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The effect of the preparation method on the physical and chemical characteristics of propolis tinctures
163-168Views:278The effect of the preparation method was examined with regards to the physical and chemical characteristics of the propolis tincture, namely the extraction time and the ethanol content of the extraction solvent to the dry matter, polyphenol, flavonoid, phosphorus, calcium and copper concentration, respectively. The dry matter, the polyphenol and the flavonoid content were the lowest in the water extract of the propolis; however, significant increase was noticed depending on the extraction time. Significantly higher concentrations were found in 50 V/V% tinctures. The highest dry matter and flavonoid contents were analysed in 100 V/V% tinctures, whereas highest polyphenol content was found in 80 V/V% tinctures. However, the differences were not significant in several cases between latter tinctures. Moreover, the increase was not determined in some cases depending on the extraction time. Phosphorus and calcium concentrations were decreased depending on the increasing ethanol content, whereas copper concentration was increased up to 80 V/V%. Higher increase was found in the case of 0 and 50 V/V% extracts than in 80 and 100 V/V% tinctures. Moreover, in latter cases, no significant differences were found on several occasions, depending on the extraction time. There was no connection between the flavonoids and the calcium as well as the phosphorus content, whereas flavonoids may be made complex with copper. However, the amount of the possible complex was negligible.
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The effect of sous-vide cooking on the antioxidant properties of oyster mushroom (Pleurotus ostreatus L.)
177-184Views:167Oyster mushrooms (Pleurotus ostreatus L.) are renowned for their antioxidant, antimicrobial, and prebiotic properties. This study explores the antioxidant characteristics, activity, and β-glucan content in freeze-dried mushroom samples, investigating the influence of sous-vide cooking. Uncooked freeze-dried P. ostreatus and three pre-cooked freeze-dried samples (70, 80, 90 °C through 4 hours) were analysed for Total Polyphenol Content (TPC), Total Flavonoid Content (TFC), Radical Scavenging (DPPH), Ferric Reducing Antioxidant Power (FRAP), and β-glucans content via HPLC and Total Dietary Fiber (TDF) via enzymatic gravimetric method. Results indicate that uncooked mushroom powder exhibited superior antioxidant capabilities compared to cooked samples. The sous-vide cooked (80 °C) mushrooms displayed the highest total phenolic and flavonoid content. Moreover, pre-cooked (70 °C) mushroom powder demonstrated the highest β-glucan content, significantly surpassing the uncooked control sample. Notably, pre-cooked groups (80, 90 °C) demonstrated significantly higher TDF levels compared to uncooked sample. This research offers valuable insights into the potential use of mushrooms as high-antioxidant, antimicrobial, and prebiotic food or feed supplements, with broad implications across various fields.
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Change of antioxidant compounds of spices during drying
77-81Views:170Spices and herbs have been used by humanity for thousands of years, so they are very important plants.
In this study, the change of dry matter content and antioxidant compounds of eight spices (basil, thyme, rosemary, mint, parsley, lemongrass, chives, coriander) have been examined the raw plants and in plants preserved by three different drying methods (an oven in 50–60°C; drying at room temperature; lyophilisation between -40 and -50°C, under pressure), because we wanted to see the change of the parameters.
The water content of raw plants was very high, i.e. the dry matter content was very low. By the application of the three drying methods nearly 100% of the water has left the plants, with the exception of the lyophilized basil and rosemary.
Based on the results related to the original material, lyophilized has proved to be the best treatment for the preservation of antioxidant compounds, however air drying also showed high results for some spices.
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Antioxidant activity and total flavonoid content of honeys
25-28Views:173The influence of honey on human health has been known since ancient times. Different components, like vitamins, amino-acids, enzymes, and the so called antioxidant activity of the honey play role in this effect, and also in the excellent quality. The aim of present study was to determine the total antioxidant activity and the flavonoid content of some honey samples. These two parameters are widely studied, and a lot of data can be used to compare and analyse. On the basis of them we can state that our results are quite similar than those we can find in literature. Characteristic feature of the examined honey samples is, that the antioxidant activity increased with the darkening of the colour. The lowest antioxidant activity and flavonoid content was produced by the acacia honeys with greenish shade of colour. The highest values was found in the very dark honeys (forest, sage, golden rod). The only exception was the coriander honey, where despite of its lighter colour, very high antioxidant activity was
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Determining the antioxidant compounds of beer
5-10Views:371The increasing consumption of beer indicates the necessity of the thorough analysis of its composition. In this study, the total phenolic content, flavonoid content and colour intensity of 24 beer samples have been determined. The samples contained pale barley, dark barley, pale wheat and dark wheat beers. The aim of the study was to determine the amount of the antioxidant compounds in beer, as well as to find correlation between different beer types and the above mentioned parameters.
Dark barley samples contained phenolic compounds in the highest concentrations, and it can also be concluded that dark beers contain phenolic compounds and flavonoids in higher concentrations than pale beers in the case of barley and wheat samples.
According to the performed statistical analysis, these beer types cannot be differentiated based on the analysed parameters. The highest percentage of correctly classified samples could be observed in case of dark barley samples, but this value has only been 75%, and the total result of correctly classified cases was only 41.7%. The analysis of more samples and parameters is required to carry out a successful differentiation.
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Development of the antioxidant indexes (FRAP, TFC, TPC) of scabbing resistant apple varieties in storage
89-94Views:155One of the most important groups of bioactive substances in apples are antioxidants, which have a health-preserving effect. The amount of these compounds varies not only during the ripening of the apple fruit, but also continuously during post-harvest storage. A growing group of health-conscious consumers are looking for apple varieties with a nutritional value that satisfies their needs.
In the scope of our research, we examined 5 apple varieties originating from the Derecske horticultural site of KITE cPlc. in 2016. The plantation was planted to be suitable for intensive apple production. Samples were collected at the time of maturity (August-October) of the given variety. The 5 examined apple varieties (Gaia, Isaaq, Modí, Smeralda and Fujion) are all resistant to apple scab (fungal disease caused by Venturia inaequalis). The 2-month storage experiment was conducted at 16–17 °C, which had an aggressive effect on our stored apples. Total polyphenol (TPC) and flavonoid (TFC) content as well as FRAP values of the apples were measured. Measurements were taken immediately after harvest and after 1 and 2 months of storage. Our results were evaluated by using the IBM SPSS Statistics 20 software. Our aim was to compare the antioxidant results of 5 scab-resistant apple varieties, which change continuously during storage.
The antioxidant content of our apple varieties increased during 2 months storage. The best result was achieved by the Modí apple variety (FRAP: 467.32 mg/100g; TFC: 317.76 mg/100g; TPC: 1771.97 mg/100g). Consumers may want to consume apples stored for a longer period of time if they are to absorb large amounts of antioxidants.
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Leaf and root evaluation of bioactive compounds of different beetroot varieties
135-139Views:220The importance of beetroot lies in the numerous health benefits, attributed to its wide-ranging array of minerals, vitamins and bioactive compounds which play a key role in the human diet. Generally, beetroot is consumed for its root, however, its leaves also contain a good amount of bioactive compounds. The experiment was carried out with four beetroot varieties in order to compare the amount of bioactive compounds in the root and the leaf. The analyzed data were total dry matter content, total polyphenol, flavonoid and vitamin C.Results have shown that roots contain the highest amount of bioactive compounds. Nevertheless, leaves can be also considered a significant source. Therefore, consumption of the young leaves is highly recommended due to their availability after thinning or at maturity stage (60 days after the germination). Of the examined varieties, ‘Libero’ demonstrated the highest total polyphenol, flavonoid and vitamin C values, although it was found to be statistically insignificant. -
Sorghum and millet as alternative grains in nutrition
91-95Views:273Sorghum (Sorghum bicolor L.) and millet (Panicum miliaceum L.) are the fifth and sixth most important cereal crops in the world. Gluten-free grains, therefore persons with coeliac disease could consume them also. In addition, they have a lot of positive effects due to their phenolic compounds (phenol acid, flavonoid, tannin). The total phenol content of sorghum is high, but Panicum miliaceum and Eleusine coracana have higher antioxidant activity. Fiber and mineral contents are also high, the protein contents are also higher than in standard cereals. Sorghum use is similar to corn: starch, glucose, syrup, and oil can be produced. Moreover, it can be used in preparing whole grain products, bread, pancake, dumpling, mush, cake, pasta and beer from sorghum. Broom and forage are also can be prepeared from them. Millet used such as mush, steamed food, cake, bread, alcoholic and non-alcoholic beverages.