湿热处理对大米淀粉理化性质及其米线品质的影响

以大米淀粉为原料,研究湿热处理对大米淀粉理化性质以及米线品质的影响。结果表明:与未处理大米淀粉相比,湿热处理后,大米淀粉的热学特性中T_0、T_P、T_C、T_C_T0、ΔH均增大;淀粉晶型仍为A型,结晶度增加4.14%;淀粉溶解率和膨润力显著降低,直链淀粉含量显著升高;淀粉糊化黏度、衰减值和回生值明显降低;淀粉凝胶硬度、弹性和耐咀嚼性增强;淀粉白度由89.7降低至80.3;添加20%湿热处理大米淀粉制作的米线感官品质和质构特性得到显著改善,断条率和蒸煮损失率分别降低5.67%,10.13%;大米淀粉溶解率、膨润力、溶解率、凝胶特性和糊化特性可有效预测米线品质。     

Effect of heat-moisture treatment on the formation and physicochemical properties of resistant starch from mung bean (Phaseolus radiatus) starch

Mung bean starch was subjected to a range of heat-moisture treatments (HMT) based on different moisture contents (15%, 20%, 25%, 30%, and 35%) all heated at 120 °C for 12 h. The impact on the yields of resistant starch (RS), and the microstructure, physicochemical and functional properties of RS was investigated. Compared to raw starch, the RS content of HMT starch increased significantly, with the starch treated at 20% moisture having the highest RS content. After HMT, birefringence remained at the periphery of the granules and was absent at the center of some granules. The shape and integrity of HMT starch granules did not change but concavity was observed under scanning electronic microscopy. Apparent amylose contents of HMT starch increased and the HMT starch was dominated by high molecular weight fraction. Both the native and HMT starches showed A-type X-ray diffraction pattern. Relative crystallinity increased after HMT. The gelatinization temperatures (To, Tp, and Tc), gelatinization temperature range (Tc–To) and enthalpies of gelatinization (ΔH) increased significantly in HMT starch compared to native starch. The solubility increased but swelling power decreased in HMT starches. This study clearly shows that the HMT exhibited thermal stability and resistance to enzymatic hydrolysis owing to stronger interactions of starch chains in granule.     

Hydrothermal treatments of Finger millet (Eleusine coracana) starch

The effect of hydrothermal treatments on the properties of Finger millet starch was investigated. Finger millet was modified by heat-moisture treatment, HMT at 100 °C, 16 h; 20% moisture level (MHT-20), 25% moisture level (MHT-25) and 30% moisture level (MHT-30) and annealed, ANN at 50 °C for 48 h (MAN). Results of the pasting characteristics shows that MNS and MAN were indicative of type ‘B’ starch which is characteristic of normal cereal starches, while HMT starches were Type ‘C’ which is characteristics of cross-linked or legume starches. MNS belonged to the type ‘A’ pattern of cereal starches. X-ray diffractometry studies (XRD) show that MNS gave strong peaks centered at 23.5, 20.3, 18.2, 17.15, and 15.15 Å, while HMT and ANN starches retained the typical ‘A’ pattern. Scanning electron microscopy (SEM) studies show that the shape and surface characteristics of the starches were irregular, polygonal-shaped granules, with less than 1% cavity or ruptured granules. Modification did not affect the appearance. All the starches swell as the temperature increased in the order MNS>MAN>MHT-20>MHT-25>MHT-30, and solubilized at different rate in the following order: MHT-30>MHT-20>MHT-25>MAN>MNS. The gelation profile of the starches ranged from 4 to 8% (w/v), while its oil and water absorption capacity ranged from 1.90 to 2.50 and 2.75 to 3.25 g/g, respectively.     

Effect of heat-moisture treatment on rice starch of varying amylose content

The effect of heat-moisture treatment (HMT) on the properties of rice starches with high-, medium- and low-amylose content was investigated. The starches were adjusted to 15%, 20% and 25% moisture levels, and heated at 110 °C for 1 h. The swelling power, solubility, pasting properties, morphology, enzymatic susceptibility and X-ray crystallinity of the starches were evaluated. HMT reduced the swelling power and solubility of the starches. The strongest effect of HMT occurred on the high-amylose starch; the pasting temperature was increased and the peak viscosity, breakdown, final viscosity and the setback were reduced. HMT increased the starch’s susceptibility to α-amylase and promoted a reduction in the starch relative crystallinity.     

两种大米淀粉及其磷酸酯淀粉理化特性的比较研究

对比分析2种大米(籼米和粳米)的全粉、淀粉和取代度均为0.068的磷酸酯淀粉的理化特性.粳米的全粉、淀粉和磷酸酯淀粉的膨胀力分别为7.5,10.7,21.6 g/g,分别高于籼米的全粉、淀粉和磷酸酯淀粉的膨胀力(5.8,8.9,17.4 g/g).2种大米淀粉经磷酸酯化后透光率增高,相应淀粉的透光率次之,全粉的透光率最低,籼米的全粉、淀粉和磷酸酯淀粉的透光率分别低于粳米的全粉、淀粉和磷酸酯淀粉的透光率.经快速黏度分析仪测定的糊化特性结果表明,淀粉或变性淀粉膨胀力高,其峰值黏度和崩解值也高,此外,蛋白质含量和直链淀粉含量也极大的影响了淀粉的糊化特性.使用动态流变仪测定的流变特性表明,在相同的温度下,籼米的全粉、淀粉和变性淀粉的储能模量(G')分别比粳米的全粉、淀粉和变性淀粉的储能模量(G')高,对于相同的大米品种,全粉的储能模量(G')最高,变性淀粉的储能模量(G')最低.     

Effect of mechanically damaged starch on wheat flour,noodle and steamed bread making quality

Wheat flour was ground in an ultrafine pulveriser to obtain different levels of damaged starch (DS). The effect of DS content on physicochemical properties of flour and quality attributes of Chinese noodles and northern‐style Chinese steamed bread were investigated. Results showed that the degree of starch damage raised from 6.54% to 12.06% as grinding intensity increased from 0 to 130 Hz (P < 0.05). The falling number, sedimentation value, starch pastes' viscosity, dough proofing stability were negatively, while water absorption, pastes thermal stability, the degree of starch pastes and dough level were positively correlated with DS content, respectively (P < 0.05). The increase in DS content from 6.54% to 8.86% did not lead to a deterioration of texture characteristic, which might be attributed to the slight declining in hardness while enhancing in springiness and cohesiveness. The flour with DS content of 6.54–9.66% was suitable for steamed bread making.     

湿热处理改善红薯粉条品质的优化工艺研究

红薯淀粉糊化特性回生值是影响红薯粉条品质的关键因素,湿热改性技术对红薯淀粉粉条品质有明显的改善效果。为了提供一种绿色安全高效生产粉条用的红薯淀粉产品,试验以红薯淀粉回生值为响应值,根据单因素试验结果建立Box-Behnken模型对改性技术进行优化。利用响应面分析法探讨红薯淀粉含水量、湿热处理温度和湿热处理时间3因素对湿热改性红薯淀粉回生值的影响。优化的工艺条件为:红薯淀粉含水量34%、湿热处理温度105.8℃、湿热处理时间1 h。在此条件下得到的湿热改性红薯淀粉制备的粉条品质显著(P0.01)的优于原红薯淀粉粉条。湿热改性红薯淀粉粉条品质中的断条率比原淀粉粉条下降70%,而粉条硬度和粉条拉伸强度有显著性的增加,由原来的23.91、0.79 N分别增加到30.81 N和1.71 N。结果表明湿热处理不仅使红薯淀粉粉条耐煮不糊汤,而且粉条弹韧性能也增强。研究用响应面法优选出的改性工艺合理可行,为产业化应用提供了参考。     

Effect of starch and non-starch components on water migration,microstructure, starch retrogradation and texture of flat rice noodles made from different rice varieties

Effects of starch and non-starch components on rice noodle quality, water migration during rehydration, texture, microstructure and starch retrogradation of dried rice flour and rice starch noodles made from five rice varieties with similar high amylose contents were examined. Rice noodle qualities depended mainly on starch properties and to a lesser extent on the presence of non-starch components. Elongation of rice flour noodles was lower than rice starch noodles due to the presence of non-starch components that interrupted the starch network. Non-starch components reduced cooking loss of flour noodles in some varieties. Water migration in rice flour noodles with a looser microstructure was faster than in rice starch noodles. Nuclear magnetic resonance imaging revealed different water migration speeds in rice flour noodles among varieties, related to noodle microstructure and retrogradation properties. For production of good quality rice noodles, manufacturers should consider not only amylose content but also non-starch components.     

Microstructural and physicochemical properties of heat-moisture treated waxy and normal starches

Starches from normal rice (21.72% amylose), waxy rice (1.64% amylose), normal corn (25.19% amylose), waxy corn (2.06% amylose), normal potato (28.97% amylose) and waxy potato (3.92% amylose) were heat-treated at 100 °C for 16 h at a moisture content of 25%. The effect of heat-moisture treatment (HMT) on morphology, structure, and physicochemical properties of those starches was investigated. The HMT did not change the size, shape, and surface characteristics of corn and potato starch granules, while surface change/partial gelatinization was found on the granules of rice starches. The X-ray diffraction pattern of normal and waxy potato starches was shifted from B- to C-type by HMT. The crystallinity of the starch samples, except waxy potato starch decreased on HMT. The viscosity profiles changed significantly with HMT. The treated starches, except the waxy potato starch, had higher pasting temperature and lower viscosity. The differences in viscosity values before and after HMT were more pronounced in normal starches than in waxy starches, whereas changes in the pasting temperature showed the reverse (waxy > normal). Shifts of the gelatinization temperature to higher values and gelatinization enthalpy to lower values as well as biphasic endotherms were found in treated starches. HMT increased enzyme digestibility of treated starches (except waxy corn starch); i.e., rapidly and slowly digestible starches increased, but resistant starch decreased. Although there was no absolute consistency on the data obtained from the three pairs of waxy and normal starches, in most cases the effects of HMT on normal starches were more pronounced than the corresponding waxy starches.     

Physicochemical Properties of Canna edulis Ker Starch on Heat-Moisture Treatment

Canna edulis Ker starch was modified by heat-moisture treatment at moisture levels ranging from 18 to 27 g/100 g starch and its physicochemical properties were investigated. Amylose content, swelling power, solubility as well as water and oil absorption capacity in native starch were higher than in all treated starches. However, alkaline water retention and acid susceptibility of native starch were lower, along with different extent of amylose leaching. The result in the X-ray diffraction measurement revealed that the crystalline type of the starch gradually changed from B-type to A-type, and the degree of crystallinity changed. Investigation on thermal properties showed that the gelatinization enthalpy decreased, whereas the onset temperature, peak temperature, concluding temperature and transition temperature range increased in modified starch than in native starch. In addition, all modified starches exhibited remarkably low values of peak viscosity, hot pasting viscosity and final viscosity, compared to those of native starch.     

高纯度大米蛋白和淀粉的分离提取

高纯度的大米蛋白和大米淀粉可以作为大米综合利用的两个主产品，本研究采用碱法将大米蛋白和淀粉分离，研究表明最适提取条件是：NaOH求度0．05N，提取2h此条件下分离体系不受破坏，且大米蛋白的蛋白含量可达94.03％(干基)，蛋白得率63．37％；大米淀粉中蛋白含量0．39％(干基)，淀粉得率47．87%。     

Suitability of pigeon pea and rice starches and their blends for noodle making

The physicochemical and pasting properties of pigeon pea and rice starches were studied to assess their suitability for noodle making. Amylose content, solubility and freeze thaw stability of pigeon pea starch were significantly higher than those of rice starch (p < 0.05). The pasting properties of peak viscosity, final viscosity, breakdown and set back showed higher values for pigeon pea starch, whereas hot paste viscosity and pasting temperature were higher for rice starch. Rice starch noodles revealed less cooking time (4 min) and less percent solids loss, whereas pigeon pea starch noodles had higher cooking time (12 min), higher percentage of water absorbed during cooking, more hardness and cohesiveness. Rice starch noodles scored higher for their transparency and slipperiness over pigeon pea starch noodles. Blending of pigeon pea starch with rice starch had significant effects on the cooking and sensory quality of noodles. Among starch blends, 70:30 blend of the pigeon pea and rice starches respectively resulted in good quality of noodles especially in terms of their higher transparency, slipperiness, overall acceptability and cohesiveness values. Blending of pigeon pea starch with 30% rice starch could produce noodles with superior quality as compared to native pigeon pea and rice starch noodles.     

玉米淀粉对鲜湿米粉品质的影响

研究了玉米淀粉添加量对鲜湿米粉的蒸煮特性、质构特性和感官品质的影响。结果表明,添加玉米淀粉会增加鲜湿米粉的断条率和蒸煮损失,对风味无不良影响。添加3%～5%的玉米淀粉可以显著增加鲜湿米粉的吸水性(P0.05),白度值亦有上升,感官评定分值较高;添加15%～60%玉米淀粉虽然会增加鲜湿米粉的硬度等指标,但断条率及其它品质指标均有劣化的趋势。因此添加3%～5%的玉米淀粉较为适宜,与纯籼米米粉品质最为接近。     

面条品质与小麦粉品质特性关系的探讨

选用品质不同的小麦粉33份制作面条,探讨小麦粉品质性状和面条煮面品质的关系。结果表明,面条品质是小麦粉多种品质性状综合作用的结果,不同小麦粉品质性状对面条外观和质地作用的方向和程度不同,蛋白质质量(面筋强度和延伸性)和淀粉糊化特性对面条品质的影响较大,蛋白质质量对面条质地有较大的正向影响,对面条外观有一定的负向影响,淀粉糊化特性对面条外观和质地均有显著正向作用,而蛋白质数量对面条适口性和韧性也有一定正向作用。面筋强度较高、淀粉特性好的小麦粉适宜制作优质面条。     

Development of oxidised and heat-moisture treated potato starch film

This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch.     

氧化淀粉对面条品质的影响研究

应用氧化淀粉对面条品质进行改良研究,详细研究了不同添加量和不同氧化度的氧化淀粉对面团的流变学性能、面条的拉伸性能、弯曲断条率、蒸煮断务率、吸水率、溶出率及面条的感官品质等的影响,探讨了氧化淀粉对面条品质影响的机理。     

薯类粉条中与淀粉相关的结构性质研究

为了解薯类淀粉粉条结构特点,选取3种木薯淀粉(SC9、SC205、LMC),3种淮山淀粉(GY2、SFY、MPY)和1种红薯淀粉(XSSP)制成的粉条为研究对象,对其色泽、微观样貌、结晶结构进行测定和比较。结果表明,各粉条的色泽、微观样貌、结晶结构差异显著。星树红薯粉条色泽最好,而双峰淮山粉条色泽较暗。淮山粉条和红薯粉条存在部分还未完全糊化的淀粉颗粒,呈现出清晰的团粒结构,木薯粉条的糊化程度最高,淀粉的团粒结构已基本消失,SC9木薯粉条可以看到均匀完整的网络结构。粉条的结晶结构均遭到破坏,不同品种薯类粉条的有序结构与无序结构比例有明显差异。