小麦粉中脂肪酸值测定提取条件优化

Optimization of extraction conditions for determination of fatty acid value in wheat flour

目的优化测定小麦粉中脂肪酸值的提取条件。方法采用GB/T 5510-2011《粮油检验粮食、油料脂肪酸值测定》中苯提取法测定,后分别使用95%乙醇、无水乙醇作为提取试剂,振荡提取时间为30、20、10min。结果用50.0mL无水乙醇代替苯,在环境温度20℃,频次为100次/min振荡器振摇10min,提取液静置3 min的条件下,测定小麦粉中脂肪酸值数值分别为31.14、26.32和34.98 (KOH) mg/100 g,用苯提取法测定数值为30.47、25.93和34.84 (KOH) mg/100 g,二者差值均在精密度范围内。结论可以采用无水乙醇代替苯用于测定小麦粉的脂肪酸值。

Objective To find safe and economical extraction reagents and experimental conditions, different extracts and experimental conditions are used to determine the fatty acid values of wheat flour high-gluten wheat flour and low-gluten wheat flour. Methods Adopting benzene extraction method in GB/T 5510-2011 Determination of fatty acid value of grain and oil inspection determining fatty acid value in wheat flour, after that, 95% ethanol and anhydrous ethanol were used as extraction reagents respectively, and the oscillating extraction time was 30, 20, 10 min. Results The 50.0 mL of absolute ethanol was used instead of benzene, with temperature 20 ℃, the frequency 100 times/min, the shaker for 10 min, and the extract was allowed to stand for 3 min, the value of fatty acid in wheat flour was 31.14, 26.32, 34.98(KOH) mg/100 g, and the value of benzene extraction method was 30.47, 25.93 and 34.84(KOH) mg/100 g. The difference between the two method was in the precision range. Conclusion Anhydrous ethanol can be used instead of benzene to determine the fatty acid value of wheat flour.