No abstract

Pavun L., Đurđević P., Jelikić-Stankov M., Đikanović D., Uskoković-Marković S. (2018): Determination of flavonoids and total polyphenol contents in commercial apple juices. Czech J. Food Sci., 36: 233-238.We propose a sensitive and selective spectrofluorimetric method for the determination of flavonoids as expressed in 'quercetin equivalent' in apple juices. The method is based on the strong emission of the aluminium(III)-quercetin complex at 480 nm with excitation at 420 nm, and it is successfully applied for the determination of flavonoids in commercial apple juices and compared with results obtained in reference spectrophotometric determination. The flavonoid content in commercial apple juices was found to range from 5.53 to 15.55 mg/l quercetin equivalent. The very good agreement between the two methods indicates the suitability of the proposed spectrofluorimetric method for the precise and accurate determination of flavonoids. In addition, the total polyphenol content was determined spectrophotometrically using the Folin-Ciocalteu (FC) method and the antioxidative activity of the tested juices was tested in a DPPH assay and these values were correlated with each other. The obtained profiles of compounds with antioxidative ability lead us to conclude that fruit juice labels based only on fruit % might sometimes misinform consumers.

No abstract

No abstract

No abstract

No abstract

No abstract

SummaryIn this review, Raman spectroscopy is described as a new and potentially powerful diagnostic tool in comparison to routine biochemical tests. Advanced instrumentation and new Raman spectroscopy techniques enable rapid and simultaneous identification and/or determination of se veral biochemical parameters, such as glucose, acetone, creatinine, urea, lipid profile, uric acid, total protein, etc, with a very low limit of detection. Raman spectroscopy could also be applied in molecule and cell characterization, as well as diagnostics of atherosclerosis in its early stage. Raman spectroscopy is nondestructive and could be applied to all kinds of samples, which simplifies the diagnostics of numerous disea ses and pathologic states. Special attention is paid to literature data illustrating the application of Raman spectroscopy for transdermal glucose monitoring and cancer diagnostics.Keywords: biochemical parameters, cancer diagnosis, glu cose monitoring, Raman spectroscopy Kratak sadr`aj U ovom prikazu opisana je primena Ramanske spektroskopije kao nove metode velikih mogu}nosti u dijagnostici, u pore|enju sa rutinskim biohe mijskim testovima. Me toda je razvijena i usavr{ena za identifikaciju i/ili odre |ivanje velikog broja biohemijskih parametara, kao {to su glu koza, aceton, kreatinin, urea, lipidni profil, mokra}na kiselina, ukupni proteini i drugi, uz veoma nizak limit detekcije. Ramanska spektroskopija tako|e se mo`e primenjivati u molekulskoj i }elij -skoj karakterizaciji, kao i za dijagnostiku ranog stadijuma ateroskleroze. Ramanska spektroskopija je nedestruktivna i mo`e se primenjivati na sve vrste uzoraka, {to pojednostavljuje dijagnostiku brojnih bo lesti i patolo{kih stanja. Posebna pa`nja u radu je posve }ena podacima iz literature koji ilustruju primenu Ramanske spektroskopije u transdermalnom monitoringu glukoze i dijagno stici kancera.