FIGURE 4. Pull-up measurement for a glass jar with a metal lug closure. FIGURE 5. Security measurement for a glass jar with a metal lug closure. Security measurement A vertical line was marked with a marking pen on each lid, and a corresponding line was marked on the jar (Fig. 5). The lid closure was turned counterclockwise until the vacuum was broken. The lid was then reapplied to the jar just until the gasket compound touched the glass thread or until the closure was finger tight. The distance between the two vertical lines marked previously was measured in 1/16 in (1.6 mm), corresponding to the security value. The security values of deionized water jars were measured. Removal torque measurement Removal torque for VRA lug lids was measured both before and after pressing the center button on jars prepared as previously described. To measure the removal torque after pushing the button, the glass jars were fixed on the torque meter. The button was pushed using the thumb until a pop sound was heard, then the torque was measured. For standard lug lids and for VRA lug lids for which the button was not pushed, removal torque was measured with the torque meter. The removal torque values of glass jars containing deionized water and tomato sauce both were measured. Statistical analysis Water samples were tested in triplicate per experimental condition. Tomato sauce samples were prepared in five replicates for removal torque measurements. Results were evaluated using Tukey's honestly significant difference test, and differences were considered significant at the 95% confidence level. RESULTS AND DISCUSSION Effect of hot-pack temperature and headspace on pullup and security values The hot-pack temperature range chosen for the measurements was 82 to 93°C, which represents canning temperatures typically used to render acid and acidified foods commercially sterile by destroying pathogenic and spoilage July/August Food Protection Trends 277