Frequency Distribution of Steady-state Oxygen Partial Pressures in Modified-atmosphere Packages of Cut Broccoli

Abstract

<jats:p>In one set of modified-atmosphere (MA) packages of cut broccoli (<jats:italic>Brassica oleracea</jats:italic> L., Italica Group), O<jats:sub>2</jats:sub> partial pressures ranged from 1.2 to 3.6 kPa at 0C [88 packages, 0.00268-cm-thick low-density polyethylene (LDPE) film, 600-cm<jats:sup>2</jats:sup> film area, 40±0.5 g cut broccoli], and in another set (94 packages, same film and area as before, 25±0.5 g cut broccoli) they ranged from 5.0 to 9.2 kPa. For characterizing O<jats:sub>2</jats:sub> uptake as a function of O<jats:sub>2</jats:sub> partial pressure and determining anaerobic fermentation induction point at 0C, a range of steady-state package O<jats:sub>2</jats:sub> partial pressures was generated by placing different amounts of cut broccoli (10 to 160 g) in LDPE packages. Oxygen uptake was modeled using a Michaelis-Menten-type equation. The maximum rate of product O<jats:sub>2</jats:sub> uptake when O<jats:sub>2</jats:sub> partial pressure was nonlimiting and the package O<jats:sub>2</jats:sub> partial pressure corresponding to half-maximum O<jats:sub>2</jats:sub> uptake were estimated as 147±3 nmol·kg<jats:sup>-1</jats:sup>·s<jats:sup>-1</jats:sup> and 0.26±0.025 kPa, respectively. Respiratory quotient and head space ethanol increased sharply below package O<jats:sub>2</jats:sub> partial pressures of 0.15 kPa, indicating stimulation of fermentation within the packages. The frequency distributions of CO<jats:sub>2</jats:sub> production rates were measured for 80 samples of 100 g each of cut broccoli at two O<jats:sub>2</jats:sub> partial pressures (21.0 kPa and 1.3 kPa) using a flow-through method. The average coefficient of variation of the CO<jats:sub>2</jats:sub> production rate was ≈5%. Frequency distributions of O<jats:sub>2</jats:sub> partial pressures were modeled as a function of product-to-product variation in O<jats:sub>2</jats:sub> uptake and package-to-package variation in film permeability using the estimated O<jats:sub>2</jats:sub> uptake characteristics and coefficient of variation. The model was used to predict the target O<jats:sub>2</jats:sub> partial pressures for the design of cut broccoli MA packages. It was predicted that the packages for cut broccoli at 0C should be designed for a target O<jats:sub>2</jats:sub> partial pressure of 2.54 kPa to have actual package O<jats:sub>2</jats:sub> partial pressures ≥1.0 kPa at 0.0001% probability level. Film specifications for MA packaging of cut broccoli at 0C were calculated based on the predicted target O<jats:sub>2</jats:sub> partial pressures.</jats:p>

Advances in polymeric materials for modified atmosphere packaging (MAP)

“…Equations 8.24 and 8.25 coupled to the model that describes the dependence of respiration rate on gas composition, temperature (and eventually time) and models that describe the dependence of packaging material on temperature, constitute the basis of MAP design (Exama et al 1993;Chau and Talasila 1994;Talasila et al 1994;Talasila and Cameron 1997;Makino and Iwasaki 1997;Maneerat et al 1997;Jacxsens et al 2000;Das 2005;Del Nobile et al 2007;Mahajan et al 2007;Torrieri et al 2007). The effect of gas composition on respiration rate is often described by the Michaelis±Menten equation with different types of inhibitions, while the effect of temperature is quantified by an Arrhenius-type equation (Lee et al 1991;Peppelenbos and Leven 1996;Mangaraj and Goswami 2008a).…”

A mathematical model for packaging with microperforated films of fresh-cut fruits and vegetables

“…Many of the early models developed for modified atmosphere packaging concentrated on the analysis of equilibrium atmospheres (Mannapperuma et al, 1989;Emond et al, 1991;Cameron et al, 1994;Talasila et al, 1994). However, for minimally processed products in particular, the time required to reach this equilibrium can represent a significant percentage of their short useful life (7-9 days).…”

Modified Atmosphere Packaging, for Minimally Processed Foods

“…For the work that observed an inhibitory effect, the degree to which pCO 2 affects r O 2 can be compared for various models by calculating the ratio: r n O 2 (at pCO 2 ¼ 10 kPa)/r n O 2 (at .1 Normalized oxygen respiration rate as a function of pO 2 at 4e7 C. 1dstrawberry (Talasila et al, 1992), 2dcut rutabaga (Zhu et al, 2001), 3draspberry , 4dgreen pepper (McLachlan and Stark, 1985) , 5dapple (Makino et al, 1996) , 6dcut garlic (McLachlan and Stark, 1985) , 7dblueberry (Song et al, 2001) , 8dcut carrot (McLachlan and Stark, 1985) , 9dcoleslaw (McLachlan and Stark, 1985) , 10dcut apple (Lakakul et al, 1999. ) , 11dcut broccoli (Hagger et al, 1992) , 12dblueberries (Beaudry, 1993) , 13dcut broccoli (Talasila et al, 1994) , 14dcut apple (Torrieri et al, 2009) , 15dmushroom (Li et al, 2009), 16dcut cantaloupe (Gomes et al, 2012) pCO 2 ¼ 0 kPa). This ratio is plotted as a function of pO 2 for various produce in Figure 33.3.…”