Division of Nutritional Sciences, Sutton Bonington Campus, University of Nottingham, Loughborough, Leicestershire, UK.
Food Nutr Res. 2013 May 23;57. doi: 10.3402/fnr.v57i0.20294. Print 2013.
Preparatory steps such as seasoning, marination, and cooking may induce changes in meat which affects the ability of the stomach to adequately digest it. This may result in peptide chains reaching the colon intact where resident bacteria ferment them resulting in the formation of putative carcinogenic phenolic by-products.
In this study, we set out to determine whether peptic digestion of beef myofibrils was influenced by prior marination.
Cubes of sirloin stewing steak were marinated in balsamic vinegar or left untreated at 4°C overnight. Samples were oven cooked and myofibrils were extracted. Myofibrils were subject to proteolytic digestion with pepsin and digestion products analysed spectrophotometrically and with gel electrophoresis.
Both marination in balsamic vinegar and cooking significantly reduced the yield of myofibrils from shop-purchased beef (P<0.05). Digestion progressed in all samples as a function of time (P<0.01), varying depending on prior treatment. Marination induced resistance to the digestive effect of pepsin during the early to mid-phase of digestion, and we identified a protein band of ∼150 kDa which was protected from peptic digestion in samples which had been marinated and cooked, but not in any other groups.
Pre-treatment of meat prior to cooking may influence specific peptides such that they become more resistant to the digestive actions of pepsin.
调味、腌制和烹饪等预备步骤可能会改变肉的性质，从而影响胃对其的消化能力。这可能导致肽链完整地到达结肠，而其中的常驻细菌会对其进行发酵，从而形成潜在的致癌酚类副产物。
本研究旨在确定牛肉肌原纤维的消化是否受到预先腌制的影响。
将牛胸肉炖牛排切成方块，用香醋腌制或在 4°C 下过夜不处理。对样品进行烤箱烹饪，并提取肌原纤维。用胃蛋白酶对肌原纤维进行蛋白水解消化，并通过分光光度法和凝胶电泳分析消化产物。
香醋腌制和烹饪均显著降低了从商店购买的牛肉中肌原纤维的产量（P<0.05）。所有样品的消化均随时间的推移而进展（P<0.01），具体取决于预处理方式。腌制在消化的早期到中期诱导了对胃蛋白酶消化作用的抵抗，我们鉴定出一种约 150kDa 的蛋白质带，在经过腌制和烹饪的样品中，这种蛋白质带受到了胃蛋白酶消化的保护，但在其他任何组中都没有。
烹饪前对肉进行预处理可能会影响特定的肽，使它们对胃蛋白酶的消化作用更具抵抗力。
