海带与小麦麸皮由来不溶性膳食纤维的酶辅助提取及其功能特性比较

采用酶辅助化学方法分别提取海带和小麦麸皮中的水不溶性膳食纤维,并对所提取样品的体外功能特性进行比较。研究发现,海带和麸皮化学组成差异较大,不溶性膳食纤维提取得率分别为8.52%和77.93%（干基）。海带不溶性膳食纤维的膨胀力为5.99 mL/g,持水力为11.82 g/g,持油力为10.05 g/g;麸皮不溶性膳食纤维的膨胀力为3.10 mL/g,持水力为5.97 g/g,持油力为5.95 g/g。在对铅离子和镉离子的吸附能力方面,海带不溶性膳食纤维分别达683.61 μg/g和528.97 μg/g,而麸皮不溶性膳食纤维分别为583.23 μg/g和548.09 μg/g。试验结果表明：海带的不溶性膳食纤维具有优良的功能特性,应用开发潜力巨大。     

不同提取方法对马铃薯膳食纤维化学组成和理化性质的影响

为明晰不同提取方法对马铃薯膳食纤维化学组成和理化性质的影响,分别采用酸解法、复合酶法、酶碱法提取马铃薯膳食纤维,比较了提取的膳食纤维化学组成、持水力、膨胀力、阳离子交换能力和胆固醇、亚硝酸根吸附能力。结果表明,复合酶法提取的膳食纤维中淀粉质量分数最低(11.70%),总膳食纤维(TDF)和可溶性膳食纤维(SDF)质量分数最高(74.72%、7.10%);酸解法提取的膳食纤维中蛋白质质量分数最低(2.77%)。酸解法、复合酶法提取的膳食纤维的持水力、膨胀力和阳离子交换能力显著高于酶碱法(P0. 05);复合酶法、酶碱法提取的膳食纤维具有较强的胆固醇、亚硝酸根吸附能力。结论:不同提取方法对马铃薯膳食纤维化学组成和理化性质影响很大。     

脱蛋白结合超微粉碎对豆渣膳食纤维成分及功能特性影响

研究脱蛋白方法结合超微粉碎处理豆渣对其化学组成和功能特性的影响,当豆渣样品进行酶或碱处理时,它的总膳食纤维(TDF),不溶性膳食纤维(IDF)的质量分数分别增加了18.6-32.9%,22.6-34.4%,并且它们的功能特性(持水力,膨胀力和持油力)显著(p < 0.05)增加,但可溶性膳食纤维(SDF)质量分数与处理前豆渣没有显着差异。经超微粉随后,随着豆渣膳食纤维粒径减小,豆渣膳食纤维中可溶性膳食纤维质量分数提高了170% 以上,持水力和膨胀力显着下降(p < 0.05),持油力先下降后上升。结果表明,应用碱性蛋白酶和超微粉碎进行前处理,得到的豆渣中TDF和SDF的含量最高,这可能是在食品中加工高质量膳食纤维的潜在方法。     

酶辅助空化处理对豆渣纤维结构和理化性质的影响

该研究通过傅里叶变换红外光谱、X-衍射、扫描电镜等分析方法分析水力空化、酶解处理对脱脂豆渣纤维结构和理化性质的影响。研究结果表明：空化处理强烈影响了豆渣纤维的理化性质,空化10 min时豆渣纤维的持水力与持油力分别达到18.43 g/g和7.35 g/g,空化处理20 min使可溶性膳食纤维含量（Soluble Dietary Fiber,SDF）由2.87%升至6.97%,溶液表观黏度降低,豆渣纤维出现蜂窝状片状结构,豆渣纤维结晶度降低。酶辅助空化处理可以进一步改善豆渣纤维的理化性质,且受酶解先后顺序强烈影响,其中,先酶解后空化豆渣中的SDF含量可达12.52%,溶液表观黏度明显降低,先空化后酶解的样品则表现出更高的持水力与持油力。酶辅助空化处理豆渣出现较多碎片结构,纤维尺寸变小。酶辅助空化处理可以作为一种有效改善豆渣纤维结构和理化性质的手段。     

酶处理马尾藻提取膳食纤维的研究

采用酶处理和化学的方法 ,研究了酶解、消化、漂白和功能活化等工艺条件对马尾藻膳食纤维提取的影响 ,筛选出马尾藻膳食纤维提取的最佳工艺条件。结果表明 ,在该工艺条件下提取的马尾藻膳食纤维的产率为 2 7 3 % ,颜色为类白色 ,膳食纤维干基含量为 82 7% ,钙含量为 5 3 6% ,膨胀力和持水力两项功能性指标分别达到 10 8mL/g和 5 3 2 0 % ,该产品的质量指标远高于小麦麸皮膳食纤维     

羧甲基化与接枝化改性对小米糠膳食纤维结构与理化性质的影响

该文研究接枝化和羧甲基化对小米糠膳食纤维的化学组成、微观结构和理化性质的影响。结果表明,接枝化和羧甲基化改性可以提高小米糠膳食纤维的可溶性膳食纤维含量、比表面积、持水力、持油力、阳离子交换能力和膨胀力。羧甲基化和接枝化改性后,小米糠膳食纤维的可溶性膳食纤维含量分别提高约7倍和11倍;持水力从1.12 g/g分别增加到2.69、2.29 g/g;持油力则从2.19 g/g分别提升至4.59、4.27 g/g。同时,接枝化和羧甲基化后,小米糠膳食纤维的阳离子交换能力分别提高5.34倍和0.75倍。此外,与未改性的小米糠膳食纤维相比,改性后的小米糠膳食纤维的色泽变深、粒度变小、比表面积增大,呈蜂窝状、多孔状的微观结构。     

红枣果汁果渣与果酒果渣膳食纤维功能特性的比较研究

为了探究红枣果汁果渣与果酒果渣膳食纤维功能特性的差异,以红枣果汁果渣和果酒果渣为原料制备膳食纤维,通过测定膳食纤维的持水力、膨胀力、溶解性、持油力、阳离子交换能力以及吸附胆固醇、胆酸钠、葡萄糖能力,评价红枣果汁果渣与果酒果渣膳食纤维的功能特性。结果表明:红枣果酒果渣膳食纤维的持水力、膨胀力、溶解性、持油力、阳离子交换能力以及吸附胆固醇、胆酸钠、葡萄糖能力均显著高于果汁果渣膳食纤维(P<0.05),且随发酵天数延长,红枣果渣膳食纤维的功能特性均逐渐增加。发酵8 d时,果酒果渣膳食纤维持水力、膨胀力、溶解性、持油力、阳离子交换能力以及吸附胆固醇、胆酸钠、葡萄糖能力较果汁果渣膳食纤维分别提高了1.10、1.11、1.75、1.39、2.03、1.49、1.10和1.83倍,表明发酵有助于提高红枣果渣膳食纤维的功能特性。     

江蓠残渣膳食纤维的酶法功能活化研究

为了改善江蓠残渣膳食纤维的性能,采用纤维素酶和木聚糖酶对漂白后的江蓠残渣膳食纤维进行功能活化研究,筛选出了较佳的复合酶活化配方;采用扫描电镜研究了活化前后膳食纤维的表面结构。研究结果表明:45u/g纤维素酶和60u/g木聚糖酶复合酶处理膳食纤维可以使膳食纤维的可溶性膳食纤维含量(SDF)、持油能力(OBC)、膨胀力(SW)和持水力(WHC)分别增加29%、26%、15%和14%,活化后的江蓠残渣膳食纤维的膨胀力和持水力分别达到4.71mL/g和648%,功能性指标超过西方国家麸皮膳食纤维的标准(膨胀力4mL/g、持水力400%);通过扫描电镜观察发现,复合酶改性后的膳食纤维的表面结构变得蓬松,有孔隙结构出现,可能是其物理性能变好的原因。     

竹笋膳食纤维的制备及其功能结构比较

比较采用发酵法、酶法和酸碱法制备的竹笋膳食纤维在化学组成、功能特性和结构方面的差异。结果表明:酶法和发酵法制备的竹笋膳食纤维中蛋白质和SDF的含量显著高于酸碱法,而IDF和TDF的含量显著低于酸碱法;3种方法制备的竹笋膳食纤维在持水力和持油力方面呈显著性差异,而在溶胀力和阳离子交换能力方面差异不显著;原子力显微观察发现3种方法制备的膳食纤维表面均呈波状起伏的山峰状结构,波峰和波谷间有不同的高度差,其中以酸碱法处理的突起最明显,酶法处理次之,乳酸发酵法处理的表面相对平整,未经处理的对照组最差。红外光谱显示,3种方法制备的竹笋膳食纤维的物质组成和化学键类型基本相同。     

组分脱除对麦麸功能特性的影响及应用

利用脱脂技术和酶解技术分别去除麦麸中的主要组分,分别以脱除植酸、脂肪、淀粉、蛋白质和4种组分全脱除的麦麸为研究对象,研究不同组分脱除对麦麸的功能性质的影响。结果表明：淀粉的脱除对麦麸的持水、持油性和膨胀力等功能特性的改善效果最为显著,蛋白质次之,脂肪和植酸对功能特性影响最小。麦麸中4种主要组分全部脱除后,膳食纤维含量达83.47%±0.38%,持水性、持油性、膨胀力等功能特性提升显著。体外消化结果表明,添加组分全脱除麦麸的饼干消化率为76.87%,与普通饼干相比消化率降低11.40%,且饼干持水性、持油性有所改善。     

超临界CO2处理对米糠纤维物性的影响

研究超临界CO2处理米糠粉前后制备的米糠纤维的膨胀力、持水力、结合水力及吸脂力的变化。结果表明,相同粒度的米糠纤维,其膨胀力、持水力和结合水力经超临界CO2处理后均有所提高,而吸脂力却有所下降。超临界CO2处理前后持水力、吸脂力均在纤维粒度0.246mm时达到最高值,膨胀力、结合水力在0.900mm和0.175mm时分别达到最高值。米糠纤维的综合物性在粒度0.246mm时最佳,且超临界CO2处理后米糠纤维的综合物性值比处理前提高27.75%,米糠纤维提取率增加36.63%。     

Impacts of Cellulose Fiber Particle Size and Starch Type on Expansion During Extrusion Processing

Objective of this study was to understand the impacts of cellulose fiber with different particle size distributions, and starches with different molecular weights, on the expansion of direct expanded products. Fiber with 3 different particle size distributions (<125, 150 to 250, 300 to 425 μm) and 4 types of starches representing different amylose contents (0%, 23%, 50%, and 70%) were investigated. Feed moisture content (18 ± 0.5 % w.b) and extruder temperature (140 °C) were kept constant and only the extruder screw speed was varied (100, 175, and 250 rpm) to achieve different specific mechanical energy inputs. Fiber particle size and starch type significantly influenced the various product parameters. In general, the smaller fiber particle size resulted in extrudate with higher expansion ratio. Starch with an amylose: amylopectin ratio of 23:77 resulted in highest expansion compared to the other starches, when no fiber was added. Interestingly, starch with 50:50, amylose: amylopectin ratio in combination with smaller fiber particles resulted in product with significantly greater expansion than the control starch extrudates. Aggregation of fiber and shrinkage of surface was observed in the Scanning Electron Microscope images at 10% fiber level. The results suggest the presence of active interactions between the cellulose fiber particles and corn starch molecules during the expansion process. A better understanding of these interactions can help in the development of high fiber extruded products with better expansion.     

不同复合酶在改善梗丝品质中的研究

为了提高梗丝在卷烟中的适用性,改良梗丝品质,选择3种不同的复合酶制剂对梗丝进行处理。通过对酶解前后梗丝的理化成分和中性致香成分分析以及卷烟感官评吸,评价3种酶制剂的效用。结果表明,由复合植物水解酶、果胶酶、蛋白酶、淀粉酶组成复合酶A 效果最好,梗丝经酶解后,水溶性总糖含量提高了23.31%,果胶的含量降低了17.26%,且填充值提高可达10%。对其主要致香成分进行分析可知,美拉德反应产物的总量提高了196.3%,4种巨豆三烯酮和β-大马酮分别提高了37.01%、50.77%。采用酶解梗丝替代未处理的梗丝掺配到卷烟叶组中,卷烟的焦油量下降0.25 m g,木质气息和刺激性明显减轻,香气质量、协调性均有提高。     

牛乳蛋白在膜反应器中的酶解

用超滤器作为牛乳蛋白酶解反应的反应器,比较了在膜反应器中酶解和在普通反应器中酶解产物的分子量分布。     

Succinylated Dioscorea cayenensis starch: Effect of reaction parameters and characterisation

Starch was extracted from Dioscorea cayenensis (yield, 87.2%) and it was subjected to succinylation under different reaction conditions. The succinyl amount and the degree of substitution (DS) in starch increased as the concentration of succinic anhydride, time and temperature increased. Optimal DS (0.217) and % succinyl content of 11.82 could be achieved at starch: catalyst (pyridine) ratio of 1:1, succinic anhydride concentration of 4% w/w at 120°C and 4 h of reaction. Succinylation did not alter starch crystallinity remarkably. Native starch granules appeared oval, round and spherical with sizes in the range 15–31 µm (length) and 10–20 µm (width). Both swelling capacity and solubility improved after succinylation. Succinylation increased paste clarity and it was dependent of the DS and storage time for the paste. Pasting temperature was reduced after modification and as the DS increased among the starch derivatives. The peak viscosity of the native starch was lower than the viscosities of all the modified starches. Succinylation reduced setback values but increased breakdown. Percentage syneresis was reduced after succinylation and progressive increases in percentage syneresis were observed as the number of cycles of freezing–thawing increased. In vitro enzyme digestibility reduced after succinylation and progressively as the DS of the modified starch increased.     

Starch Phosphates Produced by Extrusion: Physical Properties and Influence on Yogurt Stability

Starch phosphorylation with sodium tripolyphosphate (STP) was performed using a single‐screw extrusion process. The extrusion variables studied were temperature (from 99.5°C to 200.4°C), water content (16.3% to 19.7%, w/w), and STP content (0.82% to 4.18%, w/w). The resulting phosphorylated starch was evaluated with respect to expansion, water solubility index (WSI), water absorption index (WAI), degree of substitution (DS), and viscosity. The phosphorylated starch was tested as a stabilizing additive in yogurt formulations, with respect to the syneresis index (SI) and the syneresis susceptibility coefficient (SSC). The results show that the expansion increases with increasing STP content, and decreases with increasing temperature and water content employed in the process. Increasing extrusion temperatures and decreasing water content resulted in increasing WSI and decreasing WAI. The DS was dependent on STP content, increasing as STP content increased, but appeared to be insensitive to changes in water content (between 16% and 20%, w/w). The highest level of yogurt stability, as measured by the syneresis index (SI) and the syneresis susceptibility coefficient (SSC), were obtained when the yogurt was formulated with the starch of the highest DS (0.018), which had been obtained at 150°C, 18% water content, and 4.12% (w/w) of STP.     

传统发酵豆豉蛋白质生物学变化与抗氧化能力研究

选取15种具有地区代表性的豆豉,测定总酸含量、水解度、水溶性蛋白含量、酸溶性蛋白含量、褐变指数及总抗氧化能力等指标,利用描述性分析结合主成分分析、聚类分析对样品进行评价。结果表明,15种豆豉样品在质量指标上差异性很大,其中中南地区样品在指标上优于西南地区样品;细菌型豆豉在酸溶性蛋白及水溶性蛋白含量上优于霉菌型豆豉,干豆豉与湿豆豉在质量指数上差别不大。主成分分析及聚类分析表明各质量指标与抗氧化性的关联性从大到小依次为褐变指数＞总酸含量＞水解度＞水溶性蛋白含量＞酸溶性蛋白含量,干豆豉与细菌型豆豉在蛋白水解程度上要优于其他豆豉,而后发酵时间是影响豆豉总抗氧化能力的主要因素。     

三种搅拌型酸奶用变性淀粉的特性及应用

研究了3种搅拌型酸奶用变性淀粉——蜡质玉米乙酰化二淀粉磷酸酯(AWMDP)、木薯乙酰化二淀粉磷酸酯(ATDP)、蜡质马铃薯二淀粉磷酸酯(WPDP)的基本性质和应用效果。3种搅拌型酸奶用变性淀粉经95℃处理10min后仍保持膨胀的颗粒状态,但是膨胀的平均粒径大小、吸水能力不同,这主要与淀粉的来源、交联度有关。3种变性淀粉(0.5%,w/w)都使得搅拌型酸奶的表观黏度、持水力和弹性模量(G')增加,同时提高了酸奶的抗剪切变稀性。WPDP在改善酸奶的物理性能上明显优于其他2种变性淀粉。     

Spent residue from cumin – a potential source of dietary fiber

Cumin has total dietary fiber content (TDF) of 59.0%, insoluble dietary fiber (IDF) of 48.5%, and soluble dietary fiber (SDF) of 10.5%, while the spent residue from cumin (after oil and oleoresin extraction) was found to contain 62.1% TDF, 51.7% IDF and 10.4% SDF. The spent residue also contained 7.7% starch and 5% bound fat. Particle size analysis showed a direct effect on the hydration properties of the fiber. The spent residue exhibited 3.3 g/g water holding capacity, 4.0 g/g water retention capacity and 4.47 ml/g swelling capacity. Scanning electron microscopy revealed spherical starch granules embedded within cell wall material, which upon differential sedimentation gave differently sized starch granules (5.8 μm). Upon defatting the spent residue showed typically a ‘honey comb’ structure, almost devoid of starch granules. Thus, the spent residue from cumin, not having much commercial value at present, can be a rich source of useful dietary fiber and can find food applications. It can be an effective way of utilizing industrial waste from the point of view of environmental pollution from the residues of spice processing industries.     

Influence of Reheating Method and Water Content on Change of the Physicochemical Properties of Retrograded Rice Starch

The effect of the reheating method (microwave, autoclave and steam) and water content (65, 75, 85 and 95%) on change of the physicochemical properties of retrograded rice starch was investigated. The increment of gelatinization after heat treatment in the autoclave was the highest (44.9% at 95% water content), and it also showed an increasing trend regardless of reheating methods as the water content was increased from 65% to 95%. The water‐holding capacity (WHC) of the retrograded rice starch was increased compared to that of control after reheating regardless of reheating method and water content, and the maximum value (33.2%, w/v) was observed in the sample reheated with steam at a water content of 95%. The retrograded rice starch reheated in the autoclave showed a decreased peak viscosity, breakdown, final viscosity and setback. In particular, these parameters were lowest in samples reheated in an autoclave. Also, in the autoclaved samples the crystallinity of retrograded rice starch decreased as the water content increased. The microstructure of the reheated samples was filamentous type composed of numerous small cavities.