仙草提取物对贡丸质构特性、食用品质和抗氧化特性的影响

本实验的目的在于研究仙草提取物添加量对猪肉贡丸品质变化和抗氧化特性的影响。采用物理的方法测定了仙草贡丸质构特性和色泽,采用感官评定方法分析了贡丸的食用品质,并用化学的方法测定了4℃下储藏期间贡丸的硫代巴比妥酸反应物值(TBARS)和挥发性盐基氮(TVBN)变化情况。结果表明:随着仙草胶添加量的增加,贡丸的硬度、咀嚼性和弹性呈现先增加后降低趋势,色泽上L值、b值显著降低(P0.01),a值逐渐升高;与对照组相比,随着贮藏时间的增加,添加了仙草提取物的各处理组贡丸的脂肪和蛋白氧化速度显著降低(P0.05)。当仙草提取液添加量为总肉重的10%时,贡丸感官品质评分最高,与对照组相比,其硬度,弹性和咀嚼性分别提高了17.73%、9.33%和16.38%,同时还改善了风味,显著抑制了脂肪和蛋白氧化(P0.05),效果与0.02%BHA相近。     

Influence of Bacterial Cellulose (nata) on the Physicochemical and Sensory Properties of Frankfurter

The physicochemical and sensory characteristics of pork frankfurters containing different levels (10% to 30%) of bacterial cellulose (nata) were evaluated. Emulsion stability of the raw meat batter decreased with the addition of nata. For nata‐added treatments, increasing levels of nata in frankfurters resulted in decreased textural hardness and shear values. Sensory results indicated that N10 and N20 had significantly higher firmness scores than N30 and control. However, juiciness score did not differ for all treatments. Incorporation of nata at lower levels (10% to 20%) did not have detrimental effects on the physicochemical, textural, sensory, and microbiological properties of regular‐fat frankfurters. Addition of a higher level (30%) of nata essentially produced comparable sensory properties to the control, but lower levels of nata in frankfurters yielded higher sensory firmness and instrumental hardness values. Based on the composite results, manufacture of regular‐fat frankfurter containing 10% to 20% high‐fiber nata resulted in product quality comparable to the control.     

椰子纳塔发酵条件研究

研究了一株醋酸杆菌（Ａｃｅｔｏｂａｃｔｅｒｓｐ．）在椰子水培养液中发酵产生纳塔（ｎａｔａ）的适宜工艺条件：蔗糖７％,ＮＨ４Ｃｌ０．４％,ＫＨ２ＰＯ４０．２％,ＭｇＳＯ４０．０２％,ＣａＣｌ２０．０２％,ＦｅＳＯ４０．０００５％（Ｗ／Ｖ）,酵母膏０．０５％,柠檬酸０．０２％,椰子水５０％～１００％（Ｖ／Ｖ）,ｐＨ４．０,用大口容器盛装,３０℃静置培养１４～１８ｄ。在此条件下,于５００ｍｌ烧杯中发酵１６ｄ,最高可收获１８２ｇ重,３．３ｃｍ厚的纳塔,其外观和品质均符合纳塔食品的加工要求。     

Influences of xylooligosaccharides on the quality of Chinese-style meatball (kung-wan)

Physicochemical properties, sensory traits, and protein surface hydrophobicity of Chinese-style meatball (20% fat) processed from various combinations of xylooligosaccharides (XOS) and sucrose were investigated. No significant differences in pH and water-holding capacity were noted for treatments following cooking and frozen storage. Sensory springiness, hardness, chewiness, and overall acceptability of all treatments were found not significantly different. Water-soluble protein and total extractable protein concentrations of XOS4 (4% xylooligosaccharides) containing treatments were higher than other treatments at any frozen storage period (0, 4, 8, and 12 weeks). Addition of xylooligosaccharides or sucrose singly or in combination at levels investigated in this experiment resulted in Chinese meatballs with comparable quality. Substitution of sucrose with varying amounts (1, 2, and 4%) of xylooligosaccharides functioned equally on the quality of Chinese-style meatball.     

超声波促进高纤椰果发酵的研究

为了提高高纤椰果发酵产量,在浅层静态发酵过程中尝试加载超声波,研究了超声波处理条件对高纤椰果发酵的影响。结果表明,适宜的超声波处理条件对高纤椰果发酵有促进作用,利用超声波(400 W,28 kHz)从发酵48h开始进行处理,每次处理时间为180 s,每隔1.5 h处理1次,发酵240 h,纤维素干重可达到1.88 g,比空白实验提高了20.5%。     

“Nata Puree,” a Novel Food Material for Upgrading Vegetable Powders,Made by Bacterial Cellulose Gel Disintegration in the Presence of (1,3)(1,4)-β-Glucan

Pulverization is a potentially powerful solution for the resource management of surplus- and non-standard agricultural products, maintaining their nutritional values for long and ensuring their homogeneity, whereas their original textures could disappear to narrow the application ranges. Therefore, new technologies should be developed for reconstructing the powders to provide them with new physical characteristics. Herein, we developed a novel food material, nata puree (NP), by nata de coco (bacterial cellulose gel) disintegration with a water-soluble polysaccharide using a household blender. The process worked well with (1,3)(1,4)-β-glucan (BGL) as the polysaccharide, which could be substituted with barley extract. Lichenase treatment of the NP dramatically modified its physical properties, suggesting the importance of the BGL polymeric forms. NP exhibited distinct potato powder and starch binding activities, which would be attributed to its interactions with the cell wall components and a physical capture of powders by the NP network, respectively. NP supplementation into the potato paste improved its firmness and enabled its printable range shift for 3D food printing to a lower powder-concentration. NP also promoted the dispersion of powders in its suspension, and designed gelation could also be successfully performed by the laser irradiation of an NP suspension containing dispersed curdlan and turmeric powders. Therefore, NP could be applied as a powder modifier to a wide range of products in both conventional cooking, food manufacturing, and next generation processes such as 3D food printing.     

Fermentation of Monascus purpureus on Bacterial Cellulose-nata and the Color Stability of Monascus-nata Complex

Nata, a bacterial cellulose produced by Acetobacter aceti ssp. xylinum , was colored by means of fermentation with Monascus purpureus. Scanning electron microscopy (SEM) observations showed that the Monascus mycelium could grow through the cellulose network of nata. Rice powder as a major carbon source and monosodium glutamate (MSG) as a nitrogen source gave an appealing coloration after 12 d of fermentation at 30 °C. Compared to dyed nata, the color of the Monascus -nata complex had better resistance to washing, heat, freezing, acidification, and alkalization. A 66.1% decolorization was found under irradiation with 366 nm ultraviolet light after 36 h. The Monascus -nata complex has the potential to be a new vegetarian foodstuff.     

Composite Gels Containing Whey Protein Fibrils and Bacterial Cellulose Microfibrils

In this study, we investigated the gelation of WPI fibrils in the presence of bacterial cellulose (BC) microfibrils at pH 2 upon prolonged heating. Rheology and microstructure were investigated as a function of BC microfibril concentration. The presence of BC microfibrils did not influence the gelation dynamics and resulting overall structure of the WPI fibrillar gel. The storage modulus and loss modulus of the mixed WPI‐BC microfibril gels increased with increasing BC microfibril concentration, whereas the ratio between loss modulus and storage modulus remained constant. The WPI fibrils and BC microfibrils independently form two coexisting gel networks. Interestingly, near to the BC microfibrils more aligned WPI fibrils seemed to be formed, with individual WPI fibrils clearly distinguishable. The level of alignment of the WPI fibrils seemed to be dependent on the distance between BC microfibrils and WPI fibrils. This also is in line with our observation that with more BC microfibrils present, WPI fibrils are more aligned than in a WPI fibrillar gel without BC microfibrils. The large deformation response of the gels at different BC microfibril concentration and NaCl concentration is mainly influenced by the concentration of NaCl, which affects the WPI fibrillar gel structures, changing form linear fibrillar to a particulate gel. The WPI fibrillar gel yields the dominant contribution to the gel strength.     

细菌纤维素纸质复合微滤膜的开发

分别利用硫酸盐阔叶木浆、硫酸盐针叶木浆和机械浆抄造纸质基膜并测定其过滤性能;采用溶液过滤复合法,通过过滤使分散均匀的细菌纤维素在纸质基膜上形成一层致密薄膜层,即得到细菌纤维素纸质复合微滤膜。结果表明：采用打浆度为10°SR的机械浆抄造定量为90 g/m²的纸质基膜的过滤性能最好;采用该纸质基膜制备的细菌纤维素纸质复合微滤膜(细菌纤维素复合量6 g/m²)平均孔径为0.01～1 μm,达到微滤膜水平,且强度性能、耐高温性、耐碱性良好。     

细菌纤维素纤维对纸张性能的影响

研究了细菌纤维素湿膜经机械匀浆处理后,细菌纤维与植物纤维混合抄片的纸页性能.实验表明,细菌纤维素湿膜经过适当的处理后可以用于制备造纸所用的细菌纤维浆料;添加到纸页中的细菌纤维能在植物纤维间起到搭桥作用,并显著提高纸页的物理强度.     

Regulating the Function of Nanocomposite Made from Hydroxypropyl Methyl Cellulose with Bacterial Cellulose Nanocrystal

Hydroxypropyl methyl cellulose(HPMC)-based hybrid nanocomposites reinforced with bacterial cellulose nanocrystals(BCNC) were prepared and characterized.The HPMC nanocomposites exhibited good thermal stability,with a thermogravimetric peak temperature of around 346℃.The addition of BCNC did not significantly affect the thermal degradation temperature or improve the transparency of HPMC nanocomposites.However,the addition of BCNC favorably affected the light scattering properties of the nanocomposites and enhanced mechanical properties such as tensile stress and Young's modulus from 65 MPa and 1.5 GPa up to 139 MPa and 3.2 GPa,respectively.The oxygen permeability of the HPMC nanocomposites also increased with increase in the amount of BCNC added.     

细菌纤维素在草浆纸中应用的探讨

利用电子显微镜观察了细菌纤维素的微观结构，其为典型的空间网络结构，利用显微镜观测纤维素湿膜打浆分散成单根纤维的横断面形态，末端呈锯齿型，其有利于纤维的分丝帚化。在浆料中加入细菌纤维素能够有效地提高填料的一次留着率。在苇浆中加入10%（g/g）的细菌纤维素可提高裂断长22%，耐破指数8%，撕裂指数5%。     

低糖细菌纤维素冰淇淋

通过对醋酸菌的培养制成细菌纤维素，并以此为主要原料加工制成风味独特富含细菌纤维素的冰淇淋，该产品营养丰富，又真保健功能，是冰淇淋的一个新品种。     

羧甲基纤维素钠和羟乙基纤维素对冷冻猪血豆腐品质的影响

为提高猪血豆腐在冷冻条件下的品质特性,以新鲜猪血为原料,添加羧甲基纤维素钠(carboxymethyl cellulose sodium,CMC-Na)和羟乙基纤维素(hydroxyethyl cellulose,HEC),研究其对冷冻猪血豆腐蒸煮损失、色差、质构及感官品质的影响。结果表明:CMC-Na和HEC添加量均为1.00 g/100 mL时,冷冻猪血豆腐的蒸煮损失比未添加CMC-Na和HEC分别降低69.65%、86.82%(P<0.05),质构特性中的硬度、弹性、咀嚼性比未添加CMC-Na和HEC分别提高41.01%、20.03%、83.43%(P<0.05),其色泽指标红度值和黄度值高于鸭血豆腐(P<0.05),感官上嫩度软硬适中、切面密实、几乎无气孔。因此,添加CMC-Na和HEC能提高冷冻猪血豆腐的品质特性。     

光度法测细菌纤维的分散性

用分光光度计测定细菌纤维悬浮液的吸光度,可以很好地表征细菌纤维分散体的分散性能,此法方便、直观,可以作为纤维分散性的表征方法之一.     

细菌纤维素减肥功能测定及其酸奶的制作

目的:确定细菌纤维素酸奶制作工艺,验证细菌纤维素酸奶的减肥功效。方法:建立肥胖小鼠模型后,对小鼠按照500、417、333mg/kg(以体质量计)高、中、低的剂量进行细菌纤维素灌胃,每日1次,灌胃2周,检测小鼠血液中各项血脂指标;通过感官评价和质构分析确定制作细菌纤维素酸奶的关键工序参数。结果:细菌纤维素中、高剂量组和阳性药物组使营养性肥胖小鼠体质量下降极其显著(P<0.01),细菌纤维素各剂量组使小鼠血清中甘油三酯(TG)、总胆固醇(TC)和低密度脂蛋白胆固醇(LDL)水平下降显著(P<0.05),细菌纤维素各剂量组使高密度脂蛋白胆固醇(HDL-C)水平升高显著(P<0.05)。按牛奶质量的3%添加平均粒径为0.1cm的细菌纤维素颗粒,同时添加7%绵白糖,使酸奶的弹性、内聚性等品质显著改善。营养性肥胖模型小鼠的喂养实验证明各剂量组细菌纤维素酸奶减肥效果均显著。结论:细菌纤维素和细菌纤维素酸奶对营养性肥胖小鼠具有减肥作用,细菌纤维素对酸奶品质具有很好的改善作用。     

细菌纤维素生产菌株的动力学研究

对细菌纤维素生产菌株QAX993的发酵动力学特性进行了研究，基于Logistic方程，提出了细胞生长动力学、基质消耗动力学、纤维素生成动力学模型，得到了描述静态分批发酵过程的动力学模型及模型参数，同时对实验数据与模型进行了验证，模型计算值与实验数据拟合良好，模型基本上反映了该菌株分批发酵过程的动力学特征。     

细菌纤维素发酵培养基的优化

采用Plackett Burman设计法、响应面分析和最速增长途径法 ,对AcetobacterxylinumX 2静态发酵培养基进行了优化。在确定初始浓度远离最优水平后 ,寻求到最优区域。发酵培养基在最优区域时 ,A .xylinumX 2细菌纤维素的产量达到 4.6g/L ,比其初始区域的结果提高 1倍     

细菌纤维素在低脂肉肠中的应用

本研究使用醋杆菌Acetobacter xylinumC5，利用大豆乳清发酵得到的细菌纤维素作为脂肪模拟物和乳化剂，应用到肉肠的加工当中。实验证明，细菌纤维素可以部分，甚至完全替代肉肠中的肥肉。含有大豆乳清细菌纤维素的肉肠，在外观、风味、口感等方面与普通肉肠没有明显差别。将卡拉胶与细菌纤维素配合使用，可以赋予肉肠更良好的口感和组织状态。添加细菌纤维素的肉肠的热量减少了28％-56％。     

利用不同碳源调控椰果凝胶产品的结构和质构特性

本文研究了四种不同碳源(葡萄糖,果糖,甘露醇和乙醇)对两株木糖驹形氏杆菌(ATCC 53582和ATCC 23767)生产的椰果凝胶产量的影响,并研究了在相同碳源浓度下,由不同碳源生产的椰果凝胶的结构和力学性能。当碳源为葡萄糖且浓度为20 g/L时,木糖驹形氏杆菌ATCC 53582的椰果凝胶产量最高(6.07 g/L)。碳源浓度为30 g/L时,葡萄糖、果糖和甘露醇分别作为碳源生产的椰果凝胶的平均纤维网孔直径(分别为0.61μm、0.48μm和0.57μm)均小于乙醇为碳源生产的椰果凝胶(1.06μm);在相同椰果凝胶高度(0.50 mm)下它们的储能模量(分别为210 kPa、230 kPa和170 kPa)均大于碳源为乙醇生产的椰果凝胶(17 kPa);拉伸测试中,它们的杨氏模量(分别为3.54 MPa、6.49 MPa和5.49 MPa)也均大于碳源为乙醇生产的椰果凝胶(1.62 MPa)。