Preparation and Characterization of Ultrafine Fish Bone Powder

ABSTRACT

Ultrafine fish bone powder (UFBP) from silver carp (Hypophthalmichthys moli trix) was prepared using dry media milling. The characteristics of UFBP were investigated by a laser particle size analyzer, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and inductively coupled plasma (ICP) spectrometry. The size and specific surface area of UFBP particles were significantly (p < 0.05) affected by rotation speed, media/powder weight ratio, media diameter, and milling time. With the following conditions: rotation speed of 400 revolutions per minute, ratio of media to fish bone powder at 4:1, media diameter of 2 mm and 2.5 h of milling time, the optimal values of particle size (1.75 μm) and specific surface area (7.75 m²/g) were obtained. The SEM results confirmed that the particle became smaller and more uniform after milling treatment. Ash (63.71%) and protein (20.52%) were the main components of UFBP, and total calcium content was determined to be 236.90 mg/g in dried UFBP. As UFBP particle size decreased, calcium solubility significantly increased (p < 0.05), calcium content on the surface layer decreased, but the chemical compositions and structure did not change.     

Kinetics of bubble growth in wheat flour dough during proofing studied by computed X-ray micro-tomography

Bread doughs of various compositions were prepared and studied by computed X-ray microtomography (XRT) with high resolution (5 μm). Their cellular structure was followed during the last stage of proofing, from 40 min to 180 min, to focus on the films separating bubbles and their possible coalescence. Image analysis allowed to determine the porosity, the connectivity index, the bubble size and the cell walls thickness distributions which were fitted by usual mathematical functions. Images showed that different compositions led to different cellular structures. The kinetics of porosity and connectivity had sigmoid shapes with 0.7 and 1 as asymptotic values, respectively. For an average formula, mean cell width grew from 410 μm to 675 μm and the mean cell wall thickness grew from 200 μm to 230 μm. At the end of proofing, most bubbles were interconnected, i.e. they were separated by films of thickness lower than 5 μm. Changes of recipe led to different structures, which were discussed through the influence of the liquid fraction and of the sugar content on the coalescence of bubbles. These results suggested that at the end of fermentation, the dough could be considered as a three phase co-continuous medium: gas/liquid/viscoelastic matrix.     

不同结晶指数纤维素的X射线光电子能谱分析

以离子液体处理纤维素得到不同结晶指数(Icr)的纤维素样品。对所得样品首次采用X射线光电子能谱(XPS)的C1 s能谱图与O1 s能谱图,来分析不同结晶指数纤维素分子的化学状态。结合纤维素固体核磁共振(CP/MAS13C NMR)的分析结果可知,纤维素的C2峰及O1 s1峰与纤维素大分子中的氢键关系密切,其峰面积相对含量与纤维素的Icr值呈现高度相关性,相关系数分别为r10.9992和r20.9679。     

Investigation of 3D geometry of bulk wheat and pea pores using X-ray computed tomography images

Quantitative characterization of pore topology inside grain bulks is necessary to predict the air traverse time and the cooling or fumigation pattern for the design of storage management strategies. Quantification of 3D microarchitecture of the inter-granular airspace in the grain bulks can also contribute to the development of predictive models of insect movement and for designing acoustic systems for insect infestation detection. In this study, inter-connected 3D array of void spaces was characterized by geometrical quantities such as specific surface area, pore throat size and nodal pore volume. These features were obtained from a 13.1 cm × 13.1 cm × 5 cm volume of wheat and pea bulks. The grain bulks were imaged using a high resolution X-ray computed tomography system at 200 μm resolution. The spatial distributions were computed based on 3D medial axis analysis of the void space in the images using 3DMA-Rock software and a high performance Polaris computer. The other features calculated were medial axis tortuosity, throat surface area and porosity from the 3D images. Characterization of pore throat network provides reliable observation for facilitating realistic prediction of permeability and the nature of air and gas distribution inside grain bulks.     

核磁共振光谱和X射线光电子能谱对纤维低聚糖的分析

1H-1HCOSY和13C-1HHSQC谱对通过Bio-GelP-2柱(2.5cm×125cm)分离制备的纤维三糖、纤维四糖和纤维五糖进行分析。结果表明,在水溶液中纤维低聚糖还原末端C1位α构型与β构型之比(α/β)随聚合度增大而减小,纤维三糖主要是α构型(α/β,0.52),而纤维四糖和纤维五糖主要是β构型(α/β,分别是0.34和0.25)。X射线光电子能谱(XPS)分析表明纤维低聚糖的C1s主要有2种电子结合能,分别为284.8(C1s1,C—O)和286.1eV(C1s2,O—C—O),C1s1与C1s2之比(C1s1/C1s2)随聚合度增大而增大。     

Milling characteristics and distribution of phytic acid and zinc in long-, medium- and short-grain rice

Milling and polishing are important operations during the production of white rice. The degree of milling and polishing has a significant effect on the nutritional aspects of white rice, especially on minerals, due to a non-uniform distribution of nutrients in the kernel. Information on the distribution of nutrients in rice will greatly help in understanding the effect of milling and aid in designing procedures that improve technological and sensory properties of rice while retaining its essential nutrients as much as possible. In this study, three kernel shapes (short-, medium- and long-grain) of rice were selected for the study of milling characteristics and distribution of zinc (Zn) and phytic acid using abrasive milling and X-ray fluorescent microscope imaging approaches.Milling characteristics differed with kernel shapes and cultivars. Mass loss (y, %) correlated well with milling duration (x, s) and was fitted using a polynomial equation of y=ax²+bx+c (R²=0.99). Different kernel shapes of rice resulted in different patterns. Breakage in milling increased with longer duration of milling. The relation between breakage (y, %) and milling duration (x, s) fitted the exponential equation y=ae^bx. Levels of phytic acid, as well as Zn, decreased with prolonged milling. Phytic acid decreased at a higher rate than Zn. The analysis of different milling runs showed that the concentration of phytic acid decreased from the surface region inward, whereas X-ray fluorescent images indicated that the highest concentration of phosphorus was at the interface of the embryo and perisperm.Our results help in understanding the milling characteristics of different rice cultivars. Understanding these characteristics offers opportunities to optimize milling procedures for maximum phytate removal at minimum mineral losses and yield loss.     

X-ray diffraction study of bamboo fibers treated with NaOH

Bamboo fibers are a new kind of natural materials which have a big potential application in textile field due to some of their particular properties. However, high crystallinity and orientation structure can result in some undesirable properties and this will limit their further applications as textile materials. As a common used way, mercerization was adapted to treat bamboo fibers in this work in order to improve their undesirable properties. X-ray diffraction (XRD) was used to characterize their microstructure after treatment with NaOH. The amount of cellulose II and the crystallinity index based on the XRD results were calculated for the evaluation of the effectiveness of the different treatment conditions, such as alkali concentration, mercerization duration and temperature, as well as tension applied to the fibers during mercerization, on the transformation degree of cellulose I to cellulose II and decrystallization of the mercerized bamboo fibers. It has been found that each condition has different effects and that the greatest effectiveness of crystal lattice conversion and decrystallization could be achieved with such mercerization condition: 16 % alkali concentration, 10 minutes of mercerization at 20 °C without tension applied to the fibers.     

便携式X射线荧光光谱法(PXRF)在肥料重金属快速检测中的应用

为了探讨一种简单快捷的肥料重金属含量测定方法,本文采用便携式X射线荧光光谱仪(PXRF)测定了我国典型设施农业生产区肥料中As、Pb、Cu、Zn和Cr的含量,并与常规实验室方法的测定值进行比较,以验证PXRF法测定结果的准确性。结果表明:①PXRF对土壤标准物质中As、Pb、Cu、Zn的测定值与标准值之间的相对标准偏差和相对误差均小于10%,表明该仪器测定As、Pb、Cu、Zn的精密度和准确度较好;②肥料中重金属PXRF法测定的检出限均低于相应的国家或行业标准。当含量超过检出限时,有机肥和无机肥中As、Pb、Cu、Zn和Cr常规实验室方法测定值与PXRF法测定值间均达到了极显著相关,R2在0.70～0.99;③PXRF法的检测成本仅为常规仪器的10%?20%,节省了前处理的时间和费用。因此,PXRF法可用于肥料中重金属含量的快速检测与评价。     

泰山山前平原土地利用方式对潮棕壤黏土矿物组成的影响

对泰山山前平原潮棕壤区小麦/玉米轮作农田、杨树林地和荒草地三种土地利用方式黏土矿物组成进行研究,探究不同土地利用方式下黏土矿物组成的变异规律与影响因素。通过野外样地调查、室内土壤黏粒提取及其黏土矿物的X-射线衍射图谱分析等方法分析黏土矿物组成及相关土壤指标。结果表明:三种利用方式土壤以伊利石(包括结晶好伊利石和结晶差伊利石)为主要矿物,次要矿物为蛭石和高岭石,混层矿物为少量矿物组成。荒草地表层土壤伊利石含量最高(75.8%),分别较农田和林地土壤提高26.4%、23.6%。下层土壤伊利石含量较表层土壤有显著降低,荒草地土壤的降低幅度较大。结晶好伊利石含量表征土壤的风化程度,荒草地、林地、农田土壤矿物的风化作用依次增强。蛭石含量在下层土壤的差异显著且较表层土壤含量高,含量由高到低依次为荒草地、农田、林地。荒草地土壤有机碳含量和钠质分散有机无机复合体含量较林地和农田土壤有显著降低。不同利用方式土壤黏粒中伊利石含量与蛭石含量之间相互转化,受土壤速效钾含量的调控。荒地建议开垦为林地或草地,促进土壤有机碳保持和有机无机复合体形成,抑制黏土矿物在土壤剖面的迁移。     

熊果酸对胶原诱导性关节炎大鼠关节炎症相关因子mRNA表达的影响

目的 研究熊果酸（ursolic acid,UA）对胶原诱导性关节炎（collageninduced arthritis,CIA）大鼠关节X线及关节炎症相关因子mRNA表达的影响。方法 SD大鼠采取皮下注射牛Ⅱ型胶原加弗氏不完全佐剂法建立CIA模型,取造模成功后大鼠随机分为CIA模型组、UA低剂量组、UA高剂量组、甲氨喋呤（methotrexate,MTX）组、UA+MTX组并予以对应干预。另取6只正常大鼠为对照的空白组。初次免疫30 d断颈处死大鼠,关节行X线摄片,再取下大鼠炎症关节组织匀浆,提取RNA,荧光定量PCR法检测IL-17A、IL-10、IL-6、TNF-α、IL-1β、TGF-β的mRNA表达。结果 与CIA模型组相比,UA高剂量组、MTX组、UA+MTX组X线评分减低（P<0.05或P<0.01）;各治疗组IL-17A、IL-6、TNF-α、IL-1β的mRNA表达降低（P<0.01或P<0.05）;各治疗组IL-10、TGF-β因子的mRNA表达增高（P<0.01或P<0.05）。结论 UA可明显缓解CIA大鼠关节炎症,改善关节X线评分,其机制可能与调节炎症因子的产生,维持组织促炎因子与抑炎因子的平衡有关。