Processed Food May Get More Texture, Taste

Three new advances in food technology promise to make frozen, canned and airline food eminently more edible, researchers said here Tuesday.

A new, all-natural meat preservative developed by government scientists from crustacean shells would render frozen meat entrees as flavorful as fresh food, would take the cardboard taste out of cafeteria and airline food and would give packaged meals much longer shelf lives.

Other promising techniques for improving food taste reported at a meeting of the American Chemical Society include a new canning technique that allows fruit and vegetables to remain firm and crisp and a technique for removing bitter flavors from navel orange juice.

Warmed-Over Flavor

Many new meat products used in frozen and institutional foods or sold in fast-food outlets are plagued by odd tastes such as the so-called warmed-over flavor, according to chemist John R. Vercellotti of the U.S. Department of Agriculture’s Southern Regional Research Center in New Orleans. Cooked food stored and reheated at home also develops this “off-flavor,” which results primarily from the reaction of fats in the meat with oxygen in air.

Vercellotti and his colleagues have developed a simple chemical compound “that can be added to meat to prevent its deterioration” without introducing undesirable flavors of its own. The chemical, called N-carboxymethyl chitosan or NCMC, binds to iron in the meat and prevents it from catalyzing the reaction between oxygen and fats.

The preservative is made from crab, shrimp, lobster or crayfish shells, which represent a substantial solid waste problem for the seafood industry.

In contrast to meat, canned fruits and vegetables have a long shelf life with high retention of nutritional quality and vitamin content. “But the problem is that they are simply too mushy,” said chemist Malcolm C. Bourne of Cornell University in Ithaca, N.Y.

After 25 years of study, Bourne said, he has developed a way to can foods without losing their natural firmness. The secret lies in how the foods are blanched before they are canned and sterilized, he said.

Blanching is a heating process that drives air out of the fruits and vegetables so that air doesn’t collect in the can. It is typically performed at temperatures above 200 degrees Fahrenheit for periods of 3 to 10 minutes.

Bourne found that blanching at such high temperatures inactivates an enzyme in the produce that maintains firmness during heat sterilization. If the produce is blanched at a temperature of only 145 degrees for periods of 30 to 90 minutes, the enzyme, called pectinmethylesterase, makes the food crisper and firmer, so that it survives sterilization without becoming mushy.