Development of fast analytical methods for the determination of salep and its adulteration

Salep is a foodstuff obtained in powder form after a variety of treatments of tubers obtained from some species of the Orchidaceae family collected from the nature. Due to the lack of sufficient plant material for its production, it is offered to the consumers at high prices. If the products are sold in the market contain the word "salep", it is mandatory to declare the amount in the label. In addition, it is forbidden by law to remove it in any form of salep forms the country due to salep plant is an endemic species. However, in the literature, there are findings in the literature that significant levels of salep have been taken out of our country. Due to these reasons, a need arises for analytical methods to determine whether salep is present and/or to what extent it contains salep. The aim of this study is to develop fast, reliable and economical methods of analysis which can be used in determining salep adulteration. In order to reach the stated target, by supplying the salep samples grown in our country and the substances, which specified as adulterant in the literature, were analyzed by validated methods. In this context, chemical methods to determine the basic compounds; enzymatic methods to determine glucomannan and starch content; chromatographic methods for determining carbohydrate compounds; mass spectrometric methods to determine isotope ratios, elementel levels, organic acid and amino acid contents; calorimetric methods to determine melting temperature, thermal transition, and enthalpy levels were used. The data were evaluated by statistics and chemometric methods and important analysis methods were determined for the discrimination between salep and adulterants at the investigated parameters. In this context, amino acid analyzes, elementel analyzes, enzymatic analyzes, isotope analysis, carbohydrate components, organic acid analysis and parent analysis were found to be important for distinction. Determined methods, in the mixtures which between 0-10 % and 0-100 % of different ratios of contain salep were tested and the determination level of the ratio of salep in mixtures were investigated in the parameters of determined the methods. Glucomannan and total starch, malic acids, lysine, histidine, arginine, tyrosine, leucine+isoleucine and phenylalanine contents were determined as parameters which resulted in high level of correlation and linearity with salep levels in the range 0-10 %. Glucomannan and total starch, iron, copper, 13C/12C ratio, malic acid, lysine, valine, threonine, proline, glutamic acid, aspartic acid, methionine, histidine, arginine, tyrosine, leucine+isoleucine and phenylalanine which resulted in high level of correlation and linearity with salep levels in the range 0-100 %. It was concluded to be critical, the most important parameters that distinguishes the adulteration substances is glucomannan for in the mixtures which contain both 0-10 % and 0-100 % of different ratios of salep. As a result of the study, comprehensive compositions of salep samples obtained from different regions of our country in terms of analyzed parameters were determined, analytical parameters which are important in the distinction of between salep and adulterants were determined.