WHITE‐SPOT FORMATION ON PACKAGED BEEF STEAKS

Abstract

ABSTRACTBottom round (n=162), eye of round (n=80) and rib (n=126) steaks were used to identify conditions involved in formation of white‐spots on muscle surfaces of packaged meat cuts. Conditions investigated were: (a) retail packaging films, (b) angle at which cuts are displayed in the retail case, (c) maximum ambient temperature achieved during defrost of the retail case, and (d) type of film‐to meat surface contact. Neither microbes nor packaging film components (antifogging agents, plasticizer) appeared to be the cause of white‐spots. Retail packaging films were not associated with surface discoloration, incidence of white‐spots or overall appearance. Incidence of white‐spots was increased by: (a) displaying retail cuts at an angle of 15°, (b) temperature abuse between packaging and retail display, (c) defrost cycles in which ambient temperatures in the retail case reached 21 °C, (d) wrapping cuts in a manner resulting in “poor” film‐to‐meat surface contact, and (e) longer (3 days vs 1 day) periods of retail display. White‐spots appear to result from physical, rather than chemical, phenomenon with one plausible explanation being that of condensation of moisture between wrapping film and meat surfaces and concurrent washing of color pigments from muscle; such spots most frequently occur proximal to the boundary between areas of “good” vs “poor” film‐to‐meat surface contact.