Title : Quality of the herb Mentha x Piperita L. var. Officinalis Sole f. Pallescens Camus modified by drying at high temperatures in a vacuum
The study determined the effect of temperature (45 to 85 °C) during the vacuum drying process of the Mentha x piperita L. var. officinalis Sole f. pallescens Camus for the quality of the raw material. Herb color and chlorophyll content, the sum of polyphenolic compounds (TPC) and flavonoids (TFC) as well as the antioxidant activity of the extracts were analyzed using the DPPH test. Drying affects the quality of the product, however, vacuum drying occurs at a lower pressure than atmospheric pressure. A slight change in the color and chlorophyll content of the tested samples was observed due to the elevated temperature. Most TPC, TFC were obtained at 45 and 65 °C. Antioxidant activity was modified by the conditions of the drying process and the content of polyphenols.
• The tests improve the drying process while maintaining the best quality parameters of the raw material.
• A practical aspect is the possibility of using vacuum drying at high temperatures with more than twice the process time.
• The obtained raw material is characterized by the color desired by the consumer and longer storage time.