ABSTRACT
Variations in the quality of wheat kernels can be an important problem in the cereal industry. In particular, desiccation conditions play an essential role in both the technological characteristics of the kernel and its ability to sprout. In planta desiccation constitutes a key stage in the determinism of the functional properties of seeds. The impact of desiccation on the endosperm texture of seed is presented in this work. A simple imaging system had previously been developed to acquire multivariate images to characterize the heterogeneity of food materials. A special algorithm for the use under principal component analysis (PCA) was developed to process the acquired multivariate images. Wheat grains were collected at physiological maturity, and were subjected to two types of drying conditions that induced different kinetics of water loss. A data set containing 24 images (dimensioned 702 × 524 pixels) corresponding to the different desiccation stages of wheat kernels was acquired at different wavelengths and then analyzed. A comparison of the images of kernel sections highlighted changes in kernel texture as a function of their drying conditions. Slow drying led to a floury texture, whereas fast drying caused a glassy texture. The automated imaging system thus developed is sufficiently rapid and economical to enable the characterization in large collections of grain texture as a function of time and water content.
Subject(s)
Imaging, Three-Dimensional/methods , Seeds/anatomy & histology , Triticum/anatomy & histology , Algorithms , Desiccation , Multivariate Analysis , Principal Component Analysis/methods , Seeds/chemistry , Seeds/metabolism , Triticum/chemistry , Triticum/metabolism , Water/chemistry , Water/metabolismABSTRACT
We investigated the new solid-phase microextraction method by high-performance liquid chromatography with electrochemical detection for the analysis of biogenic amines. The Carbowax-Templated Resin 50 microm (purple) fibre coating offers good performances for dopamine and serotonin separation, i.e., good selectivity and high sensibility (0.1 microg l(-1)). We also tested this fibre for biogenic amines quantification of rat striatum. The coating seems to be selective towards the amines and has low affinity for the metabolites, allowing a good separation and preventing drawbacks from the biological matrix. These first results obtained using this original separation method offer large perspectives of application to many biological samples.
Subject(s)
Biogenic Amines/analysis , Chromatography, High Pressure Liquid/methods , Animals , Electrochemistry , Male , Rats , Rats, Wistar , Sensitivity and SpecificityABSTRACT
The advantages of combined cold-trapping of cheese volatiles and solid-phase microextraction-GC are demonstrated. This method is simple, cheap, compatible with classic identification equipment, and allows in-situ sampling.
ABSTRACT
The commercial SPME-HPLC interface is investigated to improve the analysis of Allium volatiles. Volatiles trapped by liquid nitrogen were previously transferred to RP-HPLC by a classical injection. In this work we compare the results obtained with classical injection and SPME used in headspace mode. This SPME-HPLC interface can be used when it is important to spare the sample, but thiosulfinates are partially degraded.
