Effect of drying methods on the chemical composition and colour of peppermint (Mentha × piperita L.) leaves

Abstract

The study was done with the two peppermint (Mentha × piperita L.) cultivars -'Krasnodarskaja' and 'Peppermint', whose leaves were dried using different methods. Investigation of fresh and dried herbs was carried out according to the biochemistry and technology methods. Essential oil was extracted using the hydro distillation method, the amount of chlorophyll a and b was measured spectrophotometrically according to the Vernon method. The highest content of essential oil (0.77%) and chlorophyll (1.69%) was found in the cv. 'Peppermint'. Chlorophyll a to b ratio was different in the fresh peppermint leaves: in the cv. 'Peppermint' it was 1.35 and in the cv. 'Krasnodarskaja' -1.44. Peppermint leaves were dried using active ventilation, convection, infrared, vacuum, microwave, and sublimation methods. The quality of dried herbs depended on the properties of plants and drying techniques. The highest content of essential oil (0.64-0.68% of dry mass) was found in the variously dried peppermint leaves of the cv. 'Krasnodarskaja'. The lowest content of essential oil (0.08% and 0.065% of dry mass) was determined in microwave dried herbs. The highest content of chlorophyll was found in the lyophilized peppermint leaves (715.0 mg 100 g -1 of dry mass) of the cv. 'Peppermint'. Regardless of the drying method, significant differences between the ratio of chlorophyll a to b were observed in the dried herbs of the cv. 'Krasnodarskaja'. The fresh and dried peppermint samples of the cv. 'Peppermint' had the lowest brightness L* value (from 22.61 to 35.24) and the lowest yellowness b* values (from 9.35 to 17.00). The biggest changes in greenness a* value were in microwave dried peppermint leaves.

Effects of selected herb extracts on iron-catalyzed lipid oxidation in soybean oil-in-water emulsion

“…The unidentified peaks corresponded to 66.72, 42.12, 37.50, 70.74, and 67.88% of the total peak areas in the rosemary, basil, peppermint, thyme, and oregano extracts, respectively, and require further studies. Polyphenol composition (types and concentrations) of herbs have been reported to be different depending on the harvest times, seasonal variations, and drying conditions (27)(28)(29).…”

Changes in the Content of Chemical Elements in the Muscle Tissue of Broilers on the Background of Plant Extract and Tetracyclines

“…Khan, H. Zaneb, S. Masood (2016) studied the effect of the extract of the leaves of the Moringaoleifera plant on the morphology of the intestines of broiler chickens. It was noted that the length of the villi in the small intestine and the excretion of mucin increased during the experiments [10], [11].…”

“…et al (2016) studied the effect of aqueous extracts of oregano (Origanumvulgare L.) and rosemary (Rosmarinusofficinalis L.) on the immunity and microbial population of the intestines of broiler chickens. Based on the results obtained, it was concluded that extracts of these herbs enhance the immunity of broilers and contribute to the balance of the intestinal flora necessary for digestion and for protection against pathogenic microorganisms [10]- [12].…”

Analysis of the cheese components’ influence on the dehydration process under reduced pressure

“…Improving the existing technologies and developing new effective ones for processing agricultural raw materials has always been one of the urgent tasks of the food industry [1][2][3][4][5][6][7][8][9][10].…”