Morphological,thermal, rheological and noodle‐making properties of potato and corn starch

A comparison between the morphological, thermal, rheological and noodle‐making properties of corn starch and potato starches separated from five different potato cultivars was made. The granule size and shape of all starches differed significantly. Potato starch granules were comparatively larger than corn starch granules, while the transition temperatures were found to be higher for corn starch. Consistency coefficients and flow behaviour indices measured by back extrusion were higher for potato starches than for corn starch. Stickiness of cooked starch pastes was observed to depend upon their consistency coefficient. The gels made from all potato starches showed higher gel strength than those from corn starch. The gel strength of starches from both corn and potato increased during refrigerated storage. The amylose content, swelling power, solubility and light transmittance values of potato starches were significantly higher than those of corn starch. Noodles made from potato starches had higher cooked weight and cooking loss than corn starch noodles. Texture profile analysis revealed that potato starch noodles also had higher hardness and cohesiveness than corn starch noodles. Hardness of cooked noodles from all starches increased and cohesiveness decreased during storage. Noodles made from starches of higher viscosity exhibited higher hardness and cohesiveness. Textural differences among cooked starch noodles appeared to be associated with morphological, thermal and rheological properties of corn starch and potato starches. © 2002 Society of Chemical Industry     

添加淀粉对马铃薯米粉品质的影响

研究3种常用淀粉对马铃薯米粉品质的影响,为马铃薯米粉加工提供参考依据。分别将0%、5%、10%、15%、20%和25%的玉米、小麦和马铃薯淀粉添加到马铃薯全粉占比30%的米粉中,测定米粉蒸煮、色差、质构和拉伸性能指标的变化。结果:添加不同淀粉使得米粉的含水量显著减小(p<0.05);玉米、小麦以及5%~20%马铃薯淀粉可使米粉透射比显著增大(p<0.05);10%玉米淀粉能使碘蓝值显著增大(p<0.05);添加10%玉米、5%小麦以及5%~20%马铃薯淀粉,能使吐浆值显著减小(p<0.05);但3种淀粉对断条率影响均不显著。添加10%玉米、10%小麦和5%马铃薯淀粉能使米粉亮度L*显著减小(p<0.05),色度值a*和b*亦发生不同改变。5%~15%玉米淀粉可有效改善米粉硬度、峰值负载,但添加量达到20%时峰值负载形变量显著减小(p<0.05);小麦淀粉可改善弹性,添加10%~15%可有效改善硬度,15%和20%可改善峰值负载和咀嚼性;马铃薯淀粉可提高米粉硬度,但添加量达20%时米粉变得黏连。在实际生产中建议玉米和小麦淀粉添加量分别为5%和10%。     

Hypochlorite oxidation of field pea starch and its suitability for noodle making using an extrusion cooker

The effect of hypochlorite oxidation on the Brabendar pasting properties of field pea starch and the suitability of native and oxidized starch for noodle making by extrusion cooking were investigated. Field pea starch was oxidized with sodium hypochlorite at a level of active chlorine ranging from 0.89 to 3.28% (starch db). The degree of oxidation was determined and expressed in terms of percentage of carboxyl and carbonyl groups, which ranged from 0.02 to 0.38% and 0.06 to 0.19%, respectively. Starch recovery and peak viscosity, hot paste viscosity, cool paste viscosity, and setback of oxidized starches decreased with increasing degree of oxidation. The cooking quality attributes of noodles prepared from native field pea starches were acceptable but were negatively influenced by hypochlorite oxidation. Substitution of potato starch (40%, db) for field pea starch yielded more glossy noodles with better cooking quality. It was also observed that Brabendar pasting properties had high correlations with noodle quality characteristics.     

Starch Noodle Quality as Related to Potato Genotypes

Starch noodles were prepared using potato starch from 8 genotypes, mung bean starch, mung bean-potato starch blends, and sweet potato starch. The cooking quality of noodles from selected potato starches compared well with commercial starch noodles. Of the unblended potato starches, Mainechip exhibited cooking quality similar to commercial starch noodles with respect to cooking loss, cooked weight, and ?rmness. Appearance and texture of starch noodles from three genotypes (E55-35, Mainechip, and Shasta) were evaluated by a trained sensory panel. Noodles made from unblended potato starches had higher glossiness and transparency than those from other starches. Noodles from both un-blended and blended Mainechip starch had the highest press and elasticity.     

添加淀粉和蛋白质对挂面力学特性的影响

通过向小麦粉中分别添加玉米淀粉、红薯淀粉、马铃薯淀粉以及大豆分离蛋白,制作挂面并对挂面的弹性模量、抗弯能力进行分析.结果表明:无论添加何种淀粉,挂面的弹性模量都会随添加量的增大而减小;添加大豆分离蛋白能使挂面弹性模量明显上升,若添加量超过0.6％弹性模量会有所回落但仍明显高于对照组.添加3种淀粉和大豆分离蛋白都会使挂面的抗弯能力下降.用断裂应力评价挂面抗弯能力比使用端部轴向位移量可靠度更高.综合考虑挂面的弹性模量及抗弯能力,挂面中玉米淀粉、马铃薯淀粉、红薯淀粉以及大豆分离蛋白的添加量分别不宜超过10％、5％、5％和0.8％.     

Influence of wheat flour substitution with potato pulp on dough rheology,microstructure and noodle quality

The effects of potato pulp (0–40%) on dough rheology and microstructures, as well as noodle quality, were investigated in this study. Substitution of wheat flour with potato pulp led to a decrease in β-sheet content, an increase in α-helix and unordered content for protein in dough, as well as a drop of the storage and loss modulus, which was mainly caused by the weakening of dough gluten strength. Scanning electron microscopy confirmed that the gluten–starch network could no longer to be observed for the formulated dough containing 30–40% potato pulp. Structural damage of dough induced the increases in optimal cooking time, cooking loss and adhesiveness, and a decrease in cohesiveness of cooked noodles. However, the samples with 20% potato pulp addition showed higher values in water absorption, hardness, springiness and chewiness, indicating that noodles with potato pulp content below 20% were acceptable.     

Studies on noodle quality of potato and rice starches and their blends in relation to their physicochemical, pasting and gel textural properties

The physicochemical, pasting, and gel textural properties of potato and rice starches and their blends were studied in relation to their noodle making performance. Amylose content, swelling power and solubility values of potato starch were significantly (P ≤ 0.05) higher than for rice starch. Pasting properties showed higher peak, final and setback viscosity for potato starch as compared to rice starch. Texture profile analysis revealed that potato starch gel had higher hardness, cohesiveness and chewiness as compared to rice starch gel. Potato starch noodles showed higher cooked weight and cooking loss and were scored higher by sensory panellists especially with respect to transparency and slipperiness. On the other hand, rice starch noodles were more firm with lower cooking loss. Addition of potato starch to rice starch significantly (P ≤ 0.05) affected the noodle characteristics. Among the starch blends studied, blending of potato and rice starch in the ratio of 1:1 resulted in good quality noodles in terms of their lower cooking time, higher cooked weight, transparency and slipperiness. The results revealed the possibility of blending of potato starch with rice starch in equal proportions to produce noodles of acceptable quality.     

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。     

马铃薯淀粉物化特性分析及其对马铃薯热干面品质影响

为研究马铃薯淀粉的物化特性,以马铃薯为试验原料并对其中淀粉进行提取,并探讨不同含量马铃薯淀粉对混粉物化特性以及生鲜马铃薯热干面和干制马铃薯热干面品质的影响。结果表明,马铃薯中淀粉含量为73.80%,马铃薯淀粉中直链淀粉含量为28.23%,支链淀粉含量为71.70%;马铃薯淀粉中快消化淀粉(RDS)、慢消化淀粉(SDS)和抗消化淀粉(RS)含量分别为20.29%、15.03%和64.68%。马铃薯淀粉添加量在60%～70%时,混粉的持水性、吸水膨胀性和粘度值较高;马铃薯淀粉含量为70%～80%时,能较好的改善生鲜马铃薯热干面的蒸煮特性和质构特性;马铃薯淀粉含量在70%时,干制马铃薯热干面的复水特性最好;随着马铃薯热干面中马铃薯淀粉含量的增加,干制热干面更易消化。综上所述,马铃薯淀粉的建议添加量为70%。     

木薯醋酸酯淀粉对面团及挂面力学特性的影响

挂面是常见的一种传统食品,为了提高挂面的品质,本文考察了木薯醋酸酯淀粉添加量对面团粉质特性、面团拉伸特性、面粉糊化特性、生挂面弹性模量、抗弯能力、断裂能力以及熟挂面的坚实度、质构特性等技术指标的影响。试验结果表明,木薯醋酸酯淀粉可有效改善面团的粉质、拉伸特性和糊化特性,使面团的吸水率、粉质指数和拉伸阻力增大,形成时间延长,弱化度和延伸度降低,适量添加可延长面团的稳定时间,提高拉伸能量;添加木薯醋酸酯淀粉可提高生挂面的弹性模量和抗弯能力,降低熟挂面的坚实度,提高挂面的黏度、弹性和粘聚性,改善挂面品质。综合分析混合粉面团的粉质、拉伸和糊化特性,并通过测试分析生、熟挂面的力学特性,最终确定木薯醋酸酯淀粉的最佳添加量为3~6%,为其在面制品中的应用提供理论参考。