Determination of moisture in cheese and cheese products

Variables related to oven-drying samples of cheese and cheese products to d etermine moisture content were examined to provide more efficient and repro ducible methods. Over 6500 samples of cheese were analyzed in an effort to modify the current AOAC procedure. The gravity atmospheric oven was unsuita ble for use in accurate moisture analysis because of wide temperature diffe rentials within the oven cavity. Use of this for oven moisture determinatio n resulted in higher variance, which corresponded to the high temperature v ariation within the oven. Cheese sample preparation using an Oster blender yielded consistently lower variance in final moisture content than did prep aration of cheese samples with a hand grater, rotary grater, and plug and p lunger. Sample size of 3 +/- 0.25 g maximized surface area-to-volume ratios and yielded a lower error in final moisture content because of better cont rol of ambient weight loss rates. Use of combination of disposable 5.5 cm d iameter aluminum sample pans with 5.5 cm diameter glass fiber filter pads f or covers produced a smaller standard deviation for moisture analysis than did the AOAC pan and insert cover and filter paper covers. All pans must be pre-dried for at least 3 h at 100 degreesC, and the glass fiber covers sho uld be pre-dried for 1 h under the same conditions. All dried pans and cove rs must be stored in a desiccator with active desiccant. Equipment upgrades from the existing AOAC standard methods provide safer more efficient metho ds of analysis.