不同品种鲜食型甘薯烘烤后品质的研究

为探究不同甘薯品种烘烤后的品质,以8个不同品种的甘薯为材料,测定其品种特征特性及烤制后的相关理化、感官、质构特性等指标,并对各指标进行相关性分析和主成分分析。结果表明,冀薯8号的干率最高,蛋白质含量最低;济薯26干率、总糖含量和淀粉含量均最低;冀薯7号总糖含量和淀粉含量最高;冀粉2号蛋白质含量最高;冀紫薯3号纤维素含量最高;冀元1号的纤维素含量最低。基于质构指标及主成分分析建立2个模型,得出8种甘薯质构综合得分由高到低依次为冀紫薯3号、冀粉3号、冀粉2号、烟薯25、济薯26、冀薯7号、冀元1号、冀薯8号。感官评价得出冀粉2号接受度最好,冀薯8号接受度最差。相关性分析表明营养品质、质地品质及感官品质之间具有一定的相关性。综合分析得出冀粉2号为8个甘薯品种中最优品种,其次是烟薯25、冀紫薯3号、济薯26、冀粉3号、冀薯7号、冀元1号、冀薯8号。     

不同熟化方式下甘薯果胶含量与质构相关性分析

目的 比较分析不同品种的甘薯在不同熟化方式下果胶含量的差异以及与质构指标的相关性。方法 采用咔唑比色法对甘薯中的可溶性果胶含量和原果胶含量进行测定,并测定了生、熟薯块的质构指标。结果 不同甘薯品种的生、烤和蒸薯中均含有可溶性果胶和原果胶,且各品种的果胶含量存在差异。在生薯的果胶含量中,原果胶含量最高;在烤薯和蒸薯的果胶含量中,可溶性果胶含量最高。参试品种的生薯、烤薯和蒸薯的质构指标间差异性较大。在生薯中,冀元2号的硬度最高,冀元1号的黏附性最大,冀元2号的胶黏性最大;烤薯中冀薯9号的硬度最大,慧谷2号的弹性最大,普薯32号的内聚性最高;蒸薯中慧谷2号的硬度最大,哈密的弹性最大,冀元1号的胶黏性最大。相关性分析结果表明,质构指标与可溶性果胶含量、原果胶含量之间存在着较好的相关性:生薯的原果胶含量与干物率呈极显著正相关,与黏附性呈极显著负相关;烤薯可溶性果胶含量与原果胶含量之间呈显著负相关;蒸薯的可溶性果胶含量与弹性呈显著正相关,原果胶含量与回复性呈显著负相关。结论 该研究结果可为甘薯品种适宜加工方式的选择和评价,以及后续甘薯新品种的选育提供参考。     

不同品种甘薯烘烤后感官、质构及香气成分的差异

选取五个品种甘薯为实验材料,研究了甘薯烘烤后理化指标、感官评分、香气成分、质构特性的差异。理化测定得出,受试品种中淀粉型甘薯蛋白质含量低于鲜食型甘薯;淀粉型甘薯总糖含量低于鲜食型甘薯;鲜食型甘薯中红瑶的总糖含量最高。感官评价得出鲜食型甘薯中红瑶、普薯32烘烤后口感较好,淀粉型甘薯中冀粉1号烘烤后口感较好;红瑶的口感最佳。质构及相关性分析得出,整体口感分别与咀嚼性、内聚性呈显著负相关（P<0.05）。红瑶的内聚性、咀嚼性数值最低,因此红瑶的口感最好。GC-MS及PLSDA分析得出,苯甲醛、苯乙醛、壬醛、橙花醇、大马士酮、芳樟醇、4-乙烯基-2-甲氧基苯酚、α-萜品烯等物质为品种间共有香气组分;芳樟醇、癸醛、2-莰烯、壬酸、糠醛五种香气成分为甘薯重要香气成分。综合得出,受试品种中最适合用于烘烤的品种为红瑶。     

加工方式对红薯淀粉体外消化性的影响

本文研究了在蒸、煮、炸、烤以及微波烤制5种加工方式对红薯水分含量、还原糖含量和淀粉的体外消化率的影响。结果发现微波烤制、煮制和蒸制对红薯水分含量的影响不明显,而烤制和油炸使红薯水分含量明显降低。5种方式处理后红薯的还原糖含量分别为微波烤制30．38％、煮制24．75％、蒸制27．31％、烤制7．2％和油炸4．77％。对比几种加工方式对红薯中淀粉的体外消化性的影响来说,微波烤制、煮制和蒸制的红薯中淀粉的体外消化性较好,且以煮制最好：而烤制和油炸红薯中淀粉的体外消化性相对较差。     

加工方式对红薯淀粉体外消化性的影响

本文研究了在蒸、煮、炸、烤以及微波烤制5种加工方式对红薯水分含量、还原糖含量和淀粉的体外消化率的影响。结果发现微波烤制、煮制和蒸制对红薯水分含量的影响不明显,而烤制和油炸使红薯水分含量明显降低。5种方式处理后红薯的还原糖含量分别为微波烤制30．38％、煮制24．75％、蒸制27．31％、烤制7．2％和油炸4．77％。对比几种加工方式对红薯中淀粉的体外消化性的影响来说,微波烤制、煮制和蒸制的红薯中淀粉的体外消化性较好,且以煮制最好：而烤制和油炸红薯中淀粉的体外消化性相对较差。     

不同熟制方式影响紫薯感官品质的机制研究

选取了泰紫薯1号、紫罗兰、越南小紫薯三种代表性鲜食紫薯品种为实验材料,以普薯32为对照,探究了烤制、蒸制、微波三种熟制方式处理后紫薯的感官评分、水分含量、淀粉含量、糖含量等指标。结合相关性分析和偏最小二乘回归法（Partial Least Squares Regression,PLSR）探究了消费者感官评价和理化指标之间的相关性关系。感官评价结果显示,蒸泰紫薯1号得分最高,甜度和质地是决定消费者喜好程度的驱动型属性;熟制方式显著影响紫薯的理化品质,熟制后紫薯水分和淀粉含量降低,还原糖和总糖含量升高。蔗糖和麦芽糖在熟制后增加,葡萄糖和果糖随品种和熟制方式呈现不同变化趋势。在熟制过程中,蒸制有利于水分保持,烤制最有利于高温糖化。相关性分析发现感官评价得分与水分、还原糖（果糖、葡萄糖）呈极显著正相关性（P<0.01）,与淀粉含量呈显著负相关性（P<0.05）,相关性大小依次为还原糖、淀粉、果糖、葡萄糖、水分。PLSR确定了影响紫薯感官品质的主要指标为还原糖、果糖、葡萄糖。本研究为建立紫薯感官预测模型、开发不同紫薯品种最佳加工工艺、指导鲜食型紫薯的选育提供一定的科学依据。     

不同加工方式下红薯中还原糖的动态变化研究

本文研究了不同加工方式（包括蒸、煮、炸、烤及烘干）对红薯中还原糖含量的动态影响。煮制、微波烤制和烤箱烤制过程中,红薯中还原糖含量先降低,而后增加,在处理末期又呈下降趋势;蒸制过程中,红薯中还原糖含量随处理时间的延长而持续增加;油炸和烘制过程中还原糖含量总体呈下降趋势;蒸制、煮制、微波烤制和烤箱烤制对红薯中水分含量的影响不明显;而油炸过程中红薯片中的水分含量随加热时间延长持续降低;而烘制过程中红薯中水分丢失主要发生在2～4h内。     

鲜甘薯理化品质与乙醇产量多元回归分析

选用11个具有代表性的甘薯品种(系),对甘薯干率、淀粉、蛋白质、可溶性糖和还原糖等理化,品质性状与乙醇产量进行相关和回归分析。试验结果表明,不同品种甘薯乙醇产量和发酵效率差异极显著,徐薯22乙醇产量最高,而苏渝303发酵效率最高;乙醇产量与干率呈极显著正相关(r=0.842,P0.01),与淀粉和蛋白质含量呈显著正相关(r=0.671,P0.05;r=0.714,P0.05),而与可溶性糖和还原糖含量之间没有达到显著性;乙醇产量与甘薯淀粉、蛋白质含量之间线性关系较好,并建立了多元回归方程(R=0.860,P0.01)。     

基于热风干燥条件下新疆红枣的质构特性

以新疆主栽制干品种骏枣、灰枣和哈密大枣为研究对象,探讨热风干燥条件下各品种间的基本营养成分与质构特性。并通过DPS和SPSS软件分析了这3种红枣间不同指标的差异,结果表明:3个品种总糖含量均≥59%,除还原糖含量外,其它各营养成分差异不显著(p>0.05);3个品种间的主要质构指标:硬度、回复性、内聚性、弹性、胶粘性、咀嚼性,存在显著性差异(p<0.05);糖、水分与质构特性有明显的相关性,即:红枣中水分与弹性负相关R=-0.934、还原糖与咀嚼性呈正相关R=0.989,通过质构指标的主成分分析得出,红枣的质构特性构成主要在第一和第二主成分上,其中在第一主成分中胶粘性、硬度和咀嚼性三个指数所占权重系数分别为0.935、0.886和0.885,第二主成分中,弹性权重比较大为0.975,由此得出胶粘性、硬度、咀嚼性、弹性四种指标可基本评价红枣的质构特性。     

卷烟及烟草薄片原料、半成品、成品的成分对比研究

对比分析了卷烟、烟草薄片原料、半成品、成品中的还原糖、可溶性糖、淀粉和蛋白质等物质,寻找烟草薄片工艺改进方向。分别采用经典的DNS法对上述样品中的还原糖、可溶性糖、淀粉等成分进行定量分析,采用国家标准GB5009.5-2010对其中蛋白质进行定量分析。同一样品平行性较好,四种成分在卷烟、烟梗、烟末、木纤维、片基、未烤薄片、薄片中含量有明显差别。结果表明,水溶性成分在薄片加工过程中损失率加大。与卷烟相比,薄片原料及半成品、成品中的淀粉、蛋白质等不良组分含量较低。     

不同品种甘薯淀粉加工特性及其与磷含量的相关性研究

对24个甘薯品种的淀粉含量、干率、可溶性糖含量、淀粉的黏度特征谱和磷含量进行了比较研究。结果表明:试验品种薯块的平均淀粉含量为22.14%,以渝薯1号最高,达31.45%;平均干物质率为31.38%,品种之间的差异较小;平均可溶性糖含量2.32%,以秦薯5号最低,为0.42%;褐变指数7.00~20.01,最低的为渝薯27;淀粉糊化温度范围为66.8~77.1 ℃,秦薯9号、苏薯24、烟薯26和济薯25淀粉的糊化温度均低于70 ℃;淀粉峰值黏度最高的品种为运薯271,达1207 BU;崩解值最低的品种为桂粉3号,为381 BU;回生值最低的品种为秦薯5号,为241BU;淀粉磷含量82~231 mg/kg,与峰值黏度极显著正相关(p<0.01)。建议进行淀粉类产品加工时,根据产品所需的特征参数选择合适的品种,实现物尽其用。受试甘薯中,以渝薯1号、渝薯27、济薯25和苏薯24的综合加工特性较好,推荐作为育种亲本。     

Effect of Thermal Treatment on Selected Cereals and Millets Flour Doughs and Their Baking Quality

Selected cereals (rice and sorghum) and millets (finger millet and pearl millet) were steamed for 20 min at ambient pressure. The rheological properties of doughs, made from these steamed as well raw grain flours, were characterized in addition to examining their baking quality. The two-cycle compression test was employed and instrumental values were correlated with sensory attributes (color, aroma, taste, stickiness, chewiness, tearing strength, cohesiveness, and rollability) using principal component analysis (PCA). Rice doughs made from both raw as well as thermally treated flour imparted maximum hardness (96.6–99.3 N) and least cohesiveness (0.05–0.09) with highest stickiness values (105–110°) among all the dough samples at the same moisture content. Pearl millet and raw sorghum flour doughs possessed the least instrumental hardness, adhesiveness, and stickiness and were the easiest to flatten. The PCA biplot showed that sensory and instrumental cohesiveness formed a cluster on the left side on the x axis while shear force, and sensory attributes like tearing strength, chewiness, stickiness, and rollability formed another cluster on the other side of the axis. Raw rice and finger millet doughs were associated with the high extent of instrumental and sensory stickiness. Thermally treated pearl millet and sorghum doughs were the best followed by treated rice and finger millet samples to give the desirable dough characteristics, and were quite close to wheat chapathi in texture.     

Influence of Heat Pretreatments of Oat Grain on the Viscosity of Flour Slurries

Heat treatment of oat grain had significant effects on the viscosity of flour slurries. Steamed oats produced highly viscous flour slurries, whose viscosity increased with time, whereas the viscosity of flour slurries produced from raw or roasted (104°C for 120 min) oats was much lower and degraded rapidly. Slurry viscosity was correlated with (1→3), (1→4)-β-D -glucan concentration in the flours and treatment of slurries with lichinase lowered viscosity significantly. Effects of steaming were partially reversed by roasting treatment and vice versa. Mixtures of equal amounts of raw and steamed flour resulted in slurries more viscous than either flour alone, but that viscosity degraded after 3 h to less than the mean viscosity of the steamed and raw controls. Water-soluble extracts from steamed flour had about twice the viscosity of raw or roasted flour extracts, but contained only 80% of the (1→3), (1→4)-β-D -glucan present in those extracts. Molecular weight analysis of soluble carbohydrates from raw, roasted and steamed soluble extracts indicated the molecular weight of β-glucans in these extracts was similar. However, if extracts were made from slurries that had incubated for 3 h, extensive degradation of β-glucans was evident in raw and roasted samples. It is likely that enzymic degradation of (1→3),(1→4)-β-D -glucans is responsible for much of the decreased raw and roasted flour slurry viscosity over extended time periods, but different heat treatments appear to also affect (1→3), (1→4)-β-D -glucan polymer interaction. © 1997 SCI.     

熟化方式对酱卤风味牛肉品质及多环芳烃含量的影响

比较蒸制、煮制、炸制、煎制、烤制和微波6 种熟化方式对酱卤风味牛肉品质（感官评分、色泽、质构、水分含量、pH值、脂肪氧化）和化学危害物多环芳烃（polycyclic aromatic hydrocarbons,PAHs）含量的影响。结果表明：烤制、蒸制、煮制熟化酱卤风味牛肉色泽品质较好;烤制、煎制和炸制熟化酱卤风味牛肉水分含量偏低,且与其他组有显著差异（P＜0.05）;蒸制熟化酱卤风味牛肉很好地保持了水分含量,具有较好的质构特性;烤制、炸制熟化酱卤风味牛肉的脂肪氧化程度偏高（P＜0.05）,而蒸制熟化酱卤风味牛肉的脂肪氧化程度最低;与其他熟化方式相比,蒸制熟化酱卤风味牛肉的感官评分较高;烤制、煎制、炸制熟化酱卤风味牛肉中苯并(a)芘、苯并(a)蒽、苯并(b)荧蒽及?4 种PAHs的总含量均高于7.0 μg/kg,蒸制、微波熟化组约为3.1 μg/kg。综合评估得出,蒸制是一种有效的酱卤风味牛肉熟化加工方式,牛肉品质与传统卤煮牛肉更为接近。     

蒸烤模式对南美白对虾食用品质的影响

以南美白对虾为研究对象,以色差值、质构品质、游离氨基酸含量及感官评分为指标,通过色彩色差计、物性测试仪、氨基酸专用高效液相色谱仪以及感官评价法考察不同蒸烤模式(纯蒸、纯烤、先蒸后烤、先烤后蒸、蒸烤交替)对虾肉食用品质的影响.结果表明:先烤后蒸模式下虾皮和虾肉的L*值显著低于其他4种模式(P<0.05);纯烤模式下虾的硬...     

蒸制时间对滇黄精色泽、可溶性成分及糖含量的影响

黄精炮制的关键工序是蒸制。为此研究了蒸制时间对产品色泽、可溶性成分及糖含量的影响,并模拟胃肠道环境试验了糖含量的变化。结果表明:色泽随蒸制时间的延长而加深;蒸制24 h,80%vol乙醇可溶性成分增加极显著(p<0.01),达到70.79%,而水溶性成分减少极显著(p<0.01),降至9.52%;滇黄精不含淀粉;蒸制48 h葡萄糖和还原糖含量分别增加达到4%和47.84%,变化都极显著(p<0.01);蒸制12 h粗多糖含量最高,达到9.73%,继续蒸制到24 h粗多糖含量下降到4.26%,变化极显著(p<0.01);模拟胃肠道环境后,葡萄糖、粗多糖含量变化不显著(p>0.05),还原糖含量变化显著(p<0.05)。综上,需要得到粗多糖含量高,葡萄糖含量低的黄精产品蒸制时间应小于12 h,需要得到还原糖、可溶性成分多的黄精产品应蒸制24~48 h。     

Volatile Compounds of Roasted and Steamed Malaysian Tropical Almond Nut (Terminalia catappa L.)

The flavor extract components contributing to the characteristic aroma notes of roasted and steamed tropical almond nuts were investigated by means of gas chromatography-olfactometry and mass spectrometry of solvent extracts. Roasting and steaming data revealed all of the main classes of compounds commonly listed as thermally generated flavors in oily seeds. A total of 72 volatile compounds were identified in the sample from roasted nuts; among these were 27 hydrocarbons, 12 aldehydes, 12 ketones, 8 acids, 4 esters, 3 alcohols, 3 furans, and a pyrazine. The steamed nuts, however, yielded 66 peaks from which 63 volatile compounds were identified (22 hydrocarbons, 9 aldehydes, 9 ketones, 9 esters, 4 acids, 9 alcohols, and a pyrazine). The small number of aldehydes, ketones, pyrazine, and alcohols identified are the ones most likely to contribute to the aroma of the nuts.     

米茶的焙炒工艺研究

以碎米为原料,经浸润焙炒等工序制得米茶,研究米茶焙炒工艺对米茶茶汤感官品质的影响。结果表明,米茶茶汤的色彩是在焙炒过程中形成的,茶汤以黄色为主,略带绿色,透明度较高。较长的焙炒时间和较低的加水量有利于增强茶汤黄绿色和色彩纯度,使感官品质增加。米茶茶汤的色泽、滋味、香气与红度呈显著的负相关,与黄度、彩度呈显著的正相关。适宜的工艺为,按碎米质量的5%加水浸润5 min,于150℃下焙炒40 min,用该工艺制作的米茶的汤汁清亮,具有浓郁的稻米焦香风味。