| Abstract [eng] |
The honeysuckle berries are dark purple color, have an elongated elliptic shape and containing several seeds. Honeysuckle berries are good source of secondary metabolites, vitamins and minerals. Due to the presence of a significant amount of biologically active substances and high nutritional value, honeysuckle has a great potential to be used as a source for health beneficial ingredients for functional foods, nutraceuticals and other healthy natural products. Unfortunately, there are limited data about bioactivity of honeysuckle pomace. The aim of this study was to compare conventional, ultrasound and pressurized liquid extraction methods for recovery of bioactive compounds and other valuable nutrients from honeysuckle pomace and to evaluate antioxidant and phytochemical composition by chromatographic and spectroscopic methods. It is expected that such results will provide essential data for valorizing honeysuckle pomace in the development of various functional ingredients for foods and nutraceuticals. The dried pomace of honeysuckle was ground to achieve a 1-mm particle size. Proximate composition of pomace, such as moisture and dry substance content (drying to constant weight); protein content (Kjeldahl method) and lipid content (Soxhlet extraction with hexane) were evaluated by AOAC official procedures. Pressurized liquid extraction (PLE) was performed with ethanol (EtOH) and water (H2O) in an accelerated solvent extractor ASE 350. Solid-liquid extraction (maceration) (SLE) was performed by ground pomace was extracted with EtOH or H2O for 24 h at room temperature under orbital shaking. Ultrasound extraction (UAE) was performed with EtOH or H2O for comparing it with ultrasound bath and ultrasound assisted extraction. Antioxidant properties of obtained extracts and solid material (QUENCHER approach) were evaluated by ABTS•+ scavenging and ORAC assays. Total phenolic content (TPC) was determined by Folin-Ciocalteu method. Chemical composition of obtained extracts such as anthocyanins and triacylglycerol’s were determined by ultra-performance liquid chromatography – quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The extract yield depended on the selected method of extraction and organic solvents. The highest yields were recovered by PLE with EtOH and H2O, 60 ± 1,61 and 54 ± 6,12 g/100 g of DW of pomace, respectively. Proximate analysis of dried pomace and residue after various extraction were performed where moisture content of row dried pomace was 10 g/ 100 g DW, and residue after a different type of extraction ranged from 5 g to 8 g/ 100 g of DW. Protein content ranged between 13-24 g/100 g of dry residue after various extraction methods (SLE, PLE and UAE). Lipid content yielded from 9-10 g/100 g of analyzed pomace. Honeysuckle pomace extracts possessed strong antioxidant activity. For instance, amount of TPC of initial material of honeysuckle pomace measured by Quencher approach was 248 mg gallic acid equivalents (GAE)/g dry pomace, while TPC of obtained extracts ranged from 19.4 to 51.2(GAE)/g extract. Obtained extracts possessed strong antioxidant capacity in ABTS•+ scavenging and oxygen radical absorbance capacity (ORAC) assays. Our study showed that honeysuckle pomace extracts a good source of phenolic compounds such as anthocyanins. The anthocyanins were identified by the interpretation of their mass spectra determined by the Q-TOF-MS. The main anthocyanins identified in honeysuckle extracts were cyanidin-3-glucoside, cyanidin-3-galactoside, cyanidin-3-arabinoside and etc. The main identified triacylglycerols in residue obtained after Soxhlet extraction were LLLn, LLL, OLL, OOL, OOO, PLL, PLO, POO. In general, honeysuckle pomace possessed wide applications in developing new functional foods and nutraceuticals with health-beneficial properties. |
