几种不同提取方法对燕麦总多酚含量的影响

本文运用紫外-分光光度计法评价几种不同的提取方法对燕麦总多酚含量的影响,通过单因素和正交实验得到传统溶剂法提取燕麦总多酚的最佳工艺条件。其中传统溶剂法提取燕麦总多酚的最佳工艺条件为:乙醇体积分数55%,料液比1∶50 g/m L,水浴温度55℃,浸提时间2 h,燕麦总多酚含量为0.99 mg/g;超声波处理提取燕麦总多酚的最佳工艺条件为:超声波功率500 W,超声时间30 min,温度55℃,燕麦总多酚含量为1.32 mg/g;微波处理提取燕麦总多酚的最佳工艺条件为:微波功率500 W,微波时间7.5 min,温度55℃,燕麦总多酚含量为1.80 mg/g;超声波-微波处理提取燕麦总多酚的最佳工艺条件为:超声波-微波功率500 W,超声波-微波协同处理时间2.5 min,温度55℃,燕麦总多酚含量为2.02 mg/g。其中超声波-微波协同处理提取燕麦总多酚用时最短,得到的含量最高,可以选取该工艺为后续的实验提供科学依据。     

燕麦片加工过程中营养品质及加工特性变化

为探讨燕麦片加工过程的主要营养成分变化,本试验于商品化燕麦片不同生产环节在线取样,分析蒸煮、烘干和微波烘烤等工艺对燕麦中营养品质及加工特性的影响。结果表明:加工不会导致燕麦蛋白质、脂肪和β-葡聚糖含量发生显著变化,但蒸煮和烘干后总酚含量分别降低5.11%和11.57%(P0.05)。加工过程中燕麦脂肪酸组成没有显著变化,糊化温度、最终黏度、崩解值和回生值显著降低;蒸煮能完全钝化脂酶活性,蒸煮和微波烘烤后燕麦蛋白质消化率显著提升6.78%和13.25%,微波烘烤导致燕麦β-葡聚糖主要组分分子质量降低6.92%。研究结果表明燕麦片加工过程中营养成分含量变化较小,但黏度特性指标降低及蛋白消化率提高,使其更有利于人体吸收与利用。     

燕麦麸皮β-葡聚糖的微波辅助浸提技术研究

以微波辅助提取技术,分别考查了微波、微波时间、功率料水比、浸提温度等因素对提取燕麦麸皮β-葡聚糖得率的影响,并与热水浸提法进行比较,确定了微波辅助提取工艺的最佳工艺参数为:料水比为1∶15、微波时间为4min、微波的功率为640W、温度为80℃,β-葡聚糖的得率可达5.1%。该工艺与传统浸提方法相比较,提取率提高,节省了水和时间。     

不同干燥方式燕麦蛋白的性质及对肌原纤维蛋白凝胶特性的影响

为研究添加不同干燥方式处理的燕麦蛋白对肉类食品质构等特性的影响,采用4种不同干燥方法(喷雾干燥、冷冻干燥、真空干燥和微波干燥)处理燕麦蛋白,考察不同干燥方法对燕麦蛋白结构和性质的影响,以及添加不同干燥方法处理的燕麦蛋白对肌原纤维蛋白凝胶特性的影响。结果表明:不同干燥方法对燕麦蛋白的结构及性质影响不同,与喷雾干燥处理的燕麦蛋白相比较,冷冻和微波干燥处理的燕麦蛋白游离氨基和羰基含量显著下降;红外光谱分析结果显示,相比较于冷冻、真空和微波干燥,喷雾干燥处理的燕麦蛋白α-螺旋和β-转角结构含量无显著性差异,但β-折叠结构含量下降而无规则卷曲结构含量上升;荧光光谱分析结果表明,相比较于冷冻和微波干燥,喷雾和真空干燥处理的燕麦蛋白的最大发射波长出现了红移;微波干燥处理的燕麦蛋白表面疏水性最低且溶解性最好。不同干燥方法处理的燕麦蛋白对肌原纤维蛋白的凝胶性质影响不同,与肌原纤维蛋白相比,添加冷冻、真空和微波干燥处理的燕麦蛋白未改变凝胶温度,而添加喷雾干燥处理的燕麦蛋白凝胶温度降低了2℃; 添加微波、真空和喷雾干燥处理的燕麦蛋白均提高了凝胶的G′ 和G″,表明混合凝胶的弹性和黏性提高,而添加冷冻干燥处理的燕麦蛋白降低了凝胶的黏性和弹性; 扫描电子显微镜结果显示,喷雾干燥处理的燕麦蛋白与肌原纤维蛋白形成的混合凝胶网络具有更为紧密的网状结构,且孔径相对较小,而冷冻干燥处理的燕麦蛋白与肌原纤维蛋白形成的混合凝胶网络较为疏松,孔径相对较大。本研究旨在为功能型肉制品,包括谷物-肉类乳化型肉制品的开发提供一定的技术参数。     

富含γ-氨基丁酸燕麦发芽条件的优化

以燕麦为研究对象,通过发芽处理制备富含γ-氨基丁酸的燕麦.利用单因素试验和响应面试验进行分析.对浸泡温度、浸泡时间、发芽温度和发芽时间4个因素进行优化,得出富含γ-氨基丁酸燕麦的最优发芽条件.通过单因素试验,筛选出对γ-氨基丁酸含量影响较大的3个因素:浸泡时间、发芽温度、发芽时间.利用响应面试验得到燕麦最优发芽条件:浸泡温度25℃、浸泡时间8h、发芽温度25℃、发芽时间16 h.在此条件下,得到的发芽燕麦中γ-氨基丁酸含量为253.55 mg/100 g,是未发芽燕麦中γ-氨基丁酸含量的12.34倍.     

燕麦水溶性β-葡聚糖的凝胶性研究

研究了裸燕麦水溶性β-葡聚糖的凝胶特性。结果表明,燕麦β-葡聚糖的凝胶形成主要受分子量、粘度、浓度和温度等因素的影响,低分子量、低粘度、高浓度和低温利于凝胶的形成。用DSC结果表明,5％燕麦β-葡聚糖凝胶的溶解温度为69℃;燕麦β-葡聚糖的凝胶强度随浓度增大而增大;Ca2 会影响凝胶强度。     

基于微波吸油膨胀处理的燕麦露加工工艺研究

以燕麦为原料,采用微波吸油膨胀处理,通过酶解、高压均质、灭菌等工艺,制作一款零添加的健康燕麦露饮料.本文主要针对微波吸油膨胀处理燕麦的工艺条件进行优化,以燕麦米吸油率和燕麦露感官评价为指标,研究植物油添加量、微波加热火力、微波处理时间、燕麦平铺厚度对燕麦露品质的影响.结果 表明,燕麦露饮料最佳加工工艺:饮料中燕麦基比例...     

燕麦β-葡聚糖的冻融法提取及其结构表征

目的:研究燕麦β-葡聚糖的冻融提取方法.方法:采用热水浸提-冻融循环提取燕麦β-葡聚糖,研究内源酶活性、水浸提温度和时间、燕麦β-葡聚糖质量分数和冻融次数等因素对β-葡聚糖得率和纯度的影响规律.采用气相色谱、红外光谱和核磁共振等手段对纯化的β-葡聚糖进行结构表征.结果:不灭内源酶活,55℃提取2h,将提取液浓缩至β-葡聚糖质量分数为1％,冻融3次,燕麦β-葡聚糖的得率为1.5％,纯度92％.通过仪器分析的方法证实冻融法提取到的物质是β-葡聚糖.结论:采用冻融法,不必添加任何化学试剂和酶,仅凭借冻融这一物理过程即可得到较高纯度的燕麦β-葡聚糖.     

燕麦糊精脂肪替代品的制备

研究了耐高温α-淀粉酶水解燕麦淀粉制取低DE值燕麦糊精脂肪替代品的工艺条件,同时探讨了潭度、pH值对其乳化性及乳化稳定性的影响。结果表明：添加耐高温α-淀粉酶5000／g淀粉（干基）时,在酶解温度90℃、底物浓度30％、酶解15min条件下能得到DE值为5．71的燕麦糊精;pH值为4．0-6．0时该燕麦糊精乳化性能最好,温度对乳化性影响不大;表明该燕麦糊精能够作为脂肪替代品。     

微波协同1-丁基-3-甲基咪唑硫酸氢盐离子液体催化酯交换合成肉桂酸正丁酯的研究

研究微波协同1-丁基-3-甲基咪唑硫酸氢盐催化酯交换反应合成肉桂酸正丁酯的新工艺,通过优化合成工艺得到了最佳工艺条件:肉桂酸甲酯的量为0.01 mol,酯醇摩尔比1∶8,催化剂用量为肉桂酸甲酯质量的16％,微波功率300W,微波温度为80℃,微波反应时间为45min,在此条件下,肉桂酸甲酯的最高转化率达36.07％.     

易煮全谷物糙米加工技术研究进展

全谷物糙米蒸煮时间长、不易熟化、适口性和消化性较差,且储藏周期短,限制了糙米粒食的消费与推广.为改善全谷物糙米蒸煮特性和满足消费者对全谷物糙米健康属性的追求,利用先进的加工技术提升其食用品质、营养功能性和储藏稳定性已成为当今全谷物糙米的研究重点.阐述了全谷物糙米的成分组成及结构特点,分析了影响全谷物糙米蒸煮品质的主要因素;重点介绍了近年国内外采用的生物和物理加工技术以及新型非热加工技术在全谷物糙米加工中的应用,并阐明其工作原理及作用特点,指出了各种加工技术存在的优缺点;对未来糙米粒食的研究方向进行了展望.本研究旨在为创制高品质、高营养、高生物利用度的易煮全谷物糙米产品提供参考.     

Effects of fiber addition on antioxidant capacity and nutritional quality of wheat bread

Wholegrain and high fiber foods are recognized as nutritious and healthful products due to their content of dietary fiber, antioxidants and bioactive compounds. In this study, wheat, rye, barley, oat wholegrain flours and two fibers namely cellulose (insoluble fiber) and xanthan gum (soluble fiber) were used to replace a portion of wheat flour in pan bread to study effects of fibers on phenolic compounds, antioxidant capacity, dietary fiber fractions, and starch digestibility in vitro. Incorporation of wholegrain flours increased free and bound phenolics and antioxidant capacity of all the breads examined to various extent depending on the source of fiber. Additionally, soluble, insoluble and total dietary fiber fractions and total minerals increased with the addition of wholegrain flours or fibers. Rapidly and slowly digestible and resistant starches were not significantly influenced by adding wholegrain flours or fibers to breads. The study demonstrates the importance of enriching wheat bread with wholegrain flours to boost antioxidants and dietary fibers. On the other hand, more research is required to better understand impact of wholegrain flours or fiber on starch digestibility in vitro and glycemic response.     

裸燕麦米和燕麦粉加工所得麸皮中β-葡聚糖和酚酸的分布

选取具有代表性的裸燕麦品种,分析燕麦麸皮和胚乳所占的比例和微观结构特征;同时分析β-葡聚糖和酚酸在燕麦麸皮（果皮、种皮＋糊粉层）和胚乳中的分布,并验证了现有燕麦米和燕麦粉主流加工方式的适宜程度。结果表明,在所选裸燕麦品种中,β-葡聚糖均富集在麸皮中,质量分数达8.57%,约是胚乳中含量的4.5?倍;麸皮中p-香豆酸和阿魏酸的含量分别达0.099?mg/g和1.00?mg/g,分别是胚乳中相应含量的24?倍和48?倍;在麸皮中,果皮中p-香豆酸和阿魏酸含量分别约为种皮＋糊粉层中的13?倍和2.7?倍。研磨制燕麦米所得第2道麸皮中,β-葡聚糖质量分数平均为1.7%,远小于麸皮中的平均含量,加工程度适宜;而燕麦制粉所得第4道和第5道麸皮,β-葡聚糖质量分数达6.73%和7.80%,接近糊粉层中β-葡聚糖含量,加工过度。综上可知,利用分析燕麦加工所得麸皮中葡聚糖和酚酸含量,可初步判定燕麦米和燕麦粉的加工程度,为其加工提供技术支撑。     

白燕2号燕麦的双螺杆挤出物的理化特性分析

为探究双螺杆挤压处理对白燕2号燕麦理化特性的影响,以白燕2号裸燕麦全颗粒为原料进行挤压处理,并对燕麦挤出物的品质进行检测与表征。结果表明,在喂料水分22%、螺杆转速42 Hz、喂料速率26 Hz、终端温度160 ℃等典型挤压条件下,燕麦挤出物的膨化率为1.16;挤压过程中发生了美拉德反应,L*降低,a*降低,b*增加,ΔE降低;总氨基酸含量减少了5.44%,各种氨基酸含量呈整体下降趋势;挤压后物料微观结构表面粗糙、富有层次感。燕麦挤出物吸水性指数上升378.4%,水溶性指数下降1.08%,可溶性β-葡聚糖含量提高了62.0%,模拟体内消化后,燕麦挤出物提取液表观黏度增大;挤压过程中同时发生了分子的解聚反应和聚合反应。由此可见,双螺杆挤压是一种有潜力提高全燕麦品质的加工技术。     

The Impact of Milling and Thermal Processing on Phenolic Compounds in Cereal Grains

Consumption of wholegrain foods has been recommended for healthy diets. The beneficial health properties of wholegrain products have been associated with the presence of higher amounts of dietary fiber and antioxidants and lower calories as compared to their respective refined ones. Phenolic compounds are mainly attributed to antioxidant properties of wholegrain foods. This review article provides a single comprehensive source that describes effects of milling and thermal processing on phenolic compounds and antioxidant properties in cereals. In general, milling and pearling processes affect the distribution of phenolic, compounds and thus antioxidant properties vary among the milling fractions. Thermal processes such as baking and extrusion could cause negative or positive effects on phenolic compounds and antioxidant properties of the end product subject to grain type and processing conditions. Thus factors that enhance health benefits of wholegrain cereal products have been discussed.     

Identification of lactic acid bacteria isolated from oat sourdoughs and investigation into their potential for the improvement of oat bread quality

The use of sourdough in wheat and rye breads has been extensively studied; however, little is known about its potential effect when baking oat bread. Consequently, the impact of sourdough on oat bread quality was investigated. Two different sourdoughs were prepared from wholegrain oat flour without the addition of starter cultures, by continuous propagation at 28 (SD 28) or 37 °C (SD 37) until the composition of the lactic acid bacteria remained stable. The dominant LAB were identified by sequence analysis of the 16S rDNA isolated from pure cultures. LAB from SD 28 belonged to the species Leuconostoc argentinum, Pedicoccus pentosaceus and Weissella cibaria, while Lactobacillus coryniformis dominated SD 37. The isolated LAB were further used as starter cultures for the production of oat sourdoughs. Fundamental rheology revealed softening of the sourdoughs compared to non-acidified and chemically acidified controls, which could not be attributed to proteolytic activity. Incorporation of oat sourdough into an oat bread recipe resulted in significantly increased loaf-specific volume as well as improved texture, independent of addition level or sourdough type. Overall, the results of this study show that sourdoughs containing lactic acid bacteria isolated from oats have the potential to enhance oat bread quality.     

Relationship between kernel size and shape and lipase activity of naked oat before and after pearling treatment

BACKGROUND: In China, some oat‐processing companies use pearling treatment to remove part of kernel lipase activity before further deactivation such as infrared roasting. Kernel size and shape are important physical properties of oat kernels. However, there are no reports concerning the change of oat kernel size and shape and lipase activity during pearling treatment. RESULTS: In this research, we tested lipase activity in the kernels of four different oat varieties and we studied the relationship between kernel size and shape and lipase activity. The effect of pearling treatment on oat lipase activity was also examined. A TM‐05C Satake mill was employed to pearl oat samples, with different pearling times ranging from 0 to 45 s at 5 s intervals. The oat lipase activity, lipid content and kernel shape and size after the pearling treatment were tested. Results showed that not only oat variety but also kernel size and shape had marked effects on lipase activity. Pearling treatment could significantly reduce lipase activity. During pearling treatment, small changes in kernel size and shape could cause a dramatic decline in lipase activity. CONCLUSIONS: Pearling treatment could be an effective pretreatment for further deactivation treatment of oats. Copyright © 2009 Society of Chemical Industry     

Sensory characteristics of wholegrain and bran-rich cereal foods – A review

BackgroundWholegrain foods are known to be health-beneficial but their sensory characteristics may be a limiting factor for consumption. The scientific literature of factors influencing sensory quality of wholegrain foods is rather scarce.Scope and approachMany cereals like rye, oats, barley and sorghum are actually used mainly as wholegrain, whereas for wheat the situation is the opposite. This review deals with factors that differentiate the sensory properties of wholegrain and bran-rich foods from those of refined cereal foods.Key findings and conclusionsWholegrain and bran contain flavour-active compounds, flavour precursors and resistant cell wall structures causing changes in flavour and texture during processing. In wholegrain foods, different chemical constituents contribute to bitterness. Increased knowledge on flavour formation has led to the possibility to not only measure but actually also design the flavour. Structure and texture are also important determinants underlying eating quality and stability of cereal foods. Hitherto established means of modulating sensory quality and thus improving acceptability of wholegrain foods are presented.     

Fundamental study on the effect of hydrostatic pressure treatment on the bread-making performance of oat flour

The use of sourdough in wheat and rye breads has been extensively studied; however, little is known about its potential effect when baking oat bread. Consequently, the impact of sourdough on oat bread quality was investigated. Two different sourdoughs were prepared from wholegrain oat flour without the addition of starter cultures, by continuous propagation at 28 (SD 28) or 37 °C (SD 37) until the composition of the lactic acid bacteria remained stable. The dominant LAB were identified by sequence analysis of the 16S rDNA isolated from pure cultures. LAB from SD 28 belonged to the species Leuconostoc argentinum, Pedicoccus pentosaceus and Weissella cibaria, while Lactobacillus coryniformis dominated SD 37. The isolated LAB were further used as starter cultures for the production of oat sourdoughs. Fundamental rheology revealed softening of the sourdoughs compared to non-acidified and chemically acidified controls, which could not be attributed to proteolytic activity. Incorporation of oat sourdough into an oat bread recipe resulted in significantly increased loaf-specific volume as well as improved texture, independent of addition level or sourdough type. Overall, the results of this study show that sourdoughs containing lactic acid bacteria isolated from oats have the potential to enhance oat bread quality.     

燕麦乳挥发性风味物质的SPME-GC-MS解析及原料关联性研究

燕麦乳作为新兴植物代乳近年来在国内外获得快速发展,燕麦乳的风味是影响产品接受度的重要因素。本文基于燕麦原料品种的差异,利用固相微萃取(SPME)-气相色谱-质谱联用(GC-MS)技术对燕麦乳挥发性风味物质进行解析,并从中筛选出适宜的燕麦原料。结果表明：燕麦原料与其加工制品(燕麦乳)的挥发性风味化合物的种类和含量存在显著差异,燕麦原料分析出14种挥发性风味化合物,经热烫、酶解、杀菌等加工处理后的燕麦乳中检测出30种化合物。结合各化合物的香气活度值(OAV)并进行主成分分析,发现己醛、2-戊基呋喃、正辛醛、壬醛、1-辛烯-3-醇、苯甲醛等挥发性物质对燕麦乳风味的贡献值较大。4种燕麦原料中ZBY01制得的燕麦乳感官评分最高、风味最佳,从其风味化合物组成上看,己醛、1-辛烯-3-醇、2-戊基呋喃等的含量较低,且可检出庚醛、壬醇等特殊香气成分。另通过对燕麦乳感官品质的总体评价,本研究初步筛选出适宜加工纯天然燕麦乳的适宜原料—ZBY01。