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Antimicrobial Activities Evaluation and Phytochemical Screening of Some Selected Plant Materials Used in Traditional Medicine
Plant extracts are a source of valuable ingredients that can be used in many industries. This paper presents research on the content of selected bioactive compounds in extracts obtained from various plant materials. Raw materials have a documented use in traditional medicine not only in Poland. The tested plants were: bitter melon (fruit), elderberry (flowers, fruit, leaves), wild rose (fruit, flesh, seeds), mountain ash (fruit), guelder rose (fruit), and sea buckthorn (fruit, leaves, pomace). The main goal of these tests is to indicate the potential raw materials that may constitute an alternative source of bioactive compounds with antimicrobial activity. The plant material was tested for the content of bioactive antioxidant compounds and possible antimicrobial activity. The content of polyphenols (phenolic acids and flavonoids) was analyzed using UPLC/PDA, sterols, organic acids, and other bioactive compounds. The minimum inhibitory concentration (MIC) was determined. The total free phenolic acids (TPC) and total free flavonoids (TFC) of all plant raw materials was varied and ranged from 0.21 (mg RUTE/1 g of extract) to 38.30 mg RUTE/1 g of extract) for TFC. The concentration of sterols was, on average, about 10 mg/1 g of extract. The value of approx. 20 mg/1 g of the extract was recorded for bitter melon and beach rose. The content of organic acids was about 1.5 mg/1 g of the extract to even 13 mg/1 g of the extract for sea buckthorn berries. The most sensitive to the extracts’ activity were the following bacteria: M. luteus, P. mirabilis, P. fragii, S. enteritidis, and E. coli. The tested plant materials can be used in various industries as a source of bioactive compounds of an antibacterial nature.
Roasting Temperature as a Factor Modifying the Caffeine and Phenolic Content of Ethiopian Coffee
The functional properties of coffee are mainly attributed to bioactive compounds, primarily caffeine and polyphenols. Their quantitative and qualitative profile depends on many factors, including the roasting process. The study aimed to assess the effect of different roasting conditions on the caffeine content and polyphenol composition of the Ethiopian variety Coffea arabica L. (from two regions: Sidama and Jimma). In total, 21 bioactive compounds were identified, including caffeine, 14 phenolic acids, 3 flavonoid glycosides, and 3 flavonoids. It was found that chlorogenic acid had the highest concentration of all phenolic compounds in the Jimma and Sidama varieties, regardless of the degree of roasting. Studies have shown that the initial stage of coffee roasting (light roast) affects chlorogenic acid content—its level increases compared to green coffee, but then decreases in subsequent roasting stages (medium and dark roast). In contrast, the concentration of caffeic acid decreases during the light roast stage, while it increases during the medium and dark roast stages. The Sidama variety contains more caffeine than the Jimma variety.
Camelina sativa Seeds and Oil as Ingredients in Model Muffins in Order to Enhance Their Health-Promoting Value
The aim of this study was to see whether it is possible to add camelina oil and seeds as ingredients in muffins in order to enhance their health-promoting value, such as their bioactive compound content, while maintaining the organoleptic attributes considered desirable by consumers. Camelina oil is characterised by a high linolenic acid content. Four types of muffins were prepared for analysis: MBnO—control muffins (containing 11.85% rapeseed oil), MCsO—muffins containing camelina oil instead of rapeseed oil, MCsS—muffins containing 6.65% camelina seeds in relation to the mass of prepared dough, and MCsOS—muffins containing both camelina oil and camelina seeds. The change in the fatty acid profile in muffins with the addition of camelina oil was significant; however, it was found that, as a result of thermal treatment, lower amounts of saturated fatty acids were formed. Among all the investigated experimental variants, muffins were characterised by the highest contents of all the phenolic acids analysed. The substitution of rapeseed oil with camelina oil had no negative effect on most of the organoleptic attributes of the muffins. Moreover, thanks to a greater content of carotenoids, camelina oil had an advantageous effect on the improvement of product colour, thus improving its overall desirability.