EFFECT OF ELECTROMAGNETIC FIELDS TREATMENT ON PEROXIDASE ACTIVITY AND POLYPHENOL CONTENT IN CABBAGE DURING STORAGE

Для увеличения масштабов производства и переработки растительного сочного сырья и сокращения использования химических пестицидов применяются различные виды физической обработки, в том числе электромагнитные поля (ЭМП). Представлены результаты изучения влияния ЭМП крайне низкой частоты (ЭМП КНЧ) на активность пероксидазы и содержание полифенольных веществ в белокочанной капусте сорта Белтис и цветной капусте сорта Ардент при хранении. Образцы обрабатывались ЭМП (25 Гц, 10 мТл, 30 мин) на лабораторной экспериментальной установке и хранились в течение 21 сут при t (4±1)°С и относительной влажности воздуха (75±3)%. Установлено, что обработка капусты белокочанной привела к увеличению активности пероксидазы на 70% через 7 сут, а через 21 сут хранения - увеличению пероксидазы на 25% и уменьшению полифенольных веществ на 13,7%. В обработанных образцах цветной капусты увеличилась активность пероксидазы на 54% через 7 сут и на 62 % через 14 сут хранения, а также количество полифенольных веществ на 8% через 21 сут хранения. Изучение закономерностей влияния обработки растительного сочного сырья ЭМП КНЧ на индукцию резистентности позволяет разработать на их основе новые способы хранения. In order to increase the scale of production and processing of vegetable juicy raw materials, it is necessary to timely develop new efficient, economical and environmentally friendly storage technologies. One possible way to reduce the use of chemical pesticides is through the use of various types of physical treatments, including electromagnetic fields. The article presents the results of studying the influence of extremely low frequency electromagnetic fields on the peroxidase activity and the total polyphenolic content in the white cabbage cultivar Beltis and the cauliflower cultivar Ardent during storage. The objects of research were treated with an electromagnetic field (25 Hz, 10mT, 30 min) in a laboratory experimental setup and were stored for 21 days at a temperature of 4±1°С and air relative humidity of (75±3)%. It was found that, in comparison with the control, the treatment of white cabbage leads to an increase in peroxidase activity by 70% after 7 days and by 25% after 21 days of storage, and an increase in peroxidase by 25% and a decrease in polyphenolic substances by 13,7% after 21 days of storage. It was also found that, in comparison with the control, the treatment of cauliflower leads to an increase in peroxidase activity by 54% after 7 days and by 62% after 14 days of storage, and leads to an 8% increase in the content of polyphenolic substances after 21 days of storage. The study of the regularities of the influence of the treatment of vegetable juicy raw materials with electromagnetic fields of extremely low frequencies on the induction of resistance can make it possible to develop new storage methods on their basis.

Chemical Composition of White Wines Produced from Different Grape Varieties and Wine Regions in Slovakia

In this work, chemical parameters such as sugar (glucose and fructose) content, organic acid (total acids, malic and tartaric acids), total phenolic content and the antioxidant activity of 12 white wines (chardonnay, pinot blanc and pinot gris) from various wine regions in Slovakia were studied in order to identify differences among the varieties and wine-growing regions. The wine samples were examined by Fourier-transform infrared spectroscopy (FTIR) and UV-VIS spectrophotometry (for determination of total polyphenolic content (TPC) and total antioxidant activity (TAA)) methods. Content of alcohol ranged between 11.50% and 13.80% with the mean value 12.52%. Mean content of total acids varied between 4.63 ± 0.09 and 6.63 ± 0.05 g.L−1, tartaric acid varied between 1.62 ± 0.09 and 2.93 ± 0.03 g L−1, malic acid was found in the concentrations ranged from 0.07 ± 0.05 and 2.50 ± 0.08 g L−1 and lactic acid was present between 1.53 and 0.01 g L−1. The content of fructose was, in general, higher in the samples from the Južnoslovenská and Nitrianska wine regions and glucose was higher in the Malokarpatská wine region. Chardonnay wines showed the highest content of total polyphenols and the antioxidant activity in the samples ranged from 51.06 ± 027 to 72.53 ± 0.35% inhibition of DPPH. The PCA analysis based on chemical descriptors distinguished the Nitrianska and Stredoslovenská wine regions. According to similarities among the wine samples, four main classes were formed by cluster analysis.

Effect of Roasting, Boiling, and Frying Processing on 29 Polyphenolics and Antioxidant Activity in Seeds and Shells of Sweet Chestnut (Castanea sativa Mill.)

Sweet chestnuts (Castanea sativa Mill.) are highly prized nuts, and the consumption of fresh chestnuts is usually preceded by roasting, boiling, and frying. The aim of this work was to simultaneously analyze 29 polyphenolic compounds for the first time in raw, boiled, roasted, and fried chestnut seeds and shells using HPLC-MS/MS. Principal component analysis depending on the HPLC-MS/MS results showed that roasting, boiling, and frying affected the contents of 25 detected phenolic compounds in a unique way, of which the most notable phenolics were gallic acid, ellagic acid, and (+)-catechin. Additionally, total polyphenolic content (TPC) was measured via the Folin–Ciocalteu method, and TPC in seeds and inner and outer shells was increased in all treatments except for microwave-roasted seeds. Furthermore, the higher TPC in the inner and outer shells when compared to seeds supported their higher antioxidant activity (AOA) determined via the DPPH experiment. AOA of seeds was increased in all treatments, while the AOA of shells was higher in roasting and lower in boiling and frying treatments. The assessment of these changes is necessary so that chestnut seed consumption and the recycling of their shells as a natural source of antioxidants can be maximized.

Description of the Guelder Rose Fruit in Terms of Chemical Composition, Antioxidant Capacity and Phenolic Compounds

The Viburnum opulus (guelder rose) fruit is a Polish native fruit that grows across almost the entire territory of the country, except for the Tatra Mountains. The fruits are rich in nutrients and biologically active compounds, however, they are rarely used for food production or as a dietary ingredient. This study assessed this fruit for dry matter (17.3% ± 0.7), extract (13% ± 0.53), titratable acidity (1.78 g/100 g ± 0.48), pectin (1.10% ± 0.97), vitamin C (47.79 mg/100 g ± 1.02), the amount of sugar identified as fructose (6.85 g/100 g ± 0.67), antioxidant activity, ABTS (14.64 ± 0.61 μM Trolox/100 g), FRAP (211.14 ± 1.04 µM Trolox/100 g) and total polyphenolic content TPC (1695.88 ± 0.86 mg GAE/100 g). The analysis of phenolic identification was performed using the ACQUITY Ultra Performance LC (UPLC) system with the binary solvent manager and PDA detector.

Innovative Combination of Dispersive Solid Phase Extraction Followed by NIR-Detection and Multivariate Data Analysis for Prediction of Total Polyphenolic Content

Recently polyphenols attracted great interest in the field of food and nutrition as well as in the pharmaceutical and cosmetics industries due to their health benefits through antioxidative behavior in the human body. However, because of the high number of compounds characterized as phenols and their structural diversity, quantification of polyphenols turns out to be a highly complex task. Although, a wide variety of analytical methods are used for the determination of total polyphenolic content, they are all found to be lacking in a variety of different tasks, such as their limits of detection and quantification, repeatability, accuracy and specificity. For this reason, a novel approach combining the advantages of solid phase purification, near infrared analysis and multivariate data analysis was investigated for the prediction of total polyphenolic content, suitable for a wide range of sample matrices. Dispersive solid phase extraction was performed and optimized using polyvinylpyrrolidone as sorbent, known to selectively bind polyphenols. Near-infrared detection of adsorbed polyphenols was carried out subsequently. Furthermore, the method was in-house validated, examining selectivity, repeatability and accuracy, working range, as well as multivariate limit of detection and limit of quantification, comparing it with two routinely used methods—namely, Folin–Ciocalteu photometric assay and Löwenthal titration. The novel established method was applied for the prediction of total polyphenolic content in tea and wine samples.

Effect of Cooking Methods on Bioactivity of Polyphenols in Purple Potatoes

Purple-fleshed potato (Solanum tuberosum L.) is a good dietary source of anthocyanins, flavonols, and polyphenolic acids, mostly chlorogenic acid. The objective of this study was to examine the impacts of cooking methods including boiling, steaming, and the newly developed vacuum-sealed boiling (VSBoil) on extractability and bioactivity of polyphenolic compounds in a purple potato (PP) cultivar, Purple Pelisse. Data showed that boiling and steaming reduced the total polyphenolic content in PP. High-performance liquid chromatography analysis showed that steaming slightly reduced the extractable chlorogenic acid content, while VSBoil increased it. For DPPH free radical scavenging activities, VSBoil and steaming effectively preserved the antioxidant activity of a polyphenol-rich extract of PP, while boiling resulted in a significant reduction compared to raw potato extract. All extracts effectively suppressed bursts of intracellular reactive oxygen species in human colonic epithelial cells upon hydrogen peroxide induction, of which the extract from the VSBoil group showed the highest antioxidant potential. In addition, all extracts showed anti-inflammatory effects in Caco-2 cells induced with tumor necrosis factor-α. In conclusion, the content and bioactivity of extractable polyphenols were largely retained in PP subjected to different cooking processes. VSBoil resulted in the highest content of extractable polyphenolic compounds and bioactivity among tested cooking methods.

Influence of Technological Maturity on the Secondary Metabolites of Hemp Concentrate (Cannabis sativa L.)

During the last decade, the popularity of hemp products has been rising rapidly. Products containing cannabidiol (CBD) are of predominant interest. Traditional hemp products are frequently enriched by CBD due to their potential therapeutic effects. Cannabidiol occurs naturally in hemp juice together with other biologically active substances, such as terpenes, flavonoids, and stilbenoids. These constituents act synergistically. This study aimed to observe the influence of the hemp plant developmental stage on its chemical composition and antioxidant activity. The hemp plants were analyzed during three vegetative stages, i.e., before, during, and after flowering. The collected samples were evaluated using the following analyses: total polyphenolic content and profile, terpenoid and cannabinoid contents, and ferric reducing antioxidant power. The results revealed statistically significant differences between the samples in almost all set parameters. The optimal period for hemp harvest depends on desirable compounds, i.e., phenolic content is the highest before flowering, while the levels of cannabinoids and terpenoids are the highest during the flowering period.

Preparation of grape pomace powders and analysis of their nutritive compositions

Grape pomace (GP) is produced in large amounts worldwide, leading to waste of resources and environmental pollution. Using grapes grown in eastern China, the main nutrients and polyphenols in grape seeds (GS), skin (GSK), and GP powders were determined by conventional chemical composition analysis and HPLC-MS/MS. The antioxidative activity of a GP polyphenol extract was identified using DPPH and hydroxyl radical scavenging assays and reducing power assay. GSK and GP contained less total dietary fiber than GS. The total polyphenolic content of GS was significantly higher than that of GSK and GP. The hydrogen- and electron-donating activities of the GP polyphenol extract were superior to those of vitamin C.

Physico-chemical Analysis, Total Polyphenolic Content and Antioxidant Capacity of Yellow Dye Extracted from Curcuma longa

Turmeric (Curcuma longa) is a well known condiment of the Asian cuisine and also used as ayurvedic medicine in the content, since ancient times due to its potential therapeutic properties. Main colouring constituent of Curcuma longa is curcumin and curcuminoids. In the present work natural yellow dye was extracted from rhizome of turmeric using an effective low cost method of solvent extraction. The developed natural yellow dye was assessed for physico-chemical analysis, toxicity, polyphenolic content and antioxidant activity. Physico-chemical assay showed good nutritional profile of the extracted natural yellow dye and quite safe at dose level 3.5g/Kg body wt. Significant phenolic content was found to be 63.32 mg GAE/100g, and also showed potent antioxidant capacity (% inhibition) ranging from 5.1-20.4 at 1-5 mg/mL concentration. Animal trials showed no mortality in the mice.

The Effect of Freeze-Drying on the Properties of Polish Vegetable Soups

The aim of this study was to investigate selected physical and biochemical properties of four vegetable freeze-dried soups. The water content, water activity, pH, color parameters, antioxidant activity (EC50), total polyphenolic content of fresh tomato, pumpkin, beetroot, and cucumber, and freeze-dried soups were measured. Sensory analysis was applied to compare sensory attributes of fresh and rehydrated soups. The sorption isotherms of freeze-dried soups were obtained with the application of the static and dynamic vapor sorption (DVS) method. The application of the freeze-drying method enabled the obtaining of dry soups with a low water content of 2–3%. The drying caused a significant change of color of all soups. The redness of soups decreased after drying for the beetroot soups from +39.64 to +21.91. The lower chroma value of 25.98 and the highest total color change ΔE*ab = 36.74 were noted for freeze-dried beetroot soup. The antioxidation activity and total polyphenolic content were reduced after drying, especially for the cucumber and tomato soups. The Peleg model was selected to describe the sorption isotherms of dried soups. The sorption isotherm of freeze-dried cucumber and beetroot soups had a sigmoidal shape of type II. The shape of the moisture sorption isotherm for freeze-dried tomato and pumpkin soups corresponded more with type III isotherms. The DVS method can be used to characterize the moisture sorption isotherms of freeze-dried products.