DIGESTION OF BEEF BY PAPAIN¹

Abstract

The plant proteinase, papain, has found considerable application as a meat tenderizer but its use for this purpose has been largely empirical. The digestion of whole beef muscle and the survival of papain heated with whole muscle have not been studied quantitatively.The procedure usually recommended for tenderizing meat with papain is to paint the meat with a solution of the enzyme, then cook it after an interval of a few minutes. To be of use, the enzyme action must be rapid. Obviously, the proteolytic action under such circumstances depends upon such factors as the optimum temperature for the digestion of meat by papain, the stability of papain at cooking temperatures in the presence of meat, the extent of contact between the enzyme and the .meat, the ability of papain to penetrate the meat during digestion, and the digestibility of the native compared with the heat-denatured proteins. I n the experiments here described an attempt has been made to estimate the importance of several of these factors. The results obtained are outlined in the summary.The effect of tenderization in meat is difficult to treat quantitatively because adequate criteria of what constitutes tenderness are lacking. The tenderness induced by proteolytic enzymes, however, is a result of protein breakdown. Although the exact relationship between tenderizing effect and protein digestion is not known, it was apparent throughout this work that, in general, the more the meat was digested as determined chemically, the softer the structure of the meat became. The digestion of meat by papain was followed by measuring the blue color which the nonprotein digestion products give with the Folin-Ciocalteau phenol reagent after precipitation of the proteins with trichloracetic acid. This color is due to tyrosine, tryptophane, and cysteine and is expressed in terms of the amount of tyrosine which would give the same color, Anson (1938). The survival of papain heated with meat under various conditions was followed by the hemoglobin method for measuring papain activity.Our results (Table 1) show that 8O0C.(176"F.) was the most favorable temperature for the rapid digestion of ground meat by papain during a 30-minute period. From 70 to 85"C.(158 to 185'F.), however, the amount of digestion by papain did not vary much. Over this temperature range during the 30-minute digestion period, the increase in reaction rate brought about by raising the temperature was, presumably, compensated for by inactivation of the enzyme. Above 85"C., raising the temperature '

The Histological Effects of Proteolytic Enzyme Addition on Freeze-Dehydrated Chicken Meat

“…Gottschall and Kies (1942) made an early attempt to study some of the modes of proteolytic enzyme action as possible tenderizers of beef. Correlations between morphological and panel observations have been conducted with particular reference to freeze-dehydrated meats, especially beef and pork.…”

Factors Affecting Enzymatic Solubilization of Beef Proteins

“…Both ficin (Whitaker, 1957b) and bromelain (Murachi and Neurath, 1960) have been shown to be activated by sulfhydryl compounds. Gottschall and Kies (1942) showed that beef contained enough sulfhydryl groups to activate completely the papain used in their studies. Fig.…”

“…Previous workers have shown that a number of proteolytic enzymes can solubilize the proteins of beef muscle and that there is a certain degree of selectivity among these enzymes in solubilizing the different protein fractions (Gottschall and Kies, 1942;Tappel Ef al., 19.56;Wang et al, 195s). Ficin, bromelain, and papain, all from tropical plants, and trypsin, from the pancreas, possess collagenase and elastase activities.…”

Tenderization of Spent Hen Muscle Using Papain, Bromelin, or Ficin Alone and in Combination with Salts

“…The usually recommended procedure for tenderizing meat is to paint the meat with a solution of papain and then cook it after an interval of a few minutes (Gottschall and Kies, 1942;Hwang and Ivy, 1951). When the meat was painted with a solution of papain and then cooked, it was found that papain would not penetrate very far in the meat under such conditions, and the papain on the surface would be inactivated by heat before much digestion could take place (Hwang and Ivy, 1951;Gottschall and Kies, 1942).…”

“…When the meat was painted with a solution of papain and then cooked, it was found that papain would not penetrate very far in the meat under such conditions, and the papain on the surface would be inactivated by heat before much digestion could take place (Hwang and Ivy, 1951;Gottschall and Kies, 1942).…”