Hughes TJ, Taylor H. (1988). J. Nat. Prod. 51(5): Figure 2. Antimutagenic activity of carotenoids extracted by two methods from tomato peel. Different letters indicate significant differences by Tukey test (P≤0.05). The bars indicate standard deviation (n=9). CAR extracted from the enzyme-treated tomato peel showed a mutagenic inhibition percentage greater than those from the untreated peel (Fig. 2). Accordingly with a previously proposed scale 7 where the antimutagenicity of various plant extracts is rated, CAR obtained from enzyme-treated peel showed a strong AM while those extracted from untreated peel had just a positive AM. The enzyme-aided extraction of CAR from tomato peel resulted in a regression equation with linear and quadratic coefficients as follows: Where Y represents the CAR content in the extraction; X 1 and X 2 1 are the linear and quadratic form of E%, and X 2 and X 2 2 are the linear and quadratic forms of PT. Y = – 36.14X X X 2 1 – 55.50X 2 2 When using the regression equation to investigate the interactive effects of E% and PT on extraction of CAR, resulted in a three-dimensional plot which is depicted in Fig. 1. The amount of enzyme is a critical variable since it degrades the major components in the cell wall which allows a greater contact between solvent and carotenoids, thus increasing the extraction yield. Figure 1. Response surface plot of the effect of enzyme percentage E% (X 1 ) and Pretreatment time PT (X 2 ) on the extraction of carotenoids. By carrying out parameter optimization on the basis of the built mathematical model, the obtained experimental conditions for the extraction of CAR were an E% of 10.24% and an PT of 4.8 h. When using the optimum conditions mentioned the total amount of CAR extracted from the enzyme-tretated tomato peel was 582 mgkg-1 dry weight, which is significantly higher (P<0.05) than 477 mg/kg dry weight obtained from the untreated peel. From this can be declared that treating tomato peel with enzymes increases the carotenoids yield extraction in 22%. The AOX of CAR obtained using enzymes was 8% higher than those obtained from the untreated peel (P<0.05). Treatment CAR content (mg/kg dry weight) AOX (µm Trolox/g dry weight) Enzyme-treated tomato peel582 a 9.04 a Untreated tomato peel477 b 8.43 b Table 1. Total carotenoid content and antioxidant activity of carotenoid extracted by two methods from tomato peel. Different letters indicate significant differences by Tukey test (P≤0.05).