Application of cold plasma treatment on inactivation of microorganism E.coli in pure culture

Cilj ovog rada bio je istražiti utjecaj hladne plazme na stupanj redukcije, oksidacijski stres stanica E. coli i fiziološke čimbenike (pH, temperaturu, konduktivnost i slobodnih radikale) tretiranih uzoraka. Uzorci su tretirani hladnom plazmom pri frekvencijama od 60, 90 i 120 Hz u trajanju od 5 i 10 min. Tehnologija hladne plazme pokazala se efikasnom za postizanje potpune redukcije broja mikroorganizama. Dužim tretmanom i povećanjem frekvencije, došlo je do smanjenja pH vrijednosti i povećanja temperature i konduktivnosti otopine. Također, utvrđen je povišeni oksidacijski stres u bakterijskim stanicama. Osim redukcije, nakon tretmana postignuto je istjecanje staničnih makromolekula kao posljedica elektroporacije stanica. Bakterijske stanice su se rekuperirale nakon 18 h pri temperaturi inkubacije od 30˚C.The aim of this study was to investigate the influence of cold plasma treatmenton degree of reduction, oxidative stress of cells E. coli and physiological factors (pH, temperature, conductivity, free radicals ) in treated samples. The samples were treated with cold plasma at frequencies of 60, 90 and 120 Hz during 5 and 10 minutes. Cold plasma technology was proved as the effective method for complete reduction of microoganisms. Longer treatment time with higher frequency showed decrease of ph value, increase of temperature and solution conductivity. Also, increased oxsidative stress was found in bacterial cells. Except reduction, leakage of celluar macromolecules was achieved after treatment as a result of electroporation of cells.Cells were recovered after 18 h of incubation at 30 ˚C

Impact of cryomilling on phenolic compounds of rapeseed cake

Cilj ovog rada bio je odrediti utjecaj vremena i tipa mljevenja (uz/bez kriohlađenja) na sastav i koncentraciju fenolnih spojeva u pogači uljane repice. Nakon proizvodnje ulja, dobivena pogača usitnjena je na kriomlinu bez i s hlađenjem pomoću tekućeg dušika kroz 2, 4, 8 i 12 minuta. U samljevenim pogačama određeni su slobodni i vezani polifenolni spojevi te tanini pomoću kromatografskih i spektrofotometrijskih metoda, nakon čega im je određena antioksidacijska aktivnost. Rezultati su pokazali da način mljevenja ima značajan utjecaj na koncentraciju polifenolnih spojeva. Mljevenjem uz hlađenje koncentracija slobodnih polifenola se smanjila, a koncentracija vezanih povećala. Nasuprot tome, koncentracija tanina nije ovisila o načinu mljevenja već o duljini mljevenja. HPLC metodom detektiran je sinapin kao dominantni polifenolni spoj pogače uljane repice u udjelu većem od 70 %. Rezultati antioksidacijske aktivnosti znatno su oscilirali te nije utvrđen značajan utjecaj tretmana ni duljine mljevenja na koncentraciju polifenola.The aim of this study was to determine the impact of time and milling type (with/without cryocooling) on composition and concentration of rapeseed cake phenolics. After the oil production, expeller extracted rapeseed cake was grounded on cryomill with or without liquid nitrogen cooling for 2, 4, 8 and 12 minutes. Free and bound phenolic compounds, as well as tannins, were determined in milled cake samples using chromatographic and spectrophotometric methods. In addition, antioxidant activity of produced cakes was also investigated. Results showed significant impact of milling type on phenolic concentration. Cryocooling decreased concentration of free phenolic compounds, increasing the bound phenolics at the same time. However, milling type had no significant impact on the tannin concentration unlike milling time that increased tannin concentration during longer process. Sinapin, the dominant phenol derivate in rapeseed cake, was detected using HPLC contributing to more than 70 % of phenolic content. Results of antioxidant activities oscillated significantly, having no statistical impact of the time and type of milling on the polyphenols

Application of cold plasma treatment on inactivation of microorganism E.coli in pure culture

Cilj ovog rada bio je istražiti utjecaj hladne plazme na stupanj redukcije, oksidacijski stres stanica E. coli i fiziološke čimbenike (pH, temperaturu, konduktivnost i slobodnih radikale) tretiranih uzoraka. Uzorci su tretirani hladnom plazmom pri frekvencijama od 60, 90 i 120 Hz u trajanju od 5 i 10 min. Tehnologija hladne plazme pokazala se efikasnom za postizanje potpune redukcije broja mikroorganizama. Dužim tretmanom i povećanjem frekvencije, došlo je do smanjenja pH vrijednosti i povećanja temperature i konduktivnosti otopine. Također, utvrđen je povišeni oksidacijski stres u bakterijskim stanicama. Osim redukcije, nakon tretmana postignuto je istjecanje staničnih makromolekula kao posljedica elektroporacije stanica. Bakterijske stanice su se rekuperirale nakon 18 h pri temperaturi inkubacije od 30˚C.The aim of this study was to investigate the influence of cold plasma treatmenton degree of reduction, oxidative stress of cells E. coli and physiological factors (pH, temperature, conductivity, free radicals ) in treated samples. The samples were treated with cold plasma at frequencies of 60, 90 and 120 Hz during 5 and 10 minutes. Cold plasma technology was proved as the effective method for complete reduction of microoganisms. Longer treatment time with higher frequency showed decrease of ph value, increase of temperature and solution conductivity. Also, increased oxsidative stress was found in bacterial cells. Except reduction, leakage of celluar macromolecules was achieved after treatment as a result of electroporation of cells.Cells were recovered after 18 h of incubation at 30 ˚C

Onion Solid Waste as a Potential Source of Functional Food Ingredients

Onion (Allium cepa L.) is one of the most basic and most consumed vegetables in human diet with a long tradition of use in food and medicine. It is grown and traded worldwide for culinary purpose because of its distinctive aroma and high nutritive value. Nowadays, onion production is increasing as well as the demand for processed onion, leading to the generation of a substantial amount of industrial waste. The waste biomass is mainly composed of outer scales, skin, roots, tops of the bulbs, and deteriorated bulbs. The use of onion waste as a potential source of functional food ingredients is one way of its valorization, highly in line with the current trends in the food industry to improve by waste reuse while responding to the increasing demand for functional food. Onion waste components exhibiting functional potential are: (i) flavonols – quercetin and quercetin glucosides, known for antioxidant activity; (ii) fructooligosaccharides, well-established prebiotics; (iii) cell-wall polysaccharides, as a part of dietary fibre, or specifically pectin as a known food additive and/or a potential source of prebiotic oligomers; and (iv) organosulfuric compounds. The use of onion waste in food production is still in the research stage, but shows promising results in the incorporation of powdered onion waste concentrates and extracts into various food matrices to obtain innovative products with improved antioxidant and prebiotic quality

Onion Solid Waste as a Potential Source of Functional Food Ingredients

Onion (Allium cepa L.) is one of the most basic and most consumed vegetables in human diet with a long tradition of use in food and medicine. It is grown and traded worldwide for culinary purpose because of its distinctive aroma and high nutritive value. Nowadays, onion production is increasing as well as the demand for processed onion, leading to the generation of a substantial amount of industrial waste. The waste biomass is mainly composed of outer scales, skin, roots, tops of the bulbs, and deteriorated bulbs. The use of onion waste as a potential source of functional food ingredients is one way of its valorization, highly in line with the current trends in the food industry to improve by waste reuse while responding to the increasing demand for functional food. Onion waste components exhibiting functional potential are: (i) flavonols – quercetin and quercetin glucosides, known for antioxidant activity; (ii) fructooligosaccharides, well-established prebiotics; (iii) cell-wall polysaccharides, as a part of dietary fibre, or specifically pectin as a known food additive and/or a potential source of prebiotic oligomers; and (iv) organosulfuric compounds. The use of onion waste in food production is still in the research stage, but shows promising results in the incorporation of powdered onion waste concentrates and extracts into various food matrices to obtain innovative products with improved antioxidant and prebiotic quality

An insight into the chemical composition of ground ivy (Glechoma hederacea L.) by means of macrocomponent analysis and fractionation of phenolic compounds

Ground ivy (Glechoma hederacea L.) has been used for generations in folk medicine to treat various diseases. Up until today, the information about its chemical and bioactive composition is still rather incomplete. The aim of this study was to evaluate macro- and microcomposition of ground ivy including the polyphenolic profile. In the present study, different phenolic fractions (free soluble, esterified, glycosylated and insoluble-bound phenolic fractions) of ground ivy were prepared and analysed using spectrophotometric methods (total phenolic content and antioxidant capacity) and HPLC-PAD methodology. Regarding the macrocomposition, the results revealed that most of the ground ivy dry matter was composed of insoluble dietary fibre (48.96% dmb) followed by proteins (17.92% dmb). Minerals also markedly contributed to the dry matter (12.74% dmb) with potassium as the main macroelement (48.49 mg/g dmb). Dominant phenolic compounds in ground ivy extract were: rosmarinic (6.64 mg/g dmb) and chlorogenic acid (1.11 mg/g dmb), and flavonol rutin (1.87 mg/g dmb). Fractionation of phenolic compounds from ground ivy confirmed that dominant esters were indeed those of caffeic acid, while glycosides those of quercetin, which corresponded to the majority of identified compounds in the initial extract. Insoluble-bound phenolics were not represented in notable content. This study provided additional reference for macro- and microcomponent and phenolic composition of rather underutilized but valuable medicinal plant – ground ivy, to be used in further research of its health properties

RUBY CHOCOLATE – BIOACTIVE POTENTIAL AND SENSORY QUALITY CHARACTERISTICS COMPARED WITH DARK, MILK AND WHITE CHOCOLATE

Belgian-Swiss cocoa company Barry Callebaut has recently revealed the fourth type of chocolate - Ruby chocolate characterized by the fresh berry taste and reddish color. Since there is no published data about its bioactive content, the aim of this study was to compare Ruby chocolate with different, well-known types of chocolates (dark, milk, semisweet and white) according to bioactive content and sensory attributes. Dark chocolate exhibited the highest total phenolic content and antioxidant capacity followed by semisweet chocolate, while Ruby chocolate, regarding total phenolic content, was ranged between milk and white chocolate, but exhibited higher antioxidant capacity than milk chocolate, probably due to the higher content of flavan-3-ols and proanthocyanidins. Semisweet and dark chocolate obtained the highest score in chocolate distinctive odour, while for the same attribute, Ruby chocolate was estimated as least preferable chocolate. White chocolate with strawberry was used because of similar sensory characteristics as Ruby chocolate, regarding taste and fruity odour, and was rated with a higher score compared to Ruby. The highest intensity of acidity was determined in Ruby chocolate, which is its main characteristic. All estimated sensory attributes were scored the best for the semisweet chocolate, while Ruby chocolate was least acceptable chocolate

Impact of cryomilling on phenolic compounds of rapeseed cake

Cilj ovog rada bio je odrediti utjecaj vremena i tipa mljevenja (uz/bez kriohlađenja) na sastav i koncentraciju fenolnih spojeva u pogači uljane repice. Nakon proizvodnje ulja, dobivena pogača usitnjena je na kriomlinu bez i s hlađenjem pomoću tekućeg dušika kroz 2, 4, 8 i 12 minuta. U samljevenim pogačama određeni su slobodni i vezani polifenolni spojevi te tanini pomoću kromatografskih i spektrofotometrijskih metoda, nakon čega im je određena antioksidacijska aktivnost. Rezultati su pokazali da način mljevenja ima značajan utjecaj na koncentraciju polifenolnih spojeva. Mljevenjem uz hlađenje koncentracija slobodnih polifenola se smanjila, a koncentracija vezanih povećala. Nasuprot tome, koncentracija tanina nije ovisila o načinu mljevenja već o duljini mljevenja. HPLC metodom detektiran je sinapin kao dominantni polifenolni spoj pogače uljane repice u udjelu većem od 70 %. Rezultati antioksidacijske aktivnosti znatno su oscilirali te nije utvrđen značajan utjecaj tretmana ni duljine mljevenja na koncentraciju polifenola.The aim of this study was to determine the impact of time and milling type (with/without cryocooling) on composition and concentration of rapeseed cake phenolics. After the oil production, expeller extracted rapeseed cake was grounded on cryomill with or without liquid nitrogen cooling for 2, 4, 8 and 12 minutes. Free and bound phenolic compounds, as well as tannins, were determined in milled cake samples using chromatographic and spectrophotometric methods. In addition, antioxidant activity of produced cakes was also investigated. Results showed significant impact of milling type on phenolic concentration. Cryocooling decreased concentration of free phenolic compounds, increasing the bound phenolics at the same time. However, milling type had no significant impact on the tannin concentration unlike milling time that increased tannin concentration during longer process. Sinapin, the dominant phenol derivate in rapeseed cake, was detected using HPLC contributing to more than 70 % of phenolic content. Results of antioxidant activities oscillated significantly, having no statistical impact of the time and type of milling on the polyphenols

The assesement of bioactive potential and sensory acceptability of coffee and its byproducts- cascara and silverskin

Through the decades, coffee has been representing one of the most consumed beverages worldwide and consequently, during the coffee cherry processing, significant amount of coffee byproducts is generating, thus ending as an agro- industrial waste. Besides macro and micronutrient content, coffee cascara and coffee silverskin are coffee by-products which can have valuable bioactive potential. For that purpose, ethanol extracts and water infusions (beverages) of green coffee, roasted coffee, coffee cascara and coffee silverskin were analysed for total phenolic content, antioxidant capacity and individual identification of polyphenolic compounds by High Performance Liquid Chromatography Analysis paired with Photo-Diode Array detector (HPLC- PDA), with further sensory analysis of beverages. Results showed that beverages were generally evaluated with the higher bioactive potential than ethanol extracts, while roasted coffee beverages exhibited the highest content of TPC and antioxidant capacity in comparison to the ethanol extract. Among all samples, green coffee beverage was evaluated as the most valuable source of 5-caffeoylquinic acid (36.7 mg/g dw), while coffee cascara (9.2 mg/g dw) contained the highest content of caffeine. Although roasted beverage expectedly scored as the highest acceptable (6.2), silverskin and cascara were evaluated with relatively satisfactory results of the overall acceptability (4.6- 5.2), thus showing the potential for the improvement in terms of preparation and, furthermore, greater consumer acceptance

Development and characterization of dopamine-loaded liposomes extracted from banana peel

Banana (Musaceae) is the second most consumed fruit in the world, after tomato. Approximately 30 % of banana fruit is comprised of peel, resulting in a substantial amount of waste from banana processing. The peel is abundant in bioactive compounds, especially in dopamine. The aim of this study was to develop liposomes containing dopamine extracted from banana peel. Aqueous extract (80 °C, 30 min) of freeze-dried banana peel was characterized spectrophotometrically for total phenolic content (25.50 mg GAE/g dmb) and antioxidant capacity using DPPH and ABTS assays (0.156 and 0.160 mmol Trolox/g dmb), while dopamine content (9.94 mg/g dmb) was determined by HPLC-DAD. Formulated liposomes were characterized by encapsulation efficiency, as well as by size and surface charge evaluated by light scattering and zeta potential, respectively. Antioxidant capacity of encapsulated extract was investigated in terms of inhibitory action on liposome peroxidation using TBARS assays. The encapsulation efficiency of dopamine into liposomes was 41.12 % and measured values of size, polydispersity index and zeta potential indicate relative homogeneity and uniformity of the formulated liposomes