One of the most frequently asked questions regardin shelf-life studies has to be: "One week at 100°F equals how many weeks at room temperature? The answer depends on the type of product and the mode degradation involved. Each of the chemical deterioration reactions require: certain amount of energy to get started. This is calle activation energy, measured in kcal/mol. Table 2 contains some typical values. The higher the activat energy is for a reaction, the greater the acceleration with increases in temperature. A simple way to exp this acceleration is to use the Q10 concept. Q10 is the increase in the rate of the reaction when the tempera increased by 10 degrees centigrade (18°F). For example, if a food has a stability of 20 weeks at 20°" and 10 weeks at 30°C, then the Quo will be 20/10 or The rate of reaction being followed is doubled for th 10°C temperature rise. This value can be calculated from the data of most storage tests where the produc has been stored at two or more temperatures regardl of whether or not they are 10°C apart. Table 3 show some relationships between weeks at 70°F and 100o various Q10 values. These temperatures are more tha 10°C apart and were, therefore, derived from equation