Fatty acid composition and tocopherol profiles of safflower (Carthamus tinctorius L.) seed oils.

The oil contents of safflower seeds ranged from 23.08% to 36.51%. The major fatty acid of safflower oil is linoleic acid, which accounted for 55.1-77.0% in oils, with a mean value of 70.66%. Three types of tocopherols were found in safflower oil in various amount α-tocopherol, ß-tocopherol and γ-tocopherol, ranged from 46.05 to 70.93 mg/100 g, 0.85 to 2.16 mg/100 g and trace amount to 0.45 mg/100 g oils, respectively. This research shows that both fatty acid and tocopherol contents differ significantly among the safflowers.

Fatty acid and tocopherol contents of several soybean oils.

The oleic acid content of seed oils varied between 21.4% (ATAEM7) and 26.6% (Türksoy). The proportion of linoleic acid of soybean oil ranged from 49.0% (Türksoy) to 53.5% (ATAEM7), while the palmitic acid of oils varied between 9.2% (Adasoy) and 11.2% (Noya). The major tocopherols were ¥-tocopherol, α-tocopherol and δ-tocopherol in all the varieties of soybean oil. As a result, this study showed that the seeds are to be a potential source of valuable oil which might be used for edible and other industrial applications.

Acrylamide formation and antioxidant level in biscuits related to recipe and baking.

Heated plant foods may contain compounds with adverse health effects (e.g. acrylamide). On the other hand, health-promoting compounds (e.g. antioxidants) have also been identified in such foods. Therefore, a baking experiment with biscuits was carried out to study the potential impact of both acrylamide and antioxidants in that food. Two different wheat flour types - wholemeal (WMF) and white flour type 550 (T550; 0.55% mineral content) - as well as recipe (fat and leavening agent) and thermal input (temperature × time) were changed. Furthermore, the effect of an enzymatic asparagine hydrolysation was tested. Antioxidants were determined with two independent procedures ABTS - (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate)) and FRAP-assay (ferric reducing ability of plasma). WMF samples resulted in an unchanged acrylamide level, but in a significantly higher antioxidant concentration when compared with T550 samples (149 and 141 µg kg(-1) acrylamide and 9.1 and 5.1 mmol TE kg(-1) FW ABTS for WMF and T550, respectively). A reduced fat content yielded in an increased volume. Raising agents had no effect on acrylamide levels, but antioxidants were higher in samples with sodium bicarbonate (SBC) than with ammonium bicarbonate (ABC). Thermal input (temperature × time; 150°C × 25 min to 240°C × 9 min) indicated an exponential acrylamide increase especially at higher temperatures (from 75 to 236 µg kg(-1)), whereas antioxidant increase was linear (from 7.0 to 7.7 mmol TE kg(-1) FW, ABTS). FRAP and ABTS values were correlated on a low level, whereas acrylamide content of biscuits was correlated with FRAP and lightness (R (2 )= 0.62 and 0.47, and 0.71 and 0.85 for WMF and T550, respectively). The enzyme asparaginase reduced acrylamide formation by about 50% for both raising agents (SBC and ABC, respectively), whereas antioxidant levels were not affected. An evaluation of recipe variants with low acrylamide and high antioxidants indicated the advantage of wholemeal biscuits.

Antioxidant activity of extracts obtained from residues of different oilseeds.

Residues of the oil-extracting process of oilseeds contain bioactive substances such as phenolic compounds, which could be used as natural antioxidants for the protection of fats and oils against oxidative deterioration. Thus, the extraction of such constituents from residual material can be considered to contribute to the added value of these residues, which could justify their isolation. In the present work the fat-free residues of eight different oilseeds whose oils are usable for nutritional applications, and also as renewable resources, were extracted with 70% methanol, 70% acetone, water, and ethyl acetate/water, respectively. The resulting extracts were investigated regarding their content of total phenolic compounds by the Folin-Ciocalteau assay, sinapine, flavanoids, and the UV-absorption spectra. Further, the antioxidant activity of the extracts was characterized by the DPPH method, the beta-carotene-linoleic acid assay, and ESR investigations. The fat-free residues of the different oilseeds contained considerable amounts of extractable substances. The yields decreased with decreasing polarity of the solvent in the order water, 70% methanol, 70% acetone, and ethyl acetate. The ratio of total phenolic compounds to the extractable compounds ranged from 3 to 19%. There was no significant correlation between the amount of total extractable compounds and the total phenolic compounds (p < 0.001). All extracts showed remarkable antioxidant activities determined with the different methods. The effects depended strongly on the solvent used for the extraction as well as on the extracted residue. A correlation between the methods used for the characterization of the antioxidant activity and the composition of the residues could not be shown.

Glucosinolates in members of the family brassicaceae: separation and identification by LC/ESI-MS-MS.

Seeds of 14 different members of the family Brassicaceae were investigated with regard to their content and composition of glucosinolates by HPLC-UV/ESI-MS-MS coupling. The seeds were extracted with hot methanol/water (70:30 v/v) and the desulfoglucosinolates isolated by anion-exchange chromatography with solid-phase extraction columns. The desulfoglucosinolates were detected by UV and identified by ESI-MS/MS with the neutral loss method. Nineteen different glucosinolates were detected in the seeds with a wide range of contents (10-200 micromol/g) and a great variation in the composition.

[Chemiluminescence method for the detection of radiation-induced oxidation products in fat-containing foods]. / Chemilumineszenzmethode zum Nachweis strahleninduzierter Oxidationsprodukte in fetthaltigen Lebensmitteln.

Radiation-induced oxidation of fatty foods was detected by a chemiluminescence method. Hazelnuts, peanuts and poultry were used as foodstuff samples. Additional investigations were performed with a model system and sunflower oil. The irradiation of the samples was carried out in a x-ray-fluorescence-apparatus. Thereby it is to note that the G-value of the x-ray-radiation is much higher than the G-value of a cobalt-60-source normally used for irradiation of food. A dependence of the integral of the light curve on the irradiation doses could be proved. Investigations with model systems which contained different amounts of alpha-tocopherol showed a decreasing chemiluminescence signal at low irradiation doses in presence of alpha-tocopherol. At higher doses the chemiluminescence signal enlarges with increasing amounts of alpha-tocopherol because irradiation products of alpha-tocopherol overlay its antioxidative effect. Irradiated poultry samples differ significantly from unirradiated samples after a deep-freeze storage of 26 weeks. A quantification of the doses is not possible without knowledge of the storage time, because the integrals decrease differently after irradiation during storage. In any case the chemiluminescence method is useful as a "screening method" for the detection of irradiation of foodstuffs with the possibility of automation and high sensitivity.