Dorota Derewiaka

Phytosterol oxides content in selected thermally processed products

Heat treatments are very popular methods of food preparation in European countries. Phytosterol present in foodstuffs undergoes oxidative changes during heat treatment, and phytosterol oxides (e.g., 7α-, 7β-hydroxysterol, 5α,6α-, 5β,6β-epoxysterol, 7-ketosterol and triol) are formed. Phytosterol oxidation products (POPs) have been associated with cytotoxic and pro-apoptotic effects in humans. On the other hand, several studies conducted on animals revealed that some phytosterol oxides lower serum triacyglycerol and blood glucose levels. The aim of this study was to evaluate the effect of heat treatment on formation of phytosterol oxidation products in selected foodstuffs. The following products were taken into considerations: minced meat (pork and beef), frozen French fries, frozen fish fillets, frozen fish products (e.g., fish sticks), wheat and egg noodles. Sterols and POPs content was evaluated by GC–MS working in total and selected ion monitoring modes. The phytosterol oxidation rate was higher in French fries and fish fillets (0.20–1.69% of total phytosterol content) than in noodles, minced meats and readymade fish products (in 0.04–0.36% range). Method of POPs determination using GC–MS is reported in this study. Results of this study show also that products of the animal origin might be considered as sources of the phytosterol oxides in the human diet.

Amaranth Seeds and Products – The Source of Bioactive Compounds

Abstract In recent years, new products obtained from amaranth seeds have entered the food market including expanded “popping” seeds and flakes. Lipids and biologically-active substances dissolved in these products are susceptible to changes. Additionally, due to the fact that fat quality has high dietary importance, there is a need to conduct detailed quality and quantity studies on the lipid composition of Amaranthus cruentus. For the samples under analysis, protein, fat, starch and ash content were determined. Fatty acids and sterols were analysed by gas chromatography. The analysis of tocopherols and squalene content was carried out with the application of high-performance liquid chromatography coupled with photodiode array and fl uorescence detectors (HPLC-DAD-FLD). Protein, fat and starch content did not change during seed processing. However in the case of tocopherols, the total tocopherol content was 10.6 mg/100 g for seeds, while in “popping” and in flakes it was reduced by approximately 35%. The squalene content ranged from 469.96 mg/100 g for seeds to 358.9 mg/100 g for flakes. No significant differences were observed in the fatty acid profile of seeds and products, but differences were observed in the sterol content.

Characteristics of Biologically-Active Substances of Amaranth Oil Obtained by Various Techniques

Amaranth seeds and their main product amaranth oil are a rich source of bioactive substances. The non-saponifi able substances which accompany lipids include: squalene, tocopherols, sterols and others. The aim of the study was to compare the content of squalene, tocopherols and phytosterols in amaranth oils obtained by various techniques. The oil was extracted from seeds (Amaranthus cruentus) with the use of supercritical fl uid extraction (SFE), extraction with a chloroform/methanol mixture and expeller pressing. Contents of squalene and tocopherols were determined with high performance liquid chromatography (HPLC) method. The content of sterols in oils was determined by gas chromatography coupled with mass spectrometry (GC-MS). The highest squalene content was found for the oil obtained as a result of supercritical CO2 extraction (6.95 g/100 g of oil). A lower content of squalene was noted in the oil extracted with organic solvents and in cold-pressed oil - 6.00 and 5.74 g/100 g of oil, respectively. The amaranth oils were characterised by a signifi cant content of tocopherols. The oil obtained as a result of fl uid extraction was characterised by the highest content of tocopherols (131.7 mg/100 g of oil). A dominating homologue (40%) was β-tocopherol. Also the same sample was characterised by the highest content of sterols (2.49 g/100 g of oil). In all samples the predominating sterol was sum of α-spinasterol and sitosterol, which accounted for 45%, 56% and 53% of total analysed sterols for the oil obtained from SFE, from extraction with solvents and from cold pressing, respectively.

Mechanical hulling and thermal pre-treatment effects on rapeseed oil antioxidant capacity and related lipophilic and hydrophilic bioactive compounds

Abstract In this study, the effect of rapeseed mechanical hulling and thermal pre-treatment by microwaves (from 2 to 10 min with 2-min intervals, 800 W) and roasting (from 20 to 100 min with 20-min intervals, 165 °C) on the content of phytochemicals in the oil was investigated. Results showed that both pre-treatments applied differentiated the oils in terms of the content of bioactive compounds. In general, oils pressed from hulled and thermally pre-treated seeds contained higher content of tocopherols, PC-8 and phytosterols, while oils pressed from non-hulled and pre-processed seeds had significantly higher concentration of polyphenols. Both microwaving and roasting contributed to an increase of antioxidant capacity of studied oils. The increase of radical scavenging activity of oils was seen mainly in hydrophilic fraction of oil, which was highly positively correlated with the amount of canolol formed during seeds heating.

Comparison of Fatty Acid Composition in Selected Dietary Supplements Containing Conjugated Linoleic Acid

ABSTRACT The market of pharmaceutical products is offering a wide range of supplements. Most of the consumers believe that these products will improve their state of health, but are they getting what they want and what they are paying for? The aim of the study was to evaluate the quality of selected dietary supplements containing conjugated linoleic acid (CLA). All supplements were available in the Warsaw markets and bought from pharmacies. Assessment of the quality of food supplements was achieved by analysis of fatty acid using gas chromatography coupled with a mass spectrometer. On the basis of the investigations carried out, it was found that content of CLA in selected dietary supplements ranged between 282 and 528 mg by weight of a single capsule. The content of bioactive ingredients found in three of the four product supplements assessed was lower than was claimed by the manufacturer.

Ocena informacji przekazywanych konsumentom na temat obecności alergenów / Evaluation of information passed on consumers on the presence of alergens

Streszczenie: Alergeny występujące w produktach spożywczych są jednym z zagrożeń, na które producent żywności musi zwrócić szczególną uwagę. Celem badania była analiza informacji przekazywanych konsumentom na temat występowania alergenów w wybranych produktach spożywczych, zarówno w przypadku żywności opakowanej i nieopakowanej dostępnej w lokalach gastronomicznych głównie na terenie Grójca i okolic.