On food and cooking the science and lore of the kitchen ( PDFDrive ) 284

while the moderate humidity causes the meat to lose moisture gradually, and thus become denser and more concentrated Muscle Enzymes Generate Flavor… The aging of meat is mainly the work of the muscle enzymes Once the animal is slaughtered and the control systems in its cells stop functioning, the enzymes begin attacking other cell molecules indiscriminately, turning large flavorless molecules into smaller, flavorful fragments They break proteins into savory amino acids; glycogen into sweet glucose; the energy currency ATP into savory IMP (inosine monophosphate); fats and fat-like membrane molecules into aromatic fatty acids All of these breakdown products contribute to the intensely meaty, nutty flavor of aged meat During cooking, the same products also react with each other to form new molecules that enrich the aroma further …And Diminish Toughness Uncontrolled enzyme activity also tenderizes meat Enzymes called calpains mainly weaken the supporting proteins that hold the contracting filaments in place Others called cathepsins break apart a variety of proteins, including the contracting filaments and the supporting molecules The cathepsins also weaken the collagen in connective tissue, by breaking some of the strong cross-links between mature collagen fibers This has two important effects: it causes more collagen to dissolve into gelatin during cooking, thus making the meat more tender and succulent; and it reduces the squeezing pressure that the connective tissue exerts during heating (p 150), which means that the meat loses less moisture during cooking Enzyme activity depends on temperature The calpains begin to denature and lose activity around 105ºF/40ºC, the cathepsins around 122ºF/50ºC But below this critical ... called cathepsins break apart a variety of proteins, including the contracting filaments and the supporting molecules The cathepsins also weaken the collagen in connective tissue, by breaking some of the strong cross-links between mature... succulent; and it reduces the squeezing pressure that the connective tissue exerts during heating (p 150), which means that the meat loses less moisture during cooking Enzyme activity depends on temperature...? ?And Diminish Toughness Uncontrolled enzyme activity also tenderizes meat Enzymes called calpains mainly weaken the supporting proteins that hold the contracting filaments in place Others