The shelf life of food products stored in plastic containers is mostly shorter than that of products stored in glass containers. This occurs partly because plastic is permeable to gasses, and allows oxygen to seep through over time.
Research by scientists at the US Department of Agriculture (USDA) found that turmeric could be used as a natural antioxidant to keep dill pickles fresh after packaging in plastic jars or pouches.
Plastic is replacing glass as a container of choice for many products, mainly due to its convenience. Plastic containers are lighter in weight, don't break and are easier to open.
As a result, there is interest among processors in putting more pickled vegetable products into plastic packages, the USDA stated in publishing the results of the research.
Food technologist Roger McFeeters, and another researcher with the USDA's agricultural research service, found that turmeric prevented the formation of aldehydes -- compounds that cause oxidative off-flavors in pickled cucumbers.
They studied pickles packaged under conditions that simulated plastic containment over time.
The researchers found that some aldehydes were present in pickles that were packed in the laboratory under airtight conditions, as well as in fresh-pack commercial pickle samples.
However, excessive production of aldehydes occurred when they injected oxygen into the same packaged pickles.
Using other similar samples, the researchers then added an amount of turmeric typically used commercially as a coloring agent, along with an amount of oxygen comparable to that which would enter a sealed plastic container over a one-year storage period.
The amounts of aldehydes produced in the pickles with added turmeric were maintained at concentrations similar to those amounts present in high-quality commercial pickle products, the scientists stated.
The findings indicate that turmeric is an effective antioxidant for fresh-pack dill pickles, they stated.
Turmeric, or Curcuma longa, is a spice commonly used in curries and other South Asian cuisine. Turmeric is also used to give a yellow color to some prepared mustards, canned chicken broth, and other foods, according to Wikipedia, the online encyclopedia.
The USDA study was published in the Journal of Agricultural and Food Chemistry.