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Metody badania aktywności antyoksydacyjnej składników produktów kosmetycznych

Skoczeń Aleksandra, Marzec Marta, Nowak Izabela

Przemysł Chemiczny

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2025

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T. 104, nr 8

779--783

PL

Przedstawiono metody pomiaru aktywności antyoksydacyjnej, takie jak testy DPPH, ABTS, Folina i Ciocâlteu oraz FRAP, które oceniają zdolność neutralizacji wolnych rodników dla potencjalnych surowców kosmetycznych. Każda z tych metod ma swoje specyficzne zalety oraz ograniczenia, w tym różnice w pH, temperaturze i specyficzności. W pracy podkreślono znaczenie kompleksowej oceny aktywności antyoksydacyjnej dla zrozumienia mechanizmów starzenia się skóry oraz rozwoju skutecznych strategii przeciwdziałających tym procesom, a także zawarto dokładne procedury pomiarowe.

EN

Methods for measuring antioxidant activity such as DPPH, ABTS, Folin- -Ciocâlteu and FRAP tests were presented. Using these tests, the ability to neutralize free radicals in potential cosmetic raw materials can be evaluated. Each of these methods has specific advantages and limitations, (pH, temp., specificity). The importance of comprehensive assessment of antioxidant activity for understanding the mechanisms of skin aging and developing effective strategies to counteract these processes was emphasized and precise measurement procedures were included.

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Eco-friendly extract derived from Dittrichia viscosa (L.) Greuter 1973, from Algerian arid region, antioxidant evaluation and biopesticide use

Islam Belhamra Youcef, Nacima Deghiche Diab, Somia Saad, Abdelmoneim Ouamene Tarek, Samira Karoune, Madjed Djoudi, Allah Kechebar Mohamed Seif, Eddine Djazouli Zahr

Journal of Ecological Engineering

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2025

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Vol. 26, nr 1

14--29

EN

To investigate the effects of Dittrichia viscosa L. Greuter 1973 extract as a biopesticide on beneficial entomofauna in a greenhouse setting in the Biskra region, our study was conducted at the experimental site (CRSTRA). The aerial parts of D. viscosa were collected, dried, and analyzed in laboratory. The antioxidant potential of the plant extract was assessed by 2, 2-diphenyl-1-picrylhydrazyl (DPPH), alkaline DMSO superoxide, O-phenanthroline chelating (Phen) and iron reducing power (RP) methods. Enzyme inhibitory was studied using the iodine/potassium iodide method. A 200 m2 greenhouse was established in November 2021 and planted with to-mato (Cecilia), divided into four blocks, each equipped with sticky traps for monitoring ento-mofauna from May 1st to June 1st. The pulverized D. viscosa extract was applied at different concentrations (D1=5 ml/l; D2=10 ml/l; D3=15 ml/l) every 10 days. Analysis of the hydro-methanolic extract of D. viscosa revealed significant antioxidant activities and effective α-amylase inhibition, indicating its potential as a free radical scavenger and a useful therapeutic agent for addressing radical-related pathological damage. Additionally, the extract's biopesticide effects on beneficial insects were evaluated. Results showed a total richness of 75 species across 7 orders and 44 families, with the most abundant species belonging to Hymenoptera (37 species), Coleoptera (14 species), and Diptera (11 species). The predominant categories included parasitoids (29%), predators (24%), pests (15%), and pollinators (11%). As a biopesticide, the extract proved effective in reducing pest populations by 50% at the highest concentration (15 ml/L). The Pielou evenness index values (H5 ml/L = 0.8787, H10 ml/L= 0.8506, H= 0.836, compared to the control = 0.4179) indicated a nearly homogeneous distribution of individuals among species. The Shannon diversity index suggested that increasing concentrations of D. vis-cosa extract (E5 ml/L = 0, E10 ml/L= 1.33, and E15 ml/L= 0.5623) did not significantly impact the presence of pollinator species in the tomato greenhouse in the Biskra region.

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Mitigating the Toxic Effects of Salinity in Wheat Though Exogenous Application of Moringa Leaf Extract

Muneeba Muneeba, Khaliq Abdul, Muhammad Faran, Khan Muhammad Dilawaz, Alharbi Sulaiman Ali, Ansari Mohammad Javed, Umer Muhammad, Aslam Muhammad Talha, Shahzad Haroon

Journal of Ecological Engineering

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2024

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Vol. 25, nr 5

268--278

EN

Allelochemicals have emerged as an important player in inducing the abiotic stress tolerance. The experiment included three components: different levels of salinity stress (SS: control, 6 dS m-1, 12 dS m-1), seed priming with moringa leaf extract (MLE: 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%), and saltwater-tolerant and salinity-sensitive wheat cultivars (Faisalabad-2008, Galaxy-2013). Results showed that salinity lowered photosynthetic pigments, photosynthesis, transpiration, internal carbon, and stomatal conductance while causing poor and delayed germination, inconsistent seedling growth, and increased hydrogen peroxide accumulation. However, hydro-priming and MLE priming enhanced emergence dynamics, growth, biochemical and enzymatic characteristics, and physiological aspects. The cultivar Faisalabad-2008 (wheat) performed well, but at high salinity levels, the hormetic impact of moringa leaf extract was more obvious, enhancing the germination and growth of cultivar Galaxy-2013, which was salinity-sensitive. Wheat cultivars’ germination and seedling growth improved most when primed with 2% MLE (Faisalabad-2008) and 2.5% MLE (Galaxy-2013). This demonstrated that moringa possesses growthpromoting compounds that efficiently mitigate the toxic impacts of salinity.

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Antyoksydacyjne działanie ekstraktów pochodzenia roślinnego

Kosińska Edyta, Sadlik Julia, Krzysztoń Karolina

Inżynieria Materiałowa

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2024

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Vol. 45, nr 2

17--26

PL

W dzisiejszych czasach wzrasta zainteresowanie związkami, jakimi są przeciwutleniacze, ze względu na ich biologiczną aktywność – zdolność antyoksydacyjną. Znajomość zawartości substancji aktywnych w różnych produktach jest niezwykle istotna w dbaniu o swoje zdrowie i prewencje chorób. W pracy poświęcono uwagę ekstraktom z cytryny, imbiru, rożeńca górskiego, brzozy oraz mięty. Pomiaru ilości antyoksydantów dokonano z użyciem trzech metod: Folina-Ciocalteu, DDPH i ABTS. Celem było oznaczenie zawartości antyoksydantów oraz porównanie wyżej wymienionych metod. Najgorsze właściwości antyoksydacyjne wykazała cytryna, natomiast najlepsze efekty posiadał korzeń różeńca górskiego.

EN

Nowadays, there is a growing interest in antioxidant compounds because of their biological activity – antioxidant capacity. Knowledge of the content of active substances in various products is extremely important in caring for one’s health and preventing disease. In this study, attention was paid to extracts from lemon, ginger, mountain ash, birch, and mint. Antioxidant amounts were measured using three methods: Folin-Ciocalteu, DDPH, and ABTS. The aim was to determine the antioxidant content and to compare the aforementioned methods. Lemon showed the worst antioxidant properties, while Rhodiola rosea root had the best results.

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Investigation of the Antioxidant and Anti-Inflammatory Capacities of Different Extracts from Cistus ladanifer L. Leaves in the Ait Ammart Region (Northern Morocco)

Benamari Omar, Labhar Amina, Ahidar Naoufal, Salhi Amin, Ahari M'hamed, Elyoussfi Abdellah, Benyoub Bouchra, Amhamdi Hassan

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 3

178--184

EN

Plants are a significant source for identifying new compounds (particularly secondary metabolites) with medicinal value for drug development, pharmaceuticals, and food additives. Many of these healing plants are frequently used in conventional medicine to treat and prevent various diseases. The purpose of the current research is to assess the total phenolic content (TPC) and total flavonoid content (TFC) for phytochemical analysis, DPPH and FRAP (Ferric Reducing Antioxidant Power) assays for antioxidant activity (AOA), and the activity of reducing inflammation exhibited by various extracts, which were determined by measurement of absorbance with a UV spectrophotometer. The outcome demonstrated that the Cistus ladanifer L leaf aqueous extract (EAqCL) has the highest yield (15.581%) and the highest phenolic content (98.28 ± 0.32 mg GAE/gext) compared to the other extracts. Whereas, ethanol extract (EECL) exhibited the highest flavonoid content (11.39 ± 1.45 mg QE/gext), DPPH-radical scavenging activity (RSA = 94.534 ± 1.24%) at 800 μg/ml and FRAP (1.017 ± 0.12) at 400 μg/mL. The extract also showed better anti-inflammatory activity (95.61 ± 0.92%) at 1000 μg/ml. According to the results obtained, this sticky shrub growing in the Ait Ammart region has great potential for exploiting natural sources of bioactive substances and producing pharmacologically active metabolites.

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Assessment of Phytochemical, Antioxidant and Antibacterial Properties of Ziziphus lotus Fruit Extracts

El Yakoubi Nosair, El Ahmed Annaoui, Rehhali Mohammed, Ansari Zineb Nejjar, Bounab Loubna, El Kbiach Mohammed L’bachir, El Bouzdoudi Brahim

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 11

377--388

EN

One of the main sources of novel chemicals with possible medical use is medicinal plants. Multiple diseases have been treated with them in traditional medicine. The purpose of this study was to explore the phytochemical characteristics, antioxidant effects, and antibacterial activities of several extracts of Ziziphus lotus fruits (ZLF). Phytochemical analysis of ZLF extracts revealed the presence of several bioactive molecules such as phenolic compounds and alkaloids. Water, methanol 50%, methanol 80%, methanol, ethanol, and hexane are the 6 different solvents which were used in order to evaluate the phytochemical profile as well as the biological activities of ZLF, and whose aqueous extract showed the best results. The aqueous extract had the highest yield, followed by methanol, ethanol, and lastly hexane (p < 0.05). The aqueous extract showed the highest total contents of phenols, flavonoids, and tannins (77.13 ± 0.11 mg GAE /g DM, 33.36 ± 0.51 mg QE/g DM, and 03.72 ± 0.16 mg CE/g DM respectively), while the Hexane extract revealed the lowest contents (12.36 ± 0.26 mg GAE/g DM, 06.20 ± 0.23 mg QE/g DM, and 01.20 ± 0.10 mg CE/g DM respectively). By using the DPPH, ABTS, and FRAP methods, and for the aqueous extract, ZLF extracts demonstrated considerable antioxidant capacities, with the values IC50 = 37 ± 0.27, IC50 = 67 ± 0.18 and IC0.5 = 31 ± 0.22 respectively. All of the ZLF extracts, with the exception of the hexanic extract on Staphylococcus aureus, showed antibacterial efficacy against the bacterial strains of Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The results obtained reveal that ZLF exhibit significant biochemical composition and considerable biological activities encouraging its nutritional and therapeutic use.

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Multifunctional sericin-chitosan-Aloe vera composite film for food packaging

Kavi Palepu, Tarangini Korumilli, Kumaravel Varuna, Rao Korukonda Jagajjanani, Wacławek Stanisław, Cheong Jun Young, Padil Vinod V.T.

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 3

297--314

EN

In recent years, the demand for innovative, sustainable, and efficient food packaging solutions has surged in response to growing concerns about environmental impact, food safety, and quality preservation. A sericin-based polymer composite film with multifunctional properties shows promise as an alternative for enhancing food packaging. In this study, sericin-based composite films were prepared by incorporating Aloe vera gel, chitosan, and glycerol into a sericin solution (1.5% w/v) through facile homogenisation at 70°C, followed by casting and subsequent drying on a glass platform. The resulting dried film exhibited uniformity, a smooth texture, and successful integration of the composite components. The film demonstrated a moisture content of 21.02% and a porosity of 3.56%, with a thickness of (62.1 ± 2.3) μm. It exhibited moderate transparency with reasonable water vapour permeability. Notably, the DPPH scavenging results indicated that the film has a potent antioxidant capacity with an efficacy rate of 99.1%, supported further by a phenolic content of 11.5 mg GAE per gram of film. Controlled solute migration of components from the composite films was observed, particularly under acidic conditions. Importantly, toxicity evaluation on A549 cells revealed no adverse effects, even at higher concentrations. Due to its consistent film-forming ability, antioxidant potency, controlled migration, and safe nature, the developed sericin polymer-based film could be an effective alternative for food packaging sensitive foods, maintaining oxidative stability, reducing moisture loss, improving quality, and extending shelf life.

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Witamina C - sekret młodej i promiennej skóry

Krygowska Karolina, Ścigaj Justyna

Analit

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2024

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Nr 14

97--100

PL

Celem niniejszego artykułu jest przybliżenie jednego z cennych składników aktywnych, a mianowicie kwasu askorbinowego - naszej witaminy C, który zaczął być doceniany dopiero od kilku lat. Zapobiega ona przede wszystkim uwalnianiu się wolnych rodników, co doskonale wpływa na stan naszej skóry [1]. Mówi się, że witamina C jest niezbędna do prawidłowego funkcjonowania organizmu. Przyspiesza ona proces gojenia się ran, aktywuje liczne enzymy, zapobiega powstawaniu zmarszczek, wyrównuje naturalny koloryt skóry, czy także wzmacnia zęby i dziąsła dodatkowo zwalczając bakterie powodujące próchnicę [2]. Czego możemy się spodziewać, gdy włączymy witaminę młodości do codziennej pielęgnacji? Jak wpływa ona na nasz organizm i o czym należy pamiętać stosując ją? Na te i inne pytania odpowiedź będzie można znaleźć w niniejszym artykule.

EN

The aim of this article is to introduce one of the valuable active ingredients, namely ascorbic acid - our vitamin C, which has only begun to be appreciated in the last few years. In particular, it prevents the release of free radicals, which is excellent for the condition of our skin. [1] Vitamin C is said to be essential for the body to function properly. It speeds up the healing process of wounds, activates numerous enzymes, prevents the formation of wrinkles, evens out the natural skin tone, or strengthens teeth and gums by additionally fighting the bacteria that cause decay [2]. What can we expect when we include the youth vitamin in our daily care? How does it affect our body and what should we keep in mind when taking it? These and other questions will be answered in this article.

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Antioxidant radical scavenging capacity and total carotenoid content of narrow-clawed crayfish (Pontastacus leptodactylus, Eschscholtz, 1823) in Atikhisar Reservoir (Çanakkale, Türkiye)

Acarlı Sefa, Kızılkaya Bayram, Vural Pervin, Barber Selçuk, Kale Semih, Acarlı Deniz

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 4

471--483

EN

n this study, antioxidant radical scavenging capacity and total carotenoid content in the meat and shells of Pontastacus leptodactylus were investigated. Concerning the antioxidant scavenging effect, the highest IC50 values were found to be 388.77 mg g-1 and 155.53 mg g-1 for females and males in July and March, respectively. The mean IC50 values of the meat were calculated as 239.83 mg g-1 and 105.21 mg g-1 for females and males, respectively. The mean total carotenoid content in the meat was found to be 14.35 and 12.78 μg g-1 for females and males, respectively. The results indicated that crayfish meat had antioxidant radical scavenging capacity and was rich in carotenoid content.

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First Report of in Vitro Biological Agent to Biocontrol of Date Palm Stipe Rot Affected by Fusarium brachygibbosum by Using Pergularia tomentosa L., Aqueous Extract

Baba Mohamed Lemine, Essghaier Badiaa, Robledo-Mahón Tatiana, Abidine Mohamed Mahmoud, Aranda Elisabet, Sánchez José, Elemine Brahim Ould, Gallego Eduardo, Sebai Khaled, Vadel Ahmedou

Journal of Ecological Engineering

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2023

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Vol. 24, nr 9

373--384

EN

Palm (Phoenix dactylifera L.) is a specie cultivated in Mauritania. The present study is focused on the potential of the aqueous extract of the Pergularia tomentosa L., as biological control agent against Fusarium brachygibbosum, the main agent of the date palm stipe rot disease in Mauritania. Fungal pathogen was isolated from symptomatic date palm stipe rot disease in Mauritania. The morphological characterization and the molecular identification by sequencing ITS1, ITS2 5.8 RNAr region showed homology of 98% with Fusarium brachygibbosum strain UOA/HCPF 16982 s during in vitro tests on leaves performed to verify its phytopathogenicity. The inhibitory effect of aqueous extract of Pergularia tomentosa L. on the phytopathogenic isolate (Fusarium brachygibbosum) of date palm, on mycelial growth and spore germination was observed. In fact, in vitro on PDA, mycelial growth ranged from 39.23 to 67.7%, depending on the concentration of the aqueous extract of P. tomentosa. The aqueous extract showed a reduction of spore germination varying from 5.3 to 23.8%. The minimum inhibitory concentrations varied from 1 to 100 mg/ml. The various extracts give high antioxidant activities exhibited by DPPH assay. Multivariant analysis by PCA plot and the heatmap were done, to evaluate the correlation between the tested parameters. These results suggest the use of Pergularia tomentosa L., extract as a biological agent to control and reduce damage caused by Fusarium brachygibbosum.

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Facile green synthesis of Cinnamomum tamala extract capped silver nanoparticles and its biological applications

Narath Sajina, Shankar S. Sharath, Sivan Saranya Kothaplamoottil, George Bini, Thomas T. Dennis, Sabarinath Sankarannair, Jayaprakash Sajithkumar K., Wacławek Stanisław, Padil Vinod V. T.

Ecological Chemistry and Engineering. S

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2023

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Vol. 30, nr 1

7--21

EN

The plant mediated biogenic synthesis of nanoparticles is of magnificent concern due to its eco-benign and single pot nature. Here, Cinnamomum tamala (C. tamala) aqueous leaf extract was utilised for the silver nanoparticles’ (Ag NPs) synthesis. The phytoconstituents in the leaf extract were analysed by standard methods. These metabolites, especially carbohydrate polymers reduce Ag ions to Ag NPs accompanied by a reddish-brown coloration of the reaction mixture. The visual observation of intense brown colour is the first indication of the formation of Ag NPs. Various spectro-analytical techniques further characterise the Ag NPs. The green synthesised spherical Ag NPs were crystalline with an average size of 38 nm. The Ag NPs were scrutinised for antioxidant, antimicrobial and cytotoxic activity and obtained good results. The free radical scavenging was studied by 2, 2-Diphenyl-l-picrylhydrazyl (DPPH) assay. The antibacterial activity of Ag NPs was assessed against human pathogens, and it shown to have good antibacterial potency against a wide spectrum of bacteria. The cytotoxic activity against HEK-293T (human embryonic kidney) cell line was evaluated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. These potent biological activities enable C. tamala capped Ag NPs to be suitable candidates for the future applications in various fields, predominantly clinical and biomedical.

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Antioxidative properties of autumn olive (Elaeagnus umbellata) fruits according to the method of fruit preservation and solvent used in extraction

Zglińska Klara, Rygało-Galewska Anna, Niemiec Tomasz

Polish Technical Review

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2022

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No. 1

19--23

EN

Fruits of autumn olive (Elaeagnus umbellata) are the abundant source of antioxidative substances such as carotenoids, polyphenols, flavonoids, fat-soluble vitamins and Vitamin C. The conducted study was aimed at the selection of the optimum method for extraction of berries. To this end, two methods for preservation of the berries were compared: drying at 60°C and freeze-drying (lyophilisation) and two types of solvent, employed in the extraction: water and methanol. The results showed that the methanol extracts produced from lyophilized fruits were characterized by the highest antioxidative activity.

PL

Owoce oliwnika baldaszkowatego (łac. Elaeagnus umbellata, ang. Autumn olive) są bogatym źródłem substancji antyoksydacyjnych, takich jak karotenoidy, polifenole, flawonoidy, witaminy rozpuszczalne w tłuszczach oraz witamina C. Przeprowadzone badanie miało na celu wybranie optymalnej metody ekstrakcji jagód. W tym celu porównano dwie metody utrwalania owoców: suszenie w 60°C i liofilizację oraz dwa rodzaje rozpuszczalników użytych do ekstrakcji: wodę i metanol. Wyniki wykazały, że najwyższą aktywnością antyoksydacyjną charakteryzowały się ekstrakty metanolowe wykonane z owoców liofilizowanych.

13

Exogenous regulation of the potatoes’ adaptive potential when using bio stimulants

Shitikova Aleksandra V., Abiala Adewale A., Tevchenkov Alexander A., Bazhenova Svetlana S., Lazarev Nikolay N., Kurenkova Evgeniya M.

Journal of Water and Land Development

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2022

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no. 54

234--238

EN

Potato from the Solanaceae family is one of the most important crops in the world and its cultivation is common in many places. The average yield of this crop is 20 Mg·ha-1 and it is compatible with climatic conditions in many parts of the world. The experiment studied the possibility of exogenous regulation of the adaptive potential available for four potato cultivars through the use of growth stimulants with different action mechanisms: 24-epibrassinolide (EBL) and chitosan biopolymer (CHT). The results allowed us to establish significant differences in growth parameters, plant height, leaf index, vegetation index, chlorophyll content, and yield structure. Monitoring growth and predicting yields well before harvest are essential to effectively managing potato productivity. Studies have confirmed the empirical relationship between the normalised difference vegetation index (NDVI) and N-tester vegetation index data at various stages of potato growth with yield data. Statistical linear regression models were used to develop an empirical relationship between the NDVI and N-tester data and yield at different stages of crop growth. The equations have a maximum determination coefficient (R2) of 0.63 for the N-tester and 0.74 for the NDVI during the flowering phase (BBCH1 65). NDVI and N-tester vegetation index positively correlated with yield data at all growth stages.

14

Effect of oggtt on physicochemical properties, antioxidant activity and volatile compounds of noodles

Bahgaat Wafaa K., Ibrahim Gamil E., Hussein Ahmed M. S.

Biotechnology and Food Science

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2022

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Vol. 84, nr 1

3--18

EN

The present investigation aimed to evaluate the effect of noodles supplementation with oggtt at (5,10,15 and 20%) on physicochemical properties, antioxidant activity as well as volatile compounds. The cooked noodles evaluation based on cooking quality like volume and cooking loss as well as colour changes. An increase in protein, fat and ash was observed with the increase of oggtt supplementation level in noodles. The whole wheat flour had the highest value of total phenolic (462.3 μg GAE g−1) compared to oggtt and all fortified noodles without cooking and after cooking. The fortification levels of 5 and 10% did not affect significantly on colour and overall acceptability of noodles. The panelists scores recommended the usage levels of 5 and 10% of oggtt noodles which did not changed significantly in comparison with control sample. The evaluation of oggtt incorporation in noodles volatile compounds performer using HS-GC/MS analysis. Thirty volatile compounds in cooked noodles after fortification with oggtt had identified. The main volatile compound herein was 2-pentyl furan, which represent 44.12, 20.14 and 18.75% in cooked control and fortified noodles with oggtt at 5 and 10% respectively.

15

Variation in radical antioxidant capacity and the total amount of carotenoids in razor clams, Ensis marginatus (Pennant, 1777), from the Çanakkale Strait (Abidealtı), Turkey

Kizilkaya Bayram, Acarli Sefa, Ertuğrul Pervin Vural, Berber Selçuk, Çelik Pinar

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 1

16--23

EN

Metabolic activities such as breathing and digestion, resulting from natural functions of the body through oxidation, lead to the formation of free radicals that cause cancer, premature cardiac aging and some chronic diseases. Antioxidants are substances that remove free radicals and prevent cell damage. Seafood significantly contributes to the elimination of free radicals, especially owing to its high quality nutrient content. In this context, the objective of the study was to determine the radical antioxidant capacity and the total amount of carotenes in razor clams. The IC50 (mg g−1) value of the DPPH radical sweeping effect varied over the months (p < 0.05), showing the highest value in June, gradually decreasing from September and reaching the lowest level in February. The total amount of carotenoids also varied, with the highest value in September (p < 0.05). The total amount of chlorophyll ranged from 6.15 µg g−1 in August to 66.71 µg g−1 in December.

16

Stabilność termooksydacyjna smarów plastycznych

Skibińska Agnieszka

Nafta-Gaz

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2021

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R. 77, nr 7

471--479

PL

Niniejszy artykuł przeglądowy dotyczy szczególnej właściwości smarów plastycznych – odporności na utlenianie. Właściwość ta, określana również jako stabilność oksydacyjna lub termooksydacyjna, ma decydujący wpływ na jakość i długość czasu pracy smarów w węzłach tarcia, łożyskach i układach smarowania. Smary plastyczne stanowią układy koloidalne, w których zagęszczacz tworzy elastyczną przestrzenną sieć, utrzymując fazę ciekłą. Przedstawiono budowę smarów plastycznych, podział smarów na rodzaje w zależności od wykorzystywanego zagęszczacza. Opisano podstawowe dodatki występujące w smarach, a szczegółowo omówiono grupę stosowanych dodatków antyutleniających. W warunkach eksploatacji smar podlega działaniu szeregu czynników, które powodują jego niszczenie, takim jak: naprężenia ścinające, ciśnienie, obciążenia, zmienne warunki pracy, szczególnie zmiany temperatury. Przedstawiono rodzaje degradacji smarów, a także metody i techniki oceny procesów starzenia. Podczas eksploatacji smar, spełniając w układzie smarowania swoje podstawowe funkcje, narażony jest przede wszystkim na działanie wysokiej temperatury. Dominującym procesem starzenia, bezpośrednio wpływającym na okres użytkowania smaru, jest utlenianie. Omówiono proces utleniania z wyszczególnieniem czterech jego etapów: inicjacji, propagacji, rozgałęzienia łańcucha oraz terminacji. Jedną z metod zapobiegania procesowi utleniania jest dobór odpowiednich dodatków uszlachetniających. Stabilność termooksydacyjna smarów plastycznych może być modyfikowana poprzez wprowadzenie odpowiednich przeciwutleniaczy, których dobór zależy od rodzaju zagęszczacza smaru plastycznego oraz temperatury pracy smaru. Zamieszczony przegląd literatury z ponad dziesięciu ostatnich lat wskazuje, jak różnorodne są sposoby modyfikacji stabilności termooksydacyjnej smarów i metody oceny tej właściwości.

EN

This review article deals with a particular property of lubricating greases – resistance to oxidation. This property, also referred to as oxidative or thermal oxidation stability, has a decisive influence on the quality and duration of lubricating greases service life in friction nodes, bearings and lubrication systems. Lubricating greases are colloidal systems in which the thickener creates an elastic three-dimensional network, maintaining the liquid phase. The structure of lubricating greases, division of greases into types, depending on the thickener used, is presented. The basic additives in lubricating greases are described, and the group of used antioxidant additives is discussed in detail. Under operating conditions, the grease is subject to factors that cause its destruction – shear stress, pressure, loads, changing operating conditions, especially temperature changes. The types of lubricating greases degradation are presented, as well as methods and techniques of aging processes evaluation. During operation, the grease fulfilling its basic functions in the lubrication system is primarily exposed to high temperatures. The predominant aging process which directly affects the service life of the grease is oxidation. The oxidation process is discussed, with the specification of its four stages: initiation, propagation, chain branching and termination. One of the methods of preventing the oxidation process is the selection of appropriate improvers. Thermal oxidation stability of greases can be modified by introducing appropriate antioxidants, the selection of which depends on the type of grease thickener and the operating temperature of the grease. The published literature review from over the last ten years shows how diverse are the ways of modifying thermal oxidation stability of greases and the methods of assessing this property.

17

Evaluation of antioxidation properties of natural polyphenol water extracts from selected plants in a model system

Telichowska Aleksandra, Kucharska Aleksandra, Kobus-Cisowska Joanna, Betka Marta, Szulc Piotr, Stachowiak Barbara

Journal of Research and Applications in Agricultural Engineering

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2021

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Vol. 66, nr 1

25--29

EN

In the recent times plants are becoming more popular. Their beneficial pro-health properties result from the content of numerous characteristic compounds. Reports are confirming their beneficial antioxidant, antibacterial and anti-inflammatory properties. The aim of this study was to compare the antioxidant potential and the characteristics of water extracts obtained from plants: yarrow herb (AM) (Achillea millefolium L.), knotweed herb (PA) (Polygonum aviculare L.), horsetail herb (EA) (Equisetum arvense L.), and motherwort herb (LC) (Leonurus cardiaca L.). Extracts osmolality was from 0,142a±0.02 mOsm/kg H2O for the AM extract to 0,176c±0,01 mOsm/kg H2O for the EA extract. The test with the use of the Folin-Ciocalteu reagent showed that the EA extract had the highest content of reducing compounds (54,24d±2,19 mg GAE/g dw). It was shown that the highest activity against the DPPH radical was obtained for the extract from Equisetum arvense L. (5.97c±0.11 mg TE/1 g dw), and this extract also showed the highest antioxidant capacity measured with the radical ABTS method (7.23b±0.06 mg TE/g dw). These analyses were also confirmed by the tests carried out using the FRAP test, EA extract also showed 40% higher activity compared to the lowest AM extract. It has been shown that the investigated herbal raw materials can be an attractive raw material with antioxidant properties that can be used in application in food technology.

PL

Surowce roślinne cieszą się coraz większą popularnością. Ich korzystne właściwości prozdrowotne wynikają z zawartości licznych charakterystycznych związków. Dostępne są doniesienia, potwierdzające ich korzystne właściwości antyoksydacyjne, przeciwbakteryjne i przeciwzapalne. Celem niniejszej pracy było porównanie potencjału przeciwutleniającego oraz charakterystyka ekstraktów wodnych uzyskanych z następujących roślin: ziele krwawnika (AM) (Achillea millefolium L.), ziele rdestu ptasiego (PA) (Polygonum aviculare L.), ziele skrzypu (EA) (Equisetum arvense L.) oraz ziele serdecznika (LC) (Leonurus cardiaca L.). Osmolalność ekstraktów wynosiła od 0,142a±0,02 mOsm/kg H2O dla ekstraktu AM do 0,176c±0,01 mOsm/kg H2O dla ekstraktu EA. Test z odczynnikiem Folin-Ciocalteu wykazał, że ekstrakt EA charakteryzował się najwyższą zawartością związków redukujących (54,24d±2,19 mg GAE/g sm). Najwyższą aktywność wobec rodnika DPPH uzyskano dla ekstraktu z Equisetum arvense L. (5,97c±0,11 mg TE/1g sm), ekstrakt ten wykazał także najwyższą zdolność antyoksydacyjną mierzoną metodą z kationorodnikiem ABTS (7,23b±0,06 mg TE/g sm). Analizy te zostały również potwierdzone w teście z użyciem metody FRAP, ekstrakt EA wykazywał o 40% wyższą aktywność w porównaniu z najniższym uzyskanym wynikiem (AM). Wykazano, że badane surowce zielarskie mogą być atrakcyjnym źródłem związków polifenolowych o właściwościach przeciwutleniających, które mogą znaleźć znacznie szersze niż dotychczas zastosowanie w technologii żywności.

18

Distilled Spirit Extraction of Phenolic Antioxidants from Fruit and Vegetable Residues

Ortinero Cesar V., Rafael Rosalie R., Rayos Charmaine Eljie R., Bautista Katherine D. A., Feliciano Mark Aldren M., Natividad Lexter R., Natividad Gaudencio M.

Journal of Ecological Engineering

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2021

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Vol. 22, nr 1

125--131

EN

There is a growing interest in natural antioxidants due to their potential in improving the quality of food and cosmetic products and their health-promoting properties. Distilled spirits contain high amount of ethanol and may be an alternative to the food-grade solvents, while agricultural by-products contain phenolic substances that may have antioxidant properties. This study was therefore conducted to find out if gin, vodka, and tequila flavored spirit, alcoholic beverages with about 40% ethanol, can extract the phenolic compounds from agricultural by-products, and to determine if the extracts possess the antioxidant activity. Peels of ripe banana (Musa acuminata), ripe mango (Mangifera indica), calamansi (Citrofortunella microcarpa), squash (Cucurbita maxima), ripe pineapple (Ananas comosus), purple yam (Dioscorea alata), and sweet potato (Ipomea batatas) were collected, dried, and ground. The phenolic substances in the plant materials were extracted with alcoholic beverages or 40% ethanol. The total phenolic content (TPC) of the extracts was determined by means of UV-Vis spectroscopy using Folin-Ciocalteau reagent and gallic acid as reference compound. The antioxidant activity of the extracts was evaluated through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Butylated hydroxyanisole (BHA) served as positive control in the DPPH assay. Non-linear regression was applied to the DPPH assay data to estimate the values of median effective concentration (EC50). All three alcoholic beverages were able to extract the phenolic materials from the plant samples. However, the ability of vodka and gin to extract the phenolic substances was either statistically comparable or better than 40% ethanol. The results of the DPPH scavenging assay showed that the M. indica peel had the strongest activity, while C. microcarpa had the weakest scavenging activity. At 1000-ppm level, the antioxidant activity of the M. indica peel was comparable with that of BHA, regardless of the solvent used for extraction. Therefore, the M. indica peel can be a source of natural antioxidants and potential substitute to synthetic antioxidants. Both gin and vodka can be used as a substitute for food-compatible solvents.

19

Potential natural sources of tocopherols and tocotrienols and possibilities their use in the food industry®

Szewczyk Kacper

Postępy Techniki Przetwórstwa Spożywczego

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2020

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nr 1

139--147

EN

Tocopherols and tocotrienols are natural compounds found in oil plants. Their antioxidant properties make them interesting for food producers and consumers looking for healthy food. The aim of this study is to present the potential natural sources of tocopherols and tocotrienols, which as antioxidants are increasingly used as food additives to extend itheir durability, and additionally enrich the product with vitamin E. The work shows their chemical structure, methods of obtaining and legal regulations allowing tocopherols and tocotrienols for use in food processing. The current ways of using them in food production were discussed.

PL

Tokoferole i tokotrienole to naturalne związkami występują-ce w roślinach oleistych. Ich właściwości przeciwutleniają-ce sprawiają, że są interesujące dla producentów żywności i konsumentów poszukujących zdrowej żywności. Celem arty-kułu jest omówienie potencjalnych naturalnych źródeł toko-feroli i tokotrienoli, które jako substancje przeciwutleniające są coraz częściej wykorzystywane jako dodatki do żywności w celu przedłużenia jej trwałości, a dodatkowo wzbogacają produkt w witaminę E. W artkule przedstawiono ich struktu-rę chemiczną, sposoby pozyskiwania oraz regulacje prawne dopuszczające tokoferole i tokotrienole do wykorzystania w przetwórstwie żywności. Omówiono dotychczasowe sposo-by ich wykorzystania w produkcji żywności.

20

Effect of silymarin on thermooxidative degradation of PLA/PHB blends

Olejnik Olga, Masek Anna

Inżynieria Materiałowa

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2020

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Vol. 41, nr 3

7--11

EN

The effect of antioxidant of natural origin, i.e. silimarine on mechanical properties and thermooxidative degradation of biodegradable polylactide and polyhydroxybutyrate (PLA/PHB) blends obtained by melt mixing in a single-screw extruder (D = 25 mm, L/D = 24) was investigated. The addition of silymarin (0.7, 1.4 and 2.1 wt. %) improves the resistance to thermooxidative degradation of PLA/PHB blends, as evidenced by the value of the aging coefﬁ cient. Moreover, thanks to its unique properties, silymarin has a stabilizing effect and can be used as a pigment for polymers.

PL

Zbadano wpływ przeciwutleniacza pochodzenia naturalnego, tj. sylimaryny na właściwości mechaniczne oraz degradację termooksydacyjną biodegradowalnych mieszanin polilaktydu i polihydroksymaślanu (PLA/PHB). Mieszaniny otrzymano metodą mieszania w stanie stopionym przy użyciu wytłaczarki jednoślimakowej (D = 25 mm, L/D = 24). Dodatek (0,7; 1,4; 2,1% mas.) sylimariny poprawia odporność na degradację termooksydacyjną mieszanin PLA/PHB, o czym świadczy wartość współczynnika starzenia. Ponadto dzięki swoim wyjątkowym właściwościom sylimaryna ma działanie stabilizujące i może być stosowana jako barwnik do polimerów.