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POSTMORTEM INVASION OF MUSCLE FOOD BY A PROTEOLYTIC BACTERIUM
Author(s) -
SIKES A.,
MAXCY R. B.
Publication year - 1980
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1980.tb02599.x
Subject(s) - food science , bacteria , chemistry , inoculation , proteases , penetration (warfare) , serratia marcescens , sodium , biology , escherichia coli , enzyme , biochemistry , genetics , organic chemistry , operations research , gene , engineering , immunology
ABSTRACT Serratia marcescens was used to study the process of bacterial invasion of intact and comminuted meats (fresh and frozen‐thawed) as well as the bacterium's ability to hydrolyze reconstituted collagen. Fresh intact pork was more susceptible to invasion when the inoculated surface was vertical to the inoculum. In comminuted beef and pork, invasion was more extensive in meat that had undergone at least one freeze‐thaw cycle. The addition of sodium tripolyphosphate (up to 0.5%, w/w) to comminuted beef and pork results in a reduction in the depth of penetration (up to 16% and 84%, respectively). Cooked (63°C and 77°C) intact beef samples were more susceptible to bacterial invasion than uncooked beef. Meat cooked to an end‐point temperature of 77°C exhibited less resistance to bacterial invasion than samples cooked to an end‐point temperature of 63°C. Fiber orientation in cooked beef samples played a significant role in the final depth of penetration. Bacterial invasion in cooked beef was more pronounced in samples where the inoculated surface was vertical to the inoculum. Results indicated that bacterial invasion is not a function of the collagenolytic acitivity present in bacterial proteases. The invasive process or mechanism is strongly influence by the hydration of the meat proteins and the availability of pores or canals, which are created during cooking or as a result of freezing and thawing of meats.