Impact of Inulin Extracted, Purified from (Chicory and Globe Artichoke) Roots and the Combination with Maltodextrin as Prebiotic Dietary Fiber on the Functional Properties of Stirred Bio-Yogurt

Inulin is a prebiotic dietary fiber that plays an integral role in producing functional dairy products with improved health benefits. Therefore, the objectives of this study are as follows: extract and purify inulin from chicory roots and globe artichoke roots;evaluate the physicochemical, functional properties and functional groups of the purified inulin;determine the functional properties of chicory roots inulin-maltodextrin and globe artichoke roots inulin-maltodextrin and compare it with that of the commercial inulin;examine the impact of various inulin on physiochemical, microstructural, textural, sensory characteristics and as prebiotic dietary fiber on probiotic bacteria’s viability of stirred bio-yogurt. The characteristics of the microstructure were investigated by scanning electron microscopy and, Fourier transforms infrared spectroscopy to detect the functional group. The resulting inulin exhibited a high yield and purity along with enhanced functional properties. Stirred bio-yogurt fortified with chicory roots inulin or globe artichoke roots inulin showed enhanced physicochemical, microstructural, microbiological, and overall sensorial acceptability followed by chicory roots inulin-maltodextrin or globe artichoke roots inulin-maltodextrin and the commercial inulin as compared to the control. Stirred bio-yogurt samples can offer various health benefits and wide applications as supplement of prebiotic dietary fiber in dairy industry.

Some Properties of Bio-Yogurt Enriched with Cellulose Fiber

In this study, bio-yogurts, which contain L. acidophilus and Bifidobacterium animalis subsp. lactis, were produced with cellulose fiber (CF) addition at a various level (0%, 0.5%, 1% and 2%) and stored at 4°C ± 1°C for 20 days. Bio-yogurts were analysed 1, 10 and 20 days after production. The storage period significantly influenced overall properties of the samples. Addition of CF has positively affected the physical and textural properties of yoghurt, such as serum separation, water holding capacity, viscosity, firmness, adhesiveness, cohesiveness, springiness, gumminess and chewiness (p < 0.05). It also slightly stimulated the development of probiotic bacteria (p < 0.05). Bio-yogurt, which contains 0.5% CF in sensory aspect, is the most appreciated.

Nisin对酸奶品质的影响研究

Nisin是乳酸链球菌产生的多肽物质 ,对引起食品腐败的大多数革兰氏阳性菌有很好的抑制作用 ,是一种高效、无毒副作用的天然生物防腐剂。试验对酸奶中的污染菌进行了初步检测 ,同时研究了 N isin添加量对酸奶中活菌的抑菌效果以及对成品酸奶感官和品质的影响。结果显示 ,酸奶中主要污染菌为霉菌、酵母菌和细菌 ;采用 5 0 0 IU N isin/m L和耐酸 CMC、复合稳定剂 A或 B,可延长酸奶的保质期 4～ 8d。

双麦麦精对酸奶益生菌及其感官性质的影响

双麦麦精是以大麦,其他麦类为原料通过酶解提取的一种天然营养物质。在酸奶制作过程中添加不同比例的双麦麦精,采用平板涂布的方法检测不同储存时间下,酸奶中的保加利亚乳杆菌和嗜热链球菌的活菌数。并且通过感官实验评定双麦麦精对酸奶口感、口味、色泽以及香味的影响。结果表明,当双麦麦精添加量为3%,蔗糖4%时,对酸奶中益生菌的促生长作用最好。同时验证了3%双麦麦精对双歧杆菌也有明显的益生作用。而且,3%添加量的双麦麦精在益生作用以及感官性质方面都比同等添加量的低聚果糖效果好。

生物供电时间温度指示器在酸奶中的实验研究

目的研究生物供电时间温度指示器(Time-temperature integrator,TTI)放电参数与酸奶品质参数之间是否存在相关性。方法实验以马铃薯为生物电池的底物,铜片和锌片为电极制作生物供电TTI,将生物供电TTI和酸奶同时置于温度37℃下存放30 min,其余时间置于2~6℃下恒温贮存,模拟酸奶从产地到消费者住所经历的多次温度变化,通过自制平台实时获取时间、温度和生物供电TTI的放电参数,以2~6℃恒温贮存的酸奶和生物供电TTI为对照,检测实验过程中酸奶的乳酸菌数和霉菌数的变化情况。结果通过实验发现生物供电TTI的输出电压幅值和放电累积量均会随环境温度变化发生相匹配的变化,同时与乳酸菌数的变化也满足一定的线性关系。结论生物供电TTI具有检测酸奶变质的潜能,通过改变TTI的电导池常数、底物种类、预处理温度和时间都可以改变其放电总量,以匹配更多的食品。

姜黄素发酵乳的制备及理化性质研究

姜黄素的水溶解度非常低,为了扩大其在食品中的应用范围,我们制备了姜黄素发酵乳。首先对发酵乳样品进行酸度、pH值、持水性、主要营养成分、质构性质以及微观结构等理化性质的检测;其次研究了姜黄素对发酵乳样品的抗氧化性、乳酸菌含量以及感官品质的影响;最后利用体外消化试验测定了姜黄素在发酵乳中的释放曲线和生物利用率。结果表明,添加姜黄素对发酵乳的酸度、pH值、持水性、主要营养成分、质构性质以及微观结构没有显著影响;此外,姜黄素发酵乳与普通发酵乳相比表现出更高的抗氧化活性,且具有相似的乳酸菌数量,但添加姜黄素会降低感官评价得分,因此姜黄素发酵乳的生产工艺需要进一步的改进。最后,体外消化结果表明姜黄素可以以缓释方式从姜黄素发酵乳中释放出来,经体外胃和肠道消化试验后,姜黄素的生物利用率为63.90%。研究结果显示,姜黄素发酵乳具有进一步发展为具有高营养价值和多功能特性的新型发酵乳产品的潜能。