【作者】 刘蒙瑜；

【导师】 顾振新；

【作者基本信息】 南京农业大学 ， 农产品加工与贮藏， 2009， 硕士

【摘要】 本文筛选了产膳食纤维菌种,以膳食纤维产量为主要考察指标,对固态发酵的培养基组成、培养条件进行优化并对发酵过程中的相关指标进行动态研究,并分析了可溶性膳食纤维的单糖组成,最后以固态发酵所得的膳食纤维为主要成分,开发莲藕膳食纤维咀嚼片。1.对固态发酵实验菌种进行筛选,结果表明：米根霉糖化能力最佳,可以将藕渣中残留的大量淀粉酶解为还原糖,利于大型真菌生长产膳食纤维。在米根霉糖化的基础上,接种灵芝、猴头和平菇等大型真菌发酵藕渣,结果表明三种大型真菌中,灵芝固态发酵后得到可溶性膳食纤维(SDF)产量最高,不溶性膳食纤维(IDF)也较高,因此确定灵芝为产膳食纤维的固态发酵菌种。2.以SDF产量为主要指标,优化了灵芝固态发酵培养基。采用Plackett-Buramn筛选试验表明：麦麸、MgSO4、FeSO4和VB1显著影响藕渣SDF的产量；在此基础上进行最陡爬坡试验,使上述四个显著因子的浓度接近响应面试验的中心浓度。响应面优化试验表明：当5 g藕渣中添加麦麸1.77 g和包含浓度为0.029 g/L MgSO4、0.011 g/LFeS04和0.052 g／L VBI的混合培养液17.0 ml时,SDF产量达到0.113g/g DW,是用基础培养基发酵得到SDF产量(0.035g/g DW)的3.2倍。3.以SDF产量为主要指标,对灵芝固态发酵培养条件进行优化。在单因素试验的基础上,采用Box-Behnken响应面试验对培养温度、接种量和培养时间进行优化,结果表明：接种量为12.7 ml,在28℃下培养6.7 d时,SDF产量可达0.233g/gDw。在此基础上对发酵过程中相关指标进行动态研究,其中IDF与SDF产量、淀粉酶和纤维素酶活力变化总体呈先升高后下降的趋势；总糖、还原糖、游离氨基酸在发酵过程中总体呈下降趋势；可溶性蛋白质含量、蛋白酶活力总体呈增加趋势。最后对发酵得到的SDF进行单糖组成测定,SDF样品由鼠李糖、木糖、甘露糖、半乳糖和葡萄糖组成,其摩尔比为：1.2：1.0：1.6：7.2：56.9。4.以固态发酵所得膳食纤维开发莲藕膳食纤维咀嚼片,优化后的莲藕膳食纤维咀嚼片配方为：复合甜味剂比例44.7%、糊精比例10.6%、复合酸味剂比例2.2%硬脂酸镁比例1%,膳食纤维比例为41.5%时,模糊综合评价表明：莲藕膳食纤维咀嚼片达到“最易接受”级别,符合消费者的食用要求。更多还原

【Abstract】 In this paper, the strain of solid state fermentation (SSF) was first selected; then, the research on optimization of substrate and incubation condition of SSF was conducted. And also the study on the change of related index during fermentation and the determination of the monosaccharide of SDF was carried out. Finally, the dietary fiber (DF) obtained from fermentation was used as the main raw material of lotus root pomace chew-tablets for further research and development.1. The strain of SSF was first selected in the experiment. Results showed that Rhizopus oryzae could saccharify starch into reducing sugar in the highest amount amount; as a result, Rhizopus oryzae was chosen as the saccharifying strain in our experiment. Then, Ganoderma lucidum, Hydonid hymenium and oyster mushroom were selected for highest production of DF. Results showed that G. lucidum could produce the highest amount of dietary fiber; therefore, Ganoderma lucidum was selected as the strain in the sequence experiment.2. Optimization of the substrate was carried out with the production of SDF as the response value. Plackett-Buraman design was applied to select the significance factors influencing SDF production and the results showed that wheat bran, MgSO4, FeSO4 and VB1 were significant variables. Then, the steepest ascent method was employed to insure the concentrations of the 4 significant variables at optimal levels of the response surface methodology (RSM) design. Finally, Box-Behnken design (BBD) was applied for further optimization to obtain the highest SDF production. The results showed that when adding wheat bran 1.77 g and 17.0 ml mixed culture solution with the concentration of 0.029 g/L MgSO4,0.011 g/L FeSO4 and 0.052 g/L VB1 to 5.00 g louts root pomace, the maximum SDF production reached 0.113 g g-1 DW which was 3.2 times as the SDF yield in the basal medium (0.035 g/gDW).3. Optimizpation of the incubation conditions was carried out with the production of SDF as the response value. Box-Behnken optimization design was conducted to further research based on the results from the single-factor experiment. When the inoculumn size was 12.7 ml, incubated at 28℃for 6 d, the SDF yield could reach 0.233 g/g DW. During fermentation, the change of related indexes was studied. The results showed that IDF and SDF production, amylase activity and cellulose activity experience a course of increasing at first, reached the peak and then dropped. Contents of total sugar, reducing sugar, and free amino acids decreased generally; while contents of soluble protein and protease increased generally during fermentation. Compositional analysis showed that SDF was composed of rhamnose, xylose, mannose, galactose and glucose in a molar ratio of 1.2:1.0:1.6:7.2: 56.9.4. The dietary fiber obtained from fermentation with G. lucidum was used as the main raw material of the lotus root pomace chew-tablet. The lotus root pomace chew-table was consisted of 44.7% of sweetenners,10.6% of dextrin,2.2% of sour taste,1% of stearic acid and 41.5% of dietary fiber from fermentation. The fuzzy comprehensive evaluation methodology was carried out for evaluation of lotus root pomace chew-tablets; the results showed the lotus root pomace dietary fiber chew-tablets were acceptable by consumers.更多还原