Determining the properties of tea waste generated at different stages of black tea production to enhance the assessment opportunities

In this study, tea wastes, occurred from 4 different stages of the black tea production line during three exile periods, from two factories of ÇAYKUR with different production methods were used as an example. The physical and chemical properties of the samples were determined and their differences from each other were revealed. Thus, it is aimed to contribute to the evaluation of tea wastes in different ways. Within the scope of the study, first of all, the tea wastes taken as samples were ground and homogenized. The properties of the samples such as moisture, water activity, bulk density and ash content were determined, and chemical composition elements such as polyphenolic substance amount, total phenolic substance amount, catechins, caffeine of the extracts obtained from the wastes were determined. In addition, cellulose, hemicellulose, lignin and soluble matter analyzes, which are important for the evaluation of tea waste, were also performed in these samples. In addition to these, biochemical methane potential analysis was carried out with an incubation that lasted for 44 days, and the first original study in this area was made. As a result of the findings and statistical analyzes, the production method, waste type, exile period and their interactions with each other are important on the bulk density of tea wastes; except for the production method, other parameters were found to be significantly effective on humidity, water activity, water extract, ash amounts. In the analysis of polyphenolic substances, these three parameters had a significant effect on the content of many polyphenols, while the type of waste (p<0.001) and the exile period (p<0.001) had a significant effect on the total amount of phenolic substances. In the analysis of cellulose, hemicellulose, lignin and soluble substances, exile period and waste types were found to be very effective. The results, which were close to each other in theoretical methane potential, differed in biochemical methane potential in exile period, location and production method. The highest methane production was determined in the teas belonging to the 1st exile period. These results showed that the tea waste, which is an important problem in the Turkish tea industry, has different characteristics depending on the exile period, waste type and production method. The data obtained have the qualities that will be useful to researchers and industrial workers in tea waste evaluation studies.