Effect of the Bleaching Process on Changes in the Fatty Acid Profile of Raw Hemp Seed Oil (Cannabis sativa).

Many refined oils from soybean, rapeseed, and sunflower, among others, are available on the food market, except olive oil. Refining, on the small production scale of niche oils, is not used due to the high cost of the refining process. Unrefined oils are characterized by intense taste, odor, color, and undesirable nutrients. The problem to be solved is determining the effects of incomplete refining of niche oils on their composition. One process, which does not require the use of complex apparatus, is the bleaching process. The results presented in this article relate to the research stage, in which the aim is to evaluate the changes occurring in the oil due to the low-temperature bleaching process with different process parameters. The presented research results provide evidence of the absence of adverse changes in the fatty acid profile of hemp oil of the varieties 'Finola', 'Earlina 8FC', and 'Secuieni Jubileu'. Seven different types of bleaching earth were used to bleach the oil in amounts of 2.5 and 5 g/100 g of vegetable oil. The fatty acid profile was obtained by gas chromatography (GC-FID). The obtained chromatograms were subjected to statistical analysis and principal component analysis (PCA). The results show that there was no effect of the type of bleaching earth and its amount on the change in the fatty acid profile of bleached oils. Only real differences between the types of hemp oils were observed. However, an overall positive effect of the bleaching process on hemp oil was found. The amount of saturated fatty acid (SFA) was reduced by 17.1% compared with the initial value, resulting in an increase in the proportion of polyunsaturated fatty acids (PUFA) by 4.4%, resulting in an unsaturated fatty acid (UFA) proportion of 90%. There was a significant improvement in the SFA/PUFA ratio by 26% over the baseline, and the omega-6/omega-3 ratio by 8.9% to a value of 3.1:1. The new knowledge from this study is evidence of the positive effect of the low-temperature bleaching process on the fatty acid profile. In contrast, the parameters of the bleaching process itself are not significant.

Analysis of Changes in the Amount of Phytosterols after the Bleaching Process of Hemp Oils.

Unrefined vegetable oils from niche oilseeds are now sought after by consumers because of their unique nutritional properties and taste qualities. The color and flavor intensity of niche oils is a big problem, and their refining is not industrially feasible due to the small production scale. The study undertaken aimed analyze the effect of changing the amount of phytosterols (PSs) after the bleaching process of hemp oils of the 'Finola', 'Earlina 8FC' and 'Secuieni Jubileu' varieties. Cold-pressed (C) and hot-pressed (H) crude vegetable oils were bleached with selected bleaching earth (BE) at two concentrations. The post-process BE was extracted with methanol. The amount of PSs in the crude oils and the extract after washing the BE with methanol was analyzed by GC (gas chromatography). The study shows that the bleaching process did not significantly affect the depletion of PSs in the oils. Trace amounts of PSs remain on the BE and, due to methanol extraction, can be extracted from the oil. The conclusion of the performed research is that the bleaching of hemp oil does not cause depletion of the oil, and it significantly improves organoleptic properties. The oil bleaching process results in an oil loss of less than 2% by weight of the bleached oil, while the loss depends on the type of BE used. The study shows that the loss of phytosterols after the bleaching process averages 2.69 ± 0.69%, and depends on the type of BE used and the oil extracted from different varieties of hemp seeds.

Quality of Oil Pressed from Hemp Seed Varieties: 'Earlina 8FC', 'Secuieni Jubileu' and 'Finola'.

In the last decade, the demand for edible niche oils has increased. Therefore, the aim of this study was to characterize the seeds hemp (Cannabis sativa L.) varieties: 'Finola' (FIN-314)', 'Earlina 8FC', and 'Secuieni Jubileu', and cold and hot pressed oils were prepared from each seed. The seeds were examined for moisture content, granulometric distribution, bulk density, and fat content. Seeds were pressed without and with preconditioning (60 °C), and oil yield and pressing time were recorded. The oil was filtered through cellulose membranes. Oil-water content, oil color, fatty acid profile, and sterol content were studied. From the study conducted, there are significant differences in the parameters of oil recovery and its quality compared to 'Finola' seed oil, which is widely reported in the literature. 'Finola' oil yield was the lowest, with an average of 79% compared to 'Earlina' (82%) and 'S. Jubileu' (84%). All oil samples contained a comparable amount of sterols, with campesterol (0.32 mg/g), ß-sitosterol (1.3 mg/g) and Δ5-avenasterol (0.15 mg/g) predominating. From the organoleptic evaluation, it was evident that both varieties hemp oils and marc ('Earlina' and 'S. Jubileu') were not bitter like the "Finola" oil and marc. More detailed studies in this direction have to be undertaken.

Low-Cost Investment with High Quality Performance. Bleaching Earths for Phosphorus Reduction in the Low-Temperature Bleaching Process of Rapeseed Oil.

Rapeseed oils are a valuable component of the diet. Mostly, there are refined oils deprived of valuable nutrients in the market, hence in recent times cold-pressed and unrefined oils have been available and popular among consumers. However, the low yield of this oil makes this product expensive. The aim of the study was to analyse the effectiveness of phosphorus reduction in crude oils, cold- and hot-pressed in the low-temperature bleaching process. Eight market-available bleaching earths was compared. The effectiveness of 90% was found with 2% (m/m) of Kerolite with hydrated magnesium silicate. An increase in the share of earths to 4% (m/m) resulted in the effectiveness of phosphorus reduction >90% in seven out of eight analysed cases. Bentonite activated with acid with the lowest MgO content was characterised by low efficiency <64%. The research shows that the effectiveness of phosphorus reduction was significantly affected by the composition of earths applied in the bleaching process at ambient temperature. The results of research confirm the high effectiveness of the process as it is not necessary to heat up the oil before the bleaching process. This method is recommended for existing and new industrial plant for two-stage rapeseed oil pressing.

Pea cultivar Blauwschokker for the phytostimulation of biodiesel degradation in agricultural soil.

Phytoremediation is a cost-effective and ecologically friendly process that involves the use of plants to uptake, accumulate, translocate, stabilize, or degrade pollutants. The present study was conducted to demonstrate the potential of pea (Pisum sativum L. spp. sativum) cultivar Blauwschokker to phytostimulate biodiesel degradation in an agricultural soil, considering the influence of biological remediation on selected physiological parameters of plants and the amount and activity of soil microflora. Biodiesel was spiked into soil in dose of 50 g kg-1 of dry mass soil. The results of the study showed that the rate of biodiesel degradation in the vegetated soil was higher than that occurring by natural attenuation. At the same time, biodiesel showed a positive effect on the growth, development, and activity of soil bacteria and fungi. Moreover, the obtained results showed an improvement in physiological parameters of plants, including an increase in chlorophyll a and total chlorophyll content and higher relative water content in leaves in the presence of biodiesel.