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Corn Samples (corn + sample)
Selected AbstractsStacked partial least squares regression analysis for spectral calibration and predictionJOURNAL OF CHEMOMETRICS, Issue 10 2009Wangdong Ni Abstract Two novel algorithms which employ the idea of stacked generalization or stacked regression, stacked partial least squares (SPLS) and stacked moving-window partial least squares (SMWPLS) are reported in the present paper. The new algorithms establish parallel, conventional PLS models based on all intervals of a set of spectra to take advantage of the information from the whole spectrum by incorporating parallel models in a way to emphasize intervals highly related to the target property. It is theoretically and experimentally illustrated that the predictive ability of these two stacked methods combining all subsets or intervals of the whole spectrum is never poorer than that of a PLS model based only on the best interval. These two stacking algorithms generate more parsimonious regression models with better predictive power than conventional PLS, and perform best when the spectral information is neither isolated to a single, small region, nor spread uniformly over the response. A simulation data set is employed in this work not only to demonstrate this improvement, but also to demonstrate that stacked regressions have the potential capability of predicting property information from an outlier spectrum in the prediction set. Moisture, oil, protein and starch in Cargill corn samples have been successfully predicted by these new algorithms, as well as hydroxyl number for different instruments of terpolymer samples including and excluding an outlier spectrum. Copyright © 2009 John Wiley & Sons, Ltd. [source] Aflatoxin Inactivation Using Aqueous Extract of Ajowan (Trachyspermum ammi) SeedsJOURNAL OF FOOD SCIENCE, Issue 1 2005Shruti S. Hajare ABSTRACT: Aqueous extract of ajowan seeds was found to contain an aflatoxin inactivation factor (IF). Thin layer chromatography analysis of the toxins after treatment with IF showed relative reduction of aflatoxin G1 > G2 > B1 > B2. Quantification of toxin using a fluorotoxin meter as well as the Enzyme Linked Immuno s orb ent Assay (ELISA) confirmed these findings. An approximate 80% reduction in total aflatoxin content over the controls was observed. This observed phenomenon of reduction in total toxin was referred to as toxin inactivation. Temperature was found to influence the rate of toxin inactivation. At 45 °C, it was found to be rapid during the initial 5 h and slowed later. The IF was found to retain considerable activity even after boiling and autoclaving, indicating partial heat stability. The activity was lost below pH 4.0. Above pH 4.0, it increased gradually, reaching the maximum at pH 10.0. IF was found to be stable to gamma irradiation. Toxin decontamination in spiked corn samples could be achieved using IF. This study emphasizes the potential of ajowan IF in aflatoxin removal from contaminated food commodities. However, the biological toxicity, if any, of the IF inactivated aflatoxins needs to be confirmed, and the work in this direction is in progress. [source] Occurrence of certain mycotoxins in corn and corn-based products and thermostability of fumonisin B1 during processingMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 4 2003A. M. Abd Alla El-Sayed Abstract A total of 57 samples of corn and corn-based products collected from various districts of Egypt were analyzed for Fusarium mycotoxins (T-2, diacetoxyscripenol (DAS( deoxynivalenol (DON) and fumonisin B1 (FB1) and aflatoxins. FB1 was detected in about 80%, 53.85%, 33.3%, and 28.57% of yellow corn, corn meal, white corn, and popcorn samples, respectively. The levels of FB1 ranged from 10 to 780 ,g/kg. T-2 and DAS were detected in 5% and 10% of yellow corn samples, respectively, and DON was detected in white corn and popcorn samples at levels of 28.8 and 10.1 ,g/kg, respectively. Starch samples were found to be free from Fusarium mycotoxins. Baking balady bread at 450°C/min reduced FB1 to 72.4% while baking Franco bread at 250°C/20 min reduced FB1 to 57.4%. Boiling of macaroni and corn in water completely removed FB1 from contaminated samples. On the other side, corn flakes samples were found to be contaminated with aflatoxins B1 and G1 at levels ranging from 6 to 10 ppm, whereas 2.9% of samples were contaminated with aflatoxin B1 > 35 ppm and G1 > 16 ppm. [source] Behavioral Monitoring of Trained Insects for Chemical DetectionBIOTECHNOLOGY PROGRESS, Issue 1 2006Glen C. Rains A portable, handheld volatile odor detector ("Wasp Hound") that utilizes a computer vision system and Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), a parasitoid wasp, as the chemical sensor was created. Five wasps were placed in a test cartridge and placed inside the device. Wasps were either untrained or trained by associative learning to detect 3-octanone, a common fungal volatile chemical. The Wasp Hound sampled air from the headspace of corn samples prepared within the lab and, coupled with Visual Cortex, a software program developed using the LabView graphical programming language, monitored and analyzed wasp behavior. The Wasp Hound, with conditioned wasps, was able to detect 0.5 mg of 3-octanone within a 240 mL glass container filled with feed corn (,2.6 × 10,5 mol/L). The Wasp Hound response to the control (corn alone) and a different chemical placed in the corn (0.5 mg of myrcene) was significantly different than the response to the 3-octanone. Wasp Hound results from untrained wasps were significantly different from trained wasps when comparing the responses to 3-octanone. The Wasp Hound may provide a unique method for monitoring grains, peanuts, and tree nuts for fungal growth associated with toxin production, as well as detecting chemicals associated with forensic investigations and plant/animal disease. [source] | |||||||||||||