Absorption kinetics of oxygen scavengers

Abstract

The oxygen (O2) absorption kinetics of six commercial O2 scavengers were studied. The scavengers were placed in bags which were filled with 240 mL of air, 4.5 L N2 + 15 mL of air, or 3.5 L CO2 + 9 mL of air. The O2 concentration in each bag was measured at hourly intervals for 8 h. The effects of variability among individual scavengers, initial O2 concentrations of 20% or 500 ppm (0.05%), temperatures of 25, 12, 2 or −1.5 °C, and scavenger capacity on the O2 absorption rate were determined. In addition, the effect of placing scavengers within over‐wrapped trays within bags, was examined. Rates of O2 absorption varied by factors of up to 2 between individual O2 scavengers of the same type, but rates of absorption by groups of four scavengers of the same type were similar. Low temperatures gave longer O2 half‐life when compared with those at higher temperatures, e.g. O2 half‐lives of 7.1 and 1.0 h at −1.5 and 25 °C, respectively, were obtained for one scavenger type. Shorter O2 half‐lives were obtained in air than in N2 atmospheres at the same temperature, e.g. O2 half‐lives of 1.0 and 3.3 h in air and N2 at 25 °C, respectively, were obtained for one scavenger type. The O2 absorption reactions were of first order for both high and low initial O2 concentrations. However, O2 concentration was the primary limiting factor for O2 absorption in atmospheres having O2 concentration of 500 ppm because of the dominance of diffusion. Scavengers, when placed within over‐wrapped trays within bags had up to 12 times longer O2 half‐lives, indicating that the O2 permeable film acts as an O2 barrier when pack atmosphere has low O2 concentrations. To obtain consistent and reproducible results, it is recommended that multiple scavengers be used in a packaging system. The appropriate number should be based on scavenger type, desired O2 absorption rate, storage temperature, and pack atmosphere (air/N2/CO2).

Oxygen Scavengers affect Gas Mixture and Color Stability of Master Packed Ground Beef

“…It is important to note that work by several other investigators showed that O2 concentration in a modified atmosphere package with an oxygen scavenger drops rapidly after a few hours of storage (Charles et al, 2006;Gill and McGinnis, 1995b;Limbo et al, 2013;Miltz and Perry, 2005;Tewari et al, 2002). The presence of ground beef also increased the average oxygen concentration compared to packages without meat (p < 0.05).…”

“…The presence of ground beef also increased the average oxygen concentration compared to packages without meat (p < 0.05). This increase in oxygen concentration in master packs may be related to entrapped oxygen in the meat, in the overwrap tray headspace or in the tray matrix in cases where polystyrene foam trays are used (Limbo et al, 2013;Tewari et al, 2002;Venturini et al, 2006Venturini et al, , 2014. The use of oxygen scavengers, A and B effectively reduced oxygen concentration during master pack storage (p < 0.05).…”

“…Previous studies involving oxygen scavengers did not compare different brands (Beggan et al, 2006;Buys, 2004;Gill and McGinnis, 1995b;Isdell et al, 1999;Limbo et al, 2013;Venturini et al, 2006;Venturini et al, 2014). In a few studies, multiple oxygen scavengers were compared, but the focus was on oxygen kinetics (Charles et al, 2006;Miltz and Perry, 2005;Tewari et al, 2002). For this reason, the current study compares 2 of the most commonly used commercial oxygen scavengers and 2 carbon dioxide concentrations in the headspace gas mixture to show the changes in gas concentrations while meat is master packed, as well as the effect of these treatments on meat color during master pack storage and retail display.…”

“…Caution must be taken since residual oxygen that is present in the headspace gas can trigger meat discoloration (Gill and McGinnis, 1995a;Sørheim et al, 2009;Venturini et al, 2006). For this reason, oxygen scavengers in the retail package play a key role in controlling oxygen concentrations (Gill and McGinnis, 1995b;Jeyamkondan et al, 2000;Limbo et al, 2013;Tewari,et al, 2002). Headspace atmospheres usually include carbon dioxide to suppress microbial growth (Kennedy et al, 2005;Martínez et al, 2005;Tewari et al, 1999), allowing fresh meat to be stored for longer periods of time (Wilkinson et al, 2006).…”

Predicting the headspace oxygen level due to oxygen permeation across multilayer polymer packaging materials: A practical software simulation tool

“…Only a few data and studies exist in literature concerning these kinetic parameters. Tewari et al (2002) investigated six commercial oxygen scavengers and reported a first order absorption kinetic for all of them at both high and low initial oxygen concentrations. The consumption of oxygen by O 2 -scavengers and the remaining concentration in the headspace is given by Eq.…”