The possibilities for disposing activated sludge from wastewater-treatment plants

Pročišćavanjem otpadnih voda nastaje otpadni mulj koji zahtjeva dodatne procese obrade prije odlaganja ili ponovnog korištenja. Otpadni mulj treba zbrinuti na način da ne predstavlja opasnost za okoliš. Od svih komponenti uklonjenih tijekom pročišćavanja otpadnih voda, mulj čini najveći dio otpada. Obično je proizveden u polutekućem ili tekućem obliku te sadrži organske i anorganske tvari sirove otpadne vode i organski sadržaj. Danas postoje razni mehanički, biološki, termički te fizikalni procesi obrade mulja. Mogućnost ponovne upotrebe mulja ovisi u velikoj mjeri o njegovom fizikalnom i kemijskom sastavu, a sastav u značajnoj mjeri ovisi o tehnološkom procesu pročišćavanja vode i obrade mulja. Procesi obrade mulja, njegovog zbrinjavanja i ponovnog korištenja predstavljaju značajan inženjerski problem u području obrade otpadnih voda.Purification of wastewater results in sludge which requires additional processes before disposal or reuse. Sludge must be disposed of in a manner that poses no threat to the environment. Of the constituents removed by treatment, sludge is by far the largest in volume. It is usually produced in the form of a liquid or semisolid liquid and contains organic and inorganic substances. There are various mechanical, biological, thermal and physical processes that are used for sludge treatment. The possibility of reuse of sludge depends largely on its physical and chemical composition, and the composition is significantly dependent on the technological process of water and sludge treatment. Processing, reuse and disposal of sludge present significant problem facing the engineer in the field of wastewater treatment

Determination of hydroxyl radicals and antioxidant capacity using electron spin resonance after high voltage electrical discharge

Visokonaponsko pražnjenje pripada u tehnike netermalnog procesiranja hrane. U ovome radu korišten je hibridni reaktor s argonom kao radnim plinom. Tretman se provodio na destiliranoj vodi i soku od jabuke kod različitih frekvencija (60, 90 i 120 Hz) kroz različito vrijeme (3, 5 i 10 min). Elektronska spinska rezonancija korištena je u svrhu određivanja hidroksilnih radikala i antioksidacijskog kapaciteta. Tretman kod 120 Hz kroz 10 min rezultirao je nastankom najvećeg broja hidroksilnih radikala u uzorcima destilirane vode, dok kod uzoraka soka oni nisu zabilježeni. Primjenom blisko-infracrvene spektroskopije uočene su strukturne promjene i kod uzoraka vode i soka. Najveći porast antioksidacijskog kapaciteta soka od jabuke zabilježen je nakon tretmana na frekvenciji od 60 Hz kroz 10 min. Za uzorke soka provedena je analiza parametara boje po CIE L*a*b* sistemu boja te su najveće promjene boje određene nakon tretmana na frekvenciji od 120 Hz kroz 10 min.Highvoltage electrical discharge is non-thermal food processing technique. In this research, experiments were conducted in hybrid reactor with argon as working gas. Treated materials were distilled water and apple juice. Plasma processing parameters were frequency (60, 90 and 120 Hz) and treatment time (3, 5 and 10 min). Electron spin resonance was used to determine hydroxyl radicals and antioxidant capacity. 10 min treatment at 120 Hz resulted in the biggest number of formed hydroxyl radicals in distilled water samples, while they were not determined in apple juice samples. Changes in structural composition were determined both in water and juice samples using near-infrared spectroscopy. The highest increase in antioxidant capacity of apple juice was observed after 10 min treatment at 60 Hz. Analysis of color parameters for apple juice was performed using CIE L*a*b* color system. The biggest change in values of color parameters were observed after 10 min treatment at 120 Hz

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

Impact of heat-assisted HVED plasma treatment on quality of apple juice

High voltage electrical discharge (HVED) plasma processing receives more and more attention due to its potential to assure microbial safety and retain quality of treated products. The influence of combined thermal and high voltage electrical discharge plasma treatment on apple juice quality was investigated. Apple juice samples were treated under defined plasma treatment parameters of time (3, 6 and 9 min), frequency (60, 90 and 120 Hz) and temperature (30, 40 and 50 oC) in hybrid plasma reactor. Prior to treatment, juice samples were inoculated with Saccharomyces cerevisiae ATCC 204508 to investigate inactivation possibilities of plasma treatment on yeasts as common juice microorganisms. Quality parameters (pH, electrical conductivity, phenolic content and antioxidant activity) of treated and untreated apple juice were investigated and compared. Results have shown effectiveness of HVED plasma treatment in yeast inactivation up to 6.6 log10 in 9 min of treatment at 120 Hz and temperature of 40 oC. In treated samples there were no significant changes in phenolic content

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

The possibilities for disposing activated sludge from wastewater-treatment plants

Pročišćavanjem otpadnih voda nastaje otpadni mulj koji zahtjeva dodatne procese obrade prije odlaganja ili ponovnog korištenja. Otpadni mulj treba zbrinuti na način da ne predstavlja opasnost za okoliš. Od svih komponenti uklonjenih tijekom pročišćavanja otpadnih voda, mulj čini najveći dio otpada. Obično je proizveden u polutekućem ili tekućem obliku te sadrži organske i anorganske tvari sirove otpadne vode i organski sadržaj. Danas postoje razni mehanički, biološki, termički te fizikalni procesi obrade mulja. Mogućnost ponovne upotrebe mulja ovisi u velikoj mjeri o njegovom fizikalnom i kemijskom sastavu, a sastav u značajnoj mjeri ovisi o tehnološkom procesu pročišćavanja vode i obrade mulja. Procesi obrade mulja, njegovog zbrinjavanja i ponovnog korištenja predstavljaju značajan inženjerski problem u području obrade otpadnih voda.Purification of wastewater results in sludge which requires additional processes before disposal or reuse. Sludge must be disposed of in a manner that poses no threat to the environment. Of the constituents removed by treatment, sludge is by far the largest in volume. It is usually produced in the form of a liquid or semisolid liquid and contains organic and inorganic substances. There are various mechanical, biological, thermal and physical processes that are used for sludge treatment. The possibility of reuse of sludge depends largely on its physical and chemical composition, and the composition is significantly dependent on the technological process of water and sludge treatment. Processing, reuse and disposal of sludge present significant problem facing the engineer in the field of wastewater treatment

Determination of hydroxyl radicals and antioxidant capacity using electron spin resonance after high voltage electrical discharge

Visokonaponsko pražnjenje pripada u tehnike netermalnog procesiranja hrane. U ovome radu korišten je hibridni reaktor s argonom kao radnim plinom. Tretman se provodio na destiliranoj vodi i soku od jabuke kod različitih frekvencija (60, 90 i 120 Hz) kroz različito vrijeme (3, 5 i 10 min). Elektronska spinska rezonancija korištena je u svrhu određivanja hidroksilnih radikala i antioksidacijskog kapaciteta. Tretman kod 120 Hz kroz 10 min rezultirao je nastankom najvećeg broja hidroksilnih radikala u uzorcima destilirane vode, dok kod uzoraka soka oni nisu zabilježeni. Primjenom blisko-infracrvene spektroskopije uočene su strukturne promjene i kod uzoraka vode i soka. Najveći porast antioksidacijskog kapaciteta soka od jabuke zabilježen je nakon tretmana na frekvenciji od 60 Hz kroz 10 min. Za uzorke soka provedena je analiza parametara boje po CIE L*a*b* sistemu boja te su najveće promjene boje određene nakon tretmana na frekvenciji od 120 Hz kroz 10 min.Highvoltage electrical discharge is non-thermal food processing technique. In this research, experiments were conducted in hybrid reactor with argon as working gas. Treated materials were distilled water and apple juice. Plasma processing parameters were frequency (60, 90 and 120 Hz) and treatment time (3, 5 and 10 min). Electron spin resonance was used to determine hydroxyl radicals and antioxidant capacity. 10 min treatment at 120 Hz resulted in the biggest number of formed hydroxyl radicals in distilled water samples, while they were not determined in apple juice samples. Changes in structural composition were determined both in water and juice samples using near-infrared spectroscopy. The highest increase in antioxidant capacity of apple juice was observed after 10 min treatment at 60 Hz. Analysis of color parameters for apple juice was performed using CIE L*a*b* color system. The biggest change in values of color parameters were observed after 10 min treatment at 120 Hz

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