Mate Bilić

Effect of extraction conditions on the extractability of phenolic compounds from lyophilised fig fruits (Ficus carica L.).

Effect of Extraction Conditions on the Extractability of Phenolic Compounds from Lyophilised Fig Fruits (Ficus Carica L.) In this work the influence of 50-80% (v/v) aqueous ethanol and the temperature of extraction (25-80°C) on the extractability of total phenolics, total flavonoids and total proanthocyanidins from different fig fruits was investigated. The best extraction conditions (80%, v/v aqueous ethanol, 80°C) obtained in the experiments with lyophilised Ficus carica L. cv. Šaraguja were used while performing the extraction of phenolic compounds from other fig varieties (Bružetka bijela, Crnica, Bjelica and Termenjača). The antioxidant capacity was measured in all fig fruits as well. It has been shown that the temperature of extraction and ethanol to water ratio have a statistically significant influence on the extraction of phenolic compounds from fig fruits variety Šaraguja. The highest content of phenolic compounds was found in fig variety Crnica while the lowest one in fig variety Bjelica. According to the results obtained in this study, fig fruits can be considered as a natural source of phenolic compounds with good antioxidant capacity.

Simulation, calculation and possibilities of energy saving in spray drying process

In this work some possibilities to improve the conventional spray drying process using programming in Excel as a calculation tool have been presented. The program gives a simple description of the drying process using thermodynamic calculations of heat and mass balance. Using the program it is possible to reduce operating costs and to improve capacity per unit of drying equipment. The minimization of energy consumption during the drying operation can be achieved by recycling exhaust air. The maximum theoretical range of recirculation is 60%. The fuel oil saving rate depends linearly on the rate of recirculation, and the theoretical maximum fuel oil saving is approximately 14%. Ecological issues were also considered as well, since decreased fuel consumption lowers harmful gas emission to the environment. All necessary data are represented in the process flow sheet, which is used for a better understanding of the drying process optimisation.

Optimization of supercritical CO2 extraction of dried Helichrysum italicum flowers by response surface methodology: GC-MS profiles of the extracts and essential oil

ABSTRACT Supercritical (SC) CO2 extraction of dried Immortelle flowers was performed at different process parameters. The optimal extraction conditions related to the yield were determined by response surface methodology (yield 4.09% at 20 MPa and 52°C). The extracts were analyzed by GC-MS and tremetone derivatives dominated: bitalin A, 12-acetoxytremetone, gnaphaliol, 1-[2-(2-methyl-2,3-dihydroxypropyl)-2,3-dihydro-1-benzofuran-5-yl]ethanone, isobutyl bitalin A, and 1-[2-(acetylprop-1-en-2-yl)-3-hydroxy-2,3-dihydro-1-benzofuran-5-yl]ethanone. Striking differences were found among the essential oil and SC-CO2 extracts composition. The major oil compounds were γ-curcumene, α-pinene, β-selinene, α-selinene, and limonene. Mono- and sesquiterpene were found among minor constituents of the extracts. Neryl acetate was present in the extracts and essential oil.