A Buffalo, N.Y., company has begun marketing a preserving process it says can freeze foods, without using chemical additives, down to zero degrees Fahrenheit without solidifying them.

Rich Products Corp. calls the new frozen food process Freeze-Flo.

According to Rich Products officials, the process, which was patented in March 1979, involves osmotically linking the free water in foods with the proteins, sugars and oils present to prevent the formation of ice crystals that cause solidification normally associated with frozen foods. The process was perfected after eight years and $2.5 million in research and development.

The end product is soft frozen food, which makes a line of frozen apple juice concentrate recently released pourable at sub-freezing temperatures and Rich Products' chocolate eclairs edible without thawing, company officials said. The process is said to require 50 percent less energy and products thaw more quickly. Freeze-flo has the added advantage of removing the medium (free water) in which bacteria grow, thus making "flozen" foods less vulnerable to improper handling, such as accidental thawing, and increasing the shelf life of most foods, officials said. In addition, the process removes the need for many of the stabilizers and preservatives included in conventionally frozen foods.

Rich Products says it is marketing its Freeze-Flo process to other companies for use in many different food categories such as dairy products, fish and meat.

According to Richard Birndorf, sales and marketing manager of Speas, a Sawyer Foods company, "Freeze-flo fits our strategy because it is an all-natural process and is indicative of the future of frozen foods."

Rich Products assists its licensees in marketing the new products and in adjusting their present production methods to the new technology, officials said.

The linkage of the free water to the unsaturated oils, sugars and proteins in the foods does affect the taste of Freeze-Flo foods, requiring careful reformulation of the foods to retain their natural flavor, Rich Products officials said.

They said consumer reaction to the Freeze-Flo technique was surveyed by United States Testing Company Inc. and that 25 percent of those questioned said they were "definitely" inclined to purchase Freeze-flo frozen foods, while another 60 percentwere listed as "probably" interested.

Freeze-Flo processed foods now on the market range from desert topping to an apple juice concentrate.