44E-16 |
Effect of processing on nutraceutical potential of quinoa |
H. DOGAN1, Z. Nanqun2, C. T. Ho2, R. T. Rosen2, and M. V. Karwe2. (1) Food Science & Technology Research Institute, TUBITAK Marmara Research Center, PO Box 21, Gebze/Kocaeli, 41470, Turkey, (2) Dept. of Food Science, Rutgers, The State Univ. of New Jersey, 65 Dudley Rd., New Brunswick, NJ 08901-8520 Quinoa (Chenopodium quinoa) contains a number of structurally diverse saponins and significant amounts of flavonoids and phenolic acids, which have been known to have a number of health promotion effects. This value-added chemical composition makes quinoa an ideal candidate to be further studied for establishing it as a functional food. The objective of this research was to investigate the effect of processing on bioactive components of quinoa. For saponins, the dried and ground quinoa seeds were extracted twice with 95% EtOH at room temperature and concentrated with successive extractions by water, hexane, ethyl acetate and butanol. The butanol fraction was subjected to column chromatography to give four (water, water-ethanol (3:7), water-ethanol (1:9) and acetone) fractions. The water-ethanol (3:7) fraction was further separated into four fractions by column chromatography. These four fractions were then purified and identified by LC-MS and NMR. Extrusion cooking of quinoa was carried out using a ZSK-30 twin-screw extruder (Krupp Werner Pfleiderer) at 16-24% (w.b.) feed moisture content, 130-170°C die temperature and 250-500 rpm screw speed. Extraction of phenolic compounds from ground quinoa seeds and extrudates was carried out with methanol and ethyl acetate, successively. Extracts were subjected to chromatographic analysis using HPLC. Five ecdysteroids were identified in quinoa seeds. Their structures were determined as ecdysterone, makisterone A, 24-epi-makisterone A, 24(28)-dehydromakisterone A and 20,26-dihydroxyecdysone. HPLC analysis of extrudates showed loss of non-polar (phenolic) fraction after extrusion and rise in intermediate polarity compounds at high processing temperature, low moisture and high screw speed. These compounds are now being characterized. This study demonstrated for the first time that quinoa seeds are a source of important phtyochemicals, some of which have been previously reported to have biological activity. It also showed that extrusion processing significantly affected the phenolic profile in quinoa.
Session 44E, Nutraceuticals & Functional Foods
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