Relevant mycotoxins in oil crops, vegetable oils, de-oiled cake and meals: Occurrence, control, and recent advances in elimination.

Mycotoxins in agricultural commodities have always been a concern due to their negative impacts on human and livestock health. Issues associated with quality control, hot and humid climate, improper storage, and inappropriate production can support the development of fungus, causing oil crops to suffer from mycotoxin contamination, which in turn migrates to the resulting oil, de-oiled cake and meals during the oil processing. Related research which supports the development of multi-mycotoxin prevention programs has resulted in satisfactory mitigation effects, mainly in the pre-harvest stage. Nevertheless, preventive actions are unlikely to avoid the occurrence of mycotoxins completely, so removal strategies may still be necessary to protect consumers. Elimination of mycotoxin has been achieved broadly through the physical, biological, or chemical course. In view of the steadily increasing volume of scientific literature regarding mycotoxins, there is a need for ongoing integrated knowledge systems. This work revisited the knowledge of mycotoxins affecting oilseeds, food oils, cake, and meals, focusing more on their varieties, toxicity, and preventive strategies, including the methods adopted in the decontamination, which supplement the available information.

Co-occurrence of aflatoxins in plant oil products from China.

Aflatoxins have been detected as contaminants of oil crops before harvesting and drying, during storage and manufacturing and could be transferable to plant oils. There are more than 20 different types of aflatoxins, among which the most commonly occurring are the B1, B2, G1 and G2. Concentrations of these four aflatoxins were determined in plant oils from retail shops in China and in crude peanut oil extracted from culled mouldy peanuts by HPLC with fluorescence detection. Overall, aflatoxins were present in 25 of the 63 samples. The four aflatoxins co-existed in vegetable oil, but the content of AFB1 was usually higher than the other aflatoxins. Particularly in the case of highly contaminated oil samples, AFB1 accounted for 68% of the total aflatoxins. According to the health risk assessment, the low margin of exposure values from AFB1 in oils suggests a high level of concern for children.

Removal of aflatoxin B1 from contaminated peanut oils using magnetic attapulgite.

The efficient magnetic adsorbent (Fe3O4@ATP) was prepared by precipitation through the dispersion of Fe3O4 nanoparticles on the natural attapulgite (ATP) and then tested as an adsorbent for aflatoxin B1 (AFB1) removal from contaminated oils. The adsorbent characterization results revealed that the Fe3O4 were incorporated into the ATP, affording the Fe3O4@ATP composite. This magnetic composite displayed a good ability to eliminate AFB1 from contaminated oils with a removal efficiency of 86.82% using a 0.3% dosage. The Fe3O4@ATP possessed paramagnetic character with a saturation magnetization of 50.86 emu/g, enabling its easy separation from the medium using an external magnet. The adsorption process followed the pseudo-second-order model and fitted the Freundlich isotherm well. Moreover, the thermodynamic studies showed that AFB1 adsorption onto Fe3O4@ATP was exothermic and spontaneous. The novelty of this study lies in the fabrication of magnetic composite adsorbents for AFB1 elimination from oils.

Detoxification of Aflatoxin B1 by magnetic graphene composite adsorbents from contaminated oils.

Safety concerns pertaining towards fungal occurrence in oil commodities have been a significant threat to human health. In this research, magnetic composite adsorbents were fabricated for the removal of aflatoxin B1 (AFB1) from contaminated oils. To this goal, graphene oxides (GO) were synthesized using Hummer's method, and graphenes (rGO) were obtained by the reduction of GO by sodium borohydride. Thereafter, magnetic graphene oxides (MGO) and magnetic graphenes (MrGO) were prepared by coprecipitation of iron oxides on GO and rGO nanosheets, respectively. The as-prepared MGO and MrGO were characterized by SEM, TEM, FT-IR, XRD, VSM, and nitrogen adsorption-desorption techniques. Results showed that MGO had two-dimensional layered nanostructure with many wrinkles on its surface, and the Fe3O4 nanoparticles were essentially encapsulated onto the composite. The adsorption behaviors for the composite adsorbents especially for the removal of AFB1 from contaminated oils were systematically explored by varying adsorbent dosage, contact time, adsorption temperature and initial AFB1 concentration. The MGO adsorbent could have great potential in the application of AFB1 removal from contaminated oils, with the merits of facile magnetic separation and high removal efficiency. However, the removal process also causes a loss of the triglyceride, pigment, and beneficial micronutrients in the oil feedstocks.

Oleochemical Properties for Different Fractions of Foxtail Millet Bran.

Foxtail millet (FM) is one of the oldest cultivated grain crops with a variety of nutritions, and foxtail millet bran (FMB), a by-product of FM milling process, is also rich in variety of nutrient substance. There are four classifications of FMB, namely coarse bran (FMCB), skin bran (FMSB), polished bran (FMPB) and mixed bran (FMMB). Because these nutrients are distributed within the different fractions of FMB, we compared some chemical composition and its oleochemical properties of four FMB samples. Results showed that the oil extracted from FMB is high value-added plant oil. It contains abundant unsaturated fatty acid (UFA), with the main UFAs were linoleic acid (65%~69%) and oleic acid (12~17%), which accounted for more than 80% of the lipids. The main triacylglycerols were trilinolein (LLL) and oleodilinolein (OLL). There were no evident difference on fatty acid, triacylglycerol and sterols profiles for FMSB, FMPB and FMMB, but the contents of amino acids, tocols, squalene and oryzanol were different.

Lipid Characterization of Chinese Wild Hazelnuts (Corylus mandshurica Maxim.).

To develop and use the hazelnut, the main composition, and the physicochemical characteristics, fatty acid compositions, triacylglycerol (TAG) distribution and tocol contents of Hazelnut (Corylus mandshurica Maxim.) which growing in Changbai mountain of Jilin province (HO1) and Anshan city of Liaoning province (HO2) in China were investigated, and the comparative study between the two hazelnut oils and American hazelnut / Turkish hazelnut were also explored. The content of crude lipid and protein in HO1 and HO2 were approximately 54% and 17%, 55% and 16%, respectively. The two hazelnut oils were abundant in unsaturated fatty acids, with the primary unsaturated fatty acids were oleic acid (78%-80%) and linoleic acid (14-16%), which accounted for above 90% of the oils. Therefore, both of the hazelnut oils were important sources of essential fatty acid. In addition, the main saturated fatty acid of the two hazelnut oils were palmitic acid (3%) and stearic acid (1-2%). The main triacylglycerols (TGA) profile were dioleolinolein (OOL), oleodilinolein (OLL) and triolein (OOO). The contents of tocol were 574.44 µg/g, 647.49 µg/g oil in HO1 and HO2, respectively, both of them were higher than that of grape seed oils (454 µg/g), olive oils (209 µg/g) and walnut oils (255 µg/g). The total phytosterol contents were over 2000µg/g and ß-sitosterol was the most predominant sterol in two oils.