by Linda McCandless
Geneva, NY -"During the last 10 years, per capita consumption of fresh produce has grown by more than 10% in the United States - an increase which has led to a relatively new market for minimally or lightly processed, fresh-like fruits and vegetables," said Chang Y. Lee, Professor of Food Science & Technology at Cornell's Agricultural Experiment Station in Geneva. One of his research goals is to extend the shelf life of cut fruits and vegetables using modified gaseous atmosphere packaging and/or heat treatments while minimizing or avoiding the use of additives.
In the bulletin "Minimal Processing of New York Apples," published in September, 1995, at the Geneva Experiment Station, Lee and Research Support Specialist Nancy L. Smith detail the research they have conducted on pre-cut, prepared, and pre-packaged apples over the past several years.
"The major obstacle to overcome is that of activated respiration of live tissues which results in reduced shelf life," wrote Lee in the 12-page bulletin. "Minimally processed apple slices are very unstable and more perishable. In addition, they are prone to enzymatic browning and spoilage."
The first step in producing high quality minimally processed apple slices is the selection of proper cultivars. Lee and Smith recommend Golden Delicious, Delicious, Cortland, and Empire as the apples best suited for minimal processing.
In 1995, Ag and Markets estimates that these four cultivars will account for 340 million pounds of the apples produced in New York, or nearly one-quarter of total production. Both Cortland and Empire apples were developed in the apple breeding program at the Station. New York State ranks second in apple production in the United States. The apple industry is worth more than $130 million.
Lee, who is anxious to expand the value-added marketing potential of New York State apples, noted that, several local apple growers are producing commercial apple slices made from New York apples and are distributing them to the upstate New York market, based on this research.
In the bulletin, the food scientists described several processing technologies which can positively or negatively affect quality, including the application of commercial browning inhibitors, additives that prevent softening, vacuum packaging, and nitrogen atmosphere packaging. In general, each cultivar demands a particular combination of processes to prolong shelf life and improve apple firmness and color.
For instance, Golden Delicious and Delicious apples resisted browning and produced firmer slices for more than 14 days when they are heat-treated at 45°C for 105 minutes and then stored at 2°C.
The best overall combination was a dipping treatment - a 10% honey solution proved particularly effective in maintaining color and firmness, noted the investigators - followed by nitrogen modified atmosphere packaging. The researchers were able to maintain apple slices processed in this way for a period of three weeks at 3-5°C.
A portion of Lee's and Smith's research was supported by the New York State Apple Research and Development Program and the New York State Apple Research Association. With this funding, the two are continuing their investigation of additional anti-browning and anti-softening agents.
The bulletin is available in the Station's bulletin room in Jordan Hall or by calling Bev Dunham in the mornings at 315-787-2249 or e-mailing her at bbd1@cornell.edu.
Return to News Page
Page created September 17, 1996 by Cathy Weeden