The study evaluated objective and subjective retail display color of ground beef produced from beef trim treated with or without lactic acid dip and stored 24 or 48 h prior to chub packaging and storage for 7, 14, or 21 d.

Ground beef produced from trim treated (TRT) with lactic acid dip (LA) or without (CON) and stored 24 h (24TS) or 48 h (48TS) was used. Samples (n = 84; 21/TRT, TS combination) were chub vacuum packaged (4.54 kg) and stored for 7, 14, or 21 d (CS) and finely ground when storage time completed. Ground beef was placed on a polystyrene tray overwrapped with low-barrier polyvinylchloride film. Packages were displayed for 3 d (2 to 3°C) under continuous fluorescent lighting. CIE L* a* b* values were taken daily during simulated retail display to calculate hue angle (tan^–1 a/b) and saturation index [(a² + b²)^1/2]. Trained panelists (n = 6) evaluated worst-point lean color daily during retail display with an 8-point verbally anchored numeric scale with 0.5 increment scores (1 = very bright red, 8 = tan to brown). Data were analyzed as a split plot design with whole plot as a 2 × 2 factorial of TS and TRT and subplot combined CS with retail day.

Visual color scores and L* values differed (P < 0.0001) among CS times and retail display day, as expected. Treatment, CS and retail display day interacted (P < 0.05) for a*, saturation index, and hue angle. Hue angle and a* values indicated a loss of redness (P < 0.05) within TRT and CS as retail display increased. Initial display a* values within TRT did not differ (P > 0.05) across CS, but LA treated chubs were more red (P < 0.05) than CON regardless of CS. Chubs stored 7 or 14 d had similar (P > 0.05) hue angles and were less discolored (P < 0.05) than 21 d stored chubs regardless of TRT at 0 d of display. Hue angle and a* values did not differ (P > 0.05) between LA and CON within CS after 0 d of display. Saturation index, or vividness, for 7 d stored chubs decreased (P < 0.05) the longer packages were displayed in retail, but chubs stored 14 and 21 d had similar vividness (P > 0.05) within d 2 and 3 of display. At initial display, chubs treated with LA were more vivid (P < 0.05) than CON within CS. Lactic acid treated and CON chubs did not differ (P > 0.05) within CS at d 1 and 3 of display. Chubs stored 7 d were more vivid (P < 0.05) than 14 and 21 d stored chubs, which did not differ (P > 0.05) at d 1, 2, and 3 of display. The vividness of LA treated chubs was greater (P < 0.05) than CON for 7 d stored chubs at d 2 of display. A TS × CS retail day interaction (P < 0.05) was observed for a* and saturation index. Saturation index and a* values for TS were similar (P > 0.05) within chubs stored 7 and 21 d at retail d 1 and 2 of display, but no redness differences (P > 0.05) within CS were observed at d 3 of display. Saturation index and a* values decreased (P < 0.05) as package display time increases within TS and CS, except 48TS vividness did not differ (P > 0.05) between d 2 and 3 of display. L* and b* values indicated LA treated chubs were lighter and more yellow (P < 0.05) than CON. Hue angle indicated 48TS was less red (P < 0.05) than 24TS.

Longer trim and chub storage is detrimental, but LA combined with other factors can delay discoloration.