共查询到17条相似文献,搜索用时 218 毫秒
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作者从研究中发现:用Roberts铜盐法测定蔗汁样本葡聚糖含量时,所得结果与蔗汁的受热有关,受热蔗汁的测定值高于真实值,作者将这种现象暂称为Roberts铜盐法测定蔗汁样本葡聚糖含量的热效应。研究表明:蔗汁中的淀粉是引起热效应的重要因素。本文最后提出了一种由淀粉引起的热效应的可行校正方法。 相似文献
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葡聚糖酶应用于甘蔗混合汁的工艺优化 总被引:1,自引:0,他引:1
制糖过程葡聚糖的存在不仅造成蔗糖损失,其高粘性也给生产带来严重的影响。利用响应面法(RSM)对葡聚糖酶降解糖厂混合汁中的葡聚糖进行了工艺优化。基于单因素实验,以葡聚糖酶剂量(mg/kg)、酶解pH、酶解温度(℃)、酶解时间(min)为响应因子,混合汁中葡聚糖含量为响应值,作四因素三水平响应面分析,得到酶解的最优工艺条件。结合糖厂实际生产,提出可供糖厂应用葡聚糖酶降解葡聚糖的参考工艺条件:葡聚糖酶剂量10~15mg/kg蔗汁,反应时间10~15min,反应pH为4.5~5.5(最优为4.90),反应温度为50~60℃(最优为54.3℃)。在此工艺范围内,得到混合汁中的葡聚糖含量为313~354mg/kg·Brix,对应其去除率为74.45%~71.10%。 相似文献
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《食品与发酵工业》2019,(10):149-154
探究β-葡聚糖与传统青稞酒发酵间存在的相互影响,为传统青稞酒生产提供科学指导。检测传统青稞酒发酵过程中总糖、β-葡聚糖和乙醇的动态变化及营养成分在青稞酒与酒糟中的分布;采用青稞淀粉和β-葡聚糖模拟酿造工艺并利用显微镜观察β-葡聚糖与淀粉混合发酵物的形态。随发酵时间的延长酒醅总糖先增后减,β-葡聚糖含量逐渐下降,酒精度逐渐上升,部分β-葡聚糖溶入青稞酒而酒糟富集了蛋白质、粗纤维、总糖、β-葡聚糖(8. 42 g/100g)和氨基酸(16 570. 08 mg/100g);模拟工艺中淀粉分解率、还原糖生成量、酒精产量随β-葡聚糖浓度的升高而显著降低(P 0. 05),且β-葡聚糖在酒精发酵过程中被部分降解。β-葡聚糖对淀粉的包裹作用可延缓或抑制酒曲对淀粉的分解,且其浓度越高抑制效果越明显。该研究为传统青稞酒酿造品质的提高和酒糟的高值化利用提供了科学参考。 相似文献
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制糖工业中葡聚糖给生产带来严重危害。利用葡聚糖酶降解甘蔗糖厂混合汁中的葡聚糖。首先监测混合汁在自然静置下葡聚糖含量、过滤速度等指标的变化。其次在不同条件(酶剂量、pH、温度及酶解时间)下对葡聚糖酶的降解作用进行研究,得到此葡聚糖酶的最佳降解范围为:酶剂量10~15mg/kg,酶解pH5.0~6.0,酶解温度50~65℃,酶解时间10~15min。在酶解的最佳范围内模拟糖厂实际生产流程进行实验验证,加入10mg/kg葡聚糖酶,清汁中葡聚糖含量降低了61.32%,沉降时间减少了13.46%,简纯度提高了0.65%,而pH、锤度无明显变化。 相似文献
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The delivery of consignments of deteriorated sugarcane to factories can detrimentally affect multiple process units, and even lead to a factory shut-down. An enzymatic factory method was used to measure mannitol, a major degradation product of sugarcane Leuconostoc deterioration in the US, in press (consignment) and crusher juices collected across the 2004 processing season at a Louisiana factory. Weather conditions varied markedly across the season causing periods of the delivery of deteriorated sugarcane to the factory. A strong polynomial relationship existed between mannitol and haze dextran (R2 = 0.912) in press and crusher juices. Mannitol concentrations were usually higher than haze and monoclonal antibody dextran concentrations, which indicates: (i) the usefulness and higher sensitivity of mannitol to better predict sugarcane deterioration from Leuconostoc and other bacteria than dextran, and (ii) the underestimation by sugar industry personnel of the relatively large amounts of mannitol present in deteriorated sugarcane that can affect processing. Greater than ∼2500 ppm/%Brix mannitol in juice predicts downstream processing problems. The enzymatic method is quantitative and could be used in a sugarcane payment formula. Approximately >300 ppm/%Brix haze dextran in raw sugar indicated that the majority of the crystals were elongated. Approximately >600 ppm/%Brix antibody dextran indicated when elongated crystals were predominant in the raw sugar. The enzymatic mannitol method underestimates mannitol in raw sugars. 相似文献
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Mannitol, formed mainly by Leuconostoc mesenteroides bacteria, is a very sensitive indicator of sugarcane deterioration that directly affects processing and can predict problems from dextran and levan polysaccharides. An enzymatic method has been developed to measure mannitol in juice pressed from consignments of sugarcane delivered to the factory. This screening tool will allow factory staff to rapidly know which consignments of cane will affect processing negatively or reject consignments that will cause unacceptable processing problems. Mannitol is directly measured on a spectrophotometer using mannitol dehydrogenase as the enzyme catalyst. The stability of the reagents, limited cane juice preparation and linearity are described. This method is accurate, comparing favorably with an ion chromatography method, and can be easily performed using existing equipment in sugarcane factories. The coefficient of variation (CV) for cane juices ranged from 1.73% to 5.13% with the highest CVs occurring for low mannitol concentrations in undeteriorated cane. Mannitol can be measured after ∼7 min at room temperature and within 4 min if a 40 °C waterbath is used. The method is highly specific for mannitol and was not affected by the presence of sucrose, glucose, fructose, or dextran. The current cost is only ∼60 US cents per analysis. Further studies on the viability of the method at the factory, and as a screening tool for breeding programs for cane freeze tolerance, are being undertaken. 相似文献
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以固定化酵母作为发酵菌株,研究了甘蔗生产燃料乙醇的预处理、发酵工艺。获得了最适工艺参数:甘蔗经切断、撕裂、压榨机压榨和板框过滤后得到甘蔗汁,在甘蔗汁中加入1 U/mL的青霉素,发酵及酒母培养的pH值为3.5~4.0,添加0.01%的硫酸镁。32~35℃,发酵21 h,乙醇浓度达到9.5%vol左右,糖醇转化率在96%左右。采用单浓度双流加连续发酵工艺进行生产试验,与淀粉质及纤维质燃料乙醇工艺进行对比,结果表明,甘蔗生产燃料乙醇的连续发酵工艺在生产上是完全可行的,工艺路线简单,生产成本低,是目前最适于大规模推广的燃料乙醇生产工艺。 相似文献
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以甘蔗、龙眼、火龙果、猕猴桃的清汁为原料开发一款亚热带水果复合发酵饮品。通过单因素分析,探讨了甘蔗清汁、龙眼清汁、火龙果清汁和猕猴桃清汁添加量对产品感官品质的影响,并以口感、色泽、香气、形态为评价因素,结合L16(45)正交试验方案,以模糊数学综合评判优化甘蔗清汁、龙眼清汁、火龙果清汁、猕猴桃清汁复合发酵饮品配方。结果表明:最佳发酵优选组合为甘蔗清汁25 mL、龙眼清汁50 mL、火龙果清汁20 mL、猕猴桃清汁12 mL,在此组合下,定量复配发酵制得的饮品综合感官品质最为理想。本研究结果可为利用甘蔗中的天然糖分为主要碳源的亚热带水果复合发酵工艺提供参考和理论依据。 相似文献