Agroindustrial project analysi

THE PROCESSING FACTOR 135soluble nutrients. Because of these effects, parboiling is a processthat enhances a rice product's nutritional value.EFFECTS OF WHEAT MILLING. Other grains than rice can be similarlyaffected by milling. From table 4-6 it is evident that the vitaminand mineral content of wheat products decreases markedlywith milling until 70 percent extraction. These data indicate thatwheat endosperm is a poor source of vitamins and minerals becausemost of these nutrients are concentrated in the germ and branand are lost during milling. The decrease in the mineral content ofwheat through milling is also important for quality control in theflour-milling industry, because high mineral content in flour isgenerally an indication of contamination by bran particles. Sincephytate phosphorous (which complexes calcium and magnesium toform biologically unavailable salts) is removed faster than calciumin milling, calcium in flour is more biologically available than inwhole wheat. Although only a small fraction of protein is removedTable 4-6. Estimated Nutrient Retention in Wheat Flour(percent)Percentage nutrient retention by degree of wholewheat extraction in flourHigh extraction Standard extraction Patent extractionNutrient (85 percent) (70 percent) (44 percent)Protein 83 63 39Carbohydrate 91 77 51Fat 58 35 15Fiber 47 3 ...VitaminsNiacin 19 10 5Riboflavin 54 24 13Thiamin 70 17 5Vitamin B-6 n.d. 10 4Vitamin E n.d. 8 2Ash (minerals) 41 18 10n.d., Not detected; ... , retained in trace amounts.Note: Estimates are derived by the following formulas:percentpercent percent percent 1 percent relative nutrientnutrient = nutrient in - nutrientin X extraction X concentrationloss [whole wheat product I 100 percent 100 percentpercent nutrient in whole wheatpercent nutrient retention = 100 percent - percent nutrient loss.