Prilog poznavanju važnijih parametara kvaliteta tradicionalnog (domaćeg) kulena

In this paper, results of the study of sensory properties, pH value and chemical composition of traditional or domestic kulen are presented. Results show certain disharmony between sensory and chemical and nutritional quality parameters, i.e. sensory quality of kulen is poorer than the chemical composition of the product. The most common quality shortages/deficits of domestic kulen is different smoking level, inadequate colour of the section/slice, presence of dry edge under casing, insufficient connection of the filling, bitter or sour taste. Most of studied samples of domestic kulen had pH value of 5.22 to 5.51, which shows that the ripening process was not finished, but also that the fermentation had been stimulated in certain way, not characteristic of domestic kulen. Change of the micro flora of domestic kulen is slow and typical for natural ripening which occurs during production of kulen in winter period. In the micro flora of kulen, bacteria which ferment sugars to lactic acid are dominant, Pseudomonadaceae and Enterobacteriaceae dye gradually, number of Micrococacea decreases, and enterococci survive ripening. Results of the chemical analysis show that kulen contains slightly over 35% of moisture, that the protein content of meat is above 25%, that the ratio between fat and protein contents was approximately equal and that the share of collagen in meat proteins is below 10%. The amount of sodium chloride in kulen (3.4-3.8%) is adequate to the amount of added table salt. Nitrate residues were detected in kulen (10.5 to 12.1 mg/kg) which originated from spices added to product (pepper, garlic). Acid number of kulen (7.5-16.6 mg KOH/g) showed value common for fermented dry sausages. TBARS-value was in the range 0.19-0.29 mg MDA/kg, in which the oxidation of fats cannot be perceived by sensory analysis.U radu su prikazani rezultati ispitivanja senzornih osobina, pH-vrednosti i hemijskog sastava tradicionalnog ili domaćeg kulena. Iz rezultata proizilazi da između senzornih i hemijskih i nutritivnih parametara kvaliteta postoji izvestan nesklad, odnosno da je senzorni kvalitet kulena slabiji od sastava proizvoda. Najčešći nedostaci kvaliteta domaćeg kulena jesu različit stepen dimljenja, neodgovarajuća boja preseka, postojanje suvog ruba ispod omotača, nedovoljna povezanost nadeva, ukus koji gorči ili kiselkasta ukus. Većina ispitivanih uzoraka domaćeg kulena imala je pH vrednost od 5,22 do 5,51, što pokazuje da proces zrenja još nije dovršen, ali i da je fermentacija stimulisana na neki način, što nije karakteristika domaćeg kulena. Promena mikroflore domaćeg kulena je spora i tipična je za prirodno zrenje koje se odvija za vreme proizvodnje kulena u zimskom periodu. U mikroflori kulena dominiraju bakterije koje fermentišu šećere do mlečne kiseline, Pseudomonadaceae i Enterobacteriaceae postepeno odumiru, broj Micrococacea se smanjuje, a enterokoke preživljavaju zrenje. Rezultati hemijskog ispitivanja pokazuju da kulen sadrži nešto više od 35% vlage, da je sadržaj proteina mesa veći od 25%, da je odnos između sadržaja masti i proteina približno jednak i da je udeo kolagena u proteinima mesa manji od 10%. Količina natrijum hlorida u kulenu (3,4-3,8%) odgovara dodatoj količini kuhinjske soli. U kulenu su utvrđeni ostaci nitrata (10,5 do 12,1 mg/kg) koji su sa začinima (paprika, beli luk) dodati u proizvod. Kiselinski broj kulena (7,5 - 16,6 mg KOH/g) ima vrednost uobičajenu za fermentisane suve kobasice. TBARS-vrednost je u oblasti (0,19-0,29 mg MDA/kg) pri kojoj oksidacija masti ne može da se percipira senzornim ispitivanjem

Važniji parametri kvaliteta funkcionalnih fermentisanih, barenih i jetrenih kobasica

The most important quality parameters of functional fermented, cooked and liver sausages are presented. Experimental fermented sausages included: a) conventional fermented sausage, b) functional fermented sausage with 2% inulin powder, c) functional fermented sausage with 4% inulin suspension and d) functional fermented sausage with 8% inulin suspension. All fermented sausages contained probiotic strain Lactobacillus casei LC 01. Experimental cooked sausages included: a) conventional cooked sausage, b) functional cooked sausage with inulin suspension, c) functional cooked sausage with flaxseed/rapeseed oil and d) functional cooked sausage with inulin suspension and flaxseed/rapeseed oil. Experimental liver sausages were: a) conventional liver sausage and b) functional liver sausage with inulin suspension. The obtained results show that functional fermented sausages have lower pH (4.77 - 4.93) and aw (0.89 - 0.90) values then the conventional sausage (pH = 5.18; aw = 0.93). Functional fermented sausages contain more proteins (24.2-24.5%) and less fat (24.4 - 29.7%) then conventional sausage (proteins = 20.9%; fat = 32.4%). The content of functional ingredients such as inulin and pea fiber (4.1-5.7%), in functional fermented sausages as well as higher number of probiotic strain Lactobacillus casei 01 (8.3-8.5 log cfu/g) than in conventional cooked sausage (8.1 log sfu/g) supports their functional potential. Addition of inulin (both in powder and suspension) and pea fiber improves the appearance, cut surface appearance and texture, but affects the colour of fermented sausages. Addition of 8% inulin suspension affects the odour and taste of fermented sausages. Cooked sausages with inulin suspension contain more water (63%) and less fat (22-23%) than conventional sausage (water - 60%; fat - 25.3%) and sausage containing flaxseed/rapeseed oil (water - 59%; fat - 26%). Protein content is similar in all experimental cooked sausages (10.2 -10.4%). Cooked sausages produced with inulin suspension contain 3.0-3,1% inulin. Sausages produced with flaxseed/rapeseed oil contain more polyunsaturated fatty acids (PUFA), (18.4 - 20.9% of total fatty acid content) and much more favourable omega-6/omega-3 fatty acid ratio (1,6 -2,5) then sausages produced without these oils (PUFA - 11.9-12.1%; omega-6/omega-3 - 22.3 -22.9). Despite the high content of polyunsaturated fatty acids,( TBARS) value in all experimental cooked sausages was 0.00 mg MAL/kg. Addition of flaxseed/rapeseed oil in the amount of 6% affects colour, odour and taste and texture of cooked sausages, but not the appearance and cut surface appearance of the product. Functional liver sausage contains less water (42.5%) and fat (43.6%) than the conventional cooked sausage (water = 44.3%; fat = 44.0%), but protein content is similar in both products (9.0-9.1%). Functional liver sausage contains 3.1% dietary fibre (inulin and pea fiber) which supports its functional potential. Sensory properties of functional liver sausage are rated excellent at the scale from 1 to 5 (average rating 5.0). On the contrary, some sensory properties of the conventional liver sausage were rated somewhat lower (odour and taste 4.8 and texture/juiciness 4.6).U radu su prikazani važniji parametri kvaliteta funkcionalnih fermentisanih, kuvanih i jetrenih kobasica. Proizvedene su sledeće eksperimentalne fermentisane kobasice: a) konvencionalna fermentisana kobasica, b) funkcionalna fermentisana kobasica sa 2% inulina u prahu, c) funkcionalna fermentisana kobasica sa 4% suspenzije inulina i d) funkcionalna fermentisana kobasica sa 8% suspenzije inulina. Sve fermentisane kobasice sadržale su probiotski soj bakterije Lactobacillus casei LC 01. Eksperimentalne barene kobasice uključivale su sledeće proizvode: a) konvencionalna barena kobasica, b) funkcionalna barena kobasica sa suspenzijom inulina, c) funkcionalna barena kobasica sa lanenim/repičinim uljem i d) funkcionalna barena kobasica sa suspenzijom inulina i lanenim/repičinim uljem. Iz grupe jetrenih kobasica proizvedene su: a) konvencionalna jetrena kobasica i b) jetrena kobasica sa suspenzijom inulina. Rezultati pokazuju da funkcionalne fermentisane kobasice imaju nižu pH (4,77-4,93) i aw (0,89-0,90) vrednost nego konvencionalna kobasica (pH = 5,18; aw = 0,93). Funkcionalne fermentisane kobasice sadrže više proteina (24,2-24,5%) i manje ukupne masti (24,4- 29,7%) nego konvencionalna kobasica (proteini = 20,9%; ukupna mast = 32,4%). Sadržaj funkcionalnih sastojaka kao što su inulin i vlakna graška u količini 4,1-5,7% u funkcionalnim fermentisanim kobasicama kao i veći broj probiotske bakterije Lactobacillus casei 01 (8,3-8,5 log cfu/g) nego u konvencionalnoj kobasici (8,1 log sfu/g) ide u prilog njihovom funkcionalnom potencijalu. Dodatak inulina (kako u obliku praška tako i u obliku suspenzije) i vlakana graška utiče pozitivno na spoljašnji izgled, izgled preseka i teksturu ali nepovoljno utiče na boju fermentisanih kobasica. Dodatak suspenzije inulina u količini od 8% nepovoljno utiče na miris i ukus fermentisanih kobasica. Barene kobasice sa suspenzijom inulina sadrže više vode (63%) i manje ukupne masti (22-23%) nego konvencionalna barena kobasica (voda = 60%; ukupna mast = 25,3%) i kobasice koja sadrži laneno/repičino ulje (voda = 59%; ukupna mast = 26%). Sadržaj proteina je sličan kod svih eksperimentalnih barenih kobasica i iznosi od 10,2 do 10,4%. Barene kobasice proizvedene sa suspenzijom inulina sadrže 3,0 - 3,1% inulina. Kobasice koje su proizvedene sa lanenim/repičinim uljem sadrže više polinezasićenih masnih kiselina (PUFA) (18,4 - 20,9% od ukupnog sadržaja masnih kiselina) i znatno povoljniji odnos omega-6 i omega-3 masnih kiselina (1,6-2,5) nego kobasice koje su proizvedene bez dodatka ovih ulja (PUFA = 11,9 - 12,1%; omega-6/omega-3 = 22,3 - 22,9). Uprkos visokom sadržaju polinezasićenih masnih kiselina, TBARS-vrednost kod svih eksperimentalnih barenih kobasica iznosi 0,00 mg MAL/kg. Dodatak lanenog/repičinog ulja u količini od 6% nepovoljno utiče na boju, aromu i teksturu barenih kobasica, ali ne i na spoljašnji izgled i izgled preseka proizvoda. Funkcionalne jetrene kobasice sadrže manje vode (42,5%) i ukupne masti (43,6%) nego konvencionalna barena kobasica (voda = 44,3%; ukupna mast = 44,0%) ali je sadržaj proteina sličan kod oba proizvoda (9,0-9,1%). Funkcionalne jetrene kobasice sadrže 3,1% dijetnih vlakana (inulin i vlakna graška) što ide u prilog njihovom funkcionalnom potencijalu. Senzorna svojstva funkcionalnih jetrenih kobasica su ocenjena maksimalnom ocenom na skali od 1 do 5 (prosečna ocena 5,00). Na suprot tome, neka senzorna svojstva konvencionalne jetrene kobasice su nešto lošija (miris i ukus 4,8 i tekstura/sočnost 4,6)

Regulation of antioxidant enzyme activities in female rat brain by ovarian steroids

The sex steroids produce their effects by acting on numerous target tissues and organs, such as the reproductive organs, bone tissue and cartilage, peripheral blood vessels as well as the central nervous system (CNS). In our studies we have monitored the change of enzyme activity of the antioxidant (AO) system in the brain of female rats depending on the ovarian steroids. We have chosen it as a new parameter that might represent an important indicator of the changes within the CNS, bearing in mind the biological importance of the enzymes of the AO system. The experimental results of our study indicate that the enzyme activity of the AO system in the brain tissue of female rats shows a certain dependence on the concentration of ovarian hormones, progesterone and estradiol, in the organism. Study of the activity of the enzymes of the AO system in the brain of female rats depending on the influence of ovarian hormones can answer whether the action of ovarian steroids on the CNS includes maintenance of a dynamic equilibrium of free radicals in the neurons

Funkcionalni proizvodi od mesa - savremeni pristup unapređenju nutritivne vrednosti i kvaliteta proizvoda od mesa

This paper presents some important properties and nutritive values of functional meat products such as fermented sausage, frankfurter type sausage and liver sausage, with emphasis on the functional food concept, nutritional and functional properties of meat and features of the most important functional ingredients. In addition to basic nutrients, functional food contains ingredients that are proven as having a positive effect on health. These ingredients include probiotics, prebiotics, synbiotics, antioxidants, structural lipids, omega- 3 polyunsaturated fatty acids, bioactive peptides, microelements and vitamins. The paper also lays out the basic chemical composition, fatty acid composition and sensory properties of experimental fermented, frankfurter type and liver sausages. Experimental sausages were examined by standard physicochemical, chemical, microbiological and sensory methods. Unlike conventional products, functional meat products contain more meat proteins, less connective tissue proteins and less fat and therefore have a better quality, higher nutritional value, and are lower in calories. Depending on the amount of pork backfat that was replaced with prebiotics, functional fermented sausages had up to 17.5% less calories than the conventional sausage and functional frankfurter type sausages up to 12% less calories than the conventional frankfurter type sausage. Functional fermented sausages contained Lactobacillus casei LC 01 more than 108 cfu/g, so these products can be characterized as probiotic sausages. Fatty acid composition of functional frankfurter type sausages was significantly improved by replacing part of the pork backfat with flaxseed and rapeseed oil, wherein the saturated/unsaturated fatty acid ratio was 0.49-0.53, and the n-6/n-3 fatty acids ratio was 1.75-2.50. Functional fermented, frankfurter type and liver sausages were enriched with inulin and pea dietary fiber, so they contained prebiotics in the amount of 2.7-5.7 g/100g. The overall sensory quality of functional products was highly rated (4.63 to 5.00). However, the addition of vegetable oil (6%) to frankfurter type sausages affected their colour, odour and taste, so their overall sensory quality was rated lower (4.36) than the conventional sausage (4.88). The addition of 8% inulin suspension to fermented sausages affected their odour and taste, so their overall sensory quality was rated lower (4.58) than the conventional (4.63). The safety of functional meat products is based on the implementation of good hygiene and manufacturing practice and the control of production in accordance with the principles of HACCP.U ovom tekstu prikazane su važnije osobine i nutritivna vrednost funkcionalnih proizvoda od mesa, i to fermentisanih, barenih i jetrenih kobasica, sa osvrtom na pojam funkcionalne hrane, nutritivne i funkcionalne osobine mesa i karakteristike najvažnijih funkcionalnih dodataka. Funkcionalna hrana, pored osnovnih nutrijenata, sadrži i sastojke za koje je dokazano da pozitivno utiču na zdravlje ljudi, kao što su probiotici, prebiotici, sinbiotici, antioksidansi, strukturni lipidi, omega-3 polinezasićene masne kiseline, bioaktivni peptidi, mikroelementi i vitamini. Takođe su prikazani i rezultati ispitivanja osnovnog hemijskog sastava, masnokiselinskog sastava i senzornih osobina funkcionalnih fermentisanih, barenih i jetrenih kobasica. Eksperimentalne kobasice su ispitane standardnim fizičko-hemijskim, hemijskim, mikrobiološkim i senzornim metodama. Za razliku od konvencionalnih proizvoda od mesa, funkcionalni proizvodi sadrže više proteina mesa, manje proteina vezivnog tkiva i manje masti, a time imaju i bolji kvalitet, veću biološku, a manju energetsku vrednost. U zavisnosti od količine masnog tkiva koja je zamenjena prebioticima, energetska vrednost kod funkcionalih fermentisanih kobasica je do 17,5 % manja nego kod konvencionalne fermentisane kobasice, a kod funkcionalnih barenih kobasica za 12 % manja od konvencionalne barene kobasice. Funkcionalne fermentisane kobasice sadrže Lactobacillus casei LC 01 u broju većem od 108 cfu/g pa se ovi proizvodi mogu oarakterisati kao probiotski. Kod funkcionalnih barenih kobasica masnokiselinski sastav je znatno poboljšan zamenom dela masnog tkiva lanenim i repičinim uljem, pri čemu odnos zasićenih i nezasićenih masnih kiselina iznosi 0,49 - 0,53, a odnos n-6 i n-3 masnih kiselina 1,75 - 2,50. Funkcionalne fermentisane, barene i jetrene kobasice obogaćene su inulinom i dijetnim vlaknima graška, tako da sadrže prebiotike u količini od 2,7 do 5,7 g/100g. Ukupan senzorni kvalitet funkcionalnih proizvoda je visoko ocenjen (4,63 - 5,00). Međutim, kod barenih kobasica dodatak biljnih ulja (6 %) uticao je nepovoljno na boju, miris i ukus, tako da je ukupni senzorni kvalitet lošije ocenjen (4,36) nego kod konvencionalne (4,88). Kod fermentisanih kobasica dodatak 8 % suspenzije inulina uticao je na miris i ukus, tako da je ukupni senzorni kvalitet lošije ocenjen (4,58) nego kod konvencionalne (4,63). Bezbednost funkcionalnih proizvoda od mesa zasniva se na sprovođenju svih mera dobre higijenske i proizvođačke prakse i kontroli proizvodnje u skladu sa načelima HACCP

Važnije osobine i nutritivna vrednost funkcionalnih proizvoda od mesa

Several properties and nutritional value of functional fermented, cooked and liver sausages are reported. Functional fermented and cooked sausages contained more proteins and less fat, consequently having being of less energetic value than conventional sausages of the same type. However, there was no difference between functional and conventional liver sausages. Probiotic bacterium Lactobacillus casei LC 01 grows very well in functional fermented sausage and it survives the storage, their number being higher than 107 per gram. Acceptable fatty acids ratio, the presence of probiotics and prebiotics, as well as omega-3 fatty acids, make functional sausages a foodstuff of high nutritional value with substantial positive effect of human health.U radu su prikazani važnije osobine i nutritivna vrednost funkcionalnih fermentisanih i barenih kobasica i jetrenih pašteta. Funkcionalne fermentisane i barene kobasice sadrže više proteina mesa, manje masti i imaju manju energetsku vrednost nego konvencionalne. Između funkcionalne i konvencionalne jetrene paštete u tom pogledu ne postoji razlika. Proteini funkcionalnih kobasica potiču od mesa, dok proteini konvencionalnih proizvoda potiču kako od mesa tako i od belančevinastih proizvoda biljnog porekla. Probiotička bakterija Lactobacillus casei LC 01 dobro se razmnožava u funkcionalnoj fermentisanoj kobasici i preživljava skladištenje u broju većem od 107 po gramu. Povoljan masnokiselinski sastav, prisustvo probiotičkih bakterija, prebiotika i omega-3 masnih kiselina čini funkcionalne kobasice kvalitetnom nemirnicom visoke nutritivne vrednosti, sa značajnim potencijalom da pozitivno utiču na zdravlje

Ispitivanje važnijih promena u toku zrenja tradicionalne fermentisane kobasice Lemeški kulen

In this paper the results of investigation of major changes during ripening of traditional fermented dry sausage Lemeški kulen are presented. During the ripening of Lemeški kulen microflora is growing very slowly, what is typical for natural ripening of fermented sausages in the winter. In microflora of Lemeški kulen lactobacilli are dominant; they ferment sugar from paprika to lactic acid. During sausage ripening the number of micrococci and enterococci decreased, while Pseudomonadaceae and Enterobacteriaceae died out. At the end of the first ripening phase, which lasted three months at low temperatures, aw value was 0,90 and pH value 5,3 and product reached bacteriological stability. At the end of the ripening process aw value decreased to 0,86 and pH value increased up to 5,5. Lemeški kulen contained less than 30% water, more than 30% meat proteins and fats, and the percentage of the collagen content in total meat proteins was 6,0 %. The fat protein content ratio was about 1,0 and the moisture-meat protein content ratio was below 1,0 (0,85). Although nitrate was not used, it was detected in the kulen; where nitrate originated from paprika. During the ripening of Lemeški kulen, acid value increased by about ten times, but peroxide number and TBARS-value (Thiobarbituric Acid Reactive Substances) remained unchanged. Sweet and hot domestic paprika from Lemeš area, added in amount of 3%, is very important for the quality of Lemeški kulen, because paprika has an antioxidative effect and also influences the colour, flavour and texture of sausage.U radu su prikazani rezultati ispitivanja važnijih promena tokom zrenja tradicionalne fermentisane kobasice lemeški kulen. Mikroflora koja učestvuje u zrenju lemeškog kulena razvija se sporo i tipična je za prirodno zrenje fermentisanih kobasica u zimskom periodu. U mikroflori lemeškog kulena dominiraju laktobacili koji fermentišu šećere iz paprike do mlečne kiseline; za vreme zrenja broj mikrokoka i enterokoka se smanjuje, dok Pseudomonadaceae i Enterobacteriaceae odumiru. Na kraju prve faze zrenja, koja pri niskim temperaturama traje tri meseca, aktivnost vode iznosi 0,90, a pH vrednost 5,3 i kulen postaje bakteriološki stabilan proizvod. Na kraju zrenja aktivnost vode se smanjuje do 0,86, a pH vrednost povećava do 5,5. Lemeški kulen sadrži manje od 30% vlage, sadržaj proteina mesa i masti veći je od 30%, a sadržaj kolagena u proteinima mesa je oko 6,0%. Odnos između sadržaja masti i proteina približno je jednak jedan, a odnos između sadržaja vlage i proteina mesa manji je od jedan (0,85). Količina natrijum-hlorida u proizvodu (4,1%) odgovara dodatoj količini kuhinjske soli. Iako se ne koriste soli za salamurenje, u kulenu su utvrđeni ostaci nitrata koji su sa paprikom dodati u proizvod. Za vreme zrenja lemeškog kulena kiselinski broj se povećava desetak puta, dok se peroksidni broj i TBARS-vrednost (Thiobarbituric Acid Reactive Substances) ne povećavaju. Za kvalitet lemeškog kulena od posebnog značaja je domaća lemeška paprika, slatka i ljuta, koja se dodaje proizvodu oko 3%; u toj količini paprika deluje antioksidativno i utiče na boju, aromu i teksturu proizvoda

Time course of hematological parameters in bleeding-induced anemia

In order to investigate daily changes of hematological parameters in bleeding-induced anemia, we treated Wistar albino male rats by daily bleeding (1.5-2 mL of blood from the tail vein for eight days). Blood samples were taken before (on day zero) and on the first to eighth days of bleeding. The values of hematocrit, hemoglobin, and erythrocyte count decreased significantly after the second, sixth, and second days of bleeding, respectively. The number of leuko­cytes and platelets, as well as Heinz body levels, increased significantly after the third and second days of treatment. The percentage of reticulocytes increased significantly from the second day and attained the maximum level (32.55 ± 0.96%) on the eighth day

Effects of cisplatin on lipid peroxidation and the glutathione redox status in the liver of male rats: The protective role of selenium

The role of oxidative stress in cisplatin (CP) toxicity and its prevention by pretreatment with selenium (Se) was investigated. Male Wistar albino rats were injected with a single dose of cisplatin (7.5 mg CP/kg b.m., i.p.) and selenium (6 mg Se/kg b.m, as Na2SeO3, i.p.) alone or in combination. The results suggest that CP intoxication induces oxidative stress and alters the glutathione redox status: reduced glutathione (GSH), oxidized glutathione (GSSG) and the GSH/GSSG ratio (GSH RI), resulting in increased lipid peroxidation (LPO) in rat liver. The pretreatment with selenium prior to CP treatment showed a protective effect against the toxic influence of CP on peroxidation of the membrane lipids and an altering of the glutathione redox status in the liver of rats. From our results we conclude that selenium functions as a potent antioxidant and suggest that it can control CP-induced hepatotoxicity in rats.U našoj studiji ispitivana je uloga oksidacionog stresa u toksičnosti cisplatina (SR) i njegova prevencija pretretmanom selenom (Se). Mužjaci Wistar albino pacova su inicirani jednom dozom cisplatina (7.5 mg CP/kg t.m., i.p.) i selena (6 mg Se/kg t.m, kao Na2SeO3, i.p.) pojedinačno ili u kombinaciji. Rezultati pokazuju da intoksikacija SR uzrokuje oksidacioni stres i promenu glutation redoks statusa: redukovanog (GSH), oksidovanog (GSSG) i GSH/GSSG indeksa (GSH RI), kao i povećanje lipidne peroksidacije (LPO) u jetri pacova. Tretman Se koji je prethodio tretmanu SR pokazao je zaštitne efekte protiv toksičnog delovanja SR na peroksidaciju lipida membrane i promenu glutation redoks statusa u jetri pacova. Na osnovu naših rezultata zaključujemo da Se, deluje kao snažan antioksidans i da može imati ulogu u kontroli SR indukovane hepatotoksičnosti kod pacova.Projekat ministarstva br. 143035

Biochemical and ultrastructural changes in the liver of European perch (Perca fluviatilis L.) in response to cyanobacterial bloom in the Gruža reservoir

We investigated the biochemical and ultrastructural changes in the liver of the freshwater fish, European perch (Perca fluviatilis), in response to Aphanizomenon flos-aquae bloom in the Gruža Reservoir, Serbia. The activities of total manganese- and copper zinc-containing superoxide dismutase (Tot SOD, Mn-SOD, Cu/Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and biotransformation phase II enzyme glutathione-S-transferase (GST), as well as concentrations of total glutathione (GSH) and sulfhydryl (-SH) groups were examined before and during the bloom period. Mn-SOD activity was significantly higher, while the activities of Cu/Zn-SOD, CAT and GSH-Px and the concentration of the -SH groups were significantly lower during the bloom. The ultrastructure of the liver revealed necrotic and apoptotic damage to the hepatocytes during the bloom period. Our work represents the first study to report the influences of an Aphanizomenon flos-aquae bloom in the Gruža Reservoir on antioxidant biomarkers and on histopathological alterations in the liver of the freshwater fish European perch (Perca fluviatilis)