title: Employing response surface methodology for the optimization of ultrasound assisted extraction of lutein and β-carotene from spinach.
abstract: The extraction of lutein and β-carotene from spinach (Spinacia oleracea L.) leaves is important to the dietary supplement industry. A Box-Behnken design and response surface methodology (RSM) were used to investigate the effect of process variables on the ultrasound-assisted extraction (UAE) of lutein and β-carotene from spinach. Three independent variables, extraction temperature (°C), extraction power (%) and extraction time (min) were studied. Thin-layer chromatography (TLC) followed by UV visualization and densitometry was used as a simple and rapid method for both identification and quantification of lutein and β-carotene during UAE. Methanol extracts of leaves from spinach and authentic standards of lutein and β-carotene were separated by normal-phase TLC with ethyl acetate-acetone (5:4 (v/v)) as the mobile phase. In this study, the combination of TLC, densitometry, and Box-Behnken with RSM methods were effective for the quantitative analysis of lutein and β-carotene from spinach extracts. The resulting quadratic polynomial models for optimizing lutein and β-carotene from spinach had high coefficients of determination of 0.96 and 0.94, respectively. The optimal UAE settings for output of lutein and β-carotene simultaneously from spinach extracts were an extraction temperature of 40 °C, extraction power of 40% (28 W/cm3) and extraction time of 16 min. The identity and purity of each TLC spot was measured using time-of-flight mass spectrometry. Therefore, UAE assisted extraction of carotenes from spinach can provide a source of lutein and β-carotene for the dietary supplement industry.
authors: Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA. ammaragr@siu.edu.|Department of Food Science and Biotechnology, College of Agriculture, University of Basrah, Basrah 61004, Iraq. ammaragr@siu.edu.
authors: Ammar
authors: A
authors: Altemimi
authors: Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA. ga4082@siu.edu.
authors: David A
authors: DA
authors: Lightfoot
authors: SIUC Mass Spectrometry Facility, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA. mkinsel@chem.siu.edu.
authors: Mary
authors: M
authors: Kinsel
authors: Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA. dwatson@siu.edu.
authors: Dennis G
authors: DG
authors: Watson
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002855:Chromatography, Thin Layer; D014975:Lutein / Q000737:chemistry* / Q000302:isolation & purification; D013058:Mass Spectrometry; D018724:Spinacia oleracea / Q000737:chemistry*; D000069453:Ultrasonic Waves; D019207:beta Carotene / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D019207:beta Carotene; D014975:Lutein