The effect of pH on shelf-life of pork during aging and simulated retail display.

The pork industry uses pH to differentiate product of varying quality; thus, the effect of pH on shelf-life is important as time during transport is extended. The objective was to develop regression equations to predict shelf-life over a range of ultimate pH (5.42-6.26). Shelf-life was evaluated after vacuum aging pork loin sections 0, 7, 14, 21, or 28d and during 3d of simulated retail display (4.5°C) for pork loin chops. Correlation coefficients indicated a strong relationship between pH and quality measurements. Regression analysis with Aging Day and pH was able to explain 87% of the variation in aerobic plate counts for pork. After 28d of vacuum aging, loin sections from the upper end of the pH distribution had about a 3log(1000X) greater aerobic plate count than did the lower end pH product. An increase in pH resulted in pork with lower L*, a*, b* and R(630)-R(580) values and as Aging Day increased, instrumental measurements of color increased slightly. Although higher pH is associated with improved pork quality, higher pH and longer aging periods will result in increased microbial proliferation and decreased shelf-life. Thus, an intermediate pH may provide the most desirable combination of quality and shelf-life when extensive aging is used.

[1]  D. G. Topel,et al.  MICROBIOLOGY OF PALE, DARK AND NORMAL PORK , 1976 .

[2]  M. S. Brewer,et al.  Consumer‐rated Quality Characteristics as Related to Purchase Intent of Fresh Pork , 1999 .

[3]  D. Ledward Haemoproteins in Meat and Meat Products , 1992 .

[4]  J. Killefer,et al.  ULTIMATE pH EXPLAINS VARIATION IN PORK QUALITY TRAITS , 2010 .

[5]  E. Borch,et al.  Comparison of shelf life of vacuum-packed pork and beef. , 2002, Meat science.

[6]  C. Gill,et al.  The microbiology of DFD fresh meats: A review. , 1981, Meat science.

[7]  H. J. Andersen,et al.  Significance of storage time on degree of blooming and colour stability of pork loin from different crossbreeds. , 2006, Meat science.

[8]  B. S. Schweigert,et al.  The Science of meat and meat products , 1987 .

[9]  B. Hudson,et al.  Developments in food proteins , 1982 .

[10]  E. D. Strange,et al.  SIMPLIFIED METHODOLOGY FOR MEASURING MEAT COLOR , 1974 .

[11]  B. Duval Commission internationale de l’éclairage (CIE) , 2001, Optique Photonique.

[12]  J. D. Kemp,et al.  PHYSICAL, CHEMICAL, SENSORY, AND MICROBIOLOGICAL PROPERTIES AND SHELF LIFE OF PSE AND NORMAL PORK CHOPS , 1980 .

[13]  M. S. Brewer,et al.  Discoloration of fresh pork as related to muscle and display conditions , 1998 .

[14]  M. S. Brewer,et al.  EFFECT OF ULTIMATE pH ON THE QUALITY CHARACTERISTICS OF PORK , 2004 .

[15]  M F Rothschild,et al.  Correlations among selected pork quality traits. , 2002, Journal of animal science.

[16]  J. D. Tatum,et al.  Benchmarking value in the pork supply chain: Characterization of US pork in the retail marketplace. , 2005, Meat science.

[17]  J. Boyer,et al.  INFLUENCE OF pH AT 24 H POSTMORTEM ON QUALITY CHARACTERISTICS OF PORK LOINS AGED 45 DAYS POSTMORTEM , 2007 .

[18]  M. S. Brewer,et al.  Postmortem pH, Muscle, and Refrigerated Storage Effects on Ability of Vacuum‐Packaged Pork to Bloom , 2008 .

[19]  D. E. Johnston,et al.  The chemistry of muscle-based foods , 1992 .

[20]  P. Davidson,et al.  Relationships between ultimate pH and microbial, chemical, and physical characteristics of vacuum-packaged pork loins. , 2008, Journal of food science.

[21]  A. Murray,et al.  Effects of pork muscle quality on bacterial growth and retail case life. , 1988, Meat science.

[22]  G. J. Banwart,et al.  Basic Food Microbiology , 1979 .

[23]  S. Rousset,et al.  Effect of Co2 or vacuum packaging on normal and high pH meat shelf-life , 2007 .

[24]  V. R. Cahill,et al.  EFFECT OF VACUUM PACKAGING ON WEIGHT LOSS, MICROBIAL GROWTH AND PALATABILITY OF FRESH BEEF WHOLESALE CUTS , 1974 .