Hydrolysis of oligosaccharides in soybean products by Debaryomyces hansenii UFV-1 α-galactosidases

α-Galactosides are abundant sugars found in legumes such as soybean. Since humans and monogastric animals lack α-galactosidase in the digestive tract, they are unable to digest these sugars, which induce flatulence. The use of α-galactosidases is promising as a means to overcome this problem, and to increase the consumption of soy products. Immobilized α-galactosidase, derived from Debaryomyces hansenii UFV-1, exhibited an activity of 40 U per g of silica and an activity yield of 50%. The optimum pH of free and immobilized α-galactosidase was 5.0 and the optima temperatures were 60 and 80 °C, respectively. The soymilk stachyose was completely hydrolyzed by different enzyme forms after incubation for 4 h at 60 °C, while raffinose was reduced by 100%, 25% and 68% by free, immobilized enzymes and permeabilized cells, respectively. The soy molasses treatment with free enzyme for 6 h promoted reduction in stachyose and raffinose contents by 100% and 50%, respectively.     

α-Galactosidase and proteolytic activities of selected probiotic and dairy cultures in fermented soymilk

The metabolic activities of Lactobacillus acidophilus (LAFTI^® L10 and La4962) Bifidobacterium (lactis LAFTI^® B94 and longum Bl536), Lactobacillus casei (LAFTI^® L26 and Lc279), Lactobacillus delbrueckii ssp. bulgaricus Lb1466 and Streptococuss thermophilus St1342 were assessed in soymilk. Strains were initially analyzed for α-galactosidase activity and organic acid production in MRS broth at 37 °C. Consequently, soymilk was fermented with each strain and cell growth, production of organic acid, metabolism of oligosaccharides and proteolytic and ACE-inhibitory activities were assessed during 48 h of incubation at 42 °C. All strains exhibited variable α-galactosidase activity, with Bifidobacterium lactis B94 showing the highest activity. The oligosaccharide metabolism depended on α-galactosidase activity. B. lactis B94, S. thermophilus St1342 and L. acidophilus La4962 reduced raffinose substantially by 77.4%, 64.5% and 55.9%, respectively. All strains reached the desired therapeutic level of 10⁸ cfu/ml in soymilk after 48 h at 42 °C. The hydrolysis of protein in soymilk likely depended on strain (P < 0.0001) and time (P < 0.0001). The strains also released bioactive peptides with ACE-inhibitory activities between 17% and 43%.     

Effect of cultivar,cultivation year and dehulling on raffinose family oligosaccharides in Australian sweet lupin (Lupinus angustifolius L.)

The aim of this study was to determine the effect of cultivar, cultivation year and dehulling on raffinose family oligosaccharides (RFOs) in current cultivars of Australian sweet lupin. Seed samples of ten cultivars grown in 2011, 2012 and 2013 were used in the study. Both whole seed and dehulled lupin samples were analysed for RFOs by high‐performance liquid chromatography with evaporative light scattering detector. Lupin cultivar had a significant effect on RFO contents. Total RFO contents in whole seed and dehulled lupin samples varied between 7.3–10.1 g/100 g DM and 7.6–16.8 g/100 g DM, respectively. Belara and Mandelup cultivars had high levels of RFOs indicating the suitability for functional foods with prebiotic effect. Gungurru and PBA Barlock contained low levels of RFOs and recommended for lupin‐enriched foods with low flatulence effect. Cultivation year with similar climatic conditions had no significant effect on RFO contents. Dehulling increases raffinose, stachyose and total RFO contents in lupin.     

Removal of oligosaccharides in soybean flour and nutritional effects in rats

The objectives of this work were to establish a safe and economically viable process for the removal of raffinose oligosaccharides (RO) from soy flour and compare the effects of RO elimination from diets with regard to nutritional parameters by testing in Wistar rats. Debaryomyces hansenii UFV-1 was cultivated in suspension of defatted soy flour (1:10 w/v). An increase in α-galactosidase activity was observed in the medium, with a consequent decrease in the RO concentration. A total reduction of RO was achieved at 36 h of incubation. The diet containing soy flour free of RO presented higher digestibility, 91.28%, in relation to the diet containing soy flour with RO, 87.14%. However, the removal of the oligosaccharides from the diet did not promote a significant improvement in the values of weight gain, and other nutritional parameters tested on rats, during the experimental period of 14 days.     

Content of low molecular weight carbohydrates in vining peas (Pisum sativum) related to harvest time,size and brine grade

Knowledge of how the content of low molecular weight carbohydrates (LMWC), including the raffinose family oligosaccharides (RFO; raffinose, stachyose and verbascose), changes in unripe peas (Pisum sativum) around harvest time, is today limited. An early and a late maturing cultivar of peas were harvested with 24 h of each other on seven different occasions, of which three were chosen for this study. The pea samples were divided into three groups by size and brine grading, and then analysed with regard to the content of low molecular weight carbohydrates. The content of raffinose and stachyose increased in all groups during a period of 5 days. Peas that sank (sinkers) in the brine grading test had a higher content of raffinose and stachyose and a lower content of sucrose than floating peas, indicating that sinkers have reached a greater degree of maturation. The content of verbascose remained the same or decreased during the study period. In conclusion, the date of harvesting green peas for freezing affects the contents of RFO.     

磁场稳定流化床反应器水解牛乳中乳糖的研究

在磁场稳定流化床反应器采用固定化β-半乳糖酶对牛乳中乳糖进行水解，研究了各种操作条件对牛奶中乳糖水解的影响，结果表明：在磁场强度14-18mT，牛乳流动速率小于14em^3／min、55℃的条件下水解牛乳120min，乳糖可水解86％。     

大豆低聚糖在主食面包中的应用

采用单因素试验设计研究国产大豆低聚糖在主食面包中的应用。主食面包中添加大豆低聚糖能延长面包老化现象,延长货架期达到2～3d,大豆低聚糖保存97.8%以上,主食面包含蔗糖量6%(以面粉计),加入大豆低聚糖量为5.14%以下。     

酸降解法制备褐藻寡糖抗氧化性的研究

从褐藻胶中提取出聚甘露糖醛酸和聚古罗糖醛酸,利用盐酸降解聚甘露糖醛酸和聚古罗糖醛酸1、2、6 h分别制备了甘露糖醛酸组分（M₁、M₂和M₃）以及古罗糖醛酸组分（G₁、G₂和G₃）,并且以肌肽和甘露糖为对照评估寡糖对DPPH自由基、超氧自由基和羟自由基的清除作用。结果表明,甘露糖醛酸以及古罗糖醛酸对DPPH自由基、超氧自由基具有良好的清除作用,且清除作用随着寡糖中还原糖含量的增加而增加。在DPPH体系中,M₃的清除效果要好于肌肽,G₃的清除效果与肌肽相近。在超氧自由基体系中,M₃的清除作用高于M₂和M₁,而G₃的清除作用略低于肌肽。在羟自由基体系中,甘露糖醛酸和古罗糖醛酸的清除效果低于肌肽和甘露醇。实验表明,酸法制备的褐藻寡糖具有较强的抗氧化能力,且抗氧化效果与寡糖的平均聚合度含量有关。      

Highly automated and fast determination of raffinose family oligosaccharides in Lupinus seeds using pressurized liquid extraction and high‐performance anion‐exchange chromatography with pulsed amperometric detection

BACKGROUND: Taking into account several requirements for the determination of raffinose family oligosaccharides (RFOs) from Lupinus seeds—e.g., conducting plant breeding projects or food product development—a reasonable combination of efficient automated sample preparation and reliable analysis need to be developed and validated. RESULTS: In this regard pressurized liquid extraction was applied to extract the RFOs from ground and defatted lupin flour. Compared to many other publications, no further pretreatment, such as protein precipitation, was necessary to obtain satisfactory results applying ion chromatography with pulsed amperometric detection. The oligosaccharide content for the examined Lupinus albus samples were in the range 5.19–9.25 g kg⁻¹ and for Lupinus angustifolius RFOs 3.49–4.75 g kg⁻¹. Stachyose has always been the main component followed by raffinose and verbascose. CONCLUSION: The developed sample preparation and analytical method is suited to quantify raffinose, stachyose, verbascose and the disaccharide sucrose and, owing to a high degree of automation for sample preparation and relatively short analysis times by pretty peak separation, particularly high sample numbers can be accomplished. Copyright © 2008 Society of Chemical Industry     

琼胶寡糖的生物酶解制备工艺研究

以龙须菜为原料,以琼胶得率为指标,采用正交实验研究了液料比、水提温度、水提时间对琼胶得率的影响,得到最佳水提琼胶工艺条件;进一步以水解度为指标,采用响应曲面法研究了pH、酶解温度、底物浓度对琼胶水解度的影响,得到最优酶解工艺。结果表明,琼胶的最佳水提条件为:液料比281(v/w),水提温度120℃,水提时间90 min,在此条件下,琼胶得率为32.8%。酶解时间2h,加酶量20 U/mL条件下的最优酶解工艺为:pH6.4,酶解温度54℃,底物浓度0.6%(w/v),此时水解度为89.75%。经薄层层析分析,酶解产物为偶数新琼寡糖(DP2、4、6、8),其中主要产物为新琼四糖,为功能性琼胶寡糖的开发应用打下基础。      

酶法制备黑莓果胶寡糖及其抗氧化活性研究

对黑莓果胶寡糖进行抗氧化活性研究,探究其自由基清除能力。对黑莓果胶进行提取,并利用果胶酶对其进行酶解,通过分级醇沉制得黑莓果胶寡糖。以DPPH、ABTS、羟自由基清除能力验证不同黑莓果胶寡糖体外抗氧化活性。结果表明,4倍醇沉寡糖对DPPH、ABTS自由基的IC50分别为0.59、4.75 mg/m L。10倍醇沉果胶寡糖对这两种自由基的清除作用更强,IC50分别为0.40、2.79 mg/m L。黑莓果胶寡糖具有显著的抗氧化活性,对DPPH自由基、ABTS自由基有很强的清除作用,且具有明显的量效关系。      

双酶混合水解玉米皮渣制备阿魏酰低聚糖研究

以玉米皮渣为原料,采用酶解方法制备阿魏酰低聚糖(Feruloyl oligosaccharides,FOs),通过比较不同酶解条件下阿魏酰低聚糖产量的差异及不同酶解方式下玉米皮渣细胞壁结构的变化,确定酶解阿魏酰低聚糖生成的方法,并优化获得玉米皮渣中阿魏酰低聚糖的最佳酶解条件。结果表明:纤维素酶和木聚糖酶混合酶解可使玉米皮渣细胞壁出现溶洞,可有效提高阿魏酰低聚糖产量;经单因素和响应面实验确定双酶混合酶解的最佳条件为混合酶的添加量为15.7 g/L,混合酶中纤维素酶添加比例为70%,酶解1 h,玉米皮渣底物添加量为100 g/L,在此条件下FOs产量最高,为1008.43μmol/L。本研究为双酶混合酶解制备玉米皮渣FOs提供理论依据。      

不同菌种对豆粕中水苏糖、棉子糖的发酵降解与检测技术研究

建立豆粕中水苏糖、棉子糖的快速检测的方法,在此基础上分析不同菌种对豆粕中水苏糖和棉子糖的降解效果。采用高效液相色谱法检测豆粕中的水苏糖和棉子糖含量。采用单一菌种和混合菌种固态发酵法进行豆粕中水苏糖和棉子糖的降解。水苏糖和棉子糖的最佳检测条件为:示差折光检测器,NH2柱,色谱柱温度35℃,流动相为乙腈∶水=65∶35,流速1.0 m L/min,进样量10μL。在上述条件下水苏糖和棉籽糖的检测限分别为4.00~40.00 mg/m L和2.00~10.00 mg/m L,平均加样回收率分别为95.68%和95.08%。单一菌种和混和菌种固态发酵结果表明,将豆粕∶玉米粉∶麸皮为9∶0.5∶0.5的比例进行混合,按15%的接种量,30℃下发酵48 h,可部分或者完全降解豆粕中的水苏糖和棉子糖。所建方法能够准确快速的检测豆粕和发酵豆粕(FSM)中水苏糖和棉子糖的含量。发酵结果表明,在很好的降解水苏糖和棉子糖的基础上,由于混合菌种发酵能提供更全面的菌体蛋白和营养物质,因此更适合用于新型发酵豆粕产品的开发和应用。     

模拟移动床色谱分离技术在功能糖生产中的应用

本文介绍了色谱分离技术的工作原理和主要特点,并通过实验考察了顺序式模拟移动床色谱分离在低聚异麦芽糖、低聚果糖、低聚半乳糖等功能性低聚糖分离纯化中的应用,得到了最佳工艺条件,为工业化生产提供了依据,扩大了模拟移动床色谱分离技术在功能糖领域的应用,为高纯度功能性低聚糖的开发奠定了基础。     

物理处理玉米皮渣对酶法提取阿魏酰低聚糖的影响

以玉米皮渣为原料,考察物理处理对其水解获得阿魏酰低聚糖产量的影响。通过测定不同方法处理前后玉米皮渣细胞壁组成和其结构变化及阿魏酰低聚糖(Feruloyl oligosaccharides,FOs)产量关系,探讨物理处理影响FOs生成的原因。结果表明:高压蒸煮处理使酶解玉米皮渣生成FOs产量提高了1.5倍,原因是高压蒸煮改变了玉米皮渣细胞壁的组成,其中纤维素和果胶质得以释放,增加了纤维素酶和木聚糖酶与底物的接触几率;微波和膨化处理均使玉米皮结构裂解,FOs产量无显著变化。      

Production of soya milk containing low flatulence‐causing oligosaccharides in a packed bed reactor using immobilised α‐galactosidase

Peanut α‐galactosidase was immobilised in calcium alginate beads and used to hydrolyse the flatulence‐causing oligosaccharides, raffinose and stachyose, in soya milk in batch and in packed bed reactor with recycle. The immobilised enzyme exhibited a slightly lower activity than the free enzyme. The activity yield of immobilised α‐galactosidase was 75.1% and the immobilisation yield was 82.6%. Batch hydrolysis using immobilised enzyme at 55 °C resulted in 96% reduction in the oligosaccharides after 12 h. For the continuous process, a packed bed reactor with recycle was used. More than 98% of the oligosaccharides were hydrolysed after 6 h of reaction at 55 °C. The immobilised enzyme also proved to be stable up to three repeated hydrolysis reactions.     

Raffinose family oligosaccharides in seed of Glycine max cv. Chiang Mai60 and potential source of prebiotic substances

Raffinose family oligosaccharides (RFOs) content in Glycine max seed of cultivar Chiang Mai60, a local soybean of Thailand, was investigated. RFOs and other low molecular weight sugars were extracted by 50% (v/v) ethanol and quantified by high‐performance liquid chromatography (HPLC). The prebiotic property of this extract was subsequently studied by in vitro method. The results showed that the concentrations of raffinose, stachyose and verbascose were 6.74 ± 1.62, 145.32 ± 18.74 and 1.60 ± 0.52 mg g^?1 dry seed, respectively, while glucose and sucrose were detected at 10.73 ± 1.35 and 13.28 ± 2.16 mg g^?1 dry seed, respectively. The growth of four Lactobacilli probiotics were increased significantly in a basal liquid medium supplemented with this ethanolic extract as carbon source compared to glucose supplementation. Subsequently, defined mixed culture was studied and it was found that growth stimulation of total Lactobacilli by extracted sugars resulted in the suppression of Escherichia coli and Salmonella enterica serovar Typhimurium growth. It could be concluded that this cultivar showed the RFOs‐rich content and a potential to be a source of an effective prebiotic substance for food application.     

Effect of soybean oligosaccharides on blood lipid,glucose levels and antioxidant enzymes activity in high fat rats

The effect of soybean oligosaccharides on blood lipid levels and oxidative stress in rats fed on high-fat diet was investigated. Rats were divided into five groups of 10 animals each. The high-fat group received a high-fat diet containing 18% (w/w) lipid in the diet (36% of total energy). Animals allocated to the soybean oligosaccharides-treatment groups (I, II and III) received the high-fat diet and orally fed with soybean oligosaccharides at a single dose of 150, 300 and 450 mg/kg body weight, respectively. Control rats received basic diet. Results showed that soybean oligosaccharides significantly reduced abnormal blood glucose, lipid level and oxidative stress in animal models at all doses examined. Soybean oligosaccharides were able to reduce oxidative stress and improve abnormal blood lipid levels induced by high-fat diets. In summary, the present study may be important for reverse cardio-cerebrovascular disease.     

乳品分析仪FT-120快速测定酸酸乳饮料中低聚糖质量浓度

使用FT-120快速测定酸酸乳饮料中低聚糖质量浓度。结果表明,FT-120测定结果中总糖质量浓度与低聚异麦芽糖质量浓度的相关性好,R=0.9997,以总糖质量浓度作为指标,初步预测样品中低聚异麦芽糖的质量浓度。方法的检出限为0.105 g/100 mL,相对标准偏差RSD值在0.162%～1.411%之间,加标回收率在90%～110%之间,方法快速,检测值可靠。     

Inactivation of soybean lipoxygenase in soymilk by pulsed electric fields

The inactivation of soybean lipoxygenase by pulsed electric fields (PEF) was studied. Effects of PEF parameters (treatment time, pulse strength, pulse frequency and pulse width) were evaluated. Soymilk was exposed to pulsed strengths from 20 to 42 kV/cm for up to 1036 μs treatment time in square wave pulse of bipolar mode. Moreover, pulse frequency (100–600 Hz) and pulse width (1–5 μs) was also tested at constant pulsed treatment time of 345 μs and strength of 30 kV/cm. Residual activity of soybean lipoxygenase decreased with the increase of treatment time, pulse strength, pulse frequency and pulse width. The maximum inactivation of soybean lipoxygenase by PEF achieved 88% at 42 kV/cm for 1036 μs with 400 Hz of pulse frequency and 2 μs of pulse width at 25 °C. Inactivation of soybean lipoxygenase by pulsed electric fields was modeled using several kinetic models. Weibull distribution function was most suitable model describing the inactivation of soybean LOX as a function of pulsed electric fields process parameters. Moreover, reduction of soybean LOX activity related to the electric field strength could be well described by the Fermi model.