SLIP MELTING POINT ESTIMATION OF FAT BLENDS BEFORE AND AFTER INTERESTERIFICATION BASED ON THEIR FATTY ACID COMPOSITIONS

In this study the relationship between slip melting point (SMP) and fatty acid composition of blends before and after interesterification were investigated. Forty-four blends were prepared using sunflower, canola and cottonseed oils as well as palm stearin and/or fully hydrogenated palm stearin in different proportions. Fatty acid compositions and SMP of samples were determined and then SMP of the blends before and after interesterification were defined as a function of five fatty acids. Specific constants of C_16:0, C_18:0, C_18:1, C_18:2 and C_18:3 fatty acids were determined as 0.455, 0.821, 0.622, 0.215 and -1.653, respectively, for the blends before interesterification and 0.532, 0.614, 0.399, 0.055 and -2.471, respectively, for the blends after interesterification by using least squares method. Slip melting point of blends were calculated using these constants and fatty acid compositions and then compared with the experimental values. No linear relationship existed between the calculated and experimental results of the blends before interesterification, but SMP of the blends after interesterification could be estimated with high (r=0.956) accuracy.     

EXTENDING THE CHILLED SHELF LIFE OF VACUUM-PACKAGED GROUND BEEF USING ASCORBIC ACID, NITRITE OR SALT

The objective of this study was to extend the shelf life of ground beef in chilled conditions. Samples were treated with 2% salt, 2% salt  +  500-ppm ascorbic acid, or 2% salt  +  100-ppm sodium nitrite. The control sample did not contain any additives. Protein, nitrite, moisture contents, pH, thiobarbituric acid (TBA) value, color attributes and microbial counts of samples were determined. Samples were vacuum packaged and stored in refrigeration, and chemical and microbial analyses were performed throughout storage. The pH of samples decreased during storage, and the sample having 2% salt and 500-ppm ascorbic acid had the greatest pH decline. TBA values generally increased ( P <  0.05) with storage time. Samples having 2% salt  +  500-ppm ascorbic acid had the lowest TBA value. On a given storage day, samples having 2% salt  +  100-ppm sodium nitrite had lower microbial microbial count than other samples, indicating the antibacterial effect of nitrite. A significant storage time  ×  treatment interaction ( P <  0.05) existed for almost all quality parameters studied.

PRACTICAL APPLICATIONS

Ground beef has commercial importance for the meat industry in Turkey. Meat processors have difficulties in marketing ground beef because of its relatively low shelf life. By adding ascorbic acid or salt, it is possible to extend shelf life and preserve its color, and to limit lipid oxidation, which will collectively help to increase market share of ground beef.