40 research outputs found

    Antioxidant and Antibacterial Activity of the Beverage Obtained by Fermentation of Sweetened Lemon Balm (Melissa offi cinalis L.) Tea with Symbiotic Consortium of Bacteria and Yeasts

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    Kombucha je napitak koji se tradicionalno dobiva fermentacijom zaslađenog crnog ili zelenog čaja (Camellia sinensis L.) s pomoću simbiotičke kulture bakterija i kvasaca (engl. SCOBY). U ovom je radu za pripremu napitka kombucha kao izvor duÅ”ika pri fermentaciji upotrijebljena melisa (Melissa officinalis L.). Tijekom sedmodnevne fermentacije mjereni su sljedeći parametri: pH-vrijednost, titracijska kiselost, udjeli ukupnih fenola i fenolnih spojeva, te sposobnost uklanjanja hidroksilnog (Ė™OH) i 1,1-difenil-2-pikrilhidrazilnog (DPPH) radikala da bi se utvrdila povezanost trajanja fermentacije s antioksidativnom i antibakterijskom aktivnoŔću fermentiranog napitka od melise. Određena je optimalna titracijska kiselost od 4 do 4,5 g/L, koju su potvrdili dugogodiÅ”nji konzumenti tog napitka. Ispitan je antibakterijski učinak napitaka povećane kiselosti od 8,12 g/L na jedanaest divljih bakterijskih sojeva. Rezultati pokazuju da se u proizvodnji fermentiranog napitka kombucha čaj (C. sinensis) može uspjeÅ”no zamijeniti melisom. Udjel ukupnih fenola i sposobnost uklanjanja DPPH radikala bili su veći u podlozi s melisom nego u tradicionalnom napitku kombucha. Za bioloÅ”ku je aktivnost napitka kombucha s melisom najvjerojatnije zaslužna ružmarinska kiselina, glavni fenolni spoj u napitku. Vrijednosti EC50 pokazuju da napitak kombucha ima veću antioksidativnu vrijednost od čajnih infuzija C. sinensis L. i M. officinalis L., čemu vjerojatno pridonose metaboliti simbiotičke kulture bakterija i kvasaca. Kombucha s melisom optimalne i povećane titracijske kiselosti imala je izraženi antibakterijski učinak, ponajprije zbog prisustva octene kiseline, ali i zbog drugih sastojaka čaja te prisustva metabolita simbiotičke kulture.Kombucha is a fermented tea beverage which is traditionally prepared by fermenting sweetened black or green tea (Camellia sinensis L.) with symbiotic consortium of bacteria and yeasts (SCOBY). In this study, lemon balm (Melissa offi cinalis L.) was used as the only nitrogen source for kombucha fermentation. During the seven-day fermentation process, pH value, titratable acidity (TA), total phenolic content, phenolic compounds, and antioxidant activity against hydroxyl (Ė™OH) and 1,1-diphenyl-2-picrylhydrazil (DPPH) radicals were measured to detect the connection between the fermentation time and antioxidant and antibacterial activities of lemon balm kombucha. Antibacterial activity of fi nished beverages with optimum acidity (TA=4ā€“4.5 g/L), the value which is confi rmed by long-time kombucha consumers, and enhanced acidity (TA=8.12 g/L) was tested against eleven wild bacterial strains. The results showed that lemon balm could be successfully used as an alternative to C. sinensis L. for kombucha fermentation. Total phenolic content and antioxidant activity against DPPH radicals of lemon balm fermentation broth were higher than those of traditional kombucha. Rosmarinic acid is the main phenolic compound of the lemon balm-based kombucha that probably provides biological activity of the beverage. Judging from the EC50 values, kombucha beverages exhibited higher antioxidant activities compared with C. sinensis L. and M. offi cinalis L. infusions, which can probably be ascribed to SCOBY metabolites. Lemon balm kombucha with both optimum and enhanced acidity showed antibacterial activity, which can be primarily ascribed to acetic acid, but also to some other tea components and SCOBY metabolites

    Influence of different combinations of wall materials on the encapsulation of butternut squash waste extract

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    The aim of this study was to evaluate the effect of different amounts of carrier agents (maltodextrin, inulin and pea protein) on the content of phenolics and carotenoids from butternut squash waste extract in encapsulates obtained by freeze-drying technique. Using Simplex-Centroid experimental design and response surface methodology (RSM), the highest content of both phenolics and carotenoids in the encapsulate was determined for a wall blend ratio 53.9 % pea protein, 46.1 % maltodextrin and 0% inulin

    Encapsulation and Degradation Kinetics of Bioactive Compounds from Sweet Potato Peel During Storage

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    Pozadina istraživanja. Svrha je ovog istraživanja bila procijeniti mogućnost koriÅ”tenja ljuske slatkog krumpira kao izvora bioaktivnih spojeva. Ispitan je utjecaj otapala (acetona i smjese acetona i etanola) na učinkovitost ekstrakcije ukupnih karotenoida i polifenola iz gomolja, mesa i ljuske slatkog krumpira. Ekstrakt ljuske slatkog krumpira isticao se dobrom antioksidativnom aktivnoŔću, pa je odabran za inkapsulaciju pomoću suÅ”enja rasprÅ”ivanjem i liofilizacije. Eksperimentalni pristup. Inkapsulacija je učinkovita metoda poboljÅ”avanja stabilnosti fitokemikalija zadržavanjem aktivne komponente unutar nosača. U ovom su radu tehnike suÅ”enja rasprÅ”ivanjem i liofilizacijom upotrijebljene za poboljÅ”anje stabilnosti bioaktivnih spojeva (karotenoida i polifenola), uz koriÅ”tenje proteina sirutke kao nosača. Glavne prednosti primjenjenih metoda u odnosu na ostale tehnike inkapsulacije su jednostavnost, kontinuitet, efikasnost, dostupnost i primjenjivost. Rezultati i zaključci. Na osnovi rezultata fizičko-kemijske karakterizacije može se zaključiti da su tehnikom suÅ”enja rasprÅ”ivanjem dobivene čestice inkapsulata manjih dimenzija, s boljim svojstvima protočnosti i boljom učinkovitosti inkapsulacije karotenoida. Retencija inkapsuliranih i neinkapsuliranih bioaktivnih spojeva praćena je tijekom skladiÅ”tenja na dnevnoj svjetlosti i u mraku. Uvjeti skladiÅ”tenja utjecali su na retenciju karotenoida, dok je veća brzina degradacije karotenoida zamijećena u svim uzorcima skladiÅ”tenim na dnevnoj svjetlosti. Fenolni spojevi imali su veću retenciju u svim ispitanim uzorcima. Kinetički parametri degradacije sugeriraju da je dulji rok trajanja inkapsuliranog ekstrakta postignut suÅ”enjem rasprÅ”ivanjem, te da je ta metoda dobra za stabilizaciju ispitanih bioaktivnih spojeva. Novina i znanstveni doprinos: Ovo istraživanje pokazuje da suÅ”enje rasprÅ”ivanjem i upotreba ljuske slatkog krumpira imaju velik potencijal za razvoj funkcionalnih dodataka hrani s poboljÅ”anim hranjivim i bioakivnim svojstvima, te ljepÅ”om bojom proizvoda.Research background. The aim of this work is to evaluate utilization of sweet potato peel as a source of bioactive compounds. The effect of solvents (acetone and acetone/ethanol mixture) on the extraction efficiency of total carotenoids and phenolics from sweet potato tuber, flesh and peel, and antioxidant activity were investigated. Sweet potato peel extract stood out in terms of antioxidant activity and was chosen for encapsulation by spray and freeze-drying. Experimental approach. Encapsulation is an effective method to improve phytochemical stability by entrapping the core material with a coating agent. In this study, spray and freeze-drying techniques were applied for improving the stability of bioactive compounds (carotenoids and phenolics) using whey protein as a coating material. The main advantages of the applied techniques over the other encapsulation techniques are simplicity, continuity, effectiveness, availability and applicability. Results and conclusions. Physicochemical characteristics revealed that spray drying resulted in the formation of lower size particles, better flow properties and encapsulation efficiency of carotenoids. The retention of encapsulated and non-encapsulated bioactive compounds was monitored during storage in daylight and dark conditions. Storage conditions affected the carotenoid retention, whereas higher degradation rate of all samples was observable in daylight. Phenolic compounds exhibited higher retention in all investigated samples. Degradation kinetic parameters suggest the longer shelf life of spray dried encapsulated extract and potent method for stabilization of bioactive ingredients. Novelty and scientific contribution. This study demonstrates that the spray drying technique and utilization of sweet potato peel have a big potential for the development of functional additives with improved nutritional, colour and bioactive properties

    THE PHYSICAL PROPERTIES, POLYPHENOL CONTENT AND SENSORY CHARACTERISTICS OF WHITE CHOCOLATE ENRICHED WITH BLACK TEA EXTRACT

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    Chocolate contains a variety of different compounds such as fats, carbohydrates, proteins, vitamins, and minerals. Fat-free cocoa particles are also extremely rich in polyphenols. While dark chocolate is a most powerful source of antioxidants, the content of these components decreases with the reduction in the content of dark cocoa particles in chocolate. White chocolate differs from milk and dark through the absence of fat-free cocoa particles containing antioxidants. Today\u27s investigations are focused on finding new methods of creating functional confectionery products. Accordingly, in this study white chocolate was enriched with100 g kg-1 of encapsulated black tea extract in order to increase its polyphenol content. The addition of encapsulated black tea extract to white chocolate increased the viscosity of enriched chocolate mass to the extent that is acceptable for the production of this kind of product. Total polyphenol content in enriched chocolate was increased over 6 times compared to white chocolate. However, black tea encapsulate contributed to foreign taste of medications in enriched chocolate, making it unacceptable by consumers

    Helichrysum italicum (Roth) G. Don Essential Oil from Serbia: Chemical Composition, Classification and Biological Activityā€”May It Be a Suitable New Crop for Serbia

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    H. italicum essential oil (EO) is one of the most popular ingredients utilized by the cosmetic industry, and it is also used as natural antioxidant and as a value-added ingredient in food products. The chemical composition of the EO H. italicum cultivated in Serbia was analyzed by gas chromatographyā€“mass spectrometry. The quantitative structureā€“retention relationship was used to predict the retention indices of the EO constituents acquired by GC-MS data, applying five molecular descriptors selected by factor analysis and a genetic algorithm. Also, antimicrobial activity, and biological activity by four common antioxidant tests (DPPH and ABTS assays, reducing power, and beta -carotene bleaching test), and in vitro antihyperglycemic and anti-inflammatory capacities were evaluated. A total of 70 EO constituents were detected, of which 17 (8.5%) could not be identified. The H. italicum EO in this study belonged to gamma-curcumene chemotype. The coefficients of determination reached the value of 0.964, demonstrating that this model could be used for prediction purposes. All applied tests showed that H. italicum EO possesses good biological activity and an interesting chemical composition. Therefore, the EO of H. italicum grown in Serbia has a potential to be used in food, cosmetic, and pharmaceutical products

    With food to health : proceedings of the 10th International scientific and professional conference

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    Proceedings contains 13 original scientific papers, 10 professional papers and 2 review papers which were presented at "10th International Scientific and Professional Conference WITH FOOD TO HEALTH", organised in following sections: Nutrition, Dietetics and diet therapy, Functional food and food supplemnents, Food safety, Food analysis, Production of safe food and food with added nutritional value

    Kinetics of Carotenoids Degradation during the Storage of Encapsulated Carrot Waste Extracts

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    The encapsulates of carrot waste oil extract improved the antioxidant properties of durum wheat pasta. The aim of this research was to study the kinetics of carotenoids degradation in the freeze-dried (FDE) and spray-dried (SDE) encapsulates of carrot waste extract during storage at four different temperatures (+4, +21.3, +30, +37 Ā°C) up to 413 days by HPLC. Carotenoids levels decreased as a function of time and temperature, following zero-order kinetics. At 4 Ā°C carotenes were stable for at least 413 days, but their half-lives decreased with increasing temperatures: 8ā€“12 months at 21 Ā°C; 3ā€“4 months at 30 Ā°C; and 1.5ā€“2 months at 37 Ā°C. The freeze-drying technique was more effective against carotenes degradation. An initial lag-time with no or very limited carotenes degradation was observed: from one week at 37 Ā°C up to 3 months (SDE) or more (FDE) at 21 Ā°C. The activation energies (Ea) varied between 66.6 and 79.5 kJ/mol, and Ea values tended to be higher in FDE than in SDE

    Antioxidant and Sensorial Properties of Polyfloral Honey with Dried Apricots after One Year of Storage

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    Total phenol (TPh) and flavonoid (TFd) contents, antioxidant and sensorial properties of polyfloral (PH), and polyfloral honey after one year of storage (PHs) with dried apricots (20, 30, and 40%) were evaluated. In comparison to honey, TPh increased 1.86 times for PH40. After storage time, TPh of PH40s increased slightly lower (1.77 times), compared to PHs. TFd slightly increased, approximately 3.23-fold, from PH to PH40, while PHs showed increase of 5.15-fold for PH40s. Antioxidant activity increased with increasing concentration of apricots in honey. EC 50 OH varied from 3.36 for PH to 2.29 mg/mL for PH40 and from 3.48 for PHs to 2.68 mg/mL for PH40s; EC 50 DPPH ranged from 30.60 for PH to 14.95 mg/mL for PH40 and from 31.22 for PHs to 17.43 mg/mL for PH40s; RP 0.5 ranged from 66.37 for PH to 31.83 mg/mL for PH40 and from 67.99 for PHs to 35.03 mg/mL for PH40s. Statistical analysis suggested that TPh and TFd were associated with antioxidant activity and colour. Sensory parameters, before and after storage, indicated very good sensory qualities. Phenolic composition, antioxidant capacity, and sensory properties were promoted after addition of dried apricots and these parameters stayed improved, since antioxidant compounds present in dried apricots aided in maintenance of honey properties along one year of storage

    Characterization of Caneberry Juices Enriched by Natural Antioxidants

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    Caneberries (raspberries and blackberries) are among the most popular berries in the world, which are consumed as fresh and processed to juice, jams, confitures and other products or as ingredients for different foods. These fruits are known as a rich source of phenolic compounds such as phenolic acids and anthocyanins. Antioxidant activity (AA) of caneberry juices was improved by addition of phenolic compounds which were extracted from two raspberry cultivars (Rubus idaeus, cv. 'Willamette' (RW) and 'Meeker' (RM)) and two blackberry cultivars (Rubus fruticosus, cv. 'Čačanka' (BC) and 'Thornfree' (BT)) pomace, a by-product in juice processing. The total phenolic contents in raspberry and blackberry pomace extracts were determined spectrophotometrically using the Folin-Ciocalteu reagens. The phenolic concentrations in caneberries (RW, RM, BC and BT) pomace extracts were 43.67 Ā± 2.13 mg GAE/g, 26.25 Ā± 1.18 mg GAE/g, 46.01 Ā± 3.26 mg GAE/g and 61.59 Ā± 1.14 mg GAE/g, respectively. In order to obtain enriched juices, phenolic compounds were applied at concentration of 0.05 mg GAE/ 100 ml. Antioxidant activities of caneberry juices and caneberry enriched juices were measured using stable 1.1-diphenyl-2-picrylhydrazyl (DPPH) radicals. AADPPH of RW, RM, BC and BT juices and enriched juices with addition of 0.01 Āµg GAE/ml, changed from 37.12% to 93.01%, 23.26% to 91.57%, 53.61% to 95.65% and 52.06% to 93.13%, respectively, while IC50 values of RW, RM, BC and BT juices and enriched juices were diminished 6.33, 19.00, 6.33 and 4.75 times, respectively. Based on the obtained results it can be concluded that phenolic enriched juices were significantly more effective on DPPH radicals. Caneberry juices enriched with waste material are a good source of natural pigments and antioxidants and could be used as functional foods

    Green techniques for preparation of red beetroot extracts with enhanced biological potential

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    Red beetroot is well known for its high proportion of betalains, with great potential as functional food ingredients due to their health-promoting properties. The objective of this study was to investigate the influence of processing techniques such as Soxhlet, cold, ultrasound and supercritical fluid extraction on the betalains content and its antioxidant, anti-inflammatory and antihyperglycemic activities. Whilst Soxhlet extraction with water has provided the highest yield, the highest content of total phenolics was found in an extract prepared using Soxhlet extraction with 50% ethanol. Amongst eight phenolic compounds detected in the extracts, protocatechuic acid was the most abundant. The concentrations of total phenolics ranged from 12.09 mg/g (ultrasound extraction with 30% methanol) to 18.60 mg/g (Soxhlet extraction with 50% ethanol). The highest anti-inflammatory activity was observed for cold extraction with 50% methanol extract. The high radical scavenging activity of supercritical fluid extracts could be a consequence of nonphenolic compounds. The chemometrics approach was further used to analyse the results to find the ā€œgreenestā€ method for further possible application in the processing of beetroot in the food and/or pharmaceutical industry. According to the standard score, the best extraction method was determined to be Soxhlet extraction with 50% ethanol
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