挤压预糊化淀粉的性能及其添加对糙米发糕品质的影响

通过挤压不同水分含量（45%、25%和18%）的大米淀粉制备预糊化大米淀粉,测定其分子量、结晶度、糊化度、水吸收指数、水溶解指数、冷糊黏度等指标,并考察了预糊化淀粉添加对糙米粉糊化特性及糙米发糕品质的影响。结果表明,与原大米淀粉相比,45%、25%和18%水分含量挤压制备的预糊化大米淀粉结晶度分别降低了51.93%、58.93%和59.04%;水吸收指数分别提高了1.56、4.69和6.11倍;水溶解指数分别提高了7.04、16.30和27.64倍;冷糊黏度分别提高了2.00、21.44和14.67倍。挤压还使大米淀粉分子发生降解,产生了更多的小链分子。预糊化大米淀粉性能变化与挤压过程中淀粉的水分含量有关。添加预糊化大米淀粉显著提高了糙米发糕的品质（P<0.05）,高的冷糊黏度和低的分子量（18%水分挤压）更有利于制备比容大（1.64 cm3/g）、孔洞细腻均匀、硬度低（338.59 g）和有弹性的糙米发糕。     

Effect of steaming time on the linear expansion of fish crackers (‘keropok’)

The effect of steaming time on ‘keropok’ was studied. The morphology of the starch granules in keropok gel at different steaming times was examined using scanning electron microscopy (SEM). There was an optimum time for the steaming of keropok which gave the best linear expansion and hardest texture of steamed gel. This occurred when the starch granules were expanded to their largest sizes and before fragmentation of the granules. A steaming time of 20–30 min is sufficient to cook the keropok gel. Excessive steaming time will result in a poor-quality product as well as extra production costs. © 1999 Society of Chemical Industry     

不同品种山药蒸制过程中淀粉消化率及抗氧化活性

本实验以不同品种山药的淀粉相关特性、生物活性成分、抗氧化能力和微观结构为评价指标,研究蒸制时间对铁棍山药、淮山药、糯山药3种山药的营养品质和抗氧化活性的影响,并探究山药微观结构和品质变化的内在联系。结果表明,蒸制处理后,3种山药样品中的总淀粉质量分数和抗性淀粉质量分数均显著减少（P<0.05）,但可消化淀粉（快消化淀粉和慢消化淀粉）及表观直链淀粉质量分数显著增加（P<0.05）,同时山药淀粉的持水力增强,溶解度下降。3种山药中,蒸制15 min的淮山药总可溶性多酚和总黄酮含量最高,分别为1.04 mg/g和0.83 mg/g,同时,其抗氧化能力也最强,铁离子还原力、1,1-二苯基-2-苦基肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除率和羟自由基清除率分别为165.56?μmol/g、58.15%和82.26%。扫描电子显微镜观察发现,蒸制后山药样品颗粒呈特征性的块状和不规则的结构,表面粗糙并有裂缝。综合比较,蒸制时间对3种山药样品的品质特征及活性成分的影响差异较大,蒸制15 min后山药样品的总可溶性多酚和总黄酮含量最高,抗氧化活性也...     

Evaluation of air-dried soy protein isolate-rice noodles prepared via combined treatment with microbial transglutaminase and glucono-δ-lactone

In this study, the effects of steaming treatments during the preparation of structurally enhanced air-dried rice noodles were investigated. Soy protein isolate-rice noodles (RNS) were combined (COM) with microbial transglutaminase (MTG) and glucono-δ-lactone (GDL), and steamed for 5 (S5) or 10 (S 10) min followed by air-drying to yield air-dried RNS-COM-S5 and RNS-COM-S10, respectively. Control samples were air-dried rice flour noodles (ADRN), steamed for 5 or 10 min before air-drying (ADRN-S5 and ADRN-S10). Compared to other air-dried RNS prepared without steaming, RNS-COM-S5 and RNS-COM-S10 showed a reduction in cooking time (5.35 min) and cooking loss (7.11%) and increased cooking yield (125%), supposedly due to low gelatinisation enthalpy, while retaining textural and mechanical properties, significantly higher (P < 0.05) than the controls. The scanning electron micrographs showed that all steamed air-dried noodles also had larger hollows, which could be responsible for the improved cooking qualities. In general, the relative order of starch crystallinity resulting from steaming treatment decreased in all steamed noodles, and RNS-COM1-S10 showed the highest order. The treatment of RNS with MTG and GDL yielded air-dried noodles with a more compact structure. Steaming is necessary to improve the rehydration characteristics of the air-dried noodles without sacrificing textural and mechanical qualities.     

真空联合超声对大米吸水和蒸饭特性的影响

浸泡和蒸饭是黄酒等米制品生产中的重要环节。浸泡不仅耗时而且影响蒸饭过程,导致出现米饭夹生或过熟等现象,影响后续的糖化和发酵过程。为了提高大米的吸水速度,改善米饭的糊化效果,采用真空超声同时处理、先真空后超声处理和先超声后真空处理对大米进行浸泡处理,研究其对大米吸水特性和蒸饭特性的影响。结果发现：先真空后超声处理能加速水分的渗透和扩散,降低大米的硬度,显著缩短大米的蒸饭时间,抑制米饭的老化。本研究为先真空后超声处理在黄酒生产中的应用提供了参考。     

不同全麦粉替代率对冷冻馒头品质的影响研究

目的 探讨不同全麦粉替代率对冷冻馒头品质影响的变化规律.方法 采用不同比例全麦粉(0、10％、20％、30％、40％、50％、60％、70％、80％、90％、100％)替代小麦粉,测定了混合粉的湿面筋含量和流变学特性,对比新鲜馒头,评价全麦粉替代率对冷冻馒头外观、质构和感官品质的影响.结果 随全麦粉替代率增加,面团湿面...     

面条蒸制过程中水分迁移及糊化特性

运用低场核磁共振、核磁成像、快速黏度分析和光学显微镜研究蒸制过程中面条的水分分布、迁移、糊化特性及微观结构的变化。对水分含量、弛豫时间（T2）、质子密度（M2）和糊化特性进行相关性分析。结果表明：面条中的水分主要以弱结合水的形式存在。在蒸制过程中,水分由面条外部向内部迁移,总水分、弱结合水和深层结合水含量整体呈现先增加后稳定的趋势,深层结合水增长趋势缓慢;弱结合水自由度逐渐增大。面条峰值黏度、衰减值随蒸制时间延长呈下降趋势。观察面条微观结构发现,蒸制使面条淀粉糊化,体积变大,表层淀粉糊化程度高于内层。相关性分析结果表明,水分含量与T22、M22和M总呈极显著正相关（P＜0.01）;水分含量、T22、M22及M总均与峰值黏度、衰减值、最终黏度呈显著负相关（P＜0.05）或极显著负相关（P＜0.01）。     

Laboratory Process Development and Physicochemical Characterization of a Low Amylose and Hydrothermally Treated Ready-to-Eat Rice Product Requiring No Cooking

A low amylose and hydrothermally treated ready-to-eat rice product that requires no cooking was prepared in the laboratory. Hot soaking for 1–3 min with subsequent variable steaming at open and under pressures remarkably altered the kernel and flour properties. Increase in water absorption and lowering of cooking time with extent of steaming were prominent. Soaking of the product at 50 °C for 20 min gave texture values more similar to cooked samples. The viscosity parameters of hot soaking alone were in between those of hot soaking with open steaming and pressure steaming. Pressure steamed samples exhibited almost constantly increasing slurry viscosity throughout the heating and cooling phases of the rapid viscosity analyzer profile. Steaming variably altered the native A-type X-ray diffraction pattern. Pressure steaming of samples with 3 min hot soaking caused complete loss of the A-type conformation with feeble peaks for B- and V-type patterns. The open steamed samples showed peaks for all A-, B-, and V-type patterns. No endotherms for amylose-lipid complexes were however found in the differential scanning calorimetry of the pressure steamed samples. The raw rice flour was highly resistant to α-amylolysis. In open steamed samples, steaming severity decreased the hydrolysis rate indicating formation of enzyme-resistant fractions, while pressure steamed samples showed higher digestibility with treatment severity.     

不同改良剂对青稞全粉发糕品质的影响

传统青稞全粉发糕具有质地粗糙、硬度大等缺点,严重影响了其感官特性,因此,该研究结合已建立的青稞全粉发糕感官评价体系和现代分析技术初步探讨了黄原胶(xanthan gum,Xan)、瓜尔胶(guar gum,Guar)和改性木薯淀粉(modified cassava starch,Cas)对青稞全粉发糕品质的改良效果。结果显示:Xan、Guar和Cas的最佳添加量分别为0.2%、0.4%和4%,且添加0.4%Guar的感官评分最高(94.00);在最佳添加量下,三种改良剂均能提高青稞全粉浆的起糊温度并降低其热糊稳定性和冷糊稳定性(p0.05);三种改良剂均能提升粉浆的持水性,其中,0.2%Xan使强结合水增加16.68%,而0.4%Guar使弱结合水增加2.47%;0.2%Xan能将发糕切面的气孔表面分率和气孔稠密度分别减小至1.38%和0.07 mm-2,而0.4%Guar能使其分别增加至24.26%和0.50 mm-2;三种改良剂均能改善青稞全粉发糕的质构特性,其中,0.4%Guar使发糕的硬度显著降低至695.78g;三种改良剂均可通过降低青稞全粉发糕的硬度、黏附力、弹性、咀嚼性以及提升回复力的方式来改善其感官品质。研究结果可以为青稞全粉发糕的品质改良提供理论参考。     

加热时间对大米淀粉特性及抗性淀粉含量的影响

采用不同的加热时间对大米进行处理,并从加热处理过的大米中提取淀粉,采用电镜扫描仪、差示扫描量热仪、质构仪、流变仪等检测仪器研究加热时间对大米淀粉的颗粒形貌、热力学性质、凝胶特性、流变等性质的影响,采用酶解法测定加热处理过的大米中抗性淀粉的含量。结果表明：随着加热时间的延长,淀粉的膨润力与溶解度先增大后减小;加热时间在0～10min 时,抗性淀粉含量减少,其范围为18.01%～8.10%;淀粉颗粒由单个独立的颗粒逐渐膨胀至相互粘连,糊化焓值降低;硬度、延伸性等都有不同程度的变化;淀粉糊的剪切稳定性降低。     

Effect of soaking medium on the physicochemical properties of parboiled glutinous rice of selected Laotian cultivars

The effect of various soaking mediums, viz. water (control), 3% NaCl and 0.2% acetic acid, and without soaking on the physicochemical properties of parboiled selected glutinous (TDK8 and TDK11) and non-glutinous (Doongara) was investigated in the present study. Results showed that the chemistry of soaking had a significant effect on the head rice yield (HRY), grain hardness, crystallinity, color, pasting and thermal properties, textural attributes, and glycemic index of these rice varieties. Soaking with NaCl and acetic acid significantly increased the grain hardness and HRY than control and without soaking treatments. Acetic acid and NaCl soaking significantly affected crystalline regions of starch resulting in reduced crystallinity in X-ray diffraction analysis and thermal endotherms in DSC analysis. NaCl soaking induced swelling of starch granules resulting in high peak and final viscosities. However, acetic acid restricted swelling resulting in reduced peak and final viscosities. NaCl and acetic acid soakings also resulted in increased hardness and adhesiveness of cooked grains than normal water soaked and un-soaked parboiled rice samples. Interestingly, change in textural attributes was prominent in parboiled glutinous rice. The color difference value for fresh parboiled samples was significantly lower for acetic acid soaked samples compared to NaCl soaked and un-soaked samples probably due to bleaching effect of acetic acid. Moreover, parboiling also resulted in significant reduction in glycemic index of glutinous rice. These findings revealed the potential application of parboiling with modified soaking techniques to improve the grain quality.     

微波辐射下糙米质构及糊化特性响应机制的研究

采用连续式微波辐射装置对糙米进行处理,探讨微波辐射工艺对糙米质构特性与糊化品质影响,分析微波辐射后糙米糊化特性与质构特性的响应关联性。结果表明,微波辐射处理对糙米糊化特性及质构具有积极作用。处理后糙米糊化温度降低,黏度值、崩解值和回生值升高;蒸煮加工后的糙米饭硬度、弹性、胶着性和咀嚼性下降,黏着性上升,有利于口感提升。在微波辐射剂量为4.0 kW·kg~(-1),微波工作时间为60 s的工艺条件下,效果相对最优。研究表明,微波处理后糙米截面出现裂缝,颗粒状淀粉增多。同时,处理后的糙米籽粒内部,淀粉颗粒排列疏松且粗糙,形态发生改变,出现微孔及凹坑,增大了淀粉颗粒的溶胀程度,改善了糙米籽粒的糊化特性及质构特性。     

Effect of Sago Starch Addition and Steaming Time on Making Cassava Cracker (Keropok)

This work was aimed at investigating the effects of steaming time and different fractions of sago starch (0, 6, 12, 18 and 24%) in mixtures with cassava starch on the properties of crackers as compared to cassava crackers. In the hydrothermal process, the steaming period was varied from 25 to 120 min. The properties of raw starches, half‐finished crackers (HFC) and puffed crackers (PC) were determined. Raw cassava starch had lower amylose content, smaller granule size, lower gelatinization and lower swelling power than sago starch. The properties of the raw starch mixtures varied according to the mixing proportions. Both sago starch content and steaming time influenced cracker quality, especially its expansion, which was related to the degree of gelatinization (DG). Increasing sago starch content caused decreased DG of HFC and hence decreased cracker expansion. Two groups of HFC were obtained; low DG (55–65%, 25‐45 min steaming time) and high DG (>80%, 60‐120 min steaming time) HFC. Generally the expansion increased as the DG increased – however, a too long steaming period (> 75 min) again reduced expansion, apparently the thinner starch gel allowed collapse of the air cells. No treatment gave complete gelatinization; which could be due to insufficient water for starch to gelatinize.     

不同原料复配对双螺杆挤压马铃薯年糕品质的影响

本研究通过在粳米粉、糯米粉、籼米粉中分别添加不同比例的马铃薯全粉,在特定双螺杆挤压条件下测定不同原料配比对挤压年糕品质特性的影响。研究结果表明:随着马铃薯全粉添加比例的增加,糯米、籼米和粳米3组年糕L*值均减小,b*值均增大;添加马铃薯全粉后,糯米组年糕蒸煮损失最大,籼米组次之,粳米组最小,且随着马铃薯全粉添加比例的增加,蒸煮损失均逐渐增大。马铃薯全粉的添加使得3组年糕硬度、咀嚼性增加;糯米组粘性增加,但弹性没有显著性变化;粳米组粘弹性先增加后减小,在马铃薯全粉添加量为40%时,其粘弹性值达到最大。扫描电镜结果表明,糯米年糕结构较疏松,粳米年糕和籼米年糕结构较紧实,添加马铃薯全粉使得年糕结构更加紧实。感官评价结果表明,粳米组得分较高。综合以上结果,以粳米粉为原料,马铃薯全粉添加量为40%时,双螺杆挤压年糕食用品质较好。     

不同类型甘薯最佳烹饪方式评价

本研究通过评价甘薯不同食用方式下食味品质,明确不同鲜食品种的最佳食用方式及其与各品质指标的相关性。以干率、蛋白质、淀粉含量均较低的两个品种冀粉2号、烟薯25和干率、淀粉、蛋白质含量均较高的两个品种冀薯8号、冀元1号为材料,选择2种烹饪方式（烤制和蒸制）对薯块进行处理,采用感官评价、TPA测试、气相色谱-质谱联用（GC-MC）等方式对烤制和蒸制甘薯的口感、质构和香味成分进行测定分析。结果表明：薯块硬度、弹性、粘附性、咀嚼性、胶粘性在两种食用方式之间差异较大。相关性分析：干率与烤和蒸薯的内聚性、咀嚼性呈正相关;与淀粉、还原糖、可溶性糖呈负相关;蛋白质与烤和蒸薯的硬度、内聚性、胶粘性、咀嚼性呈正相关;与淀粉、还原糖、可溶性糖、烤和蒸薯的回复性呈负相关;淀粉与还原糖、可溶性糖、烤和蒸薯的弹性、回复性呈正相关;烤和蒸薯的咀嚼性、胶粘性呈负相关;还原糖与可溶性糖、烤和蒸薯的弹性呈正相关;与烤和蒸薯的硬度、咀嚼性 、胶粘性呈负相关;营养特性与质地指标具有一定的相关性。薯块烤制和蒸制共检测出49种香气物质,冀粉2号、冀薯8号香味物质烤制比蒸制分别多11、8种,冀元1号、烟薯25香味物质烤制比蒸制分别少3、1种;感官评价得出冀粉2号、烟薯25烤制口感比蒸制口感好;冀薯8号、冀元1号蒸制口感比烤制好。综合得出：干率、蛋白质含、淀粉含量均较低品种冀粉2号、烟薯25适合烤制;干率、蛋白质、淀粉含量均较高品种冀薯8号、冀元1号适合蒸制。     

粉蒸肉质构特性的研究

研究了酱油、水、食盐、白糖、腌制时间、蒸煮时间对粉蒸肉质构特性的影响。结果表明,酱油对带皮肥肉的弹性、凝聚性、回复性影响较小;水是影响带皮肥肉的凝聚性、耐嚼性和无皮肥肉的弹性和耐嚼性的主要因素;食盐主要影响带皮肥肉的凝聚性和无皮肥肉的回复性;白糖是影响无皮肥肉的硬度、回复性的主要因素;腌制时间主要影响带皮肥肉的硬度、耐嚼性和无皮肥肉的回复性;蒸煮时间是影响带皮肥肉弹性、凝聚性、无皮肥肉弹性、回复性的主要因素。酱油、腌制时间、蒸煮时间对瘦肉的弹性影响较小,加水量对瘦肉的回复性影响较小。除加水量以外的五个因素变化时,瘦肉的硬度差异显著(p<0.05)。     

Texture properties of rice cakes made of rice flours treated with 4-α-glucanotransferase and their relationship with structural characteristics

Rice flours were treated using a thermostable 4-α-glucanotransferase (GTase) from Thermus aquaticus for 1, 3, and 48 h. Molecular weight of modified rice starch rapidly decreased within 1 h of reaction, then slowed down. As the reaction proceeded, the proportions of short (<DP 11) and long (>DP 30) branched chains of modified starch increased, whereas the proportion of medium chains decreased. Rice cakes were prepared with native and GTase-treated rice flours (substitution at 5%) and kept for 3 and 21 h. Texture profile analysis indicated significantly increased hardness, adhesiveness, chewiness, and resilience in rice cakes containing treated rice flours. Sensory analysis revealed that the rice cakes containing 48 h-treated flour had significantly increased springiness, hardness, toughness, and adhesiveness during both storage periods. Meanwhile, it displayed the lowest starch-like attribute and crumbliness. These results suggested that the substitution for 48 h GTase-treated rice flour could retard the retrogradation of rice cakes.     

馒头的微波烹制工艺与特性研究

采用正交试验研究加水量、醒发时间、微波剂量和烹制时间对微波烹制馒头感官品质的影响,确定最佳工艺参数,并对比分析微波和蒸汽2种不同烹制方式下馒头的微观形貌、质构特性和消化特性。试验表明,微波烹制馒头的适宜工艺参数为:加水量为50 g/100 g小麦粉,醒发时间为35 min,采用2.76 W/g的微波剂量,烹制时间为2.5 min。在此工艺条件下所制作的馒头感官品质与蒸汽烹制馒头较为接近。与蒸汽烹制馒头相比,微波烹制馒头的口感稍劣;内部微观结构较为粗糙,孔洞均匀性稍差,孔壁较厚,局部区域略呈聚集状,部分网络结构有轻微程度的断裂;硬度、黏聚性和咀嚼度较大,弹性较小;淀粉消化率较高,蛋白质消化特性与之相近。     

Amylose Content of Rice and Quality of Fermented Cake

The use of aged milled rice with an intermediate amylose content (20–25%) in the preparation of fermented rice cake yielded a steamed cake with a greater volume and an optimum softness as compared with similar cakes prepared from rice with a lower or higher amylose content. Aging of the rice decreased gas (CO₂) retention during fermentation, but improved gas retention and cake volume during steaming.     

冻融淀粉对馒头品质的影响研究

摘 要 通过分离重组的方法研究冻融淀粉对重组面团加工特性及馒头品质的影响，并通过主成分分析阐明它们之间的相关性。结果表明：随着冻融次数的增加，破损淀粉含量由22.5%增至24.1%（P<0.05），淀粉分子排列从有序向无序状态转变；由重组面团微观结构的变化可知，冻融淀粉多以分散的形式裸露在面筋网络外部，面筋网络的连续性减弱，但弹性和黏性模量上升。此外，冻融淀粉所制备的馒头比体积由1.5 mL/g降至0.9 mL/g，感官总评分呈下降趋势，硬度和咀嚼度呈增大趋势（P<0.05）。这可能是由于冻融淀粉与面筋蛋白竞争性吸水，弱化了淀粉-面筋蛋白复合体的界面稳定性，使其形成不完整的面筋网络结构，最终致使馒头品质劣变。