Evaluation of the pressing process during oil extraction from grape seeds

This study evaluated the physical properties and oil extraction from grape seeds from three white (Welschriesling, Green Veltliner, Hibernal) and two red (Zweigelt and Saint Laurent) must varieties of grapevine by cold screw pressing as the appropriate extraction process. Pressing was carried out by a screw press UNO FM 3F by Farmet Company, Czech Republic. The pressing device consists of a matrix, 220 mm screw, head, heating mantle, nozzle holder, and a nozzle of 10 mm in diameter. The minimal and maximal screw rotation speeds were chosen within the press characteristics in order to achieve a correct expression and to avoid press overload. For successful pressing of the seeds and their storage, their initial moisture content was lowered from 40 to 45% to about 5 to 8% in a chamber dryer. The temperature in the chamber dryer did not exceeded 40 °C. Seeds of all varieties were pressed at the same speeds of 20, 40, 60, and 80 rpm. The characteristics of the grape seeds are as follows: The density ranges from 602.7 to 606.3 kg.m-3, thousand seeds weigh is between 21.9 - 26.6 g, humidity between 5.6 - 7.1% of dry matter and seed oil content, determined by extraction and depending on the variety, ranges from 15.3 to 17.5% in dry basis. The results have confirmed that when the screw rotation speed is changed from 20 to 80 rpm, the press capacity increases on average from 0.84 kg.h-1 to 1.75 kg.h-1, but simultaneously the oil yield reduces from 9.85 to 6.75%. This means that one kilogram of seed may produce 67.5 to 98.5 g of oil. The quantity of the pressed oil ranges from 67.5 to 98.5 g.kg-1 and thus depends on the variety. The measured results can be used in commercial practice for optimizing the pressing process for pressing of oil from grape seeds

Antioxidant capacity, total phenolic compounds and fatty acids composition in walnut oil and bagasse pellets produced at different parameters of the screw press

Different rotational speeds and nozzle diameters of screw press were used to process walnut kernels. To evaluate the influence of pressing conditions on the quality of walnut oil and bagasse pellets the oil pressing temperature, yield of oil, total phenolic compounds, antioxidant capacity and fatty acid composition were measured. The results show that the pressing at different conditions affected the antioxidant capacity and TPC of either bagasse pellets and pressed oil. Higher values of antioxidant capacity and TPC were measured in bagasse pellets than in pressed oils. Higher amount of pressed oil was yielded by using lower nozzle diameter, however, by lowering the nozzle diameter the oil pressing temperature was rising, which affected the fatty acids. Positive correlations with oil pressing temperatures were calculated at saturated fatty acids, while the correlation coefficients of polyunsaturated fatty acids were positive, but not significant. Monounsaturated fatty acids were negatively affected by higher oil pressing temperatures showing, that monounsaturated fatty acids were more susceptible to higher temperatures than polyunasturated and saturated fatty acids.O

Comparison of rheological properties of varietal grape seed oils

The aim of this work was to determine the rheological properties of grape seed oils from different varieties selected at different temperatures. Measurement of the rheological properties of grape seed oils was performed on the instrument Anton Paar MCR 102. The rheological properties of the liquid have been performed at temperatures of 0 °C, 15 °C, 30 °C, 45 °C and 60 °C. The density of measured samples ranged from 0.905 ±0.002 to 0.948 ±0.002 g.mL-1. Subsequently, there were determined viscosity values at a shear rate of 5 s-1. As expected, the viscosity decreased with increasing temperature. Highest viscosity values reached grape seed oil of variety Pinot gris where at 0 °C the viscosity reached 0.206 ±0.037 Pa s. Samples measured at 0 °C showed non-Newtonian behavior, while at higher temperatures liquids behave as Newtonian substances. All grape seed oils samples exhibit non-Newtonian behavior at lower temperatures. In experiments carried out at 0 °C, it was observed that the tested samples tends to behave as shear-thinning system with thixotropic properties. At higher temperatures was, in line with other scientific works, observed that samples behave as Newtonian fluids. Knowledge of the rheological properties of oils are very important for their processing, storage, and may affect their quality

Seed oil content and selected qualitative parameters of oils from grape seeds

Grape seed oil (Oleum vitis viniferae) represents promising plant oil, which is used mainly in gastronomy and for pharmaceutical purposes as well as for various technical applications. In this paper, there were examined oil contents and oil quality properties of seeds taken from 8 grape cultivars. Oil contents were found to be different for each cultivar, which ranged from 11.5% (Dornfelder) to 17.5% (Riesling). The results showed a dependence between the length of the growing season for individual varie-ties and the total content of oil in seeds. Fatty acid concentrations in the evaluated oil samples were in various ranges, while the highest values were determined in linoleic acid 70.10 to 71.55%, oleic acid 15.61 to 17.14%, palmitic acid 6.87 to 8.18% and stearic acid 3.16 to 3.90%. Saturated fatty acid values were lower than the values of monounsaturated fatty acids and polyunsaturated fatty acids in all oil samples. The degree of unsaturation in the grape seed oil ranged between 88.6 - 89.21%. Thanks to its content, grape seed oil can be considered as a food supplement improving the nutri-tional value of the human diet

The Effect of Mulch Materials on Selected Soil Properties, Yield and Grape Quality in Vineyards under Central European Conditions

The results of this study provide overall information on the verification of the effect of applying two different mulching materials of an organic origin to the soil surface in the area between rows of grape vines in vineyards on selected physical and chemical properties of the soil and, at the same time, on the yield and quality parameters of the grape vines (Vitis vinifera L.). During the period under study, 2018-2020, the effect of shredded cereal straw (CS) and compost from garden waste (CO) was investigated. The control variant (CWC) was left without any cover and was regularly cultivated with a coulter cultivator to a depth of 60 mm. During the experiments, meteorological data were monitored and recorded along with soil temperature and soil moisture for each variant. The results show that the lowest temperature was measured for the straw cover variant (11.10-11.87 oC), while the highest soil temperature was measured for compost (11.93-13.16 oC). Under the straw, the moisture level in the soil was higher compared to the other variants, and there was a gradual increase (of 3%) in soil bulk density values compared to the baseline. By contrast, the compost variant showed a decrease (of 1%) in bulk density values. The differences in nutrient content were slight among the variants. The only statistically significant difference was identified for the compost variant with respect to the content of total nitrogen and phosphorus. Further results demonstrated a positive effect of both mulch material variants on grape yield, which was 6-19% higher in the variants with a cover layer. In addition, the use of mulch also had a positive effect on grape quality. For example, the sugar content-one of the main quality parameters-increased by 1-7% due to the mulch layer. Based on these results, the use of mulching materials can be recommended for areas with low total rainfall during the growing season, as well as when growing varieties with irregular yields and uneven grape quality.O

Evaluation of the Thermal Energy Potential of Waste Products from Fruit Preparation and Processing Industry

In the context of a changing climate and increasing efforts to use renewable energy sources and waste materials and to green the environment, new sources and technologies for energy recovery from waste are being sought. This study evaluates the possibilities of energy generation potential from waste products of fruit species used in the food processing industry. The results indicate good potential for energy use of materials from fruit processing due to low input moisture content of around 15 wt. %, an average energy lower heating value (LHV) of 16.5 MJ.kgMINUS SIGN 1, an average low ash content of 4.9% and meeting most of the emission limits of similar biofuels. Elemental analysis and combustion residue studies indicate safe operation within existing standards. The results of our analyses and experience from similar studies allow us to recommend most of the studied waste materials for energy generation use directly in processing plants at the local level.O

Chemometric approach to characterization of the selected grape seed oils based on their fatty acids composition and FTIR spectroscopy

Addressing the issues arising from the production and trade of low-quality foods necessitates developing new quality control methods. Cooking oils, especially those produced from the grape seeds, are an example of food products that often suffer from questionable quality due to various adulterations and low-quality fruits used for their production. Among many methods allowing for fast and efficient food quality control, the combination of experimental and advanced mathematical approaches seems most reliable. In this work a method for grape seed oils compositional characterization based on the infrared (FTIR) spectroscopy and fatty acids profile is reported. Also, the relevant parameters of oils are characterized using a combination of standard techniques such as the Principal Component Analysis, k-Means, and Gaussian Mixture Model (GMM) fitting parameters. Two different approaches to perform unsupervised clustering using GMM were investigated. The first approach relies on the profile of fatty acids, while the second is FT-IR spectroscopy-based. The GMM fitting parameters in both approaches were compared. The results obtained from both approaches are consistent and complementary and provide the tools to address the characterization and clustering issues in grape seed oils.O

Depth Application of Organic Matter in Vineyards and a Verification of Effect on Soil and Growth Conditions

Předkládaná publikace přináší ucelený souhrn výsledků, které byly dosaženy při realizaci experimentů, spojených s návrhem, konstrukčním vývojem a ověřováním zařízení pro hloubkovou aplikaci organické hmoty do příkmenných pásů vinic v období 2017-2020. Nově vyvinuté zařízení je řešeno jako traktorový návěsný stroj na jednonápravovém podvozku s ložnou korbou o objemu 3,0 m3 a s celkovou nosností 2,0 t. Pracovní ústrojí tvoří 2 zapravovací radlice s předsunutým kotoučovým krojidlem, které jsou uchyceny na bočně výsuvných nosnících. Radlice po zahloubení vytváří brázdu, do ní je přiváděn aplikovaný materiál a brázda je následně zahrnuta. Osová vzdálenost obou radlic je stavitelná s ohledem na rozdílnou šířku meziřadí vinic. Stroj umožňuje aplikovat materiál, nejčastěji kompost, do příkmenného pásu v meziřadích o šířce 2,20-3,00 m. Aplikovaná dávka je v rozmezí 20-50 t.ha-1, pracovní rychlost soupravy je 2-4 km.h-1. Vedle vývoje zařízení probíhaly současně poloprovozní experimenty ve vinicích na dvou stanovištích a to v Lednici a ve Velkých Bílovicích. Cílem těchto experimentů bylo ověření vlivu hloubkové aplikace organické hmoty. Hodnocení bylo zaměřeno na zlepšení fyzikálních a chemických vlastností půdy a současně na růst révy vinné, výnos a kvalitu hroznů. Z provedených, opakovaných sledování za období 2018-2020, vyplývá pozitivní účinek aplikované organické hmoty na zlepšení fyzikálních vlastností půdy a na snížení penetrometrického odporu. Z chemických vlastností půdy byl hodnocen obsah základních přístupných živin v půdě, půdní reakce, obsah Corg a z něho vypočítaný obsah humusu. Dále byla hodnocena kvalita humusu a stupeň humifikace. Získané výsledky opět naznačují příznivé účinky hloubkové aplikace kompostu jak na vlastnosti půdy, tak i na růst a vývoj keřů. Z provedeného ekonomického hodnocení vyplývá, že průměrná úspora nákladů na hloubkovou aplikaci, ve srovnání se standardními postupy, dosahuje 2 200-2 600 Kč. ha- 1. V závislosti na šířce meziřadí to představuje 34-49 %. Výsledky práce ukazují, že hloubková aplikace kompostu do příkmenných pásů má vliv na zlepšení půdních podmínek na produkčních plochách vinic a umožňuje dosažení vyšších výnosů i vyšší kvality produkce. Lze očekávat, že dalšími přínosy tohoto způsobu aplikace bude také zvýšení retenční schopnosti půdy a snížení eroze ve svahovitých polohách.The presented publication provides a comprehensive summary of the results achieved in the implementation of experiments associated with the design, construction development and verification of equipment for deep application of organic matter to the inter-row strips in vineyards in the period 2017-2020. The newly developed device is designed as a tractor-mounted machine on a single- axle chassis with a loading shell with a volume of 3.0 m3 and a total load capacity of 2.0 t. The working device consists of 2 defraying ploughshares with an advanced disc coulter, which are mounted on laterally extendable beams. After the countersinking, the ploughshare forms a furrow, the applied material is fed into it and the furrow is subsequently covered. The axial distance of both ploughshares is adjustable with regard to the different width of the inter-rows of vineyards. The machine allows to apply the material, most often compost, to the inter-row strips in inter-rows with a width of 2.20-3.00 m. The applied dose is in the range of 20-50 t/ha, the working speed of the set is 2-4 km/h. In addition to the development of the facility, semi-operating experiments were carried out simultaneously in vineyards at two sites in Lednice and Velké Bílovice. The aim of these experiments was to verify the effect of deep application of organic matter. The evaluation focused on improving the physical and chemical properties of the soil and at the same time on the growth of the vine, the yield and the quality of the grapes. The performed, repeated observations for the period 2018-2020 show a positive effect of the applied organic matter on the improvement of the physical properties of the soil and on the reduction of the penetrometric resistivity. From the chemical properties of the soil, the content of basic accessible nutrients in the soil, soil reactions, the content of Corg and the humus content calculated from it were evaluated. Furthermore, the quality of humus and the degree of humification were evaluated. The obtained results again indicate the beneficial effects of deep application of compost both on soil properties and on the growth and development of vine shrubs. The performed economic evaluation shows that the average saving of deep application costs, in comparison with standard procedures, reaches 2 200-2 600 CZK/ha. Depending on the width of the inter-row, this represents 34-49 %. The results of the work show that the deep application of compost into the inter-row strips in vineyards has an effect on the improvement of soil conditions in the production areas of vineyards and allows to achieve higher yields and higher quality of production. It can be expected that other benefits of this method of application will also be an increase in soil retention capacity and a reduction in erosion in sloping positions.Published Versio

Macrocheles species (Acari: Macrochelidae) associated with human corpses in Europe

The biology of macrochelid mites might offer new venues for the interpretation of the environmental conditions surrounding human death and decomposition. Three human corpses, one from Sweden and two from Spain, have been analysed for the occurrence of Macrochelidae species. Macrocheles muscaedomesticae females were associated with a corpse that was found in a popular beach area of southeast Spain. Their arrival coincides with the occurrence of one of their major carrier species, the filth fly Fannia scalaris, the activity of which peaks during mid-summer. M. glaber specimens were collected from a corpse in a shallow grave in a forest in Sweden at the end of summer, concurrent with the arrival of beetles attracted by odours from the corpse. M. perglaber adults were sampled from a corpse found indoors in the rural surroundings of Granada city, Spain. The phoretic behaviour of this species is similar to that of M. glaber, but being more specific to Scarabaeidae and Geotrupidae dung beetles, most of which favour human faeces. M. muscaedomesticae is known from urban and rural areas and poultry farms; M. glaber from outdoors, particularly the countryside; while M. perglaber from outdoor, rural, and remote, potentially mountainous locations. M. muscaedomesticae and M. perglaber are reported for the first time from the Iberian Peninsula. This is the first record of M. perglaber from human remains