34 research outputs found
Effect of Pesticides on Enzymatic Activity in Soil
The focus of this article is to provide informations about soil enzymatic activity as a biological indicator for impacts of pesticides on soils. In this experiment, an ecological soil was treated with two types of fungicide (Ridomil Gold and Bravo 500) and two of insecticides (Mospilan 20SG and Vertimec 1.8% EC). The pesticides were assessed for their effect on different enzymatic activities. They were administrated over a 28 days period and the samples of soil were taken once every 7 days and analyzed in the laboratory. For each sample was determined the enzymatic activity, pH, humidity. The enzymatic activity was assessed using colorimetrical methods. Enzymes chosen for this study were cellulase, amylase, xylanase, urease, alkaline and acid phosphatase. Results shown that the enzymatic activity can increase or decrease when the soil was treated with the fungicides and insecticides chosen for this experiment
Effect of Boiling on the Antioxidant Potential of Cabbage Varieties
The aim of this study was to investigate the effect of boiling cooking method on the total polyphenolic content, ascorbic acid concentration, pigments amount and total antioxidant activity of four cabbage varieties (De Buzau cabbage, Buzoiana cabbage, Magura cabbage and De Isalnita cabbage) from Buzau, Romania. As we expect, fresh vegetables presented greater antioxidant capacity than boiled vegetables. For all cooked vegetables, the parameters (polyphenols, ascorbic acid, chloropyll, carotenoids and antioxidant activity) decrease with increase of boiling time. After 15 minutes of boiling, content in nutrients fell below 50%
Preliminary Tests Regarding Fumigant Effect of Volatile Oils Obtained from Medicinal Plants
The objective of this work was testing 4 volatile oils obtained from new varieties of medicinal plants (yellow basil; red basil; marigold; hyssop), over Beauveria brongniartii (BbgMm1a/09) entomopathogenic fungi and Sitophilus granarius, deposit insect. The results obtained showed that at different concentrations, red basil volatile oil showed the strongest inhibitory effect compared to the other tested oils (yellow basil, marigold and hyssop). Concerning the insecticidal action, the preliminary tests with the 4 volatile oils obtained from new varieties of medicinal plants had no effect on the test insect - Sitophilus granarius
Optimization of Extraction Method of Bioactive Compounds from Elderberries (<i>Sambucus nigra</i> L.) and Testing Extract Stability
Phenolic compounds from elderberries (Sambucus nigra L.) have attracted attention due to their potential health benefits. This paper examines different extraction methods used to obtain phenolic compounds from these fruits and the stability of the extracts. Several extraction techniques (extraction with continuous agitation, ultrasound-assisted extraction, microwave-assisted extraction, maceration, and enzyme-assisted extraction) were tested and compared to evaluate the yield and the quality of the extracts. The stability of the extracts with various storage parameters (time and temperature) and processing conditions (concentration and lyophilization) was also investigated. The results showed that ultrasound-assisted extraction (UAE) provided the highest yield of total phenolic compounds (74.89 mg GAE/g), of which 71.23% were represented by total anthocyanins and 62.50% by monomeric anthocyanins, with total flavonoids of 8.11–9.41 mg RUE/g. The analysis of individual phenolic compounds reconfirms the efficiency of UAE, obtaining 0.42–0.09 mg/g gallic acid, 0.59–0.01 mg/g chlorogenic acid, 0.17–0.03 mg/g 4-coumaric acid, and 2.43–0.01 mg/g rutin. The optimization of the extraction conditions led to the conclusion that the best solvent is 45% ethanol (v/v), and the optimal parameters are 40 °C for 40 min. It was also found that the stability of the extracts can be high during long periods of time (even after 180 days). These findings contribute to the understanding of the optimization of extraction processes and storage conditions to obtain extracts rich in phenolic compounds from elderberries, with potential uses in pharmaceutical and food applications
Pesticidal Potential of Essential Oil Obtained from a New Variety of Marigold (<i>Tagetes patula</i> L., fam<i>. Asteraceae</i>)
Essential oils (EOs) extracted from various medicinal plants offer a promising alternative to non-selective chemical substances commonly employed in conventional agriculture. Their chemical composition includes several classes of chemical compounds with beneficial properties, such as monoterpenes, sesquiterpenes, and phenylpropanoids, which can selectively control microbiological elements in soil and plants. The aim of the present study was to evaluate the essential oils and floral waters obtained from a new variety of marigold (Tagetes patula L., fam. Asteraceae, “Nanuk” variety) across various parameters, including biochemical characterization using GC-MS, antioxidant activity evaluated under three methods (DPPH, ABTS, FRAP), antimicrobial properties (for three G− bacteria: Perctobacterium carotovorum, Pseudomonas marginalis, Pseudomonas syringae and against three phytopathogenic fungi: Rhizoctonia solani, Fusarium oxysporum, Botrytis cinerea), and insecticidal activity. The results showed that when applied in high concentrations, marigold essential oil has a potential bactericidal effect on P. carotovorum, as well as a potential fungicidal effect on B. cinerea.</i