Red onion dices retained better aromas and colour in sealed PLA containers

The loss of desirable aroma and flavor of fresh-cut fruits and vegetables can limit their market life and consumer acceptance. Packaging can impact product flavor by affecting respiratory gas concentrations in the package as well as having direct interactions with the aroma volatiles released from the product. The objective of this study was to evaluate the effects of two packaging materials on the volatile com?position and quality retention of diced red onions. Whole red onions were peeled, sanitized, and diced in a commercial processing facility. Diced onions (200 g) were placed into ridged polylactic acid (PLA) containers or Golden Eagle VH-62 poly?ethylene (PE) bags. The PLA containers were sealed with intact or vented (single pin hole) PLA lids and PE bags were sealed with a heat sealer. Onion packages were stored at 4.5?C and assessed after 7, 12, 14, 18, and 21 days for volatile content. In addition, package atmosphere composition, respiration rate, electrolyte leakage, pH, microbial quality, and sensory quality were assessed. After 7 days, the total headspace volatile content of onions stored in sealed PLA containers decreased by only 15% compared to 98% and 85% in the vented PLA containers and the sealed PE bags, respectively. The retention of volatiles was associated with a fresh onion odour. However, after prolonged storage off odours developed in association with anaerobic atmospheres and/or microbial growth. During the 21 days of storage, on?ion respiration rates increased 5- to 6-fold, electrolyte leakage doubled, and aerobic and anaerobic plate counts became unacceptable, exceeding 106 cfu/g after 12 days. However, these parameters were not significantly affected by packaging treatments. Complete list of authors, original title and sources:Influence of Packaging on Loss of Aroma and Quality of Diced Red OnionsForney, C. F.1; Grant, R.2; Jordan, M. A.1; Fan, L.1; Doucette, C.11Agriculture and Agri-Food Canada, 32 Main Street, B4N 1J5, Kentville, Nova Scotia, Canada2Nova Agri Inc., Centreville, Nova Scotia, CanadaInternational Horticulture Congress, Lisboa 2010, ISHS The white onion dices are by the Flexifam cutter, by FAM ? ? ? ?