Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on rabbit meat appearance,oxidative stability and fatty acid profile during retail display

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation on rabbit meat during retail display. At weaning 294 rabbits were allocated to 7 different treatments (42 rabbits/treatment). Rabbits of the control group (C) received a diet without any supplementation throughout the experiment (5–11 weeks of age). The other groups were fed diets containing 5% Spirulina (S), 3% Thyme (T) or both supplements (ST) for the whole trial (5–11 weeks; treatments S, T and ST), or for a part of the growing period (8–11 weeks; treatments C–S, C–T and C–ST). Colour parameters, pH, water holding capacity and drip loss were determined on fresh and stored Longissimus dorsi muscle of 5 rabbits/treatment. Spirulina- and Thyme-supplemented diets had a significant effect on redness and yellowness of Longissimus dorsi. Drip loss was significantly reduced in C–T and T groups that also showed the highest content of α-tocopherol and n − 3 fatty acids content and the lower lipid oxidation.     

Probiotic yoghurt functionalised with microalgae and Zedo gum: chemical,microbiological, rheological and sensory characteristics

In this study, using a central composite design, the effects of addition of Spirulina platensis and Zedo gum to plain and probiotic yoghurt samples were investigated during storage. Lactobacillus paracasei proliferation was directly dependent on the addition of microalgae and was inversely affected by storage time. Probiotic samples containing S. platensis showed the highest antioxidative activity. Maximum stability was obtained at higher amounts of Zedo gum, while organoleptic and rheological attributes improved at 0.25% Zedo gum. Given the importance of probiotic viability, supplementation of probiotic yoghurt with Zedo gum/S. platensis may be consideredas a novel nutraceutical formulation.     

Assessment of antioxidant activity and phycocyanin release of Spirulina loaded poly(ε-caprolactone) electrospun nanofibers

PCL with biodegradable property and Spirulina with various biological activities offer good alternative ingredients for the fabrication of functional nanofibers in tissue engineering. The aim of the study is to obtain PCL/Spirulina nanofibers with low diameters and to determine their wettability, antioxidant activity, and phycocyanin release to evaluate their potential as bioactive scaffolds in different applications. PCL/acetic acid/pyridine solutions with three different Spirulina concentrations were electrospun and the obtained nanofibers were investigated. The thinnest PCL/Spirulina nanofibers (117.20 nm) were obtained at 1.5% Spirulina concentration. Although PCL nanofibers with 6% Spirulina concentration showed the highest antioxidant activity and amount of phycocyanin released, PCL nanofibers with 3% Spirulina concentration having similar in vitro results showed superiority when considering the diameter and uniformity of the nanofibers and the cost of the material. The PCL/Spirulina nanofibers with small diameters and antioxidant activity could be regarded as potential extracellular matrix material for tissue engineering.     

固相萃取-气相色谱法测定螺旋藻中指示性 多氯联苯

目的建立气相色谱法测定螺旋藻中痕量多氯联苯的分析方法,以考查螺旋藻中7种指示性多氯联苯(polychlorinated biphenyls,PCBs)的残留情况。方法乙腈提取样品后,选用弗罗里矽柱对螺旋藻中指示性多氯联苯净化。色谱条件为:DB-17(30 m×0.25 mm,0.25μm)石英毛细管柱,采用程序升温分离,流速为1.0m L/min,进样量为1.00μL,电子捕获检测器检测。结果在优化的条件下,7种指示性多氯联苯在10~50μg/L范围内线性良好,相关系数(r)大于0.999,在螺旋藻空白样品中添加25、35、45μg/kg 3个水平的7种指示性多氯联苯,其加标回收率范围为90.8%~112%,相对标准偏差(RSD)范围为0.526%~3.89%。结论该方法具有操作简便、快速、准确的特点,适用于螺旋藻试样中指示性多氯联苯痕量残留的分析。     

螺旋藻蛋白酶解肽对腹腔粘膜系统的作用

目的：探索螺旋藻(Spirulina)碱性蛋白酶酶解肽对家兔腹腔黏膜系统的作用。方法：采用盐析法从螺旋藻中提取可溶性螺旋藻蛋白,以碱性蛋白酶水解得到螺旋藻蛋白水解物溶液。将所得水解物以3 种方式(口服、腹腔注射、耳静脉注射)对家兔给药,分别在给药3、2、2h 后,用ELISA 试剂盒测定血清中IL-1β、IL-6、IL-12、IFN-γ、TNF-α、IL-1Ra、IL-4、IL-10、TGF- β细胞因子的质量浓度。结果：3 个实验组与正常生理盐水组相比,IL-12 质量浓度均下降,IFN-γ、IL-10 质量浓度均升高;在3 种给药方式中,腹腔注射效果最显著,其他两组细胞因子水平均没有显著性变化。腹腔注射组中炎症细胞因子IL-1β、IL-6、IL-12、TNF-α的质量浓度均显著性降低,抗炎细胞因子IL-1Ra 和IL-4 显著性升高,说明该螺旋藻碱性蛋白酶酶解肽对降低免疫活性起到了一定作用。结论：肠黏膜系统对螺旋藻蛋白酶解肽信号传递主要是通过肠道上皮细胞、内皮细胞及单核/ 巨噬细胞、淋巴细胞之间的信号网络抑制NF- κB 和PKC/p38/MAPK 途径来降低免疫的。这与植物非营养物质能够通过抑制转录因子NF- κB 活性抑制炎症信号级联的作用机制相一致,说明短肽类成分也可以进入体内对机体的慢性疾病甚至癌症起到一定的治疗作用。     

极大螺旋藻的硒富集化培养研究

为得到大量含有机硒的极大螺旋藻(Spirulina maxima),以生物量和藻体内硒富集量作为指标,研究不同硒添加量和硒添加方式对极大螺旋藻生长及富硒效果的影响。结果表明,分8d等量(100μL)多次添加100μg/mL Na2SeO3溶液,是最佳添加量和添加方式,可得到生物量为0.903g/L,单位干藻粉有机硒含量为1413.168μg/g的富硒极大螺旋藻。     

采用不同装置培养螺旋藻的对比研究

该试验在光合自养和混合营养两种条件下,分别采用250 mL摇瓶、5.0 L全自动发酵罐和10.0 L自制光生物反应器培养螺旋藻,以藻体生物量为试验指标,比较细胞在3种装置中的生长情况。结果可知,10.0 L光生物反应器培养效果最好,在光合自养条件下藻体生物量最大为1.277 g/L,比摇瓶和全自动发酵罐培养时分别提高78.6%和61.8%,混合营养条件下最大值为1.715 g/L,比其他两种装置分别提高了6.3%和6.1%。表明自制的光生物反应器能很好地满足螺旋藻细胞生长,且结构简单,操作简便。     

细胞破壁对螺旋藻藻蓝蛋白提取效果的影响

螺旋藻细胞破壁是藻蓝蛋白提取的关键工序。采用溶胀法、超细剪切法、超声波法、反复冻融法、溶胀—超细剪切法和溶胀—超细剪切—超声波法对螺旋藻细胞进行破壁处理;通过对比分析破壁后提取液中的藻蓝蛋白得率来评价破壁方法的优劣。结果表明,溶胀法、超细剪切法、超声波法、反复冻融法、溶胀—超细剪切法、溶胀—超细剪切—超声波法得到的最高藻蓝蛋白得率分别为8.90%,7.38%,8.00%,8.26%,9.22%,8.88%。综合考虑,溶胀—超细剪切法相对其它5种破壁方法而言,其操作简单便捷,破壁效果更加显著,藻蓝蛋白得率高;溶胀—超细剪切法最佳的提取工艺为:溶胀时间12h,剪切时间5min。     

螺旋藻回用培养液组成对藻细胞生长的影响

将螺旋藻回用培养液补齐营养盐用于培养螺旋藻,考察了螺旋藻生物量、培养液中硝酸盐和磷酸盐及培养末期螺旋藻胞内生化成分含量对藻细胞生长的影响;用超滤膜对回用培养液中物质进行分子量分级,分析各级组分对螺旋藻的抑制效应,确定抑制物的分子量分布范围,并分析其成分. 结果表明,回用培养液中的螺旋藻胞外分泌物对藻细胞生长有明显抑制作用,比生长速率比新鲜培养基中低23%,且会抑制藻细胞对营养盐的吸收及胞内蛋白和叶绿素合成,对硝酸盐、磷酸盐的吸收分别低36%和37%,胞内蛋白及叶绿素含量分别为新鲜培养基中的0.85和0.65倍. 抑制物为分子量大于100 kDa的螺旋藻胞外多糖.