超高压处理对大豆膳食纤维的改性

大豆膳食纤维的生理功能与其理化性质密切相关,而理化性质又与膳食纤维的化学结构及其多相网状结构相关,因此在膳食纤维提取制备工艺日益成熟后膳食纤维的改性研究成为新的研究热点.为探索超高压处理对大豆膳食纤维性质的影响,将膳食纤维充分吸水后经700MPa静压,15 min处理后分别考察处理前后样品的持水率、膨胀率、黏度和显微结构的变化.结果表明,处理后样品的持水率、膨胀率都有较大的提高;处理后样品黏度略有下降;处理后样品的组织结构更加的疏松,空隙增多增大,但是其瓣膜状的空间结构没有改变.试验结果为大豆膳食纤维的改性研究提供参考数据.     

超高压辅助浸提鲜茶汁研究

研究了不同超高压压力水平辅助浸提对鲜茶汁产品得率、主要品质成分及风味品质的影响。研究表明,随着超高压处理压力水平的升高,鲜茶汁的可溶性固形物、茶多酚、氨基酸及主要儿茶素组分等主要品质成分含量都呈上升的趋势,但压力大于100 MPa时处理间没有显著差异;超高压辅助浸提对鲜茶汁的外观颜色及香气等感官品质有一定影响,但当压力处于100~300 MPa时,不同压力之间没有显著差异,只有当压力达到500 MPa时鲜茶汁的感官品质受到显著影响。综合比较,超高压处理（100 MPa、10 min）最适于绿茶鲜茶汁加工处理。通过电镜扫描分析,超高压处理对茶叶叶片细胞结构具有明显的破坏作用,且随着压力水平的升高,破坏强度增大,这可能也是超高压辅助浸提可以显著提高鲜茶汁产品得率的主要原因。     

豆渣水溶性膳食纤维特性研究

通过红外光谱仪、粘度计等对豆渣水溶性膳食纤维(SDF)的特性进行了研究。结果表明:豆渣水溶性膳食纤维为多糖类物质,其持水力为8.25 g·g-1,溶胀力为9.38 m L·g-1,结合水力7.11 g·g-1,阳离子交换能力为0.73 mmo L·g-1。豆渣水溶性膳食纤维溶液粘度随剪切速率的增加而降低,呈现假塑性流体。豆渣水溶性膳食纤维有吸附胆酸钠的作用,其添加量越多,溶液中胆酸钠被吸附的量也越多,吸附平衡所花的时间越长。     

亚麻籽-火麻仁植物乳制备工艺对其稳定性和营养成分的影响研究

为提升富含ω-3功能油脂的系列油料作物在植物乳饮品中的应用,基于亚麻籽和火麻仁的营养特性,以亚麻籽、火麻仁为主要原料,探究了剪切粉碎时间（1~9 min）及火麻仁添加量（1/2~1/6）对亚麻籽-火麻仁植物乳（FHPM）的稳定性和营养成分溶出等的影响,对最优组（剪切粉碎3 min,火麻仁∶亚麻籽=1∶5）所得植物乳的营养素与风味物质组成进行剖析。结果表明,随着剪切粉碎时间增加,植物乳的自稳定性逐渐下降,大于3 min时明显分层,有絮凝现象。研究1~3 min的粉碎时间对营养的影响,发现剪切时间对蛋白质、油脂、膳食纤维、总酚、木酚素的溶出均有显著影响;且随着植物乳中火麻仁所占比例提高,蛋白质和油脂的含量明显提高,但植物乳的自稳定性显著下降,表明植物乳的稳定性与植物乳体系黏度、粒径、电位、颗粒组成等理化特性有关。最优组所得亚麻籽-火麻仁植物乳粒径为4.53 μm,电位为-32.15 mV,固形物含量为5.17 g/100 mL,蛋白质含量为1.32 g/100 g,脂肪含量为3.45 g/100 g,膳食纤维含量为0.47 g/100 g,碳水化合物含量为0.57 g/100 g;植物乳具有合适的表观黏度,可在无外源稳定剂条件下4℃稳定储藏21 d。分析显示该植物乳含有小分子酮类、醛类、醇类等,呈现果味、花香味等良好风味;含有合理的氨基酸和脂肪酸组成。     

冷榨亚麻籽油的流变特性研究

通过低温压榨亚麻籽获得冷榨亚麻籽油(cold-pressed flaxseed oil, CFO),并分析了其主要理化指标,着重研究CFO的静态流变特性和动态流变特性,同时分别采用Casson、Herschel-Bulkley和Bingham模型对其流体行为进行拟合,并采用Arrhenius方程分析其粘度热动力学参数。研究结果表明：在剪切速率为0.1～200 s-1下,CFO由非牛顿流体逐渐转化为牛顿流体;当剪切速率大于10 s-1时,CFO呈牛顿流体;同时分析得出CFO的粘度活化能为3 095.4 cal/mol;CFO的粘度、剪切应力、损耗模量、塑性稠度系数、高剪切极限粘度和稠度系数随着温度升高而降低,但是温度变化对CFO的贮能模量影响不显著;另外通过比较3个流变模型得出Bingham模型适用于CFO。      

苯醚甲环唑和噻呋酰胺在香蕉上的残留消解及膳食风险评估

为分析苯醚甲环唑和噻呋酰胺在香蕉上的残留消解行为和膳食摄入风险,于2016年在云南进行了规范残留试验,研究了全蕉、蕉肉和土壤中的消解过程并进行了长期膳食暴露风险评估。结果表明：苯醚甲环唑标准曲线线性方程为y=1.45×10 ⁷x+4.14×10 ⁴,R ²=0.9962;噻呋酰胺标准曲线线性方程为y=2.99×10 ⁶x+1.43×10 ⁴,R ²=0.9954。在0.04~ 1 mg/kg添加水平下,苯醚甲环唑的平均回收率为75%~110%,相对标准偏差（RSD）为0.9%~6.2%;噻呋酰胺的平均回收率为76%~114%,RSD为3.0%~9.5%。苯醚甲环唑与噻呋酰胺在土壤、全蕉、蕉肉中的最低检测浓度（LOQ）均为0.04 mg/kg,最小检出量（LOD）均为5 pg。苯醚甲环唑和噻呋酰胺的消解基本符合一级动力学方程,苯醚甲环唑在全蕉和土壤中的半衰期分别为16、20 d,噻呋酰胺在全蕉和土壤中的半衰期分别为20、27 d。风险评估研究表明,香蕉中残留苯醚甲环唑长期膳食摄入风险可以接受,而噻呋酰胺长期膳食摄入则具有一定的风险。     

物理改性处理对菠萝皮渣膳食纤维物化特性的影响

以菠萝皮渣为原料制备膳食纤维,考察超微粉碎、蒸汽爆破和挤压膨化3种物理改性方式对菠萝皮渣膳食纤维的基本成分、理化性质、形貌结构及生物活性物质溶出量的影响。结果表明:3种物理改性方式均能提高样品阳离子交换能力,增加多酚、黄酮物质的溶出量。其中蒸汽爆破处理能显著提高可溶性膳食纤维含量,在持水持油性方面表现良好。形貌结构分析结果显示,改性后的膳食纤维结构均发生不同程度的变化,但其主要成分及化学结构未受影响。综上所述,蒸汽爆破处理有助于改善菠萝皮渣膳食纤维的品质。     

不同粒径鹧鸪茶粉体表征与理化特性的比较研究

本研究以海南植物鹧鸪茶为研究对象,比较了鹧鸪粗粉（D₅₀为120.45 mm）、细粉（D₅₀为65.86 mm）、超微粉Ⅰ、超微粉Ⅱ和超微粉Ⅲ5种粉体的表征与理化特性。通过色度测定、粒径测定、电镜扫描分析、红外光谱分析,探究5种不同粒径鹧鸪粉体的加工特性、流动性,以及5种粉体茶多糖和皂苷含量的变化规律。结果表明:随着粉体粒径逐渐减小,其溶解度、润湿性、流动性均增大,膨胀度、持水力减小;鹧鸪茶超微粉的茶多糖、皂苷含量明显高于粗粉、细粉;随着超微粉碎时间的延长,茶多糖含量逐渐增大,皂苷含量各不相同。不同粒径鹧鸪茶粉体的特性各不相同,综合比较得出,超微粉的溶解度、茶多糖、皂苷含量较高,更容易被人体吸收,生物利用度高,加工方便。因此,鹧鸪茶超微粉具有较好的开发前景。     

剪切乳化辅助酶法提取咖啡果皮可溶性膳食纤维

本文以咖啡果皮为原料,优化剪切乳化辅助酶法提取可溶性膳食纤维的工艺条件。在单因素实验基础上,采用Plackett-Burman（PB）设计筛选出显著影响咖啡果皮可溶性膳食纤维提取得率的因素,包括剪切时间、酶解时间、酶解温度和酶解pH;采用中心组合试验设计及响应面法,得到最佳提取工艺条件为固液比1∶30（g/mL）、剪切速率7000 r/min、酶添加量0.2%、剪切时间24.0 min、酶解pH 4.90、酶解温度57.0 ℃、酶解时间1.96 h,在此条件下咖啡果皮可溶性膳食纤维提取率为13.96%,与理论预测值14.00%之间无显著性差异。本研究可为咖啡果皮的高值化利用和功能产品研发提供理论支撑。     

马铃薯渣综合利用研究现状及发展趋势

介绍了马铃薯渣营养成分及主要性质,综述了马铃薯渣综合利用研究现状,包括生产高蛋白饲料、制备膳食纤维和果胶,制备燃料酒精和薯渣新型吸附剂和粘结剂、制备饲料种曲、方便面油料包可食性膜和有机化工产品等。剖析了马铃薯渣综合利用中存在的问题,即综合利用率低、食用安全性问题、技术推广困难。展望了马铃薯渣的开发应用前景与发展趋势。马铃薯渣提取膳食纤维和果胶,薯渣加工附加值提高,经济效益较高;固态发酵马铃薯渣生产蛋白饲料或生产配合饲料是薯渣处理最具发展潜力的方向。利用薯渣制作发酵培养基是进行薯渣增值的研究方向;利用薯渣制备燃料酒精及生物质混合燃料是理想的薯渣利用途径;利用马铃薯渣联合生产膳食纤维和燃料酒精是薯渣综合利用研究值得探索的新思路。     

Particle size of dietary fiber preparation affects the bioaccessibility of selected vitamin B in fortified wheat bread

Nowadays, there is an increasing interest in developing foods that have functional properties. The aim of the study was to identify the effect of the particle size (PS) of dietary fiber (DF) preparations on selected for B vitamins bioaccessibility in bread. Three different levels of particle size, obtained by sieving, were used (100, 190 and 280 μm) with different dietary fiber content in bread (2.1, 7.2 and 12.3%) according to a response surface methodology experiment design. The estimation of level of thiamine and riboflavin in bread revealed that the decreasing particle size of dietary fiber could negatively influence the bioaccessibility (69.1–91.2% and 40.9–50.2%, respectively). The interaction between the DF and PS also significantly influenced (p ≤ 0.01) the bioaccessibility of niacin (60.2–70.2%) and pyridoxine (27.52–34.01%). This research shows that the optimal particle size of dietary fiber (124.12 μm) can be used in fortifying wheat bread without significantly influencing B vitamin levels and their bioaccessibility.     

Properties of starch-palmitic acid complexes prepared by high pressure homogenization

Aqueous mixtures of defatted corn starch and palmitic acid were heated and high pressure homogenized in order to form amylose inclusion complexes. The effects of homogenization pressure (0–120 MPa) and palmitic acid concentration (0.5–8% based on starch content) on starch-palmitic acid complex formation as well as on complex index, X-ray diffraction, thermal properties, viscosity and particle size were investigated. Complex index increased with an increase in the amount of palmitic acid and homogenization pressure, and reached a maximum value (about 60%) when the fatty acid content was 4% and the homogenization pressure was 100 MPa. X-ray diffraction patterns indicated the formation of V-helical complexes between starch and palmitic acid. This technology could prospectively be used in prepared starch-lipid complexes.     

酶-重量法测定不同品种芒果皮中膳食纤维的含量

应用酶-重量法测定凯特(Keitt)、吉禄(Zill)、海顿(Haden)、爱文(Irwin)、台农1号(Tainong No.1)、红象牙(Red Ivory)、三年芒(Sannian) 7个攀西地区主推芒果品种果皮中总膳食纤维(TDF)、可溶性膳食纤维(SDF)及不溶性膳食纤维(IDF)的含量。结果表明,7个品种芒果皮中总膳食纤维含量均在45 %以上,其中海顿TDF含量最高,达到66.94 %,台农1号TDF最低,含量为46.87 %,7个品种SDF含量占TDF含量均在31 %-43 %。     

A novel strategy for the preparation of bamboo fiber reinforced polypropylene composites

In this paper, a novel strategy was used to prepare the bamboo fiber (BF)/polypropylene (PP) composites which greatly improved the distribution of BF. Both the raw and alkali treated BF were utilized for the fabrication of composites and silane coupling agent was used to improve the adhesion of BF and PP. The effects of BF content and the alkali treatment of BF on mechanical, thermal, morphological, dynamic mechanical properties and water absorption were studied. The Fourier transform infrared spectroscopy (FT-IR) analysis indicated that the hydrophilic nature of raw BF was significantly reduced by alkali treatment. In addition, the mechanical properties and the water absorption of the composites were found to increase with the increment of BF loading. Most importantly, the mechanical properties of the alkali treated BF showed much higher values than that of raw BF while the water absorption of alkali treated BF was much lower than that of raw BF. The results indicated the interaction of fiber-matrix was greatly improved by the alkali treatment. Moreover, from the Scanning Electron Microscopy (SEM) images, it further proved that the distribution of BF was improved by the way of papermaking to premix BF and PP fiber. The Dynamic mechanical thermal analysis (DMA) results showed that the storage modulus of the composites was increased with further increase in BF content.     

The nutritional components and physicochemical properties of brown rice flour ground by a novel low temperature impact mill

A low temperature impact mill (LTIM) was created and used for grinding brown rice. The nutritional components and physicochemical properties of the resulting flour were investigated and compared with those ground by traditional wet colloid mill (CM) and dry high-speed universal grinder (HUG). It was found that LTIM produced a fine flour with unimodal particle size distribution, and well retained non-starch nutrients. Especially, the phenolic content of flour prepared by LTIM was two times higher than that prepared by CM. LTIM also led to less damaged starch content than HUG. The damaged starch content related well with the thermal and gel hydration properties. Interesting, comparing the particle size distribution before and after enzymolysis, it was found that LTIM could pulverize dietary fiber of brown rice efficiently. The results from this study indicated that the LTIM may provide a promising technology for pulverizing brown rice thus open its new applications.     

Influence of noncellulosic contents on nano scale refinement of waste jute fibers for reinforcement in polylactic acid films

In the present study, nanofibrils of cellulose are extracted from waste jute fibers using high energy planetary ball milling process in wet condition. The rate of refinement of untreated fibers having non-cellulosic contents was found slower than treated fibers due to strong holding of fiber bundles by non-cellulosic contents. At the end of three hours of wet milling, untreated fibers were refined to the size of 850 nm and treated fibers were refined to the size of 443 nm. In the subsequent stage, composite films of poly lactic acid (PLA) were prepared by solvent casting with 3 wt% loading of untreated jute nanofibrils, treated jute nanofibrils and microcrystalline cellulose. The influence of non-cellulosic contents on mechanical properties of PLA films are investigated based on results of tensile test, dynamic mechanical analysis and differential scanning calorimetry. The maximum improvement was observed in case of treated jute nanofibril/PLA composite film where initial modulus and tensile strength increased by 207.69 % and 168.67 %, respectively as compared to neat PLA film. These improvements are attributed to the increased interaction of treated jute nanofibrils with PLA matrix due to their higher precentage of cellulosic contents and mechanically activated surface.     

挤压膨化碱处理豆渣制备水溶性膳食纤维工艺的研究

以豆渣为原料,并在碱液处理后直接挤压膨化制备豆渣水溶性膳食纤维.以水溶性膳食纤维得率为指标,对物料水分、挤压温度、螺杆转速及氢氧化钠浓度进行了单因素试验.采用响应面分析方法,对挤压膨化提高碱处理豆渣水溶性膳食纤维的工艺条件进行了优化,并建立了物料水分、挤压温度、螺杆转速三因素的回归模型.确定了挤压膨化碱处理豆渣制备水溶...     

Viscoelastic behaviour of untreated and chemically treated banana Fiber/PF composites

The dynamic mechanical properties such as storage modulus, loss modulus, and tan δ of banana fiber reinforced PF composites fabricated by RTM and CM techniques were investigated as a function of fiber content, fiber treatment, temperature and frequency. Storage modulus (E′) increases with increase in fiber content and records maximum for the composites having a fiber loading of 40 wt % at all temperature ranges. The loss modulus and damping increases to great extent by the addition of filler, a maximum was observed for filler with 10–20 wt % fiber content followed by a slight decrease in loss modulus and damping with increasing filler content. Alkali treatment of the fiber shows a great enhancement in E′ and T _g of the composites. Comparison is made between the composites fabricated by RTM and CM. RTM composites exhibited higher storage modulus and lower damping compared to CM composites.     

Evaluation of Particle Size Influence on Proximate Composition,Physicochemical, Techno-Functional and Physio-Functional Properties of Flours Obtained from Persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> Trumb.) Coproducts

The aim of the work was to study the influence of particle size in the composition, physicochemical, techno-functional and physio-functional properties of two flours obtained from persimmon (Diospyros kaki Trumb. cvs. ‘Rojo Brillante’ (RBF) and ‘Triump’ (THF) coproducts. The cultivar (RBF and THF) and particle size significantly affected all parameters under study, although depending on the evaluated property, only one of these effects predominated. Carbohydrates (38.07–46.98 g/100 g) and total dietary fiber (32.07–43.57 g/100 g) were the main components in both flours (RBF and THF). Furthermore, insoluble dietary fiber represented more than 68% of total dietary fiber content. All color properties studied were influenced by cultivar and particle size. For both cultivars, the lower particle size, the higher lightness and hue values. RBF flours showed high values for emulsifying activity (69.33–74.00 mL/mL), while THF presented high values for water holding capacity (WHC: 9.47–12.19 g water/g sample). The bile holding capacity (BHC) and fat/oil binding values were, in general, higher in RBF (19.61–12.19 g bile/g sample and 11.98–9.07, respectively) than THF (16.12–12.40 g bile/g sample and 9.78–7.96, respectively). The effect of particle size was really evident in both WHC and BHC. Due to their dietary fiber content, techno-functional and physio-functional properties, persimmon flours seem to have a good profile to be used as potential functional ingredient.