乳化猪皮的制备及在盐水火腿中的应用

对猪皮的乳化方法及在盐水火腿中的应用进行了研究.结果表明,经清洗.预煮.绞碎,添加2.5倍的冰水用胶体磨乳化,是生产乳化猪皮的最好方法;用乳化猪皮生产盐水火腿的最佳条件是100kg的原料内添加10kg的乳化猪皮,在配制盐水时加入45kg冰水,并在滚揉结束前1 h将乳化猪皮加入.     

猪皮出胶的控制及肘花肉的生产

初步研究了猪皮出胶的过程并改进了肘花肉的生产工艺，即先将猪皮预处理后在50℃热水中浸泡2.5h冷却备用；将猪瘦肉绞制并在0-4℃条件下腌制12h，装模蒸煮，冷却和包装、杀菌后可获得较佳的感官、口感品质并达到长期保存的目的。     

猪皮胶原粉的制备工艺及功能特性研究

本研究在4℃条件下用弱酸加酶法提取可溶性胶原并干燥成粉,然后对已提取过的猪皮用60%乙醇溶液作载体进行胶体磨研磨,制备不溶性胶原粉。进一步对其进行胶原含量及功能特性的测定。结果表明：猪皮胶原粉的最佳制备工艺为：采用pH2.0 醋酸+0.2% 胃蛋白酶、料液比1:15 条件下提取猪皮48h,可溶性胶原溶出率为0.602%;剩余猪皮采用60% 乙醇载体研磨后干燥可制得不溶性胶原粉。所得胶原粉各项功能特性优良,通过羟脯氨酸含量测定得出可溶性胶原粉胶原纯度为95.1%,不溶性胶原粉胶原纯度为82.9%,工艺路线易于实现规模化生产。     

猪皮的结构及其加热以后的变化

<正>猪皮重约占胴体重的1/10左右,其主要部分为真皮层,真皮层含有大量的胶原蛋白纤维,其含量可占干物质的99%.据文献记载,猪皮的蛋白含量可高达33%,其中,胶原蛋白的含量为29%,弹性蛋白为0.3%,角质蛋白为2%.而猪瘦肉的蛋白含量仅为16.7%.由此看来,猪皮的蛋白质含量高干瘦肉,其营养价值是十分可观的.我国劳动人民很早就有食用猪皮的习惯和方式.在长江以南的地区,用油炸猪皮做成的汤称为假鱼肚汤,味美可口,很受欢迎.肉皮冻更是     

以提取褐藻糖胶的废渣制备膳食纤维

采用化学处理法以提取褐藻糖胶的海带渣制备膳食纤维，筛选出海带膳食纤维提取和漂白的最佳工艺每件，提取出海带膳食纤维产品。结果表明，海带膳食纤维的产率达14．67％，白度为11．52％。     

玉米纤维胶的制备和特性研究进展

玉米纤维胶(Corn Fiber Gum,CFG)在水中溶解性好、粘度低,具有代替阿拉伯胶等树胶在食品加工中作为稳定剂、乳化剂、增稠剂和黏着剂的应用前景。此外,玉米纤维胶还含有阿魏酸等生理活性物质。不同的制备方法对玉米纤维胶的结构、物理化学性质及生理活性物质的含量影响明显。本文综述了玉米纤维胶的制备方法、结构理化特性及对其乳化性质的研究进展。     

魔芋胶/威兰胶复合膜的制备及性能

以魔芋葡甘聚糖(KGM)和威兰胶(WG)为基材,制备了一系列复合膜。通过单因素试验和正交试验,探讨了魔芋粉和威兰胶复合溶液浓度、WG/KGM比例、烘干温度、烘干时间等因素对复合膜的制备及复合膜透明度、水溶性、水蒸汽透过系数等性能的影响。并采用分子模拟方法,研究了KGM、脱乙酰KGM(da-KGM)与WG之间的相互作用。结果表明,膜制备的最佳工艺条件为:复合溶液浓度0.6%,WG/KGM比例2∶8(g/g)、烘干温度70℃、烘干时间7 h。KGM(daKGM)和威兰胶分子间存在氢键相互作用,da-KGM和威兰胶分子间比KGM与威兰胶间的氢键更多,相互作用更强。     

阳离子松香胶的现场制备及应用

一种安全的水溶性阳离子活性树脂PDE-1,在抄纸时直接用水冲稀加入浆内,可使阴离子皂化或分散松香胶现场转化为阳离子松香胶,达到减少胶料和硫酸铝用量,实现近似中性施胶、提高纸品质量,与市售阳离子松香胶相比,可大大降低成本,使用十分方便.     

高吸水纤维的制备方法及应用

文章简要介绍了高吸水纤维的特点,国内外研究现状及其制备方法,并对其用途进行了概述,阐述了高吸水纤维的发展前景.     

基于鱼皮明胶的可食膜改性及其应用

鱼皮明胶是一种资源丰富、具有良好成膜性的蛋白源,可食性鱼皮明胶膜的研制已成为食品包装领域的研究热点。本文介绍了鱼皮明胶的基本结构和特性,详细综述了鱼皮明胶可食膜的改性及其应用,旨在为鱼皮明胶可食膜的开发利用提供依据。      

快速冻融猪皮明胶理化性质分析

对冻融法猪皮明胶的基本理化性质——色差、SDS-PAGE、氨基酸组成、全质构、流体特性、起泡性和泡沫稳定性进行测定。结果表明,冻融法明胶与传统酸法明胶基本理化性质相似,颜色略微深于传统酸法明胶;冻融法明胶质构特性优良,硬度(368. 0 g)显著高于传统酸法明胶(341. 0 g)(P <0. 05);流体特性结果表明冻融法明胶拥有更高的黏度;起泡性研究表明,冻融法明胶溶液质量浓度从10 g/L到30 g/L,其起泡性和泡沫稳定性均优于传统酸法明胶; SDS-PAGE和氨基酸组成结果显示,赋予快速冻融明胶更好功能特性的原因在于,冻融法明胶较传统酸法明胶含有更多高分子亚基组分和更低的小分子组分,以及更高的亚氨基酸含量(252 g/kg)。快速冻融猪皮明胶具有优良的理化加工特性,为明胶的清洁化生产提供了思路。     

酶法提取猪皮胶原及其结构表征

利用胃蛋白酶提取猪皮胶原 ,并测定了所提取猪皮胶原的分子量、等电点、变性温度、紫外及红外吸收光谱 ,结果表明 :提取的猪皮胶原最大程度地保持了其天然结构 ,适合用作生物医学材料。     

猪皮胶原的提取及其结构表征

分别以鲜猪皮和经过自制CO2 超临界处理器处理过的猪皮为原料 ,以醋酸钠 -盐酸为缓冲液 ( pH =2 .0 ) ,利用国产胃蛋白酶提取猪皮胶原。通过测定分子量、等电点以及利用DSC、IR等方法 ,对所提取的猪皮胶原结构进行了表征。结果表明 :从经过自制CO2 超临界处理器处理过的猪皮中提取的猪皮胶原的纯度 ,要比从未经自制CO2 超临界处理器处理过的猪皮中提取的猪皮胶原的纯度高很多 ,其它性质基本不变 ;同时两者都最大程度地保持了猪皮胶原的三股螺旋结构 ,因而适合用作生物医用材料及原料。     

可食性明胶复合膜及其在食品包装上的应用研究进展

明胶是一种天然生物高分子,来源广泛,价格低廉,具有良好的成膜性、生物相容性、生物降解性等。作为膜材料,单一成分的明胶膜存在着热稳定性差、机械强度低、对水敏感、潮湿环境下易变质等缺陷,通常需要对其进行改性处理。明胶通过与蛋白质、糖类、脂类复合,或添加活性功能成分可以改善明胶基膜的性能,从而使明胶基膜具有广阔的应用前景。本文综述了明胶与生物聚合物、活性功能成分复合制备明胶基复合膜的研究进展及其在食品包装上的应用。      

Preparation and functional characterisation of fish skin gelatin and comparison with commercial gelatin

Gelatin was extracted from the skin of farmed giant catfish (GC) and tilapia (TP) at a yield of 19.50% and 23.34% (wet wt). It was high in protein (84–88%) but low in fat (0.09–1.24%) and ash content (0.15–0.17%). The GC exhibited lower emulsifying activity (24–35%), but greater foam ability (98–110%), water holding capacity (477–844%) and fat binding capacity (2541–3314%) than commercial beef skin gelatin (BF) (P < 0.05). GC and TP showed comparable functional properties to BF. SDS‐PAGE patterns of TP gelatin showed high band intensity for the α‐ and β‐components, while the lowest band intensity of the major component was found in the BF. From the study, it can be concluded that the farmed freshwater fish skin GC and TP is a prospective source for producing a significant gelatin yield with desirable functionalities. Because of these, fish skin gelatin could be more effectively and widely used in food industries as a good food ingredient.     

Preparation and characterisation of chicken skin gelatin as an alternative to mammalian gelatin

The aims of this study were to report for the first time, the extraction and physico-chemical properties of chicken skin gelatin compared to bovine gelatin. Extracted chicken skin gelatin 6.67% (w/v) had a higher bloom value (355 ± 1.48 g) than bovine gelatin (259 ± 0.71 g). The dynamic viscoelastic profile of chicken gelatin exhibited higher viscous and elastic modulus values compared to bovine gelatin for a range of concentrations and frequencies. Thermal properties studied by differential scanning calorimetry (DSC) showed that the melting temperature of 6.67%, chicken skin gelatin was significantly greater (p < 0.05) than that of bovine gelatin, indicating lower stability of bovine gelatin compared to chicken skin gelatin. Results obtained in this study showed that Gly (33.70%), Pro (13.42%), H.Pro (12.13%) and Ala (10.08%) were the most dominant amino acids in chicken skin gelatin which contributed to the higher gel strength and stability. Raman spectra of chicken skin and bovine gelatin were similar and displayed typical protein spectra. Chicken gelatin showed strong hydrogen bonding compared to bovine gelatin as the tyrosine doublet ratio (I₈₅₅/I₈₃₀) of chicken gelatin was significantly lower than that of bovine gelatin. Significantly, the alpha helix and β-sheet type structures were higher for chicken skin gelatin compared with bovine gelatin. The average molecular weight of chicken gelatin was 285,000 Da. These findings, obtained for the first time for chicken skin gelatin, show that it has high potential for application as an alternative to commercial gelatin.     

Thermal characterisation of gelatin extracted from yellowfin tuna skin and commercial mammalian gelatin

Glass transition and other thermal characteristics of gelatin from different sources were studied by differential scanning calorimetry (DSC) and modulated DSC (MDSC). The initial glass transition temperatures of equilibrated gelatin samples at 11.3% relative humidity, determined from reversible heat flow thermogram of MDSC, were 23, 75 and 59 °C, respectively, for tuna skin, bovine and porcine gelatin. When gelatin samples were equilibrated at higher relative humidity of 52.9%, glass transition temperature of fish skin and bovine gelatin decreased to −3 and 57 °C, respectively. Further increase of equilibration relative humidity to 75.3% showed increased value in the case of tuna skin, whereas bovine and porcine did not show any significant change. DSC and MDSC results indicated that tuna gelatin showed lower glass transition compared to mammalian source gelatin equilibrated at the same constant relative humidity. In general glass transition measured by DSC was found lower than the values measured by MDSC. The results in this study showed that the degree of plasticization varied with the source of gelatin as well as their extraction methods.     

明胶添加量对兔皮明胶膜特性与结构的影响

从兔皮中提取明胶制备明胶膜,通过测定不同明胶添加量下膜的机械性能、水蒸气透过率、亚基组成和结构,探究明胶添加量对明胶膜特性与结构的影响。结果表明随着明胶添加量的增加,明胶膜体系内网络空间结构变大,从而膜的厚度增加。力学结果显示,明胶添加量为4 g/100 m L（w/v）时,明胶膜抗拉强度最高（p<0.05）;明胶添加量为6 g/100 m L（w/v）时,明胶膜断裂伸长率最低（p<0.05）。水蒸气透过率结果表明随着明胶添加量的增加,水蒸气透过率呈现上升趋势。凝胶电泳结果显示,明胶添加量为4 g/100 m L（w/v）时,低分子量的蛋白组分产生更多交联,形成蛋白质-蛋白质交联的结构,此浓度下明胶膜的抗拉强度最大。FT-IR分析表明:当明胶添加量增加至4 g/100 m L（w/v）时,酰胺A带向高波数移动,说明肽链上的N-H基团并没有与甘油的-OH基团相互反应,而是明胶分子的官能团之间产生更强的相互作用,形成独特的网络结构。同时,酰胺Ⅰ带曲线拟合结果也表明当明胶添加量为4 g/100 m L时,膜内稳定结构较多,明胶分子之间的相互反应达到最大化,明胶膜的稳定性和成膜性能较优。      

罗非鱼皮明胶酶解物及其模拟消化产物的抗氧化活性

以罗非鱼皮为原料提取罗非鱼皮明胶,选用风味蛋白酶和胰蛋白酶制备罗非鱼皮明胶酶解物,采用ABTS自由基、DPPH自由基、羟基自由基及亚油酸过氧化体系,初步评价罗非鱼皮明胶酶解物的抗氧化活性,再通过模拟体外胃肠道消化实验,结合分子质量分布测定,进一步考察罗非鱼皮明胶酶解物的抗氧化活性。结果显示,在酶解过程中,风味蛋白酶及胰蛋白酶酶解的水解度逐渐升高,在3 h时达到最高,分别达到5.8%和25.36%。在酶解60 min时其TCA可溶性肽得率最高,风味蛋白酶、胰蛋白酶酶解物分别达56.82%和54.44%。通过比较半抑制浓度（IC₅0）,确定了酶解60 min时风味蛋白酶酶解物的清除DPPH自由基及抑制亚油酸过氧化能力较胰蛋白酶酶解物强。模拟体外胃肠道消化后,酶解物羟基自由基清除活性均显著提高（p<0.05）,亚油酸脂质过氧化活性明显降低,消化前后样品分子量分布范围均主要集中于3000⁵000 Da,消化后风味蛋白酶及胰蛋白酶酶解物3000⁵000 Da组分的含量分别提高了45%及13%。以上研究结果表明,罗非鱼皮明胶酶解后制备的明胶水解物具有一定的抗氧化能力,具有潜在的开发价值。