PREPARATION AND EXPERT EVALUATION OF JELLY-FRUIT MARMALADE FORTIFIED WITH QUERCETIN

The technique of obtaining a water-soluble pectin-quercetin complex has been developed. The spectral properties of the resulting complex have been studied. The absorption spectrum of ethanol solution of quercetin with a volumetric particle of ethanol is 96% is characterized by the presence of absorption bands π-π* transitions in the UV region at λ = 251 nm and n → π* transitions at λ = 369 nm. The absorption band of quercetin at λ = 369 nm is broaden in an aqueous solution in the presence of pectin due to interactions with pectin. The luminescence of quercetin at 541 and 655 nm is quenched in the water-soluble pectin-quercetin complex. The FTIR spectra of the pectin-quercetin complex lack absorption bands that relate to the functional groups of quercetin, which indicates that quercetin contacted the polysaccharide, forming a complex compound. The obtained jelly-fruit marmalade fortified with quercetin in the form of pectin-quercetin complex as a functional component. The morphological characteristics of raw materials and product are established by optical microscopy. Micromorphological signs of apple pectin powder are polydispercial of the particles of irregular shape, size from 10 to 350 μm. The surface of large particles (250-350 μm) is covered with crystals in size 10-30 μm. The crystalline particles of quercetin have a straight shape, in size polydispersy up to 50 μm in length and up to 5 μm wide. There are no crystalline particles of quercetin on the microphoto of marmalade samples and polydispersed pectin particles, homogeneous, amorphous, and student consistency. Expert evaluation of marmalade, which is fortified with quercetin, found that the samples correspond to regulatory documents on such indicators as: humidity - decreases from 17.5% to 16.1%; acidity - increases from 8.5% to 9.4%. The mass fractions of reducing substances and ashs increase slightly with the increase in quercetin concentration in marmalade samples, but also do not check the normative data. The antioxidant activity of the samples increases with increasing quercetin content from 0.35 mg/g to 0.69 mg/g.