Fabrication of emulsions prepared by rice bran protein hydrolysate and ferulic acid covalent conjugate: Focus on ultrasonic emulsification

The aim of the paper was to investigate the effect of ultrasonic emulsification treatment on the fabrication mechanism and stability of the emulsion. The covalent conjugate made with rice bran protein hydrolysate (RBPH) and ferulic acid (FA) was used as the emulsifier. The effects of high intensity ultrasound (HIU) power with different level (0 W, 150 W, 300 W, 450 W and 600 W) on the stability of emulsion were evaluated. The results showed that ultrasonic emulsification can significantly improve the stability of the emulsions (p < 0.05). The emulsion gained better stability and emulsifying property at 300 W. It was able to fabricate emulsion with smaller particle size, more uniform distribution and higher interfacial protein content. It was confirmed by fluorescent microscopy and cryo-scanning electron microscopy (cryo-SEM) furtherly. And it was also proved that the emulsion treated by proper HIU treatment at 300 W had better storage stability. Excessive HIU treatment (450 W, 600 W) had negative effects on the stability of emulsion. The stability of emulsion (300 W) against different environmental stresses was further explored, which established a theoretical basis for the industrial application of emulsion in food industry.     

Wheat Bran Modifications for Enhanced Nutrition and Functionality in Selected Food Products

The established use of wheat bran (WB) as a food ingredient is related to the nutritional components locked in its dietary fibre. Concurrently, the technological impairment it poses has impeded its use in product formulations. For over two decades, several modifications have been investigated to combat this problem. Ninety-three (93) studies (review and original research) published in English between January 1997 and April 2021 reporting WB modifications for improved nutritional, structural, and functional properties and prospective utilisation in food formulations were included in this paper. The modification methods include mechanical (milling), bioprocessing (enzymatic hydrolysis and fermentation with yeasts and bacteria), and thermal (dry heat, extrusion, autoclaving), treatments. This review condenses the current knowledge on the single and combined impact of various WB pre-treatments on its antioxidant profile, fibre solubilisation, hydration properties, microstructure, chemical properties, and technological properties. The use of modified WB in gluten-free, baked, and other food products was reviewed and possible gaps for future research are proposed. The application of modified WB will have broader application prospects in food formulations.     

麦草碱木质素的微波辅助液化降解

研究了微波辅助条件下液化剂、催化剂、反应温度和反应时间对麦草碱木质素进行液化降解制备生物油收率的影响,并利用红外光谱(FT-IR)、气相色谱质谱联用仪(GC-MS)和核磁共振氢谱(1H-NMR)对产物进行表征。结果表明,微波辅助下以甲醇为液化剂,硫酸铁为催化剂液化降解碱木质素可以显著缩短液化反应时间,在160℃相对较低液化温度下反应5 min,生物油的收率达到55.22%。液化降解后的木质素残渣结构变化少,表明木质素降解产物的重新聚合的几率低,碱木质素反应原料可以回收再利用以提高原料利用率。生物油主要为单酚类物质,其中,S型、G型和H型单体的含量分别为57.72%、25.28%和8.98%。核磁共振氢谱中β-O-4键和C-C键质子峰的存在说明生物油中含有部分的二聚体和低聚体酚类化合物。     

石墨炉原子吸收光谱法测定麦麸颗粒中镉

为消除石墨炉原子吸收光谱法测定麦麸中镉时基体产生的背景干扰,在消解液中加入镉标准溶液配制基体匹配工作曲线进行测定,对灰化温度、原子化温度及基体改进剂等条件进行优化,确定最佳分析方法。结果表明：在选定条件下镉在0.0~3.0 μg/L范围内工作曲线相关系数为0.9991,检出限为0.027 μg/L,定量限为0.091 μg/L,加标回收率为89.50%~104.12%,精密度为1.64%~4.30%,质控物质测定结果准确。该方法操作简便,快速准确,精密度良好,适用于麦麸中镉元素的测定。     

基于无人机高光谱遥感的冬小麦全氮含量反演

氮素是作物生长发育必需的营养元素之一,作物的全氮含量是表征其氮素状况的主要指标。田块尺度的冬小麦全氮含量空间分布监测可以辅助其精准定量追肥,减少环境污染。无人机高光谱遥感具有分辨率高、时效性高、成本低等优势,可为作物长势信息反演提供重要数据源。XGBoost（extreme gradient boosting）作为一种新兴集成学习算法,运行效率高,泛化能力强,可以有效的应用于构建冬小麦全氮含量遥感反演模型,预测田块尺度冬小麦全氮含量空间分布。以农业部蒙城砂姜黑土生态环境站内拔节期冬小麦为研究对象,开展以下工作: （1）以低空无人机搭载高光谱成像仪获取冬小麦拔节期冠层成像光谱影像,结合地面采样数据,获取126个样点全氮含量数据;（2）分析拔节期冬小麦冠层光谱特征,并根据Person相关系数分析176个波段的光谱反射率与全氮含量之间的相关性;（3）构建基于XGBoost算法的不同土壤肥力条件下拔节期冬小麦全氮含量无人机高光谱反演模型。结果表明: （1）176个波段（400~1 000 nm）的光谱反射率与冬小麦全氮含量之间具有较强的相关性,除了735.5 nm外其他波段光谱反射率与全氮含量之间的相关系数均大于0.5;（2）基于XGBoost算法构建的拔节期冬小麦全氮含量无人机高光谱遥感反演模型具有较高的反演精度（R2=0.76,RMSE=2.68）;（3）基于XGBoost算法的冬小麦全氮含量反演模型可以获取不同土壤肥力条件下田块尺度的全氮含量空间分布图,总体上呈现较为显著的空间差异。该研究可为冬小麦精准定量追肥提供一定的科学依据,也为发展无人机高光谱遥感的精准农业应用提供了参考。     

光敏细胞质不育小麦花药发育过程中ABA免疫电镜定位

运用胶体金免疫电镜定位方法研究了不同光周期条件下光敏细胞质不育小麦发育过程中ABA的分布,短日照条件下,花粉母细胞细胞质基质及小液泡内有金颗粒分布;单核至二核花粉时期花粉内金颗粒逐渐增多,二核至成熟花粉时期花粉内金颗粒逐渐减少,不同发育时期的花粉内金颗粒的分布位置有变化,绒毡层或降解中的绒毡层细胞内有较多金颗粒分布,长日照条件下花粉败育,不同发育时期的花粉内金颗粒分布数量均比同时期的可育花粉内明显增多,单核期以前败育的花粉,解体的花粉细胞质及细胞核内有较多金颗粒分布;后期败育的花粉,花粉母细胞至二核花粉时期花粉（母细胞）内金颗粒有不断增加的趋势,二核期以后,花粉逐渐液泡化,解体的花粉细胞质及逐增大的中央液泡内在大量的金颗粒分布,绒毡层细胞内金颗粒有逐渐减少的趋势,文中对ABA在雄蕊,花粉发育过程中的作用,由光周期诱导的ABA含量增加在雄性不育中的作用进行了讨论。     

Influence of Farming System and Forecrops of Spring Wheat on Protein Content in the Grain and the Physicochemical Properties of Unsonicated and Sonicated Gluten

The potential for enhancing the spring wheat protein content by different cultivation strategies was explored. The influence of ultrasound on the surface and rheological properties of wheat-gluten was also studied. Spring wheat was cultivated over the period of 2018–2020 using two farming systems (conventional and organic) and five forecrops (sugar beet, spring barley, red clover, winter wheat, or oat). The obtained gluten was sonicated using the ultrasonic scrubber. For all organically grown wheat, the protein content was higher than for the conventional one. There was no correlation between the rheological properties of gluten and the protein content in the grain. Gluten derived from organically grown wheat was more elastic than those derived from the conventional one. Sonication enhanced the elasticity of gluten. The sonication effect was influenced by the forecrops. The most elastic gluten after sonication was found for organic barley and sugar beet. The lowest values of tan (delta) were noted for conventional wheat and conventional oat. Cultivation in the monoculture gave gluten with a smaller susceptibility to increase elasticity after sonic treatment. Sonication promoted the cross-linking of protein molecules and induced a more hydrophobic character, which was confirmed by an increment in contact angles (CAs). Most of the organically grown wheat samples showed a lower CA than the conventional ones, which indicated a less hydrophobic character. The gluten surface became rougher with the sonication, regardless of the farming system and applied forecrops. Sonication treatment of gluten proteins rearranged the intermolecular linkages, especially disulfide and hydrophobic bonds, leading to changes in their surface morphology.     

段式正交信号校正方法及在小麦近红外光谱数据分析中的应用

针对光谱数据峰宽、局部效应显著、含有噪音、变量个数多及彼此间常存在严重的复共线性等问题,改进和设计一种光谱数据局部校正方法:基于窗口平滑的段式正交信号校正方法,并将之结合偏最小二乘回归,以实现光谱数据的预处理及定量分析。通过NIPALS算法初始化将滤去的正交成分,以近邻分段方式进行逐个波长点的正交信号校正。而后将去噪后的光谱矩阵作为新的自变量阵,通过偏最小二乘回归构建其与性质参变量间的校正模型。通过小麦近红外漫反射光谱数据的应用实验结果表明,本方法正交成分估计稳定,去噪明显,模型的预报性能优于其它方法,PLS成分数减少,模型更加简洁。     

Catalytic conversion of defatted rice bran into value added chemicals using copper ferrite: A sustainable approach

The most crucial and demanding universal issue lies in the enrichment of sustainable drive technology. As traditional resource, petrochemical becomes increasingly scarce in the future; mankind must turn to renewable alternatives to yield liquefied fuels and valuable commodities through sustainable process. It has been reported that furan compounds serve as an excellent platform molecule derived from defatted rice bran. The current work aims at the synthesis of copper ferrite nano catalyst by microwave assisted solution incineration approach. The catalytic properties stood verified by X-ray diffraction, SEM, EDAX and BET techniques. The catalytic performance of the copper ferrite catalyst were reinforced through in-situ microwave assisted acetalization reaction of furfural with discrete solvents like methanol, ethanol, and 1-propanol at optimum reaction conditions for the preparation of wide range of commodity chemicals such as carboxylic acids, alkyl esters, di alkyl acetals, di ketones which are of commercial importance. The comparative study of relative yield of the products with different solvents is reported. The formation of the value-added products were confirmed by GC-MS, FT-IR technique. The catalysts from the reaction mixture are recovered by magnetic field.