Authors:Zs. Hajdu, L. Lorántfy, N. Jedlinszki, K. Boros, J. Hohmann, and D. Csupor
The radish-like hypocotyls of Maca (Lepidium meyenii Walp., Brassicaceae) are widely consumed as common vegetable in the Andean highlands. It is considered as healthy food, rich in carbohydrates and protein, a herbal medicine with a general invigorating reputation and fertility and sexual performance enhancer. The latter is the most popular contemporary application of the plant in Europe. The number and variety of industrial products on the market is increasing. Here we report the development of a simple and reliable analytical protocol for the qualitative and quantitative analysis of maca content of preparations and for the detection of synthetic phosphodiesterase inhibitors. Fourteen products were analysed by the method based on TLC and HPLC-DAD analysis developed by us. Our experiments revealed that beside good-quality products, the majority of the multicomponent preparations did not contain the declared herbal component or the quantity of the measured macamide was very low. Furthermore, one preparation is adulterated with a synthetic phosphodiesterase inhibitor. The presented method is suitable for quality control of L. meyenii products.
In the industrial practice Howard mould count (Howard, 1911) is used for the estimation of mould contamination of foods. It was developed originally for the investigation of mould contamination of tomato purée. It is also used nowadays for quality control purposes for other food products as well. Recently this constitutes the basis of the acceptance of the finished products in international trade. This technique demands experts with a lot of practice and morphological proficiency. The investigation makes use of eyes and so the tiredness of the investigator can cause uncertainties.The possibility of other methods for the determination of mould contamination of tomato purée was investigated to replace the Howard method. The NIR technique — as a rapid, non-destructive, reagentless and accurate method — was anticipated as a suitable method for the mentioned purpose. Canned tomato purée had been allowed to become mouldy then the sample was blended with non-mouldy samples in different ratio, so a series of tomato purées containing known amounts of mouldy purée was prepared. Howard mould counts and ergosterol content — another mould contamination relating value — was used as reference for NIR calibration.At quantitative investigation better results were obtained using ergosterol values. The best correlation coefficient (R=0.93) and the smallest standard error of calibration (SEC=0.008 mg g−1 ergosterol) was achieved with triangular smoothing and second derivation of the spectra. At qualitative investigation Polar Qualification System (PQS) was used. Clusters between samples with low and high ergosterol levels could be separated.
The subject of the article is the evaluation of three acoustical algorithms on industrial production lines. The algorithm is used for the inspection of work-pieces in a noisy industrial environment. High efficiency performance requirements restricted running time and expected precise results make these inspections problematic. A sequential and two parallel algorithms and processing methods for these measurements were developed. These algorithms are real-time and multi-channel processing methods on industrial production lines. They carry out series of precision measurements in the time frame available. After the inspection the quality class and usability of the pieces are determined. These computer-aided inspections are more effective than human measurements because they are more precise, can be repeated multiple times, even with different quality requirements. They are usable on high-speed industrial production lines to obtain results in digital format.
1 Introduction The propagation of elastic waves is widely used in the field of non-destructive testing [ 5 ], in particular for qualitycontrol and detection defect in mechanical components of machines and industrial installations. Inspection