USING SYNTHESISED ORGANIC COMPOUNDS AS ENVIRONMENTALLY FRIENDLY RETARDANTS FOR ORNAMENTAL PLANTS
The pre-sowing treatment of scarlet sage (Salvia splendens Ker Gawl.) seeds with 4-methyl-2-piperidin1-yl-pyrimidine-5-carboxylic acid at concentrations of 0.01, 0.05, and 0.1% proved to have an obvious inhibiting effect. Prior to sowing, the seeds of Salvia splendens were soaked in a water suspension of 4-methyl-2-piperidin-1-yl-pyrimidine-5-carboxylic acid and 4-methyl-2-morpholin-4-pyrimidine-5-carboxylic acid with concentrations of 0.01%, 0.05%, and 0.1% for 18 hours. On the 42nd day of the experiment, the seedlings, having been preliminarily hardened for 12 days, were removed from the greenhouse and planted on the field. The pre-sowing treatment of Salvia splendens seeds with 4-methyl-2-morpholin-4-pyrimidine-5-carboxylic acid proved to have the inhibiting effect at concentrations of 0.01 and 0.05%. The height of the seedlings decreased by 13.3-43.7%. It was revealed that 4-methyl-2-piperidin-1-yl-pyrimidine-5-carboxylic acid at concentrations of 0.01, 0.05, and 0.1% decreased the growth of the seedlings by 30.4-43.7%, and 4-methyl-2-morpholin-4-pyrimidine-5-carboxylic acid at concentrations of 0.01 and 0.05% decreased the growth of the seedlings by13.3-22.2%. By contrast, the effect of pyrimidinecarboxylic acids on seed germination and plant height of another annual flower – spreading marigold (Tagetes patula L.) was stimulating. It was investigated some different concentrations from 0.01 to 0.05 %. The same concentrations of identical compounds were tested, but effects from them were opposite for Tagetes patula, and Salvia splendens seedlings. Сonsequently, the species-specific effect of pyrimidinecarboxylic acids on seed germination and plant height for ornamental grasses takes place. Therefore,4-methyl-2-piperidin-1-yl-pyrimidine-5-carboxylic acid and 4-methyl-2-morpholin4-pyrimidine-5-carboxylic acid are recommended as growth retardants for Salvia splendens.
Read ArticleEXPERIMENTAL STUDY OF THE INFLUENCE OF TEMPERATURE ON PASTEURIZATION OF PÊRA RIO IN NATURA ORANGE JUICE
Background: Heat treatment is one of the most used methods to preserve food, such as orange juices, which are an excellent source of ascorbic acid. To avoid vitamin C degradation and reduce loss, fast heating is recommended. However, little is known about heat transfer during juice pasteurization. Aim: Therefore, this work aimed to determine the vitamin C content and the convective heat transfer coefficient in the pasteurization of orange juice. Methods: To perform the experiment, in the juice container, two regions were analyzed: the central region and near the wall. For the time-temperature control, thermometers were installed in the two regions mentioned. Every 120 seconds, the temperature was measured. The vitamin C content in the juice was evaluated before and after pasteurization using the iodometric method. The convective coefficient was evaluated using the method of dimensionless numbers and the experimental method. Results and Discussion: In pasteurization, the solution was heated to 80 °C, where heating lasted 3000 seconds and cooling for 2520 seconds. The graph showing the relationship of the convective heat transfer coefficient and temperature follows the same trend of the literature. The convective coefficient is higher in the region near the wall. As time passes and temperature decreases, the central region tends to equilibrium, and the coefficient becomes more constant. The vitamin C content remained constant before and after pasteurization. The values of the dimensionless numbers used in the calculations are in the same order of magnitude as the literature. Conclusions: The pasteurization did not cause ascorbic acid degradation since the heating step was fast in the heat treatment. The graphic showed that there is a dependence of the dimensionless of temperature with the dimensionless Biot and Fourier. It was noted that studying the thermal behavior in the cooling of orange juice is extremely important to ensure its quality.
Read ArticleNATURAL EXTRACTS AS A PROMISING SOLUTION FOR GRAM-POSITIVE ANTIBIOTIC RESISTANCE: A COMPREHENSIVE REVIEW
Background: Antibiotic resistance is currently one of the biggest problems in public health. Infectious diseases are the second human death cause, and the emergence of antimicrobial-resistant bacteria increases mortality and morbidity rates. There is a growing clinical need for the development of new antibiotics. In this line, WHO issued an alert about 12 bacteria with an urgent need to develop new antibiotics. Aims: This review aims to analyze the current knowledge of their antibacterial activity against the gram-positive pathogens listed by WHO and their extraction techniques. Methods: We systematically reviewed the literature in PubMed, searching publications describing the use of natural extracts as antibiotics over bacteria. The exclusion criteria consisted of limiting papers on natural extracts tested over the bacteria culture related to eleven selected bacteria, according to an alert issued by WHO in 2017, and seven plant extracts. Results: All the gram-positive bacteria present in the WHO alert have been treated, with different degrees of advance, with some of the plant extracts and plant-based compounds reviewed. Currently, they are in the preclinical stage. Edible herbs are more often used, as well as artemisia and wine byproducts. Discussion: Natural products based on plants have shown to be efficient in inhibiting bacterial growth, even in antibiotic-resistant strains. The classical extraction methods are still in use and have been improved with the available technology to improve efficiency and yield. Conclusions: Ongoing evidence shows that plant extracts and plant-based compounds are effective as antibacterial, with minimal effects on the host cell, a promising antibiotic source. Furthermore, they are sustainable, environmentally friendly, and renewable.
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