Kinetics of pH and colour of meat emulsions containing various fillers during smokehouse cooking

The cooking kinetics of meat emulsions containing various fillers was determined by monitoring changes in pH and colour during smokehouse cooking. The fillers used were buttermilk powder, corn starch, microcrystallline cellulose, modified corn starch, modified wheat flour, soy-protein concentrate and whey-protein concentrate. The cooking process was modelled using reaction kinetics and Eyring's absolute reaction rate theory. Enthalpy and entropy changes of activation were calculated for various properties and fillers.     

STRESS RELAXATION KINETICS OF MEAT BATTERS CONTAINING VARIOUS FILLERS DURING SMOKEHOUSE COOKING

Changes in stress relaxation properties during smokehouse cooking of meat batters containing various fillers were determined. The fillers used were butter-milk powder, corn starch, modified corn starch, modified wheat flour, soy-protein concentrate, whey-protein concentrate, and micro-crystalline cellulose. The cooking process was modelled using reaction kinetics and Eyring's absolute reaction rate theory. Enthalpy and entropy changes of activation were calculated for various properties and fillers.     

GELATION KINETICS of MEAT EMULSIONS CONTAINING VARIOUS FILLERS DURING COOKING

A cylindrical shaped thermal scanning rigidity monitor (TSRM) was developed to determine shear rigidity modulus of meat batters during cooking. A meat fatprotein ratio of 1.8, moisture content of 62% and 8.6% filler were used. the fillers were buttermilk powder, corn starch, micro-crystalline cellulose, modified corn starch, modified wheat flour, soy-protein concentrate and whey-protein concentrate. Plots of rigidity modulus versus product-temperature showed two major thermal transitions. the first and most important transition (53 to 61°C) was due to myosin gelation. the second transition (64 to 69°C) was ascribed to the collagen softening. the maximum rigidity-temperature slopes of 0.60 to 1.02 kPa/°C occurred after the first transition.     

Effect of cooking time and ingredients on the performance of different starches in white sauces

The effect of white sauce ingredients and increased cooking time at 90 °C on the degree of gelatinization of corn, waxy corn, rice, potato and modified waxy corn starches was studied. The changes in pasting properties, linear viscoelastic properties, and microstructure were determined. In all the native starches in water, a longer cooking time at 90 °C caused greater starch granule swelling and more leaching of solubilized starch polymers into the intergranular space. These effects were more noticeable in the waxy corn and potato starches. The potato starch was the most affected, with complete disruption of the starch granules after 300 s at 90 °C. The microstructural changes which transformed a system characterized by starch granules dispersed in a continuous phase (amylose/amylopectin matrix) into a system with an increase in the continuous phase and a decrease in starch granules were associated with a decrease in system viscoelasticity. The elastic moduli were higher in the sauce than in the starch in water system. However, with the exception of potato starch, the white sauce showed lower viscoelasticity than the starch in water system. The white sauce ingredients decreased the effect of cooking time on the starch gelatinization process, particularly in potato starch.     

Selection Criteria of Meat Emulsion Fillers Based on Properties and Cooking Kinetics

Textural and functional properties of meat emulsions with or without fillers were determined in the raw state, at product-temperatures of 30, 40, 50, 60, 65, and 70°C, and after showering. Reaction kinetics modelled the cooking process, and based on property changes, during cooking, kinetics parameters were calculated. Regression models of enthalpy changes of activation for product properties were developed as a function of filler properties. Regression models of fully cooked meat emulsion properties with respect to filler properties were also developed. Filler selection was based on regression models.     

A multiple-step slit die rheometer for rheological characterization of extruded starch melts

Extrusion cooking is a very important process in the field of cereal and snack manufacturing. The rheological properties of the starch based matrix strongly influence this process. A newly developed online rheometer was mounted on a twin screw extruder in order to measure these properties. It was possible to obtain viscosity of wheat flour and corn grits at typical extrusion cooking conditions over a shear rate range of three decades. Flow curves for varying screw speed and water content at a constant thermomechanical history of the starch were measured. Also the temperature dependence of the apparent viscosities could be determined showing activation energies in the range found for synthetic polymers. Furthermore, additional pressure drops that occur at step changes of the slit height were detected. Thus, it was possible to evaluate visco-elastic properties of extruded starch melts at different extrusion cooking conditions.     

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.     

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。     

Granular Properties of Different Starch Phosphate Monoesters

Different starch types (corn, rice, and potato starch, corn amylose and corn amylopectin) were phosphorylated by reaction with a mixture of mono and disodium phosphate at different molar ratios (mol phosphate/mol anhydrous glucose) under heat and vacuum. The starch granules of the modified and the native starches were microscopically examined for their sizes and morphology. The correlation between the variation in granular size of the modified starches with the extent of phosphorylation and some other physicochemical properties was studied. The granular size was generally increased while the iodine absorption capacity was decreased by phosphorylation. There were strong correlations between the variation in the starch granular size in dependence on phosphorylation and the corresponding changes in some physicochemical parameter of starch, e.g. solubility, swelling and paste clarity. This relationship was most evident in the case of phosphorylated corn amylopectin. Starch granular size can be taken as a quick indicator of the physicochemical properties of the native and modified starches.     

Development and Physicochemical Characterization of New Resistant Citrate Starch from Different Corn Starches

Resistant starch has drawn broad interest for both potential health benefits and functional properties. In this study, a technology was developed to increase resistant starch content of corn starch using esterification with citric acid at elevated temperature. Waxy corn, normal corn and high‐amylose corn starches were used as model starches. Citric acid (40% of starch dry weight) was reacted with corn starch at different temperatures (120–150°C) for different reaction times (3–9 h). The effect of reaction conditions on resistant starch content in the citrate corn starch was investigated. When conducting the reaction at 140°C for 7 h, the highest resistant starch content was found in waxy corn citrate starch (87.5%) with the highest degree of substitution (DS, 0.16) of all starches. High‐amylose corn starch had 86.4% resistant starch content and 0.14 DS, and normal corn starch had 78.8% resistant starch and 0.12 DS. The physicochemical properties of these citrate starches were characterized using various analytical techniques. In the presence of excess water upon heating, citrate starch made from waxy corn starch had no peak in the DSC thermogram, and small peaks were found for normal corn starch (0.4 J/g) and Hylon VII starch (3.0 J/g) in the thermograms. This indicates that citrate substitution changes granule properties. There are no retrogradation peaks in the thermograms when starch was reheated after 2 weeks storage at 5°C. All the citrate starches showed no peaks in RVA pasting curves, indicating citrate substitution changes the pasting properties of corn starch as well. Moreover, citrate starch from waxy corn is more thermally stable than the other citrate starches.     

Starch noodles: History,classification, materials,processing, structure,nutrition, quality evaluating and improving

Starch noodles, produced from purified starch of various plant sources, are a major category of Asian noodles. This review summarizes the current knowledge on: (1) Definition, naming, history and categories of starch noodles. (2) The morphological, physico-chemical, thermal, rheological characteristics and molecular structure of materials including mung bean starch, pea starch, sweet potato starch, potato starch and corn starch. (3) Processing technology of starch noodles including dropping, extruding and cutting. (4) Structure of starch noodles: it is composed of hydrolysis-resistant crystalline zone, network-like framework and filler mass. (5) Nutrition of starch noodles: it could be evaluated by the digestibility of starch, hydrolysis properties of gelatinized and retrograded starches, hydrolysis property of starch noodles. (6) Quality evaluating of starch noodles: it includes sensory, cooking and texture property. Correlation between the physical properties of starch, processing variables and the sensory, cooking and texture property of starch noodles are summarized. (7) Quality improving for non-mung bean starch noodles: (a) using other materials such as red bean starch, pigeonpea starch, potato starch, sweet potato starch, corn starch, to substitute totally or partly mung bean starch; (b) adding chemically modified starch; (c) adding physically modified starch; (d) biologically treating starch; (e) using additives such as chitosan, polysaccharide gums.     

Functional properties of some meat emulsion extenders

Functional properties (gel strength, cold and hot water absorption, solubility in cold and hot water, water holding capacity and pH) were determined for some meat emulsion extenders‐ buttermilk powder, corn starch, microcrystalline cellulose, modified com starch, modified wheat flour, soy‐protein concentrate and whey‐protein concentrate. For these extenders, pH varied from 5.02 to 6.73, water holding capacity from 0.14 to 0.55, gel strength from 0.01 to 5.38 N, cold water solubility from 0.002 to 0.874, hot water solubility from 0.0004 to 0.8755, cold water absorption from 0.9 to 12.3, and hot water absorption from 3.4 to 12.3.     

不同添加物对挤压重组米血糖生成指数和理化性质的影响

研究燕麦膳食纤维、大米蛋白、高直链玉米淀粉的添加对挤压重组米熟化后血糖生成指数(GI)及理化性质的影响。结果表明:高直链玉米淀粉挤压重组米(HMER)熟化后的GI值相比天然大米(NR)显著降低(P<0.05),原因是添加高直链玉米淀粉促使米样形成更多难酶解的V型淀粉结晶。燕麦膳食纤维挤压重组米(DFER)和大米蛋白挤压重组米(RPER)蒸煮后的GI值高于NR而略低于挤压空白米(ER)。红外光谱图和X衍射结果表明:添加燕麦膳食纤维和高直链玉米淀粉会促进挤压重组米的淀粉老化,而添加大米蛋白则会抑制挤压重组米淀粉老化。HMER在透明度和颜色上与天然大米相近,而DFER、RPER则与天然大米差别较大。HMER、DFER、RPER的蒸煮性质和蒸煮后的黏度与挤压空白米(ER)无显著差异(P>0.05)。DFER、RPER蒸煮后的硬度显著低于ER(P<0.05),而HMER和ER的硬度无显著性差别(P>0.05)。     

淀粉-脂肪酸改性高岭土的制备及其在包装纸上的应用

To improve the bondability between clay filler and lignocellulosic fiber,Kaolin clay particles were modified using a starch-fatty acid complex method.The coating efficiency of starch on clay particle surfaces was investigated by measuring the dissolved starch in the supernatant.The experimental results indicated that more than 98%of the applied starch was precipitated onto the surface of the filler,and the resulting starch-fatty acid-clay composites had relatively good resistance against moderate shear force.The morphology,particle size,andζpotential of the starch modified filler were also determined with scanning electron microscopy,Malvern particle size analyzer,and Malvern Zetasizer,respectively.An aqueous slurry of linerboard pulp containing 5～15wt%modified fillers was used for handsheet preparation,and the effects of the addition of modified filler on the paper properties were studied.At a dosage of 10%of the modified filler(based on filler), the retention of the filler was higher than 75%.The strength properties of paper with starch modified fillers were improved by approximately 15%when compared against those of paper with unmodified fillers.     

交联羟丙基羧甲基复合改性玉米淀粉的性能研究

以玉米淀粉为原料,利用乙醇溶剂法进行羟丙基醚化改性,再采用环氧氯丙烷交联剂和一氯乙酸进行处理而制得复合改性淀粉。采用傅里叶变换红外谱仪、X射线衍射仪和扫描电镜等对玉米原淀粉、羟丙基淀粉、交联羟丙基淀粉、羟丙基羧甲基淀粉和交联羟丙基羧甲基淀粉的微观结构进行了表征。红外分析表明改性淀粉在1287 cm-1处出现羟丙基的吸收峰,同时在1328~1603 cm-1处出现了-COO-吸收峰,说明原淀粉已接入了羟丙基和羧甲基基团。利用X-射线衍射分析改性淀粉仍属A型衍射图,证实了反应主要发生在无定形区。复合变性前后淀粉的表观形貌变化,证实了淀粉其反应不仅发生在淀粉颗粒表面,也发生在淀粉颗粒内部。讨论了改性淀粉的理化性质,结果表明交联羟丙基羧甲基淀粉具有良好的透明性、冻融稳定性、流变性。     

不同取代度玉米淀粉磷酸酯理化性质的研究

目的:对不同取代度的玉米淀粉磷酸酯的理化性质进行系统研究。方法:以尿素为催化剂,利用磷酸二氢钠与淀粉反应制备玉米淀粉磷酸酯,测定其取代度、溶解度、膨润力、透光率、表观粘度、抗老化性和冻融稳定性。结果:随着反应时间的延长,所得玉米淀粉磷酸酯的取代度逐渐增大;与原玉米淀粉相比,不同取代度玉米淀粉磷酸酯的溶解度、膨润力、透光度、表观粘度、抗老化性和冻融稳定性都有明显提高。结论:根据不同取代度的玉米淀粉磷酸酯的理化特性,可将其应用于不同的食品生产中,以提高食品的质量。     

The Effect of Protein and Fiber on the Kinetics of Starch Gelatinization and Melting in Waxy Corn Flour

The in situ presence of corn proteins and fibers along with starch in waxy corn flour affect the DSC scan of starch only slightly. The kinetic behaviors of cooking waxy corn flour with limited water contents (25% and 35%, w/w) are very similar to that of cooking waxy cornstarch. There are increases in reaction rate constants for samples with 25% water content when corn flour data are compared to that of corn starch. For samples with 35% water, the rate constants are very close for flour and starch. Cooking of corn flour requires a lower activation energy than cooking of cornstarch.     

Production and physicochemical properties of 2-octen-1-ylsuccinic derivatives from waxy corn starch

Waxy corn starch was esterified with 2-octen-1-ylsuccinic anhydride (OSA) using response surface methodology. The molecular structure and paste properties were also investigated. Results indicated that the optimum parameters for esterification were as follows: reaction period 4 h, temperature 36.7 °C, pH of reaction system 8.3, concentration of starch slurry 36.9%, and amount of OSA 3%. The degree of substitution was 0.0187 and the reaction efficiency was 80.6%. The ester carbonyl group in OSA starch was characterized by Fourier Transform Infrared Spectroscopy at 1723 cm(-1). Compared with native starch, OSA derivative had higher peak viscosity, better freeze-thaw stability, and decreased gelatinization temperature and digestibility by porcine pancreatic alpha-amylase. Scanning electron microscopy showed that the gels from OSA starch had less and smaller pores; however, the native starch gels changed to sponge-like structure after 4 freezing/thawing cycles. The OSA modified waxy corn starch offered a potential to be used in frozen foods. PRACTICAL APPLICATION: (a) To optimize operating conditions to achieve OSA modified waxy corn starch with a high degree of substitution; (b) to give a deeper insight into the physicochemical properties of OSA modified waxy corn starch, which offered a potential to be used in frozen foods.     

Corn Alkaline Cooking Properties Related to Grain Characteristics and Viscosity (RVA)

The relationship between kernel properties and alkaline cooking characteristics of 14 corn cultivars with different kernel characteristics was evaluated. Corn hardness was measured by abrasion (TADD), flotation, subjective ratings and a viscometric technique (RVA). Hard corn required longer time for cooking as both cooking and steeping hydration rates were lower compared to soft corn. RVA viscosity measurements were correlated with hardness from TADD, flotation and subjective tests, and alkaline cooking parameters. The rate of water uptake during simmering was correlated with RVA viscosity slope. Hard corn endosperm particles consistently required longer time for hydration and gelatinization of starch to develop viscosity. RVA data complemented flotation hardness data to predict cooking properties. RVA could be used as a model to predict cooking properties of corn.     

蛹虫草固态发酵对玉米粉加工性质及消化性的影响

利用蛹虫草固态发酵法对玉米粉性质进行改良。测定发酵前后玉米粉的理化性质,利用快速粘度分析仪和质构仪测定发酵前后玉米粉加工性质,来探究蛹虫草发酵对玉米粉性质的影响。研究结果表明,发酵0~2 d理化成分变化不显著（P>0.05）,2 d后发生明显变化,至发酵第3 d,总淀粉含量降低了11.7%,直链淀粉增加了29.8%;经固态发酵后,水溶指数增加了87.7%,吸水指数降低了28.2%;固态发酵可改善玉米粉的糊化特性和质构特性,到发酵的第3 d,峰值粘度降低了47.3%,回生值下降了34.9%,凝胶硬度和咀嚼性分别降低了45.4%和34.8%,提高了玉米主食制品适口性。蛹虫草固态发酵后的玉米粉具有更高的营养价值,到发酵的第3 d,可溶性蛋白、必需氨基酸,分别增加了52.3%和26%;慢消化淀粉及抗性淀粉分别提高至原来的1.83和1.41倍。通过本研究所得玉米粉的改良方法,可改善玉米粉的加工性能和淀粉消化性,为蛹虫草在玉米主食制品品质改良方面提供一定参考。