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The Nutritional Labeling and Education Act of 1990 has increased the need for more rapid, efficient, and nonpolluting techniques of analyzing the nutrients in foods, particularly dietary fiber. The use of near-infrared spectroscopy (NIRS) for the prediction of total dietary fiber content of cereal products was investigated in this study. Cereal and grain products, including breakfast cereals, flours, brans, crackers, and samples containing commercial oat and wheat fibers, were selected for analysis. Products (n = 91) were dry milled, and total dietary fiber was measured by the AOAC (991.43) enzymatic-gravimetric method. Total dietary fiber values ranged from <1 to 52% of dry weight. Milled cereal products (n = 91) were scanned from 1100 to 2498 nm with a NIRSystems 6500 monochromator. Using ISI software for scanning and data analysis, a dietary fiber calibration was obtained with partial least squares as the regression method. The standard error of cross validation and multiple coefficient of determination were 1.58% and 0.99, respectively. For equation validation, an independent group of cereal products (n = 31) was dry milled, and total dietary fiber was determined. The samples were scanned, and total dietary fiber was predicted by NIRS. Samples were predicted with a standard error of performance of 1.51%, coefficient of determination of 0.99, bias of −0.38, and slope of 1.06. This study shows that NIRS can be used to rapidly and accurately predict total dietary fiber content in a wide range of cereal products. Keywords: Dietary fiber; near-infrared spectroscopy; nutrition labeling

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Nitrate reductase activity in excised embryos of Agrostemma githago increases in response to both NO3-and cytokinins. We asked the question whether cytokinins affected nitrate reductase activity directly or through NO3-, either by amplifying the effect of low endogenous NO3-levels, or by making NO3-available for induction from a metabolically inactive compartment. Nitrate reductase activity was enhanced on the average by 50% after 1 hour of benzyladenine treatment. In some experiments, the cytokinin response was detectable as early as 30 minutes after addition of benzyladenine. Nitrate reductase activity increased linearly for 4 hours and began to decay 13 hours after start of the hormone treatment. When embryos were incubated in solutions containing mixtures of N03-and benzyladenine, additive responses were obtained. The effects of NO3-and benzyladenine were counteracted by abscisic acid. The increase in nitrate reductase activity was inhibited at lower abscisic acid concentrations in embryos which were induced with NO3-, as compared to embryos treated with benzyladenine. Casein hydrolysate inhibited the development of nitrate reductase activity. The response to NO:-was more susceptible to inhibition by casein hydrolysate than the response to the hormone. When NO3-and benzyladenine were withdrawn from the medium after maximal enhancement of nitrate reductase activity, the level of the enzyme decreased rapidly. Nitrate reductase activity increasd again as a result of a second treatment with benzyladenine but not with NO3-. At the time of the second exposure to benzyladenine, no NO3-was detectable in extracts of Agrostemma embryos. This is taken as evidence that cytokinins enhance nitrate reductase activity directly and not through induction by NO3-.Borriss (1)