羧甲基魔芋葡甘露聚糖/海藻酸钠的微囊制备及拉伸性能研究

通过二步加碱法对魔芋葡甘露聚糖进行改性以达到不同取代度的羧甲基魔芋葡甘露聚糖。将改性后的羧甲基魔芋葡甘露聚糖与海藻酸钠共混,采用锐孔法制备微囊。以牛血清蛋白作为模型药物,对微囊的包封率和载药率进行测定。参照GB/T1040.3-2006方法测定其拉伸性能。研究发现:当取代度为75%,羧甲基魔芋葡甘露聚糖与海藻酸钠质量比为3:1,温度为50.0 ℃,pH为7.0时,共混后的羧甲基魔芋葡甘露聚糖与海藻酸钠具有良好的拉伸性能;当牛血清蛋白质量为30.0 mg时,包封率和载药率分别为74%和76%,达到良好的包封和载药效果,这在生物医药领域具有潜在的应用价值。     

改性魔芋精粉对樱桃保鲜性能的研究

以魔芋精粉为原材料,用没食子酸、马来酸酐、多聚磷酸钠3种试剂对其进行改性,制成保鲜剂,在常温下进行保鲜实验,结果表明:经该膜保鲜过的樱桃,在储藏过程中感官及各项理化指标与空白相比较,取得了较好的保鲜效果,其中以没食子酸改性魔芋精粉的保鲜效果较好。     

魔芋葡甘聚糖-海藻酸钠复合益生菌微胶囊的构建及性能评价

为提高双歧杆菌、植物乳杆菌、干酪乳杆菌3种复合益生菌经胃肠道后的存活率,采用内源乳化法,将菌株包埋在魔芋葡甘聚糖(konjac glucomannan,KGM)和海藻酸钠(sodium alginate,ALG)中制成微胶囊,通过正交实验对工艺参数进行优化,并对其性能进行检测。制备微胶囊的最佳工艺参数:ALG质量分数为3%,KGM质量分数为0. 6%,水油体积比为1∶3,Ca CO3与ALG质量比为1∶3,包埋率达到(76. 2±5. 1)%。微胶囊提高了益生菌在模拟胃液中的存活率,增强了对胆盐的耐受性。通过血清生化指标和组织病理学观察,该材料对小鼠无毒性。灌胃KGM后,小鼠肠道乳杆菌科相对丰度升高,脱硫弧菌科等有害菌相对丰度降低,说明KGM能促进肠道有益菌生长,抑制有害菌。该研究为KGM的应用探索了一条新途径,并为复合益生菌微胶囊产业化生产及推广应用提供参考。     

焦磷酸钠对魔芋葡甘聚糖酯化交联改性研究

焦磷酸钠对魔芋葡甘聚糖进行酯化交联改性,实验结果表明:反应最佳条件为焦磷酸钠∶魔芋葡甘聚糖=1∶8(w/w)、pH3、温度50℃、时间2h。改性KGM溶胶透明度、黏度、冻融稳定性及抗菌性明显改善,改性KGM膜耐洗刷性比未改性KGM膜明显增强。     

三聚磷酸钠对魔芋葡甘聚糖酯化交联改性研究

三聚磷酸钠对魔芋葡甘聚糖进行酯化交联改性。实验结果表明,反应最佳条件为三聚磷酸钠∶魔芋葡甘聚糖=1∶9(W/W),反应pH为2,反应温度60℃,反应时间2h。改性KGM透明度、粘度、冻融稳定性均比未改性KGM明显改善,并具有一定的耐酸、耐高温能力,且有相当的抑菌效果。     

Elastic gels based on flaxseed gum with konjac glucomannan and agar

Food Science and Biotechnology - In this study, we prepared hydrocolloid gels in which flaxseed gum (FSG), konjac glucomannan (KGM), and agar (AG) were blended in different ratios for use as a...     

魔芋葡甘聚糖-壳聚糖-羧甲基纤维素钠复合可食性保鲜膜研究

将魔芋葡甘聚糖(KGM)、壳聚糖(CTS)和羧甲基纤维素钠(CMC-Na)作为成膜基质,以盐酸调节pH,添加甘油作为增塑剂,研究了各种成分的添加比例、甘油添加量及烘干温度对成膜性能的影响,制备出可食性复合保鲜膜.通过对膜的阻湿性、阻氧性、抗拉强度、断裂伸长率等指标进行测定,研究了膜的性能.结果表明:当三种主要成膜材料的配比(KGM:CTS:CMC-Na)为1:2:1、甘油含量为1.5%、烘干温度为40℃时,复合膜形成一种新的结晶体,具有最大的阻隔性能、较强的抗拉强度和中等强度的断裂伸长率,并能在短时间内迅速溶解,此时膜性能最优.     

傅里叶近红外光谱法快速检测魔芋葡甘聚糖中掺假羧甲基纤维素含量

采用傅里叶近红外光谱检测魔芋葡甘聚糖中羧甲基纤维素掺假比例,以基线校正、平滑、矢量归一化、一阶求导和二阶求导法对光谱进行处理,利用偏最小二乘法建立了相应的数学模型,并通过交互验证和外部验证检验了鉴别模型的预测精度和可靠性。所建立的校正集模型的决定系数R_c~2值为0.933~0.997,校正均方根误差范围为7.64%~1.56%;结合验证集模型的决定系数和均方根误差确定以一阶导数(5平滑点)处理光谱,所得模型预测效果最佳,模型的预测均方根误差为8.37%;校正模型中羧甲基纤维素在魔芋葡甘聚糖中掺假水平的预测值和实际值的相关系数为0.9905。结果表明,近红外光谱结合化学计量法在有效、快速、准确地定量检测魔芋葡甘聚糖中掺假羧甲基纤维素的可行性。      

Characteristics of wheat dough and Chinese steamed bread added with sodium alginates or konjac glucomannan

In this study, wheat flour was dry-blended with sodium alginates (ALG) and konjac glucomannan (KGM) at 0.2% and 0.8% w/w flour as-is moisture basis. Dough mixing and stretching properties were assessed by farinograph and extensograph, respectively. Chinese steamed bread (CSB) samples prepared were compared in terms of spread ratio, specific volume and staling behaviour. In general, ALG and KGM addition was found to produce dough with rigid and weak network, respectively. Chinese steamed bread with ALG (0.2%) or KGM (0.8%) addition was relatively low in spread ratio and specific volume, but softer and more resistant to staling on storage as compared to the control sample.     

Significant improvement for the functional properties of konjac glucomannan based on phase separation

Konjac glucomannan (KGM) serves as a stabiliser due to its high molecular weight and viscosity. However, these properties limit its addition in food products, especially in drinks. The main aim of this study was to improve the functional properties of KGM by a green and effective method, that is phase separation. It was found that increasing temperature accelerated phase separation of KGM/gum arabic mixture. KGM‐rich phase was characterised and its physical properties were investigated by different methods. Crystal property showed no significant changes after phase separation. Nevertheless, rheological properties indicated that the viscosities of samples after phase separation (FKGM) decreased dramatically. Their emulsifying capacities also improved. Moreover, the differences in molecular rearrangement at the oil–water interface were also studied by using interfacial rheology. These results suggested that FKGM with low viscosity had better interfacial properties, and thus may have potential applications as food ingredients.     

蜂胶/魔芋涂膜酸石榴保鲜技术研究

研究了以蜂胶、魔芋为主剂制成的多糖高分子复合保鲜液结合低温条件,对云南建水酸石榴进行涂膜处理后的呼吸强度、Vc、总糖含量、果面褐变指数等生理指标的影响。结果表明,蜂胶/魔芋复合涂膜液结合低温处理对建水酸石榴的保鲜效果较好,有效地抑制了云南建水酸石榴的呼吸作用,减少了营养成分和水分的损失,可有效延长期货架期和保持其最佳食用品质。     

Sprouting and quality control of fresh ginger rhizomes by modified atmosphere packaging with film perforation

The quality of ginger rhizomes packaged in low density polyethylene bags (modified atmosphere packaging — MAP) without perforations (P-0), with 2 perforations (P-2), and 12 perforations (P-12) have been investigated for 5 months at 12±1°C. Sprouting and rotting rates of ginger in P-2 and P-12 were lower than ginger in P-0. Weight loss was higher in P-12 than P-0 and P-2. Surface L* (lightness) and a* (redness) values in P-2 and P-12 were lower and higher, respectively, than those found for P-0. Sensory appearance and overall acceptability were rated significantly better in P-2 and P-12 than in P-0. Internal color, firmness, soluble solids, and pH of ginger in MAP were not affected by presence of perforations. Therefore, MAP with the appropriate number of perforations (in this work, 2 perforations) could be a useful method to control sprouting and maintain quality except for surface color of stored ginger rhizomes.     

含肉桂水提物的魔芋葡甘聚糖涂膜液对冷鲜猪肉的保鲜效果

以热水浸提和真空冷冻干燥法制备肉桂水提物,测定了其总酚及总黄酮含量,以及体外抗氧化性和抗菌性。研究了1%肉桂水提物+0.8%魔芋葡甘聚糖（KGM）涂膜液对猪肉进行浸渍涂膜的保鲜效果。在体外实验中,肉桂水提物可清除2,2-联氮-二（三-乙基-苯并噻唑-6-磺酸）二铵盐（ABTS）自由基,清除能力为（0.36±0.04）mg V_C/mg。可抑制金黄色葡萄球菌和大肠杆菌的生长,抑菌圈直径分别为（15.2±0.2）mm和（13.5±0.4）mm。经肉桂水提物+KGM涂膜液对冷鲜猪肉进行涂膜后,能延缓冷鲜猪肉中菌落总数、p H、硫代巴比妥酸（TBARS）值以及颜色的变化。以菌落总数为参考指标,利用肉桂水提物涂膜处理的冷鲜猪肉与未经涂膜处理的冷鲜猪肉对比,在4℃储藏条件下货架期延长3 d。肉桂水提物+KGM涂膜液对冷鲜猪肉具有保鲜作用。      

Anthocyanin-fortified konjac glucomannan/sodium alginate composite edible boba: characteristics of texture,microstructure, in vitro release behaviour and antioxidant capacity

Konjac glucomannan/sodium alginate composite edible boba (KGM/SA-boba) with good taste is very popular in China, and it is an outstanding carrier for health potential ingredients. In this work, KGM/SA-boba were fortified with 0.25, 0.50, 0.75 and 1.00% purple sweet potato anthocyanin (PSPA), then characterised by the water distribution, texture, microstructure, in vitro release property of PSPA and antioxidant capacity. LF-NMR analysis demonstrated that the free water of KGM/SA-boba could transfer to tightly bound water with the addition of PSPA that made it with better water-binding ability, higher springiness and lower hardness. And the results of SEM and rheology showed that PSPA could stabilise the microstructure of KGM/SA-boba by forming more amorphous regions and hydrogen bonds proved by the results of DSC and FT-IR. Furthermore, 50% of PSPA in PSPA-fortified KGM/SA-boba can be released at the first hour in a simulated gastrointestinal environment. And the scavenging capacity of DPPH and ABTS of the PSPA-fortified KGM/SA-boba after digestion was higher than that of PSPA alone. Generally, PSPA could improve the texture while KGM/SA-boba in turn would make PSPA more stable in the gastrointestinal digestive system.     

Quick dissolvable,edible and heatsealable blend films based on konjac glucomannan – Gelatin

A novel quick dissolvable, edible and heatsealable blend film of konjac glucomannan and gelatin was prepared successfully by using the solvent-casting technique with different blending ratios of the two polymers. The structure of the blend films was investigated by using differential scanning calorimeter, Fourier transform infrared spectrum and transparence analysis, etc., the physical properties of the films such as mechanical property, heat-sealing, water–vapor transmission ratio and water-solubility were also examined. The results indicated that the blend system of konjac glaucomannan and gelatin had a conditional miscibility. A new crystal occurred and hydrogen bonding interaction was strengthened when the KGM content in the blend films was around 40 wt%. The blend film had the best miscibility, a good tensile strength, heatseal and the least water–vapor transmission ratio at the same ratio. All the blend films showed a wonderful water-solubility and could dissolve not more than 30 s. Taking the degradability into account, the blend film K4 might be a perfect material for edible inner packaging.     

不同黏度魔芋葡甘聚糖对食欲和能量摄入量的影响

目的探讨食品的黏度特性对受试者餐后食欲和能量摄入量的影响。方法通过网络发布3因素进食问卷(three-factor eating questionnaire, TFEQ)招募受试者;以视觉模拟评分法(visual analogue scales, VAS)记录受试者餐后的饥饿感、饱腹感、进食欲望和期望进食量的变化;计算受试者的平均食欲率(meanappetite ratings, MAR)及其食欲的曲线下面积(area under the curve, AUC),并以此作为测试餐饱腹性能的评价指标;为受试者提供随意午餐并记录其进食至完全满足时的能量摄入量。结果同控制组测试餐相比,低、中、高黏度测试餐的饱腹感指数(satiety index, SI)依次达到了127.63%、141.81%和178.43%。并且,与控制组受试者相比,低、中、高黏度组受试者的饱腹感依次提高了31.50%、46.66%和78.63%,饥饿感则分别下降了28.54%、42.92%和60.93%。经不同黏度的测试早餐干预后,在随后的测试午餐实验中,低、中、高黏度组受试者的能量摄入量相比于控制组依次下降了6.69%、10.40%和12.50%。结论食物的黏度对受试者的食欲有显著的影响,一定范围内,食物的黏度越大,其饱腹感指数越大,受试者的饱腹感也随之增加,而饥饿感随之减小。因此,利用魔芋葡甘聚糖(konjacglucomannan,KGM)的高黏特性可以显著提升食物的饱腹性能,从而有效抑制受试者餐后的进食欲望并降低其能量摄入量。     

苯甲酸根插层水滑石/果胶复合保鲜膜对草鱼保鲜效果研究

目的改善保鲜膜的性能,拓展果胶的应用领域。方法以果胶为基质,改性后的苯甲酸根插层水滑石纳米材料为填充物,制备一种新型保鲜膜。分别用X射线衍射(X-ray diffraction,XRD)、红外光谱(Fourier transform infrared spectrometer,FI-IR)对纳米水滑石和复合保鲜膜进行表征,并探讨苯甲酸根插层水滑石复合物的添加量对草鱼保鲜效果的影响。结果 MgAl-苯甲酸根-LDHs添加量为0.05%时草鱼保鲜效果最佳,且空白组的菌落总数、硫代巴比妥酸值(thiobarbituric acid,TBA)、挥发性盐基氮(total volatile basic nitrogen,TVB-N)、pH值均高于各处理组。结论复合保鲜膜具有较好的保鲜效果,并且能延长货架期8 d左右。     

Effect of alkalis on konjac glucomannan gels for use as potential gelling agents in restructured seafood products

Four dispersions of 3% glucomannan in water, deacetylated with 5% 0.6 N and 1 N KOH (lots L1 and L2) and 0.6 N and 1 N NaOH (lots L3 and L4) as gelling agents, were evaluated for use in raw restructured seafood products. Several properties (pH, moisture content, water binding capacity, cooking loss and lightness) together with puncture data (breaking force and breaking deformation) were determined after 1 and 10 days of chilled storage at 5 °C. All these data were analyzed together with different viscoelastic parameters obtained at small amplitude oscillatory strain (SAOS) after 1 day of chilled storage, showing that L1 and L4 samples were the most suitable gels for incorporation in raw restructured fish products. In both cases the highest stress (σ_max) and strain (γ_max) amplitude values were found in the linear viscoelastic (LVE) range; however, L1 showed both high strain amplitude and breaking deformation values. Moreover, creep and recovery (transient) data showed that L1 was the most time-stable gel with the highest elasticity and the lowest relaxation exponent (n). L4 gel showed strong rigidity, i.e. the highest values of breaking force and storage moduli (G′) and the highest n value, making it less gel-like. Both L1 and L4 gels became significantly less gel-like over 10 days of chilled storage due to the loss of gel strength (S) and a noticeable increase of n. These chilled storage effects were more intense in L4 than in L1.