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Dextransucrase (DS) is a glucosyltransferase (E. C. 2.4.1.5) that catalyzes the transfer of glucosyl residues from sucrose to dextran polymer and liberates fructose. This enzyme isassociated with a wide application range of dextran and oligosaccharides. DS production by Leuconostoc mesenteroidesT3 was optimized using a Central Composite Design under the Response Surface Methodology. Three variables were chosen for optimization: distillery stillage, sucrose and manganese concentration. The results showed that sucrose and manganese concentrations had a positive linear effect on DS production while all variable interactions (stillage-manganese, stillage-sucrose, and sucrose-manganese) had significant influences on the DS production. The maximal DS yield of 3.391?0.131 U cm-3, was obtained in the medium with 64.33 % distillery stillage concentration, 5.30% sucrose concentration and 0.022 % manganese concentration. Our study revealed the potential of distillery stillage combined with sugar beet molasses, supplemented with sucrose and manganese to be employed as a valuable medium growth for lactic acid bacteria and production of DS. Also, taking into consideration the origin of the substrates, utilization of industrial by-products in this way has a great environmental relevance and is in accordance with circular economy.

Water kefir is a beverage fermented by a microbial consortium captured in kefir grains. The kefir grains matrix is composed of polysaccharide, primarily dextran, which is produced by members of the microbial consortium. In this study, we have isolated lactic acid bacteria (LAB) from non-commercial water kefir grains (from Belgrade, Serbia) and screened for dextran production. Among twelve LAB isolates three produced slime colonies on modified MRS (mMRS) agar containing sucrose instead of glucose and were presumed to produce dextran. Three LAB were identified, based on morphological, physiological and biochemical characteristics and 16S rRNA sequencing, as Leuconostoc mesenteroides (strains T1 and T3) and Lactobacillus hilgardii (strain T5). The isolated strains were able to synthesize a substantial amount of dextran in mMRS broth containing 5% sucrose. Maximal yields (11.56, 18.00 and 18.46 g/l) were obtained after 16, 20 and 32 h for T1, T3 and T5, respectively. Optimal temperature for dextran production was 23oC for two Leuconostoc mesenteroides strains and 30 °C for Lactobacillus hilgardii strain. The produced dextrans were identified based on paper chromatography, while the main structure characteristics of purified dextran were observed by FT-IR spectroscopy. Our study shows that water kefir grains are a natural source of potent dextran producing LAB. Vodeni kefir je napitak koji nastaje fermentacionom aktivnošću bakterija mlečno-kiselinskog vrenja, kvasca i sirćetnih bakterija. Ova kompleksna smeša mikroorganizama smeštena je unutar polisaharidnog matriksa - kefirnog zrna. Glavnu šećernu komponentu matriksa čini dekstran koji sintetišu bakterije mlečno-kiselinskog vrenja. Dekstran je homo polisaharid velike molekulske mase čija je monomerna jedinica glukoza. Zahvaljujući dobroj rastvorljivosti i stabilnosti, dekstran ima široku primenu u različitim granama industrije, kao što su medicina, farmacija, prehrambena, tekstilna i hemijska industrija. Nerastvorni dekstran može da posluži kao nosač za imobilizaciju biomolekula. Imajući u vidu veliku primenjivost dekstrana, cilj ovog rada je bio izolovati bakterije mlečno-kiselinskog vrenja iz zrna vodenog kefira koje produkuju ovaj egzopolisaharid sa visokim prinosima. U radu je prikazana izolacija i karakterizacija tri selektovana soja i optimizacija uslova za produkciju dekstrana. Na osnovu morfoloških, fizioloških i biohemijskih osobina i 16S rRNK sekvenciranja utvrđeno je da su izolati T1 i T3 sojevi vrste Leuconostoc mesenteroides, dok je izolat T5 identifikovan kao Lactobacillus hilgardii. Za produkciju dekstrana korišćena je modifikovana MRS podloga sa 5% saharoze, kao jedinim izvorom ugljenika. Maksimalni prinosi dekstrana (11,56, 18,00 i 18,46 g/l) su dobijeni nakon 16, 20 i 32 h fermentacije, za T1, T3 i T5, redom. Optimalne temperature za produkciju dekstrana su 23 °C za dva Leuconostoc mesenteroides soja, a za Lactobacillus hilgardii 30 °C. Uzorci sintetisanih polisaharida su identifikovani kao dekstrani na osnovu papirne hromatografije, dok su glavne strukturne karakteristike prečišćenih dekstrana utvrđene na osnovu FTIR spektroskopije. .

The agricultural raw industry generates large amounts of annually by- -products that create disposal problems. Hitherto, there have been no reported papers about the simultaneous production of cellulase and β-amylase from these raw materials using Paenibacillus sp. that would reduce the costs. Thus, in this paper simultaneous cellulase (CMC-ase and avicelase) and β-amylase production using barley bran and the application of the natural isolate Paenibacillus chitinolyticus CKS1 and potential enzymes in the hydrolysis process was studied. Response surface methodology was used to obtain the maximum enzyme activity (CMC-ase 0.405 U mL-1, avicelase 0.433 U mL-1 and β-amylase 1.594U mL-1). Scanning electron microscopy showed degradation of the lignocellulosic–starch structure of barley bran after fermentation. The CKS1 bacterial supernatant, which contains cellulases and β-amylase, could hydrolyze cotton fibres and barley bran, respectively. The main products after enzymatic hydrolysis of cotton fibres and barley bran, glucose (0.117 g gmat -1) and maltose (0.347 g gmat -1), were quantified by high performance liquid chromatography (HPLC). The produced enzymes could be used for hydrolysis of cotton fabric and barley bran to glucose and maltose, respectively. Application of simultaneous enzymes production using an agricultural by-product is economically and environmentally accepted and moreover, valuable biotechnological products, such as glucose and maltose, were obtained in this investigation. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31035 and Grant no. III 45020]

The purpose of this study was to examine the antioxidant properties of 70% ethanolic extracts of cereal grains and their different morphological fractions. Wheat (Triticum durum L.), barley (Hordeum vulgare L.), rye (Secale cereale L.), and buckwheat (Fagopyrum esculentum) were used. The total phenolic content (TPC), determined by the Folin-Ciocalteu method and antioxidant activities (AOA) were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, ferric ion-reducing antioxidant power (FRAP) and thiobarbituric acid (TBA) methods. The following hierarchy of antioxidant activity was provided for 70% ethanolic extracts originated from whole grain: buckwheat gt barley gt wheat gt rye. In respect to hulls, the antioxidant hierarchy was the same. The outer layers of grains had higher amount of phenolic compounds and subsequently higher antioxidant activity. Buckwheat had the highest amount of total phenolics, with the highest DPPH radical scavenging activity and capacity for Fe3+ reduction, but it had the lowest lipid peroxidation inhibition ability. Cilj rada je bio da se ispita antioksidativna aktivnost etanolnog ekstrakta zrna cerealija i njihovih morfoloških frakcija. Ispitivani se : pšenica (Triticum durum L.), ječam (Hordeum vulgare L.), raž (Secale cereale L.) i heljda (Fagopyrum esculentum). Određivan je sadržaj ukupnih fenola (TPC) metodom po Folin-Ciocalteu i antioksidativna aktivnost (AOA) po tri najčešće korišćene metode: DPPH (sposobnost neutralizacije 2,2-difenil-1-pikrilhidrazil radikala), FRAP (antioksidativna sposobnost redukcije Fe III jona) i TBA ( metoda sa tiobarbiturnom kiselinom). Antioksidativna aktivnost etanolnog ekstrakta celog zrna opada u sledećem nizu: heljda gt ječam gt pšenica gt raž. Isti odnos je dobijen i za mekinje. Spoljni slojevi zrna imaju veći sadržaj polifenola, pa sledstveno tome i veću antioksidativnu aktivnost. Heljda sadrži najviše polifenola i ima najveću antioksidativnu aktivnost određenu DPPH i FRAP metodom, ali ima najmanju sposobnost inhibicije lipidne peroksidacije.

The importance of coffee waste utilization is based on the fact that it contains a large amount of biologically valuable components. Preparation of espresso coffee produces substantial quantities of polyphenolic acids that have a significant antioxidant activity. In this work, the contents of polyphenols and antioxidant activity of extracts obtained from spent espresso coffee were analyzed using different solvent systems. A 70% solution of methanol and a 70% solution of ethanol and distilled water were used as solvents. The total amounts of polyphenols were determined by the Folin-Ciocalteu method, while the antioxidant activities were determined by DPPH inhibition (2,2-diphenyl-1-picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Power). Both methods confirmed that the order of antioxidant activity of obtained dried extracts is as follows: water extract lt methanol extract lt ethanol extract, which was in accordance with their polyphenols content. Mild prooxidant activity was observed in the concentration of 200 μg/ml while investigating the DPPH inhibition. Prooxidant activity is a characteristic of some polypenolic acids that is considered to be one of the mechanisms of anticancer activity. The inhibition of DPPH radical, expressed by IC50 values, was compared with the results of the commercial antioxidants such are ascorbic acid and BHT (butylated hydroxytoluene). Comparing the IC50 values of ascorbic acid and BHT with the IC50 values of tested extracts it can be concluded that waste coffee extracts could be a good source of natural antioxidants. U radu je određivan sadržaj polifenola i antioksidativna aktivnost osušenih ekstrakata otpadne espreso kafe dobijenih primenom različitih rastvarača. Kao rastvarači, u ekstrakcijama su korišćeni 70% rastvor metanola, 70% rastvor etanola i destilovana voda. Određen je ukupan sadržaj polifenola i antioksidativna aktivnost metodama inhibicije DPPH (2,2-difenil-1-pikrilhidrazil) radikala i FRAP (engl. ferric reducing antioxidant power). Inhibicija DPPH radikala je izražena preko IC50 vrednosti, a rezultati su poređeni sa rezultatima komercijalnih antioksidanata, askorbinskom kiselinom i BHT (butil-hidroksi-toluen). Obe metode su potvrdile da je redosled antioksidativne aktivnosti dobijenih suvih ekstrakta sledeći: vodeni ekstrakt lt metanolni ekstrakt lt etanolni ekstrakt. Poređenjem sa vrednostima IC50 za askorbinsku kiselinu i BHT može se zaključiti da ekstrakti otpadne kafe mogu biti dobar izvor prirodnih antioksidanata.

Cellulases are industrially important enzymes with a potential to convert cellulose into fermentable sugars. Novel bacterial isolate Paenibacillus sp. CKS1 was tested for cellulase activity and the optimal conditions for carboxymethyl cellulase (CMCase) production were determined. Maximum CMCase activity was obtained in the third passage of the bacterial culture after 3 days of incubation at 30°C. Cellobiose and yeast extract was the optimal source of carbon and nitrogen for induction of CMCase activity. In addition, with initial pH 7 of the medium and 40 ml of working volume in 500 ml culture flasks with shaking at 150 rpm, the maximum CMCase activity in a crude culture supernatant reached value of 0.532±0.006 U/ml. For crude CMCase, optimal temperature was 50°C and optimal pH 4.8, respectively. HPLC analysis confirmed the bacterium is capable to hydrolise CMC to glucose and other soluble sugars. [Projekat Ministarstva nauke Republike Srbije, br. TR 31035]

Abundant knowledge of the significance of food quality for all human living functions as well as growing human population and the occurrence of world "hidden hunger", directed food producers toward new production processes of and new product development that must satisfy the specific needs of different categories of consumers. The differences are reflected in sex age, religious affiliation, activity, health, social status etc. "Organic", "natural, minimal processing, functional (and often called "therapeutical") food nowadays represents the key interest of nutritionists, physicians and food producers. Such food should have a beneficial influence on human health, besides satisfying the nutritive and energetic necessities, by protective, prophylactic and healing performance. This paper discusses facts about the influence of food on human health, problems of malnutrition in developing and developed countries, presents states of food production in the world and in Yugoslavia, legislation and regulations on nourishment and food production, the disadvantages of former concepts of development of this production and possible directions of future trends with a particular review on functional food production. Obimna saznanja o značaju kvalitetne hrane za životne funkcije čoveka rastuća svetska populacija i pojava "skrivene gladi" (nedostatak mikroelemenata i vitamina u ishrani) i posledice koje iz toga nastaju u svetu i kod nas, usmeravaju proizvođače hrane na nalaženje novih postupaka proizvodnje i novih proizvoda kojima bi se zadovoljile specifične potrebe različitih kategorija potrošača, različitih s obzirom na pol, starosnu dob etničku pripadnost, aktivnost, zdravstveno stanje, socijalni status i slično. "Organska", "prirodna", minimalno procesirana, funkcionalna (i danas sve češće nazivana "terapeutska") hrana trenutno predstavljaju ključni interes nutricionista, lekara i proizvođača hrane i reakcija su na dramatična zbivanja u svetu prouzrokovana pojavom "ludih krava" i GMH (genetski modifikovana hrana), toksika u stočnoj hrani Listeria sp. u mesu i mesnim prerađevinama i si. da bi se proizvela funkcionalna hrana, koja pored ispunjenja svih nutritivnih i energetskih potreba, treba da poboljša opšti zdravstveni status ljudskog organizma delujući protektivno profilaktički i lekovito. Za ostvarenje tog cilja potrebna je nova sveobuhvatna promena dosadašnjeg koncepta u proizvodnji hrane. Taj nov koncept mora se bazirati na dva osnovna principa, principu EU nazvanom "od farme do trpeze" (farm to food") i svetski prihvaćenom principu "održivog razvoja". Ona zahteva punu integraciju svih činilaca proizvodnje hrane počevši od obrade zemljišta, uzgoja stoke, preko procesiranja hrane i njene isporuke kupcu sa imperativnim ciljem da se zadovolje sve stroži zahtevi kupaca i maksimalno očuva prirodni potencijal u proizvodnji hrane tj., očuva životna sredina. Imperativni su i precizna kvantitativna i kvalitativa analitička i operativna kontrola u svim fazama proizvodnje (HACCP, ISO9000 i ISO14000) kao i stroga zakonska regulative. U cilju sagledavanja navedenih trendova u svetu u ovom radu izneti su podaci o uticaju hrane na ljudsko zdravlje, o problemima ishrane stanovništva u nerazvijenim i razvijenim zemljama, sadašnjem stanju u proizvodnji hrane u svetu i kod nas zakonodavstvu i regulativama u domenu ishrane i proizvodnje harane nedostaci dosadašnjeg koncepta razvoja u toj proizvodnji i mogući pravci budućeg razvoja, sa posebnim osvrtom na proizvodnju funkcionalne hrane. Istaknuto je da u našoj zemlji postoje značajne mogućnosti u ovoj oblasti proizvodnje koje za sada nisu iskorišćene. Organizacijom u ovoj proizvodnji kroz povezivanje svih relevantnih segmenata te proizvodnje (proizvođača prerađivača i potrošača), korišćenjem postojećeg prirodnog i ljudskog potencijala, donošenjem sveobuhvatne zakonske regulative uz podršku (finansijsku i moralnu) vlade i njenih institucija, naša zemlja bi mogla ostvariti značajan prodor na svetsko tržište, ostvariti značajan devizni priliv i uposliti veliki broj sada nezaposlenih. Mnoge zemlje Evrope to su već učinile ili se zato intenzivno i seriozno pripremaju. Mi šansu imamo i moramo je iskoristiti.

Food poisoning is the one of the main health hazards even today. More than 200 known diseases are transmitted through food. The causes of foodborne illness include viruses, bacteria, parasites, toxins, metals, and prions and the symptoms of foodborne illness range from mild gastroenteritis to life-threatening neurological, hepatic and renal syndromes.The prevention of food poisonings represents very serious task for food manufacturers. Beside food control according to the concept "from the farm to the table" there is increased need for the development of new technology for longer shelf lifes of food. Food fermented by lactic acid bacteria (LAB) and traditionally considered to be safe. There are many substances produced by LAB that affect the shelf life of fermented food, by active suppression of poisoning microorganisms growth. Because of that, the LAB is recently considered as bioprotective agents that have important role in food safety. Pojava oboljenja izazvanih hranom - trovanja hranom, predstavljaju i danas znacajan rizik po zdravlje ljudi. Vise od 200 poznatih bolesti se prenosi putem hrane. Uzročnici trovanja hranom obuhvataju viruse, bakterije parazite, toksine, metale i prione a simptomi ovih oboljenja variraju od blagih gastrointestinalnih smetnji do životno opasnih neuroloških hepatičnih i renalnih sindroma. Prevencija trovanja hranom predstavlja veoma ozbiljan zadatak za proizvodače hrane. Pored kontrole zdravstvene i higijenske ispravnosti, u svim fazama proizvodnje (prema konceptu od farme do trpeze), neophodno je razvijati nove tehnologije i tehnike koje doprinose trajnosti i bezbednosti hrane. Hrana fermentisana bakterijama mlečne kiseline se tradicionalno smatra bezbednom. Kao proizvod metaboličke aktivnost ovih bakterija stvaraju se različite supstance koje doprinose poboljšanju trajnosti fermentisanih proizvoda, aktivnom supresijom rasta patogenih mikroorganizama uzročnika kvarenja hrane. Zbog toga se ove bakterije i produkti njihovog metabolizma smatraju bioprotektivnim agensima sa značajnom ulogom u kontroli zdravstvene bezbednosti hrane.