Hydrolyzed gelatin coating cuts fresh meat purge, lipid oxidation, color loss.

New sanitation materials and procedures, tighter temperature controls, new packaging materials and coatings have enabled processors to dramatically increase the shelf life of fresh meat products. Such a product's shelf life has probably run its course when it has an unacceptable odor, appearance and color, which appear before microbial counts reach unacceptable levels.

Adding a hydrolyzed gelatin coating to meat may reduce lipid oxidation, purge and color loss. So scientists at The Ohio State University wanted to see if purge, lipid oxidation and loss of color could be reduced on fresh beef, pork and poultry when these products are spray-coated with hydrolyzed gelatin. They found that a hydrolyzed gelatin coating decreased purge, lipid oxidation and color loss, and may result in less wasted fresh meat.

Hydrolyzed gelatin was sprayed onto the exterior of meats at 0.14 mg per [cm.sup.2] and 0.20 mg per [cm.sup.2]. The meat was packed in trays that pulled a vacuum. The trays were flushed with 80% oxygen and 20% carbon dioxide, then sealed with oxygen-impermeable film. For each meat, 12 coated samples and six controls were stored in the dark at 4 C. Investigators determined the percent of weight loss caused by purge and the extent of lipid oxidation at 0, 7 and 14 days.

A higher gelatin content led to better results on the beef that was stored for 14 days. The 0.20 mg per [cm.sup.2] spray-coated samples had less than a 1% purge, while the control and 0.14 mg per [cm.sup.2] samples had more than a 2% purge. The 0.20 mg per [cm.sup.2] and 0.14 mg per [cm.sup.2] samples and the control had 0.67 mg, 1.04 mg and 1.56 mg of malonaldehyde per 1000 g of meat, respectively. The 0.20 mg per [cm.sup.2] sample was redder than the 0.14 mg per [cm.sup.2] sample, and redder than the control. Similar trends were seen with pork and chicken.

There is increased demand for higher valued-added fresh meat and poultry products, such as battered meats, seasoned fresh pork sausages, marinated chicken breast and marinated pork loin. The relatively short shelf life of fresh meat and poultry items often hinders the development of new products and their commercial success. Delaying or inhibiting the growth of spoilage organisms and limiting product contamination in meat would help improve the quality of fresh processed meats. Extending their shelf life is a commercial necessity.

Further information. Sheryl Barringer, Department of Food Science, The Ohio State University, 2015 Fyffe Road, 317 Parker, Columbus, OH 43210; phone: [phone]; fax: [phone]; email: [e-mail].