Optimization of fish processing process preparation for histamine detection with SERS method

Histamin je najvažniji biogeni amin koji pri povišenoj koncentraciji u hrani morskog podrijetla predstavlja toksikološki rizik. Ramanova spektroskopija se pokazala brzom i invazivnom metodom za detekciju histamina, dok su tradicionalne metode skuplje i složenije te teže primjenjive u industrijskim uvjetima. Cilj ovog istraživanja bio je pročistiti ekstrakte različitim otapalima kako bi se histamin izdvojio iz vodenog sloja i bolje detektirao SERS (površinski pojačano Ramanovo raspršenje) metodom, te time izbjeći dugi postupak uparavanja i skratiti navedenu metodu. Koeficijent koleracije (R2= 0,9614) i intenzitet vrpce histamina na 1570 cm-1 pokazali su se najboljima kod ekstrakta B1 (ekstrakcija HCl-om), dok je kod ekstrakta B2 (ekstrakcija s izooktanom i vodom) najveća točnost metode (95,45%) kod vrpce histamina na 1264 cm-1. Zbog otežanih uvjeta u radu s ekstraktima B i C (ekstrakcija 0.1 i 0.5M NaOH), te tijekom dodavanja i miješanja isptivanih otapala (HCl, izooktan, cikloheksan), može se zaključiti da te postupke nije preporučljivo primjenjivati.Histamine is the most important biogenic amine which represents a toxicological risk at elevated concentrations in sea food. Raman spectroscopy proved to be a fast and invasive histamine detection method, while traditional methods are more expensive, complex and difficult to apply in industrial conditions. The aim of this study was to purify the extracts with different solvents in order to separate histamine from the aqueous layer and enable better detection by the SERS (Surface Enhanced Raman Scattering) method. Thus the relatively long evaporation process was to be avoided and the method would shorten. The correlation coefficient c (R2= 0.9614) and the histamine band intensity at 1570 cm--1 were the best for analysing extract B1 (extraction with HCl). The highest method accuracy (95.45%) in extract B2 (extraction with isooctane and water) was achieved by the histamine band at 1264 cm-1. Due to difficulties in analysing extracts B and C (extraction with 0.1 and 0.5 M NaOH), and during the addition and mixing with investigated solvents (HCl, isooctane and cyclohexane) such procedures are not recommended for use

Chronic renal failure – cardiovascular risk factor.

Cardiovascular diseases are a major cause of morbidity and mortality in patients at the end stage of renal disease. Left ventricular hypertrophy, coronary heart disease and heart failure are the most prevalent cardiovascular diseases in dialysis patients. The patients on chronic dialysis have a 10 to 20-fold higher risk of development of cardiovascular disease than the general population. The aim of this article was to define the frequency of risk factors (traditional and non-traditional) for cardiovascular diseases in dialysis patients. The most frequent traditional factors in this study were hypertension (62%) and hyperlipidemia (60%), while anemia (86%) and hyperhomocysteinemia (82%) were the most frequent non-traditional factors. To present the study and repeat again that dialysis patients have high risk of development of cardiovascular disease and this population should be an ideal target group for primary prevention

Valvular heart disease in patients undergoing chronic hemodialysis.

Valvularna bolest srca uobičajena je pojava kod pacijenta na kroničnoj dijalizi. Abnormalnosti uključuju valvularno i anularno zadebljanje te kalcifikaciju bilo koje od srčanih valvula, uzrokujući regurgitaciju i/ili stenozu. Valvularno zadebljanje ili skleroza kod pacijenata na kroničnom programu dijalize najčešće zahvaća aortnu i mitralnu valvulu. Kalcifikacija aortne valvule registrira se i do polovice hemodijaliznih pacijenata, javljajući se od 10 do 20 godina ranije nego u općoj populaciji. Valvularna regurgitacija javlja se najčešće na mitralnoj, trikuspidnoj i nešto rjeđe aortnoj valvuli. Cilj rada bio je utvrditi učestalost bolesti srčanih zalistaka u asimptomatskih bolesnika na kroničnom programu dijalize. U analizu je uključeno ukupno 50 pacijenata i to 35 (70%) liječenih hemodijalizom i 15 (30%) kontinuiranom ambulatornom peritonejskom dijalizom. Valvularno zadebljanje ili skleroza dijagnosticirani su kod 20 (40%) bolesnika. Kod 9 (18%) pacijenata dijagnosticirana je skleroza mitralnih, a kod 11 (22%) skleroza aortnih listića. Kalcifikacije srčanih zalistaka dijagnosticirane su kod 12 (31%) pacijenta. Blaga aortna stenoza bila je prisutna kod 3 (6%) pacijenta. Mitralna regurgitacija bila je dijagnosticirana kod 38 (76%) pacijenata, aortna regurgitacija kod 14 (28%), a trikuspidna regurgitacija kod 24 (48%) pacijenata. Radi evaluacije stanja valvularanog aparata svim pacijentima na kroničnom programu dijalize potrebno je učiniti ehokardiografski pregled, obzirom na visoku učestalost valvularnih bolesti srca.Valvular heart disease is a common phenomenon in patients undergoing chronic hemodialysis. Abnormalities include valvular and annular thickening and calcification of any of the heart valves, causing regurgitation and/or stenosis. Valvular thickening or sclerosis in patients undergoing chronic dialysis treatment usually affects the aortic and mitral valve. Aortic valve calcification is recorded in up to a half of hemodialyzed patients, occurring from 10 to 20 years earlier than in the general population. Valvular regurgitation occurs mostly in mitral, tricuspid and less commonly in aortic valve.The aim of the article was to determine the incidence of valvular heart disease in asymptomatic patients undergoing chronic dialysis. The analysis involves a total of 50 patients, of whom 35 (70%) are treated by hemodialysis and 15 (30%) by continuous ambulatory peritoneal dialysis. Valvular thickening or sclerosis was diagnosed in 20 (40%) patients. Sclerosis of mitral cusps was diagnosed in 9 (18%) patients and sclerosis of aortic cusps was diagnosed in 11 (22%) patients. Heart valve calcifications were diagnosed in 12 (31%) patients. Mild aortic stenosis was present in 3 (6%) patients. Mitral regurgitation was diagnosed in 38 (76%) patients, aortic regurgitation in 14 (28%), and tricuspid regurgitation in 24 (48%) patients. The evaluation of the valve apparatus for all patients undergoing chronic dialysis program requires echocardiographic examination that is to be performed, considering the high prevalence of valvular heart diseases

Influence of concentration acetic acid on physico chemical and organoleptic characteristics of marinated fish

Cilj ovog rada je bio ispitati fizikalno-kemijske i organoleptičke promjene koje se događaju na filetima srdela tijekom mariniranja pri 2% i 4% octene kiseline. Od fizikalno-kemijskih metoda određivali se gubitak na masi (kalo), boja (L*,b* vrijednost), udio vode, udio NaCl i pH vrijednost. Rezultati su pokazali da je tijekom 4 sata mariniranja došlo do većih promjena u gubitku na masi (kalu), te u boji fileta (L*, b* ) kod marinade s 4% octene kiseline, dok je trećeg dana mariniranja došlo i do promjene u pH vrijednosti. Kod ispitivanja organoleptičkih svojstava marinirane ribe trećeg dana mariniranja pokazalo se da su fileti marinirani u marinadi s 2% octene kiseline pogodniji za konzumaciju.The aim of this study was to investigate physico-chemical and organoleptic changes that occur in sardine fillets marinated at 2% or 4% acetic acid. Of the various physico-chemical methods were determinated weight loss, colour (L*, b* value), water and NaCl content, and pH value. The results showed that during the 4 hours of marinating changes in the weight loss and colour (L*, b*) in marinade with 4% of acetic acid and after three days of marinating there were also changes in pH value. When testing the organoleptic properties of marinated fish on the third day shown that the fillets marinated with 2 % of acetic acid are more suitable for consumption

Influence of concentration acetic acid on physico chemical and organoleptic characteristics of marinated fish

Cilj ovog rada je bio ispitati fizikalno-kemijske i organoleptičke promjene koje se događaju na filetima srdela tijekom mariniranja pri 2% i 4% octene kiseline. Od fizikalno-kemijskih metoda određivali se gubitak na masi (kalo), boja (L*,b* vrijednost), udio vode, udio NaCl i pH vrijednost. Rezultati su pokazali da je tijekom 4 sata mariniranja došlo do većih promjena u gubitku na masi (kalu), te u boji fileta (L*, b* ) kod marinade s 4% octene kiseline, dok je trećeg dana mariniranja došlo i do promjene u pH vrijednosti. Kod ispitivanja organoleptičkih svojstava marinirane ribe trećeg dana mariniranja pokazalo se da su fileti marinirani u marinadi s 2% octene kiseline pogodniji za konzumaciju.The aim of this study was to investigate physico-chemical and organoleptic changes that occur in sardine fillets marinated at 2% or 4% acetic acid. Of the various physico-chemical methods were determinated weight loss, colour (L*, b* value), water and NaCl content, and pH value. The results showed that during the 4 hours of marinating changes in the weight loss and colour (L*, b*) in marinade with 4% of acetic acid and after three days of marinating there were also changes in pH value. When testing the organoleptic properties of marinated fish on the third day shown that the fillets marinated with 2 % of acetic acid are more suitable for consumption

Optimization of fish processing process preparation for histamine detection with SERS method

Histamin je najvažniji biogeni amin koji pri povišenoj koncentraciji u hrani morskog podrijetla predstavlja toksikološki rizik. Ramanova spektroskopija se pokazala brzom i invazivnom metodom za detekciju histamina, dok su tradicionalne metode skuplje i složenije te teže primjenjive u industrijskim uvjetima. Cilj ovog istraživanja bio je pročistiti ekstrakte različitim otapalima kako bi se histamin izdvojio iz vodenog sloja i bolje detektirao SERS (površinski pojačano Ramanovo raspršenje) metodom, te time izbjeći dugi postupak uparavanja i skratiti navedenu metodu. Koeficijent koleracije (R2= 0,9614) i intenzitet vrpce histamina na 1570 cm-1 pokazali su se najboljima kod ekstrakta B1 (ekstrakcija HCl-om), dok je kod ekstrakta B2 (ekstrakcija s izooktanom i vodom) najveća točnost metode (95,45%) kod vrpce histamina na 1264 cm-1. Zbog otežanih uvjeta u radu s ekstraktima B i C (ekstrakcija 0.1 i 0.5M NaOH), te tijekom dodavanja i miješanja isptivanih otapala (HCl, izooktan, cikloheksan), može se zaključiti da te postupke nije preporučljivo primjenjivati.Histamine is the most important biogenic amine which represents a toxicological risk at elevated concentrations in sea food. Raman spectroscopy proved to be a fast and invasive histamine detection method, while traditional methods are more expensive, complex and difficult to apply in industrial conditions. The aim of this study was to purify the extracts with different solvents in order to separate histamine from the aqueous layer and enable better detection by the SERS (Surface Enhanced Raman Scattering) method. Thus the relatively long evaporation process was to be avoided and the method would shorten. The correlation coefficient c (R2= 0.9614) and the histamine band intensity at 1570 cm--1 were the best for analysing extract B1 (extraction with HCl). The highest method accuracy (95.45%) in extract B2 (extraction with isooctane and water) was achieved by the histamine band at 1264 cm-1. Due to difficulties in analysing extracts B and C (extraction with 0.1 and 0.5 M NaOH), and during the addition and mixing with investigated solvents (HCl, isooctane and cyclohexane) such procedures are not recommended for use