Effects of Increasing Concentrations of Sodium Sulfite on Deoxynivalenol and Deoxynivalenol Sulfonate Concentrations of Maize Kernels and Maize Meal Preserved at Various Moisture Content

Under moderate climatic conditions, deoxynivalenol (DON) contamination occurs frequently on cereals. Detoxification measures are required to avoid adverse effects on farm animals. In the present study, a wet preservation method with sodium sulfite (Na₂SO₃) and propionic acid was tested to titrate the optimum Na₂SO₃-dose for maximum DON reduction of contaminated maize kernels and meal and to examine the interaction between dose and moisture content in dependence on the preservation duration. The DON concentration decreased with increasing amounts of supplemented Na₂SO₃ and with increasing duration of the preservation period in a bi-exponential fashion. Additionally, the feed structure and moisture content had a significant influence on the decontaminating effect. Variants with 30% moisture content favored higher DON reduction rates compared to 14% moisture, but especially at low moisture contents, DON reduction was more pronounced in maize kernels than in maize meal. In addition to the decrease of DON, a concomitant formation of three different DON sulfonates was observed which differed in their formation pattern over the time course of preservation. The overall results and statistical analysis clarified that Na₂SO₃ addition of 10 g/kg maize at 30% moisture for eight days was necessary to obtain a complete DON reduction.     

转基因食品安全性检验的核酸检测技术研究

以国际市场上转基因食品的主流产品转基因大豆及玉米和我国生产的转基因辣椒为材料 ,以PCR方法为基础 ,研究适用于转基因食品安全性检验的核酸检测技术。针对抗除草剂 (孟山都公司 )GM 大豆 ,转Bt 176玉米 (Novartis Ciba Geigy公司 )及转抗菌肽辣椒 (华农 )产品的插入基因及调控序列设计不同引物进行PCR检测。建立了转基因大豆、玉米、辣椒的鉴别和相关标记基因、目的基因检测的技术 ,该方法简便快速 ,检测结果与标准及申报材料相符。     

Graft copolymers of ethyl methacrylate on waxy maize starch derivatives as novel excipients for matrix tablets: Physicochemical and technological characterisation

Nowadays, graft copolymers are being used as an interesting option when developing a direct compression excipient for controlled release matrix tablets. New graft copolymers of ethyl methacrylate (EMA) on waxy maize starch (MS) and hydroxypropylstarch (MHS) were synthesised by free radical polymerization and alternatively dried in a vacuum oven (OD) or freeze-dried (FD). This paper evaluates the performance of these new macromolecules and discusses the effect of the carbohydrate nature and drying process on their physicochemical and technological properties. Grafting of EMA on the carbohydrate backbone was confirmed by IR and NMR spectroscopy, and the grafting yields revealed that graft copolymers present mainly a hydrophobic character. The graft copolymerization also leads to more amorphous materials with larger particle size and lower apparent density and water content than carbohydrates (MS, MHS). All the products show a lack of flow, except MHSEMA derivatives. MSEMA copolymers underwent much plastic flow and less elastic recovery than MHSEMA copolymers. Concerning the effect of drying method, FD derivatives were characterised by higher plastic deformation and less elasticity than OD derivatives. Tablets obtained from graft copolymers showed higher crushing strength and disintegration time than tablets obtained from raw starches. This behaviour suggests that these copolymers could be used as excipients in matrix tablets obtained by direct compression and with a potential use in controlled release.     

ω3 polyunsaturated fatty acids and maize flour diets

OBJECTIVES: Nutrition disorders caused by a 6.5% maize protein diet (M), unbalanced in its indispensable amino acid pattern, provokes an arrest on cellular proliferation and maturation in the thymus of growing rats. We investigated the effect of diet supplementation with different amounts of ω3 polyunsaturated fatty acid (M = 0 mg/d, M1 = 12 mg/d, M2 = 24 mg/d, respectively) on thymus, plasma lipid concentrations, and hepatic tissue.METHODS: A well-nourished age-matched control group received stock diet from weaning. The animals (8 to 10 per group) received the diets for 9 d. At the end of the experimental period, they were killed, thymuses were removed, and cell number, absolute number of T cells labeled by the monoclonal antibody W3/13, plasma lipid profile (total cholesterol, triacylglycerols, high- and low-density lipoprotein cholesterols), and oxidative stress in hepatic tissue were determined.RESULTS: Only M2 reached the values of the control group when cell number and absolute number of T cells were compared. No statistical differences were observed among the M, M1, M2, and control group when high- and low-density lipoprotein cholesterols and hepatic lipid peroxidation were considered.CONCLUSIONS: The supplementation of a 6.5% maize protein diet with 24 mg/d of ω3 polyunsaturated fatty acid can recover the proliferation and absolute number of T cells labeled with W3/13 without affecting lipid profile and hepatic lipid peroxidation.     

Maize Prolamins Could Induce a Gluten-Like Cellular Immune Response in Some Celiac Disease Patients

Celiac disease (CD) is an autoimmune-mediated enteropathy triggered by dietary gluten in genetically prone individuals. The current treatment for CD is a strict lifelong gluten-free diet. However, in some CD patients following a strict gluten-free diet, the symptoms do not remit. These cases may be refractory CD or due to gluten contamination; however, the lack of response could be related to other dietary ingredients, such as maize, which is one of the most common alternatives to wheat used in the gluten-free diet. In some CD patients, as a rare event, peptides from maize prolamins could induce a celiac-like immune response by similar or alternative pathogenic mechanisms to those used by wheat gluten peptides. This is supported by several shared features between wheat and maize prolamins and by some experimental results. Given that gluten peptides induce an immune response of the intestinal mucosa both in vivo and in vitro, peptides from maize prolamins could also be tested to determine whether they also induce a cellular immune response. Hypothetically, maize prolamins could be harmful for a very limited subgroup of CD patients, especially those that are non-responsive, and if it is confirmed, they should follow, in addition to a gluten-free, a maize-free diet.     

卫星搭载玉米雄性不育突变系的遗传稳定性研究

目的 通过卫星塔载玉米种子选育雄性不育突变体，定向培育成新不育系供生产应用。方法 利用卫星搭载飞行15d的川丹9号玉米种子返地种植后，选育出不育突变体，并通过直接杂交获得了不育系，结果 不育材料花粉败育彻底，不育性状表现稳定，呈现出由隐性单基因控制的核不育的遗传特点。结论 雄性不育突变体的出现与卫星搭载有关，为基因突变的结果。     

乳熟期鲜食玉米穗不同部位碳水化合物的变化

对乳熟期鲜食玉米穗不同部位碳水化合物的变化研究表明，籽粒中可溶性总糖（TSC）质量分数为先增加后降低，蔗糖（SUC）和TSC的变化趋势相似，淀粉质量分数逐渐增加，可溶性酸性蔗糖转化酶的活性先增加后降低．穗轴中SUC及TSC质量分数在授粉后任何时期总是高于籽粒，淀粉质量分数远低于籽粒．苞皮中TSC与SUC质量分数缓慢减少，在籽粒灌浆初期积累有大量的TSC，为籽粒迅速灌浆做出了贡献，淀粉质量分数远低于穗轴．鲜食玉米采收后应低温放置或及时加工，以抑制糖快速转化为淀粉，防止鲜食玉米品质下降．