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Frequently Asked Questions - TechnologyWhat is the "falling number" in a flour specification and what is its significance? The falling number test measures the alpha amylase activity of a flour (usually bread type) by determining the rate at which a metal ball passes through a cooked blend of flour and water. A properly malted bread flour will have a falling number of 250 to 290. Under-malted flours will have higher numbers and lower numbers indicate higher levels of amylase activity. How much does vital wheat gluten increase the protein content of a flour/gluten blend? Most vital wheat glutens are guaranteed to contain 75% protein, dry basis, or about 71% protein, as is. The addition of each pound of gluten to 100 pounds of flour increases the protein content of the flour/gluten blend by approximately 0.6%. Example: 100 pounds of flour at 11.0% protein plus 1 pound of gluten produces a blend containing 11.6% protein. How do I adjust for salted vs unsalted margarine in a formula? Most salted margarines contain between 2.5 and 3% salt. When you replace 10 lbs of salted margarine with an equal weight of unsalted margarine, you must add 4 oz of salt to the formula. Vice versa, for every 10 lbs of unsalted margarine replaced with salted margarine, you must reduce the salt in the formula by 4 oz. The salt is added to margarine for a better flavor and to inhibit mold growth. The unsalted margarine must be refrigerated until it is used in production, or it will spoil within a few days. What is specific heat and what is the specific heat of bread and dough? The specific heat of a substance is the amount of heat required to raise the temperature of one pound of the substance 1°F or, (when cooling) the amount of heat
which must be removed to lower the temperature l°F. Water has a specific heat of 1; to cool one pound of water 1°F would require the removal of 1 British thermal unit (BTU) of heat energy. The most common numbers used for the specific heat of bread and dough are: What is the recommended mesh size for the flour sifter between the storage bin and the use area? A 30 mesh Tyler screen is recommended. This mesh size is optimum for flour flow and will remove insect adults and larvae, but does not remove insect eggs. At what temperature should bulk shortenings be stored? A good rule of thumb is to store shortenings at 15° to 20°F above the Wiley melting point of the shortening. What is °Brix? Is it applicable to all liquid sweeteners? °Brix is a measurement of solids in a pure sucrose solution. For other liquid sweeteners, such as HFCS, corn syrup and invert syrups, °Brix is not a true measure of solids. Most brix equipment is calibrated for a pure sucrose solution. When used for other sweeteners, a calibration chart must be used in conjunction with the sucrose equipment to obtain a true solids number for that particular liquid sweetener. What is water activity? Water activity is not particularly a new concept in the food industry. As defined in the proposed GMP's issued June 8, 1979, "Water activity" (Aw) is a measure of the free moisture in a product and is the quotient of the water vapor pressure of the substance divided by the vapor pressure of pure water at the same temperature. It is impossible to do justice to the concept of water activity in a few sentences. The March 1980 issue of the AIB Technical Bulletin is devoted to water activity covering both theoretical and practical aspects of its use in the food industry. What conversion factor should I use for converting from powdered dextrose to high fructose corn syrup in bread? Powdered dextrose is really dextrose hydrate, containing 9% water and 91% dextrose. High fructose corn syrup (42% fructose) contains approximately 71% solids and 29% water. To convert on a solids basis, the pounds of dextrose should be multiplied by the factor of 1.28 to obtain the amount of high fructose corn syrup to use. In many bakery foods, dextrose is used at a fairly high level because of the lower sweetness factor as compared to sucrose and high fructose corn syrup. Since all of the sweetener added above 2% or 3% (flour weight basis) is added for sweetness and other functions, some bakers consider the sweetness factor when converting from dextrose to high fructose corn syrup, the sweeter product. In this case, the factor generally used ranges from 1.0 to 1.1 when converting from powdered dextrose to high fructose corn syrup. How do I calculate the number of oxidant tablets to use in my dough? Also, if I am using bulk oxidant, what calculations are used? Tablets. You must know the number of parts per million each tablet adds to 100 pounds of flour.
Then the formula is: Occasionally my bread has a distinct off-odor resembling spray paint or nail polish. What is the cause of this odor? This problem is nearly always caused by the wild yeast, endomycopsis. This yeast is found in nature and is carried into the plant by air currents. The yeast converts starch into acetone, which is the odor detected in the bread. The yeast can best be eliminated by washing the equipment with vinegar. What is the MTI in my bread flour reports, and what is its significance? MTI, or Mixing Tolerance Index, is a measurement of dough strength as determined by the Farinograph recording dough mixer. The MTI is the measure of breakdown rate of the dough after it has reached its optimum or peak mixing time. An MTI of 20 indicates only slight breakdown and a strong flour, 30 is a mellow flour, and 40 to 50 indicates a slightly weak flour. An MTI of more than 50 indicates a weak flour.
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