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Nutmeg (Myristica fragrans) and star anise (Illicium verum) are popular spices worldwide originally from South East part of Asia. In addition to as food condiment, they have been used extensively in traditional medicine and lately as a subject of research in the field of pharmacology and medical sciences. Most research has been done on the subject of essential oils, especially for star anise, while data on seed oil properties are much scarcer. The main problem in the oil extraction of nutmeg is the hardness of the nut, while, for star anise seed, it is relatively low oil yield (around 10%). This presents a significant problem for screw press production and demands different methods of extraction for better oil yield and quality. The aim of this research was to compare three different methods of oil extraction with n-hexane agitation-assisted extraction (AAE), Soxhlet extraction (SE), and accelerated solvent extraction (ASE) at 25 and 100 °C and to compare the processes on the basis of invested time, oil yield, and fatty acid and sterol profile of the oils. The determination of fatty acid composition was carried out by GC–flame ionization detection (FID) analysis of fatty acid methyl esters, while the sterol composition was determined with GC–MS. The highest yield of oil was obtained using the Soxhlet method, while the best results combining time and yield were obtained with the ASE method at 100 °C. The main fatty acid in star anise seed oil was lauric acid (average 62.30%) with significant differences across extraction methods (p < 0.05), while myristic acid (average 75.69%) was the most abundant in all samples of nutmeg oil. The main sterol in all samples was β-sitosterol.

AbstractFennel (Foeniculum vulgare Mill.) is a well-known aromatic plant, widely used as spice and remedy herb. It provides many beneficial effects and is used as diuretic and expectorant, as well as for various dyspeptic disorders. Beside essential oils, fennel seeds are abundant with various phenols, which are known as strong antioxidants and thereby contribute to human health. Among different extraction methods for phenols isolation, pressurized liquid extraction (PLE) represents a novel technique with numerous advantages over conventional extraction approaches. Its efficiency manifests through combination of high temperature and pressure, enabling extraction time shortening, as well as decreased solvent consumption, thus being environment-friendly technique. In order to achieve maximum extraction yield, it is of great importance to select optimal PLE conditions, e.g., extraction temperature and time. Additionally, solvent selection also affects on content of targeted compounds, where phenols amount depends on polarity of solvent. Hence, the aim of this study was to examine the effect of temperature (75 and 100 °C), static time (5 and 10 min) and cycle number (1, 2 and 3) on total phenols (TP) and total flavonoids (TF) content, as well as the antioxidant capacity (AC) in fennel seeds using three-step exhaustive PLE. Firstly, grinded dry fennel seeds were subjected to PLE using non-polar solvent (hexane) under the mentioned conditions in order to remove seeds' lipid fraction. Afterwards, defatted samples were extracted with polar solvents by the increasing polarity: aqueous acetone solution (30 %, v/v) followed by aqueous methanol solution (30 %, v/v). Obtained acetone (AE) and methanol (ME) extracts (n = 24) were analyzed for TP (Folin-Ciocalteu method), TF (aluminium chloride colorimetric assay) and AC [ferric reducing antioxidant power (FRAP) method]. Multivariate analysis of variance (MANOVA) and Tukey's HSD test (p ≤ 0.05) were applied for statistical analysis of collected data. Expectedly, AE were described with higher values of analyzed parameters (grand means: TP = 416.18 mg/100 g, TF = 41.87 mg/100 g, AC = 359.57 mg AAE/100 g) in comparison with ME (grand means: TP = 80.25 mg/100 g, TF = 16.41 mg/100 g, AC = 96.13 mg AAE/100 g. Furthermore, all examined influences significantly affected TP, TF and AC in all samples, except temperature on TP in ME. Thus, conditions of 100 °C/10 min/3 cycles showed the greatest yield of tested parameters in AE, while 100 °C/5 min/1 cycle were sufficient for maximum TP and AC levels in ME. Regarding TF in ME, slightly longer extraction time was required to achieve the highest efficiency (100 °C/10 min/1 cycle).

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