Evaluation of Quality and Digestibility Characteristics of Resistant Starch-Enriched Pasta

Resistant starches (RS) can be used in food industry to enhance the dietary fiber content of different cereal based products such as pasta and bread. The aim of present study was to develop and evaluate the physical and functional properties of starch-based products enriched with RS. The in vitro enzymatic digestibility, cooking properties, and viscometric characteristics (using rapid visco analyzer = RVA) of the pasta products were determined. The results showed that the addition of resistant starches (RS-s) influenced the quality of both the raw and cooked pastas. Enzymatic digestibility and five RVA parameters (peak viscosity, trough, breakdown, setback, and final viscosity) were significantly reduced (p < 0.05) in pasta products with added RS. Cooking quality characteristics were unaffected by RS addition. The results also indicated that interactions between RS-s and other flour components may influence the in vitro digestibility of pasta products. According to the sensory evaluation of products, RS-s did not alter the sensory properties of pastas. However, the type of flour had significant effect on the sensory preference.     

螺旋藻蓝色素的研究

本文研究了从螺旋藻中提取蓝色素的工艺以及ＰＨ、热、光、金属离子和一些常用食品添加剂对螺旋蓝色素的影响效应，，找出了提取该色素的最佳工艺条件和使用条件，为其在工业生产上的应用提供了科学依据。     

pH值对钝顶螺旋藻生长的影响

pH值不但影响培养液中营养基质的离解程度，而且对螺旋藻的生长、代谢乃至细胞形态都造成显著的影响。本文得出：钝顶螺旋藻生长的pH范围为8.5～10．0，最适生长pH为9．0～9．6，pH值超过10．5时，对螺旋藻的生长产生抑制作用。混合营养培养时，通过对螺旋藻生长过程中pH值变化的研究，得出：与无机碳源相比，有机碳源作为营养源更易被螺旋藻利用并合成细胞物质。     

氮源对螺旋藻生长及胞外多糖的影响

本文研究了氮盐对螺旋藻生长及胞外多糖积累的影响,发现低氮培养条件对螺旋藻生物量积累影响不太明显,但却有利于螺旋藻胞外多糖的积累。氮源不仅是决定螺旋藻生物量的积累的主要因素,也是螺旋藻胞外多糖的限制因素。     

Kinetics of Protein Quality Loss in Enriched Pasta Stored in a Sine Wave Temperature Condition

The rate of loss of protein quality in enriched pasta was studied at constant temperature (30, 37 and 45°C) and under a continuous sine wave temperature fluctuation (25/45°C with a 24-hr period). Both loss of lysine by the fluoro-dinitro benzene (FDNB) method and a bioassay (Tetrahymena thermophila growth) for protein quality were employed. Significant loss of protein quality occurs in about 1 yr at temperatures above 30°C. The bioassay method showed that nutrient losses other than lysine could be occurring. Data from the constant temperature studies were used to predict the losses that occurred for the sine wave condition using the Hicks-Schwimmer model as modified with an Arrhenius approach. The prediction model gave about 15% error in comparison to actual losses. In addition, the rate of loss for the sine wave (25/45°C) was greater as predicted than the rate of loss at a constant mean temperature of 35°C.     

钝顶螺旋藻藻蓝蛋白储存稳定性研究

对温度、日光光照等条件以及不同添加剂对藻蓝蛋白水溶液稳定性的影响进行研究。研究得出,藻蓝蛋白应低于40℃避光保存,应于中性条件下保存;葡萄糖、氯化钠和山梨糖醇可以有效提高藻蓝蛋白的稳定性,分别于室温放置72 h后藻蓝蛋白色素保存率从50.90%提高到了78.10%、67.02%和69.08%;按质量比1∶1∶0.3复合葡萄糖、氯化钠和山梨糖醇作为稳定剂加入藻蓝蛋白后于4℃放置14 d,藻蓝蛋白色素保存率比未加添加剂的藻蓝蛋白提高54.4%;于25℃下放置,加了复合添加剂的藻蓝蛋白色素保存率比未加添加剂的提高16.1%。     

不同的脱蛋白方法用于螺旋藻多糖提取工艺的研究

对比了两种不同的脱蛋白方法(酶 Sevage法和三氯醋酸法)在螺旋藻多糖提取工艺中的应用。研究结果表明，不同的除蛋白方法不仅影响蛋白质的去除率和多糖的得率，而且所得到的螺旋藻多糖在组分、分子大小及单糖组成上存在较大差异。     

螺旋藻多糖提取优选工艺条件的研究

对螺旋藻多糖的提取工艺进行优化.选择浸提pH值、温度、浸提固液比以及浸提次数作单因素梯度试验,通过方差分析,并进行LSD多重比较作显著性分析,确定其条件范围,再进一步通过正交试验L9(34)验证单因素试验,从而获得螺旋藻水溶性多糖浸提工艺的优化组合:pH值11,浸提温度80℃,固液比1:30,浸提次数2次.经95%乙醇沉淀、氯仿正丁醇溶液(体积比4:1)分离纯化,得脱蛋白粗多糖,粗多糖的浸提率最多可达4.213%.     

Textural Characteristics of Wholewheat Pasta and Pasta Containing Non-Starch Polysaccharides

Pasta enriched with nonstarch polysaccharides, and wholewheat pasta were assessed for cooking quality. Xanthan gum improved pasta firmness when added at 1 and 2%, without affecting moisture uptake or degree of swelling when cooked for a constant time. Dynamic rheological testing indicated development of a network structure with addition of gums which contributed to overall pasta tirmness. Food grade pea fiber, at 5 and 10%, caused moderate reduction in firmness. Wholewheat pasta was similar in firmness to pasta with 10% pea fiber, as measured by Instron. Dynamic rheometry measurements indicated a weak network in wholewheat pasta. Small strain dynamic tests were more sensitive to subtle changes in network structure than were large deformation compression tests.     

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。     

钝顶螺旋藻超氧化物歧化酶分离纯化技术研究

为研究从螺旋藻中分离纯化SOD的最优化方法,采用细胞破碎方法、最佳丙酮用量、最佳硫酸铵饱和度和DEAE-52离子交换层析技术分离纯化螺旋藻中的SOD并作比较分析。结果表明:从螺旋藻中分离纯化的SOD的比活高达2179U/mL,提纯倍数24.2;纯化的SOD经SDS-PAGE分析,呈现的谱带均一且对H2O2非常敏感,推断为Fe-SOD。因此采用优化技术可以从螺旋藻中分离纯化获得高纯度和高比活的SOD。     

不同米色小米营养品质与蒸煮特性研究

为探明不同米色小米间品质差异,本文选取5种具有色差代表性的小米(沁州黄、黄金苗米、白小米、黑小米和绿小米)进行研究。对原花青素、多酚、矿物质等营养成分,直链淀粉、糊化温度、胶稠度蒸煮特性进行测定分析。营养品质研究结果表明不同米色小米之间差异较大,深色小米(绿小米、黑小米)原花青素含量分别为0.295、0.261 mg/g,显著(P<0.05)高于其他米色小米,黄色小米(沁州黄、黄金苗米)总胡萝卜素含量在1.98~2.07 μg/g之间,显著(P<0.05)高于其它米色小米。黄色小米(沁州黄、黄金苗米)易于糊化,蒸煮品质较好,直链淀粉含量在28.53~29.01 mg/g之间,糊化温度在87.60~88.45 ℃之间,显著(P<0.05)低于其它米色小米,胶稠度在93.26~94.85 mm之间,显著(P<0.05)高于其他米色小米。相关性分析表明小米中总胡萝卜素与直链淀粉含量、糊化温度显著(P<0.05)负相关,相关系数为-0.96、-0.98,与胶稠度显著(P<0.05)正相关,相关系数为0.97。     

螺旋藻多糖分离纯化工艺优化

为探讨螺旋藻多糖提取的最佳工艺条件,对提取温度、pH、水料比、时间、提取次数进行了优化,并通过正交试验确定了最佳提取条件,即:提取温度85℃,pH 9.8,水料比45,提取时间4.5 h.在上述条件下螺旋藻多糖的平均提取率为4.85%.提取液经DEAE-52纤维素柱层析,得到单一洗脱峰,表明提取的多糖为单一组分.     

混合营养培养对钝顶螺旋藻生长及多糖含量的影响

本论文研究了不同混合营养培养条件对钝顶螺旋藻生长和多糖含量的影响，通过试验发现混合营养培养能有效提高钝顶螺旋藻的细胞产率和胞内、胞外多糖含量，尤其是在添加复合有机碳源时，其细胞产率和胞内多糖含量更高，均优于添加单有机碳源的情况。考虑细胞产率和胞内多糖含量两个重要指标，以同时添加2．0g／1醋酸钠和4．0g／1葡萄糖为最佳添加量。