• Food Science and Biotechnology
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• v.18 no.1
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• pp.66-72
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• 2009

An aqueous ribose-cysteine model system (initial pH 5.6) was conventionally heated to the same browning at varying temperatures ($120-180^{\circ}C$), supercritical carbon dioxide (SC-$CO_2$, 20 MPa) was also applied on the same matrices for same periods at each temperature and about 20% reduction of the absorbance at 420 nm was observed as compared with sole thermal treatment. The headspace volatiles from Maillard reaction mixtures were analyzed by solid-phase microextraction (SPME) in combination with gas chromatography and mass spectrometry (GC-MS), and predominated with sulfur containing compounds, such as thienothiophenes, polysulfur alicyclics, thiols, and disulfides. Reaction temperature exhibited complex effects on volatiles formation and those effects became further complicated by the SC-$CO_2$ treatment. The formation of noncarbonyl polysulfur heterocyclic compounds and thienothiophenes was generally favored at high temperatures. Most volatiles were inhibited in SC-$CO_2$ as compared with thermal treatment alone, however, the well-known meaty aromatic compounds, such as thiols and disulfides, were obviously enhanced.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.123-130
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• 2015

Seaweed Sargassum horneri extracts were obtained using supercritical carbon dioxide ($SC-CO_2$) and different solvents. $SC-CO_2$ was kept at a temperature of $45^{\circ}C$ and pressure of 250 bar. The flow rate of $CO_2$ (27 g/min) was constant during the entire 2-h extraction period, and ethanol was used as a cosolvent. Six different solvents [acetone, hexane, methanol, ethanol, acetone mix methanol (7:3), and hexane mix ethanol (9:1)] were used for extraction and agitated by magnetic stirring (250 rpm) in the dark at $25^{\circ}C$ for 20 h; the ratio of material to solvent was 1:10 (w/v). Antioxidant properties of S. horneri extracted using $SC-CO_2$ with ethanol and different solvents have shown good activity. The highest activity belongs to $SC-CO_2$ with ethanol extracted oil, showing DPPH, ABTS, total phenolic content, and total flavonoid levels of $68.38{\pm}1.21%$, $83.51{\pm}1.25%$, $0.64{\pm}0.02mg/g$, and $5.57{\pm}0.05mg/g$, respectively. The S. horneri extracts showed a significant correlation between the antioxidant activity and phenolic content. Based on these results, the $SC-CO_2$ extract (ethanol) of the seaweed extract from brown seaweed may be a valuable antioxidant source.