論文の公開元へ加工処理方法が異なる紫花豆の抗酸化活性の比較
概要
浸漬および加熱処理に用いる水量が異なる紫花豆煮豆を作り、それらの抗酸化活性を検討した。浸漬と加熱処理に用いた水量(ml)が生豆の重さ(g)の２倍の条件で加工した煮豆抽出液が、最も高いDPPHラジカル消去活性(12.11±0.27μmol/g 煮豆)を示した。浸漬と加熱処理に用いた水量(ml)と生豆の重さ(g)の比が大きくなるにつれて、その煮豆抽出液のDPPHラジカル消去活性は低くなった。これらの煮豆抽出液に含まれるDPPHラジカル消去活性とポリフェノール含量との間には正の相関が認められた(相関係数 r＝0.9952)。これらの結果は、煮豆を作るときに用いる浸漬および加熱処理の水量を少なくするほど、その煮豆に含まれる抗酸化活性は高くなることを示している。しかし、煮豆を加工するときに用いる水の量を少なくすると硬い煮豆になる欠点がある。豆の硬さを緩和するために少量の食酢や重曹を添加する煮豆法により製造した紫花豆の煮豆と蒸煮法による蒸し豆の抗酸化活性を検討した。その結果、今回検討した加工法の中では、蒸煮法で作った蒸し豆の機能性の方が食酢や重曹を添加して作った煮豆のそれらよりも高いことを明らかにした。
Scarlet runner beans (purple) were boiled in different amounts of water used for soaking and heating treatment and their antioxidant activity was investigated. The highest DPPH
radical scavenging activity (12.11±0.27 μmol/g boiled beans) was observed in the boiled bean extract processed using twice the amount of water (mL) for soaking and heating treatment than the weight (g) of the raw beans. The DPPH radical scavenging activity of the boiled bean extract decreased with the increase in the ratio of the amount of water (mL) used for soaking and heat treatment to the weight of the raw beans (g). There was a positive correlation between DPPH radical scavenging activity and the polyphenol content of these boiled bean extracts (correlation coefficient r = 0.9952). These results indicate that the lower the amount of water used in the soaking and heating process for making boiled beans, the higher the antioxidant activity. However, if the amount of water used to process the boiled beans is reduced, the beans become hard. The antioxidant activity of scarlet runner beans (purple) treated with the boiling method with a small
amount of vinegar or baking soda to reduce their hardness and those treated with the steaming method was investigated. In conclusion the functionality of steamed beans prepared by the steaming method was higher than that of boiled beans prepared by adding vinegar or baking soda among the processing methods investigated in this study.
