Adsorption behavior of activated carbon for the elimination of zearalenone during bleaching process of corn oil

Zearalenone is a mycotoxin produced by Fusarium species.It frequently contaminates cereals used for foods or animal feeds,especially deposited in crude corn oil.Certain amounts of zearalenone can be removed during refining processes.In this study,we studied the influence of activated carbon and six industial absorbents(zeolite,diatomite,attapulgite,perlite,montmorillonite and activated clay)on the elimination of zearalenone during bleaching process of corn oil and explored the absorption mechanism of activated carbon.Results showed that activated carbon had an excellent adsorption capacity of zearalenone compared with the other six industrial adsorbents.For activated carbon,a high removal rate of zearalenone(exceeding 83%)from heavily zearalenone-polluted corn oil was achieved and the removal rate of zearalenone was kept above 60%after five regeneration cycles.The research on the adsorption mechanism of activated carbon showed that Freundlich adsorption isotherm model and pseudo-second-order kinetic model could well described the adsorption process.The thermodynamic study demonstrated that adsorption process was spontaneous and exothermic.Fourier transform infrared spectroscopy and Raman spectroscopy further revealed that activated carbon was effectively combined with zearalenone viaπ-πinteraction.Thus,activated carbon is an efficient and suitable adsorbent to control the levels of zearalenone during bleaching process of corn oil.This study not only proposed a systematic research scheme for the mechanism study of activated carbon for the elimination of zearalenone in corn oil,but also provided the scientific basis for developing effective methods to eliminate zearalenone in refined vegetable oils.

Retardation of 4-Hydroxy-2-Transnonenal (HNE), a Toxic Aldehyde Formation by Antioxidants in Heat-Treated Corn Oil at Frying Temperature

The antioxidative properties of four antioxidants such as rosemary extracts (RE), tert-butylhydroquinone (TBHQ), ascorbyl palmitate (AP), citric acid (CA) and their mixtures were investigated on the formation of 4-hydroxy-2-transnonenal (HNE) in commercial corn oil heated at 185°C for up to 6 hours. Among the antioxidants 100 ppm RE and a mixture of 200 ppm tertiary butylated hydroquinone (TBHQ) + 100 ppm ascorbyl palmitate (AP) + 50 ppm citric acid (CA) exhibited excellent antioxidative activity, as determined by the thiobarbituric acid reaction (TBARS) assay, measuring the formations of the secondary lipid oxidation products and by high-performance liquid chromatography (HPLC), measuring the formation of the toxic α, β-unsaturated hydroxyaldehyde HNE after heat treatment of corn oil at 185°C up to 6 hours. TBHQ, AP and CA alone did not show much protective properties. The synergistic effects of TBHQ + AP + CA mixture shown to reduce the formation of HNE after 6 hours heat-treated corn oil by 27%. RE 100 ppm was also found to be a very effective antioxidant, reducing the formation of HNE after 6 hours heat-treated corn oil in the same condition by 29%.

The Antioxidant Activity of Barley Malt Rootlet Extracts in Heated Corn Oil at Frying Temperature

In this study the antioxidant activity of barley malt rootlet (BMR) extracts was evaluated in heat treated corn oil up to 5 hours at 185°C frying temperature. The antioxidant activity of BMR extracts was measured at 25, 50, 100 and 150 ppm concentrations. The free and bound antioxidant phenolics were extracted from BMR using three different extraction methods. Conventional solvent extraction (CSE), microwave assisted extraction (MAE) and autoclave assisted pretreated solvent extraction (APSE). In the present experiment, the total phenolic content and antioxidant activity of the various extracts were measured. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the ability of the BMR to protect lipid peroxidation in corn oil at 185°C frying temperature. The formation of TBARS at 5 hours of heat treated corn oil has shown similar antioxidant levels in 150 ppm butylated hydroxytoluene (BHT) or MAE free phenolic extract added to corn oil. TBARS value for BHT was 1.896 ± 0.013 μg/mL of corn oil and for MAE was 1.896 ± 0.034 μg/mL of corn oil. The highest level of antioxidant activity was found for the free phenolic extracts. The order of inhibition of oxidation was found to be for free phenolics as follows: BHT (100 ppm) > APSE (50 ppm) > MAE (100 ppm) > CSE (100 ppm).

Olive and Corn Oil Enriched Diets Changed the Phospholipid Fatty Acid Composition in Mice Liver after One-Thirds Hepatectomy

We examined the effect of dietary fats on the kinetics of liver regeneration after one-third partial hepatectomy (PH) in male Balb/c mice. Corn and olive supplemented diets were chosen as a model of n-6 and n-9 diets. Phospholipid fatty acids were determined by gas chromatography (GC) after previous fractionation by solid-phase extraction using aminopropyl (NH2) column, and data were analysed by nonparametric Kruskal-Wallis test. Diet enriched with corn and olive oil did not affect the balance of lipid disorders during liver regeneration after 1/3 PH. Desaturases activity direction has changed depending on the used diet. The key role in the alteration of the polar fatty acids profile at all stages of liver regeneration and examined dietary fats is played by activity of stearoyl-CoA desaturase (SCD).

Effect of Different Vegetable Oils (Red Palm Olein, Palm Olein, Corn Oil and Coconut Oil) on Lipid Profile in Rat

The objective of the study was to evaluate the effects of different vegetable oils [red palm olein (RPO), palm olein (PO), corn oil (CO) and coconut oil (COC)] on lipid profile in rat. Sixty six Sprague Dawley male rats were randomly divided into eleven groups of 6 rats per group and were treated with 15% concentrations of RPO, PO, CO and COC for 4 and 8 weeks. Rats in control group were given normal rat pellet only while in treated groups 15% of additional vegetable oils were given. The results at 4 weeks showed a decline in Low Density Lipoprotein Cholesterol (LDL-C) values at RPO and PO groups whereas in CO and COC groups the LDL-C were increased compared to the control group. The High Density Lipoprotein Cholesterol (HDL-C) values increased in RPO and PO groups whereas it was declined in CO and COC groups compared to the control group. At 8 weeks, there was no significant difference (P ≥ 0.05) in HDL-C of rats treated with vegetable oils compared to the control group. However, the LDL-C in RPO and PO was significantly decreased (P ≤ 0.05) in the LDL-C and there was no significant difference (P≥0.05) for CO and COC groups compared to the control groups. The mean value of the LDL-C after 8 weeks in the control group, RPO, PO, CO, and COC groups were 66.1 mg/dl, 31.9 mg/dl, 41.1 mg/dl, 50.41 mg/dl and 54.31 mg/dl respectively. There was significant decreased (P ≤ 0.05) in the total cholesterol (TC) in RPO group for 4 weeks compared to the control group while the TC in PO, CO and COC were within the normal range. The results of TC in all treated rats for 8 weeks were within the normal range. There was no significant difference in TC of rats treated with vegetable oils compared to the control group. Triglycerides (TG) in all treated rats for 4 weeks were within the normal range whereas the TG in RPO, PO and CO groups for 8 weeks were significant increase (P ≤ 0.05) compared to the control group but there was no significant difference between the control group and COC group.

ω-3 Rich Tetracarpidum conophorum Oil Exhibits Better Prevention Effects for Cardiovascular Risk Factors than Corn Oil in Adult of Albinos Wistar Male Rats

Cardiovascular diseases are serious pathologies that affect an increasing number of people. Several preventive measures are generally used, including supplementing of oils in foods. Our objective was to compare the effects of Tetracarpidum conophorum oil (TC) and corn oil (CO) on serum lipid profiles of normal male rats. 42 Wistar rats were divided into 7 groups. Diets included TC oil (groups TC5, TC10 and TC20) and corn oil (groups CO5, CO10 and CO20) in proportions of 5%, 10% and 20%, with a control group (T). After 5 weeks of feeding, several parameters were measured during and after the study, including body weight, food intake and organ weights (kidney, liver and fat). Lipid profiles (total cholesterol, TG, HDL and LDL), glucose and protein levels were measured in the serum. The increase in body mass was inversely proportional to the amount of oil in the food. The decrease in body mass and adiposomatic index of group TC10 was significant (p < 0.05) compared with the other groups. The lowest glycaemia (64.17 ± 5.14 mg/dl) was noted with the diet containing 20% TC oil. A significant reduction in total cholesterol, LDL fraction and blood triglycerides was observed in the groups supplemented with TC and corn oils compared to controls. Results were also more beneficial for the TC10 group. HDL-cholesterol levels were significantly higher (p < 0.05) in the oil-supplemented groups than in the control group. Castelli’s risk indices decrease significantly (p < 0.05) with increasing oil content for TC. The oils had no impact on blood protein contents. One can conclude that a diet containing 10% crude oil from TC kernels could prevent or alleviate cardiovascular diseases and glycemia.

Comparison of Phosphorous Absorption, Quality and Yield Between High Oil Corn and Common Corn as Influenced by Phosphorous Application

A field trial was carried out to investigate phosphorous (P) absorption, grain quality and yield between high oil corn and common corn. The results indicated that high oil corn var.Tongyou 1 obtained lower highest P absorption rate (HAR) and later occurring date of HAR, in comparison with common corn var. Simi 25. The highest HAR and the earliest occurring date of HAR was obtained by the treatments of P45 and P75 in Tongyou 1 and Simi 25 separately; while the total amount of P accumulated by maize plant was achieved by P105 treatment in both varieties. P in grain relied mainly on root uptake at maturation that accounted for 85.7-96.8% and 79.3-84.3% for Tongyou 1 and Simi 25, respectively. Tongyou 1 contained more oil and protein contents, but less starch content with lower grain yield. P application at appropriate rate enhanced contents of protein and fatty acid, but the increment of starch content was neglectable. Acknowledgements This study was financed by the National Key Tech- nologies R & D Program (2004BA520A13), P.R.China.

Corn cob modified by lauric acid and ethanediol for emulsified oil adsorption

Corn cob is a naturally renewable material with developed micropore and hydrophobic characteristics, which enables it to show good oil adsorption capacity. In order to improve oil adsorption capacity, corn cob was modified with lauric acid and ethanediol. The structure of raw and modified corn cob was investigated using Fourier transform infrared(FTIR) spectroscopy, scanning electron microscopy(SEM), Brunauer-Emmett-Teller(BET) method, thermogravimetric analysis(TGA) and Ze Ta potential analyzer. The effects of p H level, adsorption time, adsorbent dosage, and initial oil concentration on oil absorbency of corn cob were studied. The results indicate that the modification significantly improved the lipophilicity of corn cob, making the modified corn cob with much better adsorption capacity on oil absorbency. Compared with raw corn cob, the maximum saturated adsorption capacity of modified corn cob is 16.52 mg/g at p H 5, and the increasing percentage is found to be 141%, which indicates that the modification causes a better adsorption capacity for oil removal. In addition, due to high oil adsorption capacity, affordable price and low secondary pollution, the modified corn cob could be considered promising alternative for the traditional oil adsorbent to clean up the emulsified oily water.

Study on Microwave Preparation of Conjugated Linoleic Acid from Corn Germ Oil

[Objective] The optimal craft of preparing conjugated linoleic acid from corn germ oil by dint of microwave method was studied. [Method] Microwave power, microwave mode of action, the amount of catalyst and solvent were selected for single-factor-experiment. Then, based on the single-factor-experiment, the catalyst and solvent amount, and microwave function time were chosen for orthogonal experiment so as to determine the optimal craft of preparing CLA from corn germ oil. UV absorption spectra and infrared absorption spectrum were used to analyse the structural features of natural corn germ oil and CLA. [Result] The optimal preparation condition was as follow: the catalyst was 0.6 times heavier than oil, solvent was 3 times heavier than oil weight, microwave worked for ten minutes. Under the optimal condition, CLA was 56.3% and conversion rate was 99.47 %. The results indicated that non-conjugated double bonds of linoleic acid can be isomerized and changed into conjugated double bonds under the conditions of microwave irradiation.

The interactions between Chinese local corn and WTI crude oil prices:an empirical analysis

This paper investigates the relationship between China’s fuel ethanol promotion plan and food security based on the interactions between the crude oil market, the fuel ethanol market and the grain market. Based on the US West Texas Intermediate(WTI) crude oil spot price and Chinese corn prices from January 2008 to May 2018, this paper applies Granger causality testing and a generalized impulse response function to explore the relationship between world crude oil prices and Chinese corn prices. The results show that crude oil prices are not the Granger cause of China’s corn prices, but changes in world crude oil prices will have a long-term positive impact on Chinese corn prices. Therefore, the Chinese government should pay attention to changes in crude oil prices when promoting fuel ethanol. Considering the conduction e ect between fuel ethanol and the food market, the government should also take some measures to ensure food security.

Soybean seed protein, oil, fatty acids, and mineral composition as influenced by soybean-corn rotation

Effects of crop rotation on soybean (Glycine max (L) Merr.) seed composition have not been well investigated. Therefore, the objective of this study was to investigate the effects of soybean-corn (Zea mays L.) rotations on seed protein, oil, and fatty acids composition on soybean. Soybeans were grown at Stoneville, MS, from 2005 to 2008 in five different scheduled cropping sequences. In 2007, following three years of rotation with corn, seed oleic acid percentage was significantly higher in any crop rotation than continuous soybean. The increase of oleic fatty acid ranged from 61 to 68% in 2007, and from 27 to 51% in 2008, depending on the rotation. The increase of oleic acid was accompanied by significant increases in seed concentrations of phosphorus (P), iron (Fe), and boron (B). In 2007, the increase of P ranged from 60 to 75%, Fe from 70 to 72%, and B from 34 to 69%. In 2008, the increase of P ranged from 82 to 106%, Fe from 32 to 84%, and B from 62 to 77%. Continuous soybean had higher linoleic:oleic ratio and linoleic: palmitic + stearic + oleic ratio, indicating that relative quantity of linoleic acid decreased in rotated crops. The total production of protein, oil, stearic and oleic fatty acids was the lowest in continuous soybean. The total production of palmitic acid was inconsistent across years. The results show that soybean- corn rotation affects seed composition by consistently increasing seed oleic fatty acid, P, Fe, and B concentrations. Higher oleic acid, unsaturated fatty acid, is desirable for oil stability and long-shelf storage. The mechanisms of how these nutrients are involved are not yet understood.

天然抗氧化剂对玉米油热致异构体的影响

玉米油在加工贮藏过程易发生异构化生成反式和共轭脂肪酸异构体,开展玉米油反式和共轭脂肪酸的调控研究对保障消费者安全与营养健康至关重要。人工抗氧化剂由于毒性累积已被许多国家禁用或严格限制,天然抗氧化剂已开始引起人们的高度关注。该研究采用气相色谱检测方法研究了天然抗氧化剂对玉米油热致异构体形成的影响。结果表明,玉米油反式和共轭脂肪酸含量随着加热温度和加热时间的增加而增加。天然抗氧化剂具有抑制玉米油反式脂肪酸(0.28%~6.59%)和诱导玉米油共轭脂肪酸(0.53%~16.42%)形成的作用,抑制率为鼠尾草酸>特丁基对苯二酚>L-抗坏血酸棕榈酸酯>茶多酚>维生素E,诱导率为维生素E>茶多酚>特丁基对苯二酚>L-抗坏血酸棕榈酸酯>鼠尾草酸。复配抗氧化剂的抗异构和诱导异构作用低于单独使用抗氧化剂,综合分析鼠尾草酸和L-抗坏血酸棕榈酸酯可作为有效的天然抗异构和诱导异构剂。

玉米油中主要真菌毒素去除方法研究进展

玉米油因其营养价值高而倍受消费者的青睐,但玉米油在加工过程中真菌毒素污染带来的质量安全风险隐患也是当前关注的焦点。随着真菌毒素新的阻控技术工艺研究的不断深入和应用,玉米油在加工过程中的真菌毒素控制也取得了显著效果。文章结合玉米油在加工过程中真菌毒素的污染特征和迁移变化规律,系统归纳了污染玉米油的主要真菌毒素种类和污染现状,以及国内外相关的法律法规和限量标准,并结合玉米油的加工技术工艺特点,重点阐述了国内外相关的去除技术工艺。旨在为我国玉米油加工过程中真菌毒素阻控新技术、新工艺的研发及应用提供借鉴。

Screening,identification and antagonistic effect of antagonistic bacteria JTFM1001 against aflatoxin contamination in corn

Aflatoxin is a strong carcinogenic and toxic fungal toxin produced by Aspergillus flavus and other Aspergillus species,and can seriously threaten the health of consumers,thus becoming a global concern.Corn,as an important oil and economic crop,is highly susceptible contaminated by aflatoxin.In this study,antagonistic bacteria with strong inhibitory effect on aflatoxin were screened to provide support for the treatment aflatoxin contamination control in corn.Ten strains which have strong antagonistic effects against A.flavus were isolated from healthy corn from different corn producing areas in China.Among them,the antagonistic bacteria JTFM1001 through corn kernels in vivo and field experiment,the inhibition effect of aflatoxin contamination reached above 70%and 55%,respectively.And the strain was identified as Bacillus subtilis based on its morphological,physiological and biochemical characteristics and phylogenetic analysis of 16S rDNA.In addition,our data showed that it can colonize in the rhizosphere and survive for a long time,forming the dominant flora,with broad application prospect.Finally,we were surprised to find that the antibacterial metabolites secreted by the antagonistic bacteria was one of the mechanisms of its inhibition of A.flavus and aflatoxin.This will provide us with new ideas and perspectives on the effective prevention and control of aflatoxin contamination in corn and corn oil.

响应面法优化迷迭香脂溶性提取物脱色工艺

旨在为迷迭香脂溶性提取物在食用油保鲜方面的应用提供参考,以玉米油提取的迷迭香脂溶性提取物(可作为抗氧化剂)为原料,对其进行脱色处理,以脱色率为指标,通过单因素试验和响应面试验优化脱色工艺条件,并采用高效液相色谱法测定脱色前后迷迭香脂溶性提取物中脂溶性抗氧化成分(鼠尾草酸和鼠尾草酚)的含量。结果表明:与活性白土及活性白土与活性炭复配(质量比1∶1、1∶2、2∶1)脱色剂相比,活性炭对迷迭香脂溶性提取物的脱色效果最好,最佳脱色工艺为活性炭添加量2.1%、脱色温度50℃、脱色时间59 min,在此条件下脱色率为(75.02±0.37)%;脱色前后迷迭香脂溶性提取物中脂溶性抗氧化成分含量分别为4.0655%和3.8836%。综上,优化条件下迷迭香脂溶性提取物的脱色效果较好,且脱色对其脂溶性抗氧化成分含量影响较小。

响应面优化十六烷基二甲基苄基氯化铵改性蒙脱土脱除玉米油中玉米赤霉烯酮工艺

为提高十六烷基二甲基苄基氯化铵改性蒙脱土(1627-MMT)脱除玉米油中玉米赤霉烯酮(ZEN)的效率,在对比不同改性蒙脱土对玉米油中ZEN脱除效果的基础上,以ZEN吸附脱除率为考察指标,采用单因素实验和响应面实验优化1627-MMT脱除玉米油中ZEN的工艺条件(1627-MMT添加量、吸附时间、吸附温度),并测定脱毒前后玉米油的理化性质及总甾醇和总生育酚含量变化。结果表明:相比其他3种改性蒙脱土,1627-MMT的ZEN脱除效果最佳;1627-MMT脱除玉米油中ZEN的最优工艺条件为1627-MMT添加量5%、吸附温度105℃、吸附时间23 min,在此条件下ZEN吸附脱除率为(89.16±0.10)%,脱毒后玉米油中ZEN含量为349.64μg/kg,符合欧盟标准限量要求(≤400μg/kg);脱毒后玉米油的红值下降了72.34%,酸值下降了41.67%,过氧化值下降了42.00%,总甾醇和总生育酚的保留率分别为92.07%和85.34%,脂肪酸组成及含量无明显变化。综上,1627-MMT不仅可有效脱除玉米油中ZEN,还可降低玉米油的酸值、过氧化值及色泽,并对玉米油中的甾醇、生育酚含量及脂肪酸组成影响较小,在玉米油中ZEN的脱除中具有一定的应用潜力。

提高玉米油精炼收率的相关措施

介绍了玉米油精炼传统五脱工艺,分析了传统五脱精炼过程中影响油收率的主要因素。分别从玉米毛油质量控制、加工过程控制及设备选型和运行管理维护方面提出提高收率的措施。

Analysis on Plant and Quality Traits in an Improved Population of Corn

An improved population NEAU 2 was tested in Triple Test Cross design to analyze the genetic structure of 31 plants and quality traits. The results suggested that additive effect played an important role in all of these traits except for filling property trait V1. Nine traits such as grain yield and volume weight were determined mainly by the additive effect. Globulin and starch content were controlled by significant dominant effect. The leaf number above ear and most quality traits studied were controlled by both additive and dominance effect, and 4 traits such as 100 kernel weight were determined by both additive and epistasis effect. However, the heredity of plant height, ear position, and so on was determined by all these kinds of genetic effects. In quality improvement, direct selection could increase the content but not improve the quality of corn protein. Direct selection for albumin content and the ratio of glutelin to zein was effective and might be a better way to improve the protein quality of corn. Starch content might be raised by direct selection, but it might increase the content of amylopectin meanwhile. It was better to increase gross fat content by direct and indirect selection through the weight ratio of embryo to endosperm, which might also be effective to increase gross fat.

酪蛋白酸钠-玉米油预乳化液响应面优化及其在低脂肉糜凝胶中的应用

为了降低动物脂肪在肉糜凝胶制品中的使用,本研究旨在通过酪蛋白酸钠和玉米油制备预乳化液以部分替代动物脂肪。首先,通过单因素实验探讨了玉米油与酪蛋白酸钠质量比、酪蛋白与水添加比和预乳化液添加比对肉糜凝胶蒸煮损失和硬度的影响;然后,通过响应面试验,以蒸煮损失为响应值得出玉米油∶酪蛋白酸钠为7.27∶1,酪蛋白酸钠∶水为0.21∶1,预乳化液的添加比为37.58%。最后,进一步对比了优化实验组与对照组之间的区别,结果表明:预乳化液的添加能够使肉糜凝胶具有更加致密和均匀的微观结构;预乳化液对肉糜粘弹性的不利影响主要体现在凝胶形成前期,而不可逆凝胶形成后这种影响逐渐减少;与对照组相比,实验组肉糜凝胶亮度值(L^(*))和红度值(a^(*))表现出显著性差异(P<0.05);预乳化液的添加能够显著增加肉糜凝胶的硬度和咀嚼性(P<0.05),但不利于凝胶内聚性(P<0.05),而对弹性和可恢复性形变无显著影响(P>0.05)。综上,玉米油预乳化液能够部分替代动物脂肪,在一定程度上改善凝胶特性,达到减少使用动物脂肪的目的。