Controlled Atmosphere Packaging Keeps Cut Honeydew Melon Fresh LongerBy
Cut-up honeydew melons stay fresh and marketable longer, thanks to new
controlled atmosphere procedures worked out by scientists with the
Agricultural Research Service.
The researchers' goal: simulate the modified atmosphere packaging that
supermarket chains use to extend fresh produce's shelf life. The result: Cut-up
honeydew stayed fresh 2 days, or 20 percent, longer with reduced microbial
growth. Honeydew cubes prepared at the supermarket typically have a sale date of
only 2 or 3 days after they're cut.
Alley E. Watada, food technologist at ARS'
Quality Laboratory in Beltsville, MD, subjected cut-up honeydews to a
controlled atmosphere of 2 percent oxygen and 10 percent carbon dioxide at 41
degrees F for 9 days. His control sample was stored in air.
On day 5, melon cubes from the controlled atmosphere had less bacterial
growth and a stronger honeydew aroma than those held in air. Day 6 showed the
controlled-atmosphere samples still moist with good green color, aroma, taste
and sweetness, most of which lasted through day 9. Honeydew cubes stored in air
had microbial growth and an offensive odor on day 9.
Similar benefits can be reaped by supermarkets using modified atmosphere
packaging if the proper gas mixture is maintained. This mixture will change if
the holding temperature in the supermarket rises. As temperature increases, so
does the respiration rate; but the rate of oxygen (air) transmission into the
package cannot keep pace with the increased oxygen usage. Eventually, the oxygen
is depleted. This anaerobic condition harms the honeydew melon and increases the
chance of harmful bacteria growing in the package. Thus, packaged cut-up
honeydew melons must be kept at 41 degrees F at all times.
Scientific contact: Alley E. Watada, Horticultural Crops Quality
Laboratory, Beltsville, MD 20705-2350; phone (301) 504-6128, fax (301) 504-5107,