Karim Zida, Holmes Melvin, Orfila Caroline
Nutrition and Public Health Group, School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK.
Food Colloids and Processing Group, School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK.
Food Chem. 2017 Feb 15;217:498-504. doi: 10.1016/j.foodchem.2016.08.058. Epub 2016 Aug 21.
The effect of the chlorogenic acid isomer 5-O-caffeoylquinic acid (5-CQA) on digestion of potato starch by porcine pancreatic alpha amylase (PPAA) was investigated using isolated starch and cooked potato tuber as substrates. In vitro digestion was performed on five varieties of potato with varying phenolic content. Co- and pre-incubation of PPAA with 5-CQA significantly reduced PPAA activity in a dose dependent manner with an IC50 value of about 2mgmL(-1). Lineweaver-Burk plots indicated that 5-CQA exerts a mixed type inhibition as km increased and Vmax decreased. The total polyphenol content (TPC) of peeled tuber tissue ranged from 320.59 to 528.94mg 100g(-1)dry weight (DW) in raw tubers and 282.03-543.96mg 100g(-1)DW in cooked tubers. With the exception of Désirée, TPC and 5-CQA levels decreased after cooking. Principle component analysis indicated that digestibility is affected by multiple factors including phenolic, dry matter and starch content.
以分离淀粉和煮熟的马铃薯块茎为底物，研究了绿原酸异构体5-O-咖啡酰奎尼酸（5-CQA）对猪胰α淀粉酶（PPAA）消化马铃薯淀粉的影响。对五个酚类含量不同的马铃薯品种进行了体外消化实验。PPAA与5-CQA共同孵育和预孵育均能显著降低PPAA活性，且呈剂量依赖性，IC50值约为2mg/mL（-1）。Lineweaver-Burk图表明，5-CQA表现为混合型抑制，因为Km增加而Vmax降低。去皮块茎组织的总酚含量（TPC）在生块茎中为320.59至528.94mg/100g（-1）干重（DW），在熟块茎中为282.03 - 543.96mg/100g（-1）DW。除德西蕾品种外，烹饪后TPC和5-CQA水平均下降。主成分分析表明，消化率受多种因素影响，包括酚类、干物质和淀粉含量。
