Straw stems of technical hemp: quality assessment

Abstract

Background. Currently, the existing methodology on the quality of both raw materials and products from technical hemp, which certifies its origin, quality and functional purpose, is outdated. The Institute of bast crops of the National Academy of Agrarian Sciences of Ukraine has developed a method for assessing the quality of technical stalks of hemp after harvest, but it has not yet been approved by the state enterprise UkrNDNTS. Also, this methodology has no harmonization with the technique for finished products obtained from technical hemp stems, and the main indicator of the quality of stems – the number (sort-number) in various normative documents has different meanings.
The analysis of recent researches and publications revealed the shortcomings and advantages of existing domestic methods for determining the quality of stems of technical hemp after harvest and showed the need for a new harmonized methodology.
The aim of the articleis to develop a new optimized method for assessing the quality of new varieties of technical hemp on different harvesting technologies.
Materials and methods. To conduct scientific research, new varieties of technical hemp were selected, which were bred by the Institute of Bast Crops of the National Academy of Agrarian Sciences of Ukraine at different periods of maturity (green, full maturity), which are zoned and distributed in Ukraine: Victoria, Gliana, Nika. The complex method of commodity evaluation of raw materials is used, which is based on determination of the basic qualitative characteristics of technical hemp stems.
Results. The commodity evaluation of all qualitative indices of technical hemp raw materials was conducted, on the basis of which the general level of quality – the number of raw material or its grade is established.
To obtain an objective commodity evaluation of raw material of technical hemp, an expert method with mathematical and statistical processing of the obtained expert assessments is used. As a result of the research, it was found that the general level of quality of stems of technical hemp straw after harvesting should be determined on the basis of the values of the four most important consumer indicators: stem length, fiber yield, stem diameter and color of the group of stems (according to the developed methodology). Based on the obtained data, a table with a fixed range of points was developed that corresponds to a  certain level of quality of stems of technical hemp, that is, the number: the highest grade, І, ІІ, ІІІ, IV.
Conclusion. According to the results of theoretical and experimental studies, a method for assessing the quality of stems of technical hemp straw has been developed after different harvesting periods.
In calculations by the method of commodity evaluationof the general level of quality of stems of technical hemp after harvest, the most important indicators for determining the raw material number are determined.
These studies will form the basis of a new regulatory documentation on the quality of stems of technical hemp after harvesting.