Effects of Temperature, Light and Storage Time on the Physicochemical and Sensory Characteristics of Vacuum- or Nitrogen-Packed Frankfurters

Abstract

Frankfurters prepacked in vacuum or nitrogen gas were stored for 49 d at −4, 0, 3 and 7°C under dark and light conditions. Effects of temperature, light and storage duration on physiocochemical (gas composition, TBA, pH, ERV, nitroso-hematin) and sensory (color and off-odor) characteristics of both package samples were then examined. The relative volume of nitrogen decreased gradually but the change was not significant (P>0.05) during the 49-d study. No significant increases in CO₂ concentration were observed between both package treatments at −4 and 0°C, whereas the largest increase in CO₂ content (4.8–16.8%) occurred at 7°C after 21 d of storage. TBA, pH, ERV and nitroso-hematin values were not differently affected by either modified atmosphere types, regardless of storage temperature and illumination used. With respect to surface discoloration and off-odor, nitrogen-packed frankfurters exhibited a lower incidence of discoloration and off-odor and were of satisfactory appearance, even after 35 d of storage at 7°C. Vacuum-packed samples, however, could not be effectively stored longer than 21 d due to formation of brown and green discolorations. Light generally had a significant effect on surface discoloration of vacuum-packed frankfurters. Data indicate that color and odor changes were not related to the values of TBA, ERV and nitro so-pigment but significant relationships were noted between pH. CO₂ and microflora counts at 7°C.