SPSFAM ERP

sample is extracted with 25 mL of hot water to give fructan concentrations of 0.4-1.6 mg/mL; equivalent to approximately 14.4-58.2 µ g of sugar in the PAHBAH assay mixture. For samples containing 40-100% w/w fructan content, 100 mg of sample is extracted with 25 mL of hot water and on cooling, an aliquot (1 mL) of this extract is diluted by adding to 2 mL of water (3-fold dilution), to give fructan concentrations of 0.53 to 1.3 mg/mL; equivalent to approximately 19.3-47.3 µ g of sugar in the PAHBAH assay mixture. The linearity of the PAHBAH color reaction with fructose and glucose is shown in Figure 1. The linear range for fructose and glucose reached 90 µ g of sugar in the PAHBAH assay mixture with r 2 values of 0.9997 and 0.9999, respectively. Also, the color response with the two sugars is identical. The linearity of pure fructan samples is shown in Figure 2 .

Figure 1. Linearity of the PAHBAH color reaction with fructose and glucose.

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