水牛内底革植鞣工艺的改进

通过对传统植鞣水牛内底革生产工艺的改进,使生产周期从20d缩短为8-10d,栲胶用量降低10%-15%,减轻了职工的劳动强度,减少了废液的排放.     

Chemotactic and Angiogenic Potential of Mineralized Collagen Scaffolds Functionalized with Naturally Occurring Bioactive Factor Mixtures to Stimulate Bone Regeneration

To develop cost-effective and efficient bone substitutes for improved regeneration of bone defects, heparin-modified mineralized collagen scaffolds were functionalized with concentrated, naturally occurring bioactive factor mixtures derived from adipose tissue, platelet-rich plasma and conditioned medium from a hypoxia-treated human bone marrow-derived mesenchymal stem cell line. Besides the analysis of the release kinetics of functionalized scaffolds, the bioactivity of the released bioactive factors was tested with regard to chemotaxis and angiogenic tube formation. Additionally, functionalized scaffolds were seeded with human bone marrow-derived mesenchymal stromal cells (hBM-MSC) and their osteogenic and angiogenic potential was investigated. The release of bioactive factors from the scaffolds was highest within the first 3 days. Bioactivity of the released factors could be confirmed for all bioactive factor mixtures by successful chemoattraction of hBM-MSC in a transwell assay as well as by the formation of prevascular structures in a 2D co-culture system of hBM-MSC and human umbilical vein endothelial cells. The cells seeded directly onto the functionalized scaffolds were able to express osteogenic markers and form tubular networks. In conclusion, heparin-modified mineralized collagen scaffolds could be successfully functionalized with naturally occurring bioactive factor mixtures promoting cell migration and vascularization.     

Identification of peptides in traditional and probiotic sheep milk yoghurt with angiotensin I-converting enzyme (ACE)-inhibitory activity

Two sets of traditional Greek sheep milk yoghurt were produced: the first one (YC) using normal yoghurt culture (Lactobacillus delbrueckii subsp. bulgaricus ?10.13 and Streptococcus thermophilus ?10.7) and the second (PR) with the same normal culture mixed with Lactobacillus paracasei subsp. paracasei DC412. YC and PR had similar physicochemical properties and proteolysis patterns throughout storage. Both products showed similar peptide profiles by RP-HPLC but quantitative differences were observed in respect to storage time. Single-strain cultures of the microorganisms used showed similar peptide profiles for both lactobacilli, yet L. delbrueckii subsp. bulgaricus was the most proteolytic of all three microorganisms. The peptide content and the ACE-inhibitory activity of the water-soluble extracts of yoghurts, YC and PR, increased throughout storage. Major peptides were identified from yoghurt PR and from the separate cultures of L. delbrueckii subsp. bulgaricus and L. paracasei subsp. paracasei. Most of these peptides were derived from β-casein. A peptide, β-CN f114-121, with well-established ACE-inhibitory and opiate-like activity was identified in yoghurt PR. Further identified peptides were regarded as potential ACE-inhibitors according to their sequence.     

Antioxidant effect of a crude phenolic extract from sorghum bran in sunflower oil in the presence of ferric ions

Whole grain condensed tannin sorghum, its bran and a crude phenolic extract (CPE) prepared from the bran were evaluated for total phenols (TP), condensed tannins (CT) and antioxidant activity (AA). Antioxidant effect of the CPE from the sorghum bran was evaluated in sunflower oil in the presence of ferric ions by measuring peroxide values (PVs) and anisidine values (AVs) during storage at 65 °C, in comparison with tertiary butyl hydroquinone (TBHQ). Sorghum bran contained three times more TP and AA, and seven times more CT than the whole grain. The CPE had highest levels of TP, CT and AA. Sunflower oil with CPE had lower PVs and AVs compared to control samples. Oil samples with TBHQ had PVs lower than, but AVs similar to samples containing CPE. In the presence of ferric ions, the CPE was less effective in reducing PVs, but was more effective than TBHQ in reducing AVs.     

老汤精粉在食品工业中的应用

综述了老汤的形成、加工方法、特点、调味机理及在食品工业中的应用、展望了其应用前景。     

Antimicrobial properties of grape seed extracts and their effectiveness after incorporation into pea starch films

Chemical analysis and antimicrobial nature of grape seed extracts (GSE) and their Reisling Vitis vinifera L. application as fortificants for edible starch films were investigated. GSE possessed an antioxidant activity of 17.18 ± 1.29 mmol TROLOX equivalents g_extract⁻¹ and total phenolic content of 327.58 ± 7.24 mmol gallic acid equivalents g_extract⁻¹ mainly attributed to their flavonoid and phenolic acid composition determined by high-performance liquid chromatography accomplished to a diode array detector and a electrospray ionisation mass spectrometer in negative mode (HPLC-DAD/ESI-MS). GSE inhibited the growth of Gram-positive food-borne pathogens while Gram-negatives were not inhibited. After GSE were incorporated into pea starch films, thickness of enriched films increased and the puncture and tensile strength decreased compared to control films. Furthermore, migration of phenolic compounds from the films to different food simulants, aqueous, acidic and alcoholic solution was determined according to 89\109\EEC directive. A higher particle migration in acidic simulants was found. Finally, the effect of GSE incorporated pea starch films was tested in vitro with pork loins infected with Brochothrix thermosphacta. GSE films reduced the bacterial growth in 1.3 log colony forming units mL⁻¹ after 4 days incubation at 4 °C.     

温度对P110钢在水泥挤出液中钝化膜性能的影响

目的 探究P110套管钢在不同温度下生成的钝化膜的性能差异,找到能使P110套管钢生成最稳定钝化膜的温度,同时了解该温度下氯离子对钝化膜的破坏规律。方法 利用极化曲线、交流阻抗谱（EIS）和Mott-Schottky测试,研究了P110套管钢材料在pH值为13.0的水泥挤出液中浸泡4 d的钝化行为,讨论了在低、中、高（40、65、90 ℃）三种温度下生成的钝化膜的稳定性,并用扫描电子显微镜（SEM）对各试样表面微观形貌进行观察。最后在溶液中加入不同浓度的氯离子,通过测试极化曲线了解氯离子对钝化膜的破坏规律。结果 试样在40、65、90 ℃下的腐蚀电流密度分别为2.2727×10?6、4.0452×10?7、1.7081× 10?5 A/cm2,膜电阻分别为100 100、238 200、5480 Ω?cm2。40、65 ℃下所生成的钝化膜呈p型半导体特征,而90 ℃下呈双极型半导体特征。65 ℃下,随着氯离子浓度的增加,试样的腐蚀电位负移,耐蚀性逐渐降低,腐蚀速率增大,当浓度达到0.1 mol/L时,钝化膜的膜层结构已被破坏。结论 P110套管钢在pH值为13.0的水泥挤出液中浸泡4 d,表面能够生成钝化膜。在65 ℃溶液中生成的钝化膜耐蚀性最好,膜层结构更加致密,40 ℃次之,90 ℃最差。氯离子对钝化膜有侵蚀作用,高浓度的氯离子可以直接导致稳定钝化膜的破坏。     

葛根素的提取与膜分离研究

采用紫外—可见分光光度计测量葛根素的含量,采取乙醇回流水浴提取,通过单因素法和正交试验分别研究提取时间、提取温度、乙醇的浓度、料液比四个因素对葛根素提取的影响。纯化部分主要依靠膜分离技术对提取液进行微滤、超滤、纳滤处理,通过对通量与时间、压力等因素关系的研究,得到合适的膜分离操作工艺条件。