Change in Digestibility of Gamma-Irradiated Starch by Low Temperature Cooking

Combination effect of irradiation and low temperature cooking on starch digestibility has been investigated as a basic research for application of radiosterilization on starch fermentation. The digestion of corn starch by glucoamylase after cooking at low temperature was enhanced by γ-irradiation and the required cooking temperature was decreased from 75-80°C to 65°C by 25 kGy. Gelatinization of starches except tapioca starch was enhanced by irradiation and it corresponds to the digestibility. The digestibility of potato starch which has a high viscosity was especially enhanced at low temperature cooking because the viscosity was markedly decreased by irradiation. These results show that the irradiation of starches is useful not only for the sterilization of fermentation broth but also for the enhancement of digestion.     

Production of Grain Whisky and Ethanol from Wheat,Maize and Other Cereals

Wheat replaced maize as the main cereal raw material for Scotch grain whisky production 20 years ago. However, other cereals might also have potential for use in grain distilleries and ethanol production. Studies of the properties of wheat, maize, sorghum and millet, showed that they had good potential for grain distilling and ethanol production at comparable nitrogen levels, and had physiological processing characteristics within the range accepted for wheat or maize. Rapid‐Visco Analysis (RVA) studies of low and high nitrogen wheat confirmed that, as well as influencing the amount of alcohol produced, the total nitrogen content of the grain had a strong influence on its processing characteristics. In contrast, the alcohol yield potential of maize, sorghum and millet appeared to be largely unaffected by the grain nitrogen levels. The study shows that, while it is possible for wheat to produce similar alcohol levels to those previously associated with maize, cereals other than wheat can potentially be used without detriment to alcohol yield or processing performance. These could be possible long term alternatives, if the economic viability of wheat was to change. The extracted cereal starches also showed significant differences from the original cereals, which had important implications for successful processing, both in terms of cereal selection as well as cooking and fermentation performance.     

Oxidation of Starch by Thermochemical Processing

The oxidation of starches of different amylose content with several oxidants has been investigated to maximize carboxyl content, increase water solubility and give products with new and novel properties. Methods of preparation studied were ambient-batch, jet cooking, jet cooking-drum drying, and drum drying alone. Other variables evaluated were reaction pH, jet cooking temperature, and oxidant concentration. Hypochlorite was the most effective oxidant and gave the highest carboxyl content in all preparation methods. Oxidized starches prepared by jet cooking and/or drum drying were of low viscosity and water soluble. SEM's of commercial oxidized starch showed intact granular structure, whereas samples prepared by instantaneous high temperature procedures showed complete gelatinization. Gel permeation chromatography showed structural depolymerization of the starches when high temperature processing was used. Copper binding capacity was evaluated on selected samples.     

利用马铃薯为原料制醋酒精发酵工艺的优化

为了开发新的食醋品种,研究了以马铃薯为原料制醋工艺中酒精发酵工艺。利用3因素3水平正交试验法,通过对蒸煮温度、蒸煮时间和酒精发酵温度这三个对酒精发酵有重大影响作用的因素进行优化,得到酒精发酵最佳条件为：蒸煮温度130 ℃、蒸煮时间4 min和发酵温度30 ℃。在此最佳发酵工艺条件下,酒精发酵的酒精度可达12.4%vol。     

Comparison of various types of starch when used in meat sausages

Technological and sensory properties of meat sausages formulated with 4·0% of either potato flour, modified (acetylated distarch phosphate) potato starch, wheat, corn or tapioca starch were compared. Sausages were analyzed after cooking at temperatures between 65 and 85°C followed by storage at 5°C and -25°C. Characteristics evaluated were weight loss during cooking and storage, instrumentally and sensory assessed firmness, taste and smell of sausages. The results revealed differences in the suitability of starches for use in meat sausages. Part of the differences could be ascribed to differences in gelatination properties of the starches. With the criteria used for evaluating quality, potato flour was rated as the best suited starch followed by wheat starch while tapioca was rated as the least suited. Corn starch required cooking temperatures above 75°C and showed relatively low freeze/thaw stability. The modified potato starch stored well both above and below the freezing point.     

Einfluß der Art der Energieübertragung auf strukturelle und funktionelle Merkmale von Stärke

Effect of the Form of Energy Transfer on the Structural and Functional Characteristics of Starch. The effect of the form of energy transfer on the structural and functional characteristics of starch was investigated. The changes in the molecular structure and functional properties of the starch resulting from vibration milling, drum-drying and extrusion cooking were established. These findings were compared with one another according to process specific characteristics. It could be shown that main and secondary valency bonds were broken due to vibration milling and extrusion cooking. On the other hand, drum-drying did not result in any molecular breakdown. The changes in the molecular structure resulted in an increased solubility of the starch. These changes in structure did not affect amylose and amylopectin to the same degree. The differences in the molecular structure were influenced by the form of energy transfer. Thus the mechanical energy transfer played a prominent role in the molecular breakdown during extrusion cooking and vibration milling. Those functional properties which depended on the molecular structure of modified starches were therefore developed according to the processes used. Extrusion cooking was by far the most flexible process in this respect. However, it was not possible to exclusively effect either mechanical or thermal energy transfer during extrusion cooking. Thus no extrusion cooked product possessed the water-binding properties typical of drum-dried starches.     

Altering pasting characteristics of sweet potato starches through amino acid additives

ABSTRACT:  This study assessed the effects of amino acid additives, aspartic acid, leucine, lysine, and methionine, on the pasting and thermal characteristics of white- and orange-fleshed Beauregard sweet potato starches. A rapid visco analyzer 3D was used to determine pasting properties. In comparing pasting characteristics, starch from orange-fleshed sweet potato was found to be easier to cook, had a lower potential for retrogradation, and was less stable during heating than the white-fleshed sweet potato starch. The RVA analysis showed that the charged amino acids, aspartic acid and lysine, altered pasting characteristics of the 2 starches more than the neutral amino acids, leucine and methionine. Aspartic acid had similar effects on both starches, making them less stable during cooking and lowering the potential for retrogradation. Lysine, when added to the orange-fleshed sweet potato starch, decreased the breakdown, allowing for more stability during cooking. This study showed that pasting properties of sweet potato starches can be altered by the addition of amino acids.     

Herstellung von Stärkederivaten durch Heißextrusion

Production of Starch Derivatives by Cooking Extrusion. It was possible to produce starch derivatives from corn and potato starches and maize grit by cooking extrusion process with a conical, counter-rotating twin-screw extruder. The used chemical reagents for derivatization were citric acid for citrate-starches, sodium trimetaphosphate for phosphate-starches and 2,3-epoxypropyl-trimethyl-ammonium chloride and 3-chloro-2-hydroxypropyl-trimethyl-ammonium chloride for cationic starches. With citrate starches 60–70% of bound citric acid yields were found in the extrudates. Heat treatment of extrudates after extrusion increased the amount of bound citric acid to 68–77% and icreased Brabender-viscosity values. Shear stability and freeze-thaw stability were also improved. For phosphate starches 15–30% of bound phosphate were found in the extrudates. After heat treatment bound phosphate was increased to 20–35%. Physical and functional properties were also improved. The production of cationic starches by cooking extrusion process was also possible. There was about 50–60% of bound nitrogen from reagents in the extrudates. This yield was further increased to 65–90% after heat treatment.     

Starch-based noodles: Current technologies,properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.     

Characteristics of Different Types of Starch in Starch Noodles and Their Effect on Eating Quality

Several commercial starch noodles made from legume, tuber, geshu (kudzu and sweet potato) and fernery starches were used to study the characteristics of starch in starch noodles and their effect on eating quality of starch noodles. Scanning electron microscopy observation found that the special inner structure of starch noodles was composed of some broken starch granules and some gel-like substances. Tuber and legume starches had the highest and lowest solubility, swelling power, swelling factor, setback, breakdown, peak viscosity, and final viscosity, respectively. Legume and tuber starches had the highest and lowest gelatinization temperature, respectively. Tuber and geshu starches had the highest amylose leaching rate, while legume starches owned the lowest value (p < 0.05). Tuber starches had the highest conclusion temperature of gelatinization (151.12~158.86°C). Fernery starches had the lowest value of retrogradation enthalpy (967.33 J/g dry starch). Legume starch noodles had the lowest broken rate (0.00~1.67%), swelling ratio (332.64~343.57%), and cooking loss (2.40~2.74%), and the highest hardness (87.47~93.29 g/mm2), shear deformation (0.49~0.52), and elasticity (0.58~0.62), However, tuber and fernery starch noodles did the opposite, tuber and legume starch noodles had the highest and lowest cohesiveness, respectively. All the above cooking and starch properties test results of starch noodles demonstrated that, compared with others, legume starch noodles are relatively well in eating quality. The correlation analysis showed that the cooking and physical quality of starch noodles could be perfected significantly by improving the swelling and pasting properties for starch of starch noodles, while thermal properties had no obvious influence on them.     

增强、助留剂YZ-138在造纸中的应用

木薯高取代阳离子淀粉YZ-138是针对以二次纤维为原料抄造牛皮箱板纸而开发的增强、助留剂。该文介绍了YZ-138的特性,并通过其在连续蒸煮方式和间歇蒸煮方式不同纸厂的应用实例表明,与普通阳离子淀粉和两性淀粉相比,YZ-138在留着及增强方面均要好得多。     

挤压蒸煮技术在变性淀粉生产中的应用

主要阐述了挤压加工原理,以及用挤压机作反应器生产氧化、酯化、交联和醚化等多种类型的变性淀粉,并对其相关性质进行了简要分析。认为挤压蒸煮技术是快速、连续生产多种变性淀粉的一种经济可行的方法。     

三种天然植物淀粉辅料对米粉丝品质特性的影响

以天然绿豆淀粉、玉米淀粉及马铃薯淀粉3种天然植物淀粉为原料,探讨其作为辅料添加对米粉丝蒸煮品质和质构特性的影响。结果表明,添加适量的绿豆淀粉、玉米淀粉或马铃薯淀粉可显著提高米粉丝的烹煮品质及质构特性。绿豆淀粉添加量在0.5~1.5%时加工的米粉丝具有较高的烹煮品质,其添加量在1%时可以显著提高米粉丝的质构特性;玉米淀粉的添加量为6%时米粉丝的烹煮品质较佳,其添加量在4~6%时可显著提高米粉丝的质构特性;马铃薯淀粉的添加量为2%时,米粉丝具有最高的烹煮品质,其添加量在2~3%时可使米粉丝的质构特性显著提高。综合考虑,当绿豆淀粉、玉米淀粉或马铃薯淀粉的添加量分别达到1%、6%和2%时能够显著改善米粉丝的蒸煮和质构品质特性。     

In Vitro Digestibility of Native and Resistant Starches: Correlation to the Change of its Rheological Properties

The broadly investigated and applied resistant starches have several health benefits: they can help, for instance, in the treatment of obesity and prevention of colon cancer; therefore, the accurate knowledge of the properties of these starches is elementary. In our study, the digestibility properties of two native starches (maize and wheat) and two resistant starches (RS2, Hi-maize™260; RS4, Fibersym™70), as well as their stoichiometric mixtures before and after cooking (at 100 °C), were investigated. Moreover, correlations were investigated between two different enzymatic methods and the rapid visco analyzer (RVA) method. Our aim was to prove strong relationship between rheological and enzymatic digestibility characteristics. To conclude the results of our measurements regarding resistant starches, it can be stated that the two resistant starches show different digestibility in raw and cooked form. After cooking, RS2 caused a linear decrease in the initially and the totally liberated glucose concentration in cooked mixtures; thus, these parameters can be predicted in the function of resistant starch addition. Additionally, we did not find any synergistic effects in the mixtures after heat treatment. Significant (p < 0.05) and strong correlations were found between enzymatic digestion and RVA methods in both cases of untreated and gelatinized starches. These results provide promising information for the prediction of in vitro digestibility from RVA results. Our results may confirm the theory that there is a relationship between the physicochemical and enzymatic digestibility properties of starches.     

Influence of Cooking Method on Digestibility of Legume and Cereal Starches

The influence of processing on starch nutrition was evaluated. Cereal starches including wheat, normal corn and high amylose corn; legume starches including field pea, kidney bean and mung bean; and potato starch and glucose were evaluated as carbohydrate sources. Starches were fed raw, or cooked in a pressure kettle or autoclave, dried in a spray drier or freeze-drier, or simultaneously cooked and dried on a drum drier or by extrusion cooking. Except for potato and high amylose corn, cooking the starches provided no nutritional advantage, as evaluated by weight gain, feed efficiency ratio, or apparent protein digestibility. Spray-dried starches were less dense and appeared to influence growth by restricting food consumption.     

酒精发酵无蒸煮工艺的研究现状

在淀粉质原料生产酒精的过程中,无蒸煮工艺对于减少能源的投入意义重大,受到世界各国科研工作者的重视,并且目前已取得一些可喜的成就。无蒸煮工艺大致分为生料发酵,低温蒸煮,挤压膨化和超细磨。通过研究这几种无蒸煮工艺的理论基础,工艺要点及应用情况,可对工厂的酒精发酵产生导向意义,同时为淀粉发酵生产酒精的节能提供新的研究思路。     

Use of the Rapid Visco-Analyzer to Measure Starch Pasting Properties part II: Effects of Emulsifiers and Sugar-Emulsifier Interactions

The Rapid Visco-Analyzer (RVA) was used to study the effects of sucrose ester (SE) emulsifiers and a propylene glycol ester (PGE) emulsifier on starch cooking properties. Maize, tapioca and wheat starches were affected to different degrees by F-160 SE with a hydrophil-lipophil balance (HLB) of 15. Up to a concentration of 0.05 parts emulsifier to 1 part starch, the F-160 SE increased peak viscosity, time to peak and maximum setback viscosity of the starches. These data suggested that the SE functioned by forming a clathrate complex with the starch molecules. When cooking properties of maize starch were studied in the presence of SEs with HLB 6, 11 and 15, the effects of the SE did not appear to be directly related to HLB. The PGE did not appear to form a clathrate complex with wheat starch, as indicated by a decrease in peak viscosity and time to peak. Cooking properties of the starches were also measured in the presence of sugars (dextrose, sucrose, corn syrup solids and polydextrose) at a level of 2 parts sugar to 1 part starch, plus emulsifiers at a ratio of 0.02:1. Peak viscosity, time to peak and maximum setback viscosity were affected synergistically in the presence of both sugar and emulsifier as compared to additive effects of the two ingredients acting alone. Although reaction mechanisms could not be defined from the data obtained, the RVA proved useful for quickly demonstrating the effects of multiple ingredients on starch cooking properties.     

20种蚕豆淀粉物理特性、糊化回生特性与粉丝品质的关系

对20种中国主产区蚕豆淀粉粉丝烹煮品质和感官品质进行了评价,并对蚕豆淀粉的物理特性指标、糊化回生指标与相应的粉丝品质进行相关性分析。淮安大蚕豆等5个蚕豆品种的淀粉制作的粉丝品质最好,而青海马牙等3个蚕豆品种的淀粉制作的粉丝品质较差。蚕豆淀粉部分物理特性指标与粉丝品质的密切相关表现在:持水性越低,溶解度越低,膨润力越低,粉丝品质越好。淀粉的冻藏缩水率、透光率与粉丝的烹煮、感官品质指标相关性不大。蚕豆淀粉的RVA参数与其粉丝感官品质指标密切相关,其中衰减度、峰粘度、保持强度等对其影响最大。蚕豆淀粉凝胶强度越大,粉丝的烹煮品质和感官品质越好。在评价蚕豆淀粉品种的粉丝加工适应性时,一方面可以通过测试蚕豆淀粉的溶解度、持水性、膨润力和凝胶强度来预测其粉丝烹煮品质和感官品质的好坏;另一方面可以用RVA测试蚕豆淀粉,预测其相应的粉丝感官品质的优劣。     

Using Ozonation and Amino Acids to Change Pasting Properties of Rice Starch

ABSTRACT:  In this study, the effects of ozonation and the addition of amino acids on rice starches were determined in terms of pasting properties using a rapid visco-analyzer. Results from viscosity analysis showed that 30-min ozone treatment on commercial rice starch exhibited the greatest swelling extent among the treatments and least retrogradation tendency. The control pure oxygen treated sample had the best cooking stability. The addition of lysine (6%) to 30-min ozonated commercial rice starch significantly reduced peak viscosity (PV), minimum viscosity (MV), and final viscosity (FV) by 918, 1024, and 1023 cP, respectively. Moreover, it decreased Ptime, resulting in the faster swelling upon heating and less rigid gel formation upon cooling. Furthermore, the presence of lysine in 30-min ozonated starch isolate (WSI) also significantly reduced PV, MV, FV, pasting time, and total setback (TSB) and produced starch gel with the best cooking stability and the least retrogradation tendency. Ozonated starch exhibited similar pasting properties to those from oxidized starches treated with low concentrations of chemical oxidizing agents. The combination of lysine with ozonation resulted in pasting properties similar to starches treated with high levels of chemical oxidizing agents. The ozonated starch could be used as a thickening agent, whereas ozonated starch with lysine might be an alternative for a highly chemically oxidized starch. Therefore, ozonation alone or the combination of ozonation and addition of lysine might be used to develop new starch ingredients with various functionalities without using typical chemical modifications.     

化学交联改性对高链玉米淀粉体外大肠发酵特性的调控机制

以高链玉米淀粉为原料,分别使用三偏磷酸钠、三氯氧化磷、环氧氯丙烷3 种化学交联剂制备不同交联度的交联淀粉。采用体外粪菌发酵模型和高通量测序技术评价不同化学交联度交联淀粉的体外大肠酵解特性。结果表明,不同种类交联淀粉的发酵速率均能随交联剂用量的增加而降低,同时,3 种交联淀粉均提高了有益菌Roseburia、Ruminococcus的相对丰度。但相比于三偏磷酸钠和三氯氧化磷交联淀粉,环氧氯丙烷交联淀粉抑制体外发酵速率的效果更为明显,同时能够更多地促进丁酸生成。