Bagging Chopped Lettuce in Selected Permeability Films

Abstract

<jats:p>Chopped `Salinas' crisphead lettuce <jats:italic>(Lactuca sativa</jats:italic> L.) was packaged in four types of polymeric films and stored at 1 or 5C for 14 days. Discoloration and off-flavors developed in lettuce stored in the two films in which the naturally produced CO<jats:sub>2</jats:sub> rose above 20%. In the two films (oriented low-density polyethylene) with O<jats:sub>2</jats:sub> transmission rates higher than 3000 ml·m<jats:sup>-2</jats:sup>· day<jats:sup>-1</jats:sup>·atm<jats:sup>-1</jats:sup> at 22C, CO<jats:sub>2</jats:sub> remained below 20%, O<jats:sub>2</jats:sub> was between ≈ 2% and 15%, and the lettuce was acceptable after 14 days of storage at either 1 or 5C. Appearance and flavor were affected more by temperature than by length of storage.</jats:p>

Effects of Low‐dose Gamma Irradiation on the Shelf Life and Quality Characteristics of Cut Romaine Lettuce Packaged under Modified Atmosphere

“…However, increasing CO 2 levels to 15% enhanced brown lesions and decreasing O 2 levels to 0.5% intensified browning and development of anaerobiosis. Naturally developed modified atmosphere (after vacuum sealing) in cut lettuce packages with CO 2 levels less than 20% and O 2 levels of 1% to 4% induced little discoloration or fermentation of lettuce (McDonald and Risse 1990). In this study, the suboptimal CO 2 levels (>20%) and O 2 levels (<0.5%) probably accelerated the discoloration and formation of off-odors.…”

Quality of Minimally Processed Lettuce as Influenced by Packaging and Chemical Treatment

“…These living materials, wrapped in gas semipermeable films, will modify the atmosphere due to respiratory oxygen uptake and carbon dioxide output. Beneficial effects from modified atmosphere (MA) have been reported previously (Priepke et al 1976;Ballantyne et al 1988;McDonald et al 1990). When MA is used in combination with chilled storage, substantial reductions in deleterious microbial growth and physiological and chemical changes can be achieved.…”

Low O2 Atmospheres Affect Storage Quality of Zucchini Squash Slices Treated with Calcium

“…STUDIES have shown that controlled atmosphere (CA) extends the shelf life of some fruits and vegetables (Kader, 1986). Similarly, CA or modified atmosphere (MA) has been beneficial for some fresh-cut products such as chopped lettuce (McDonald et al, 1990), shredded cabbage (Kaji et al, 1993), broccoli spears (Barth et al, 1993), and strawberries (Larsen et al, 1995). In film packaged fresh-cut products, atmosphere can become modified extensively, with O 2 depleted below the extinction point.…”