挤压对大豆蛋白构象及其组织化结构的影响研究进展

随着挤压技术的发展,以大豆蛋白为主要原料经过挤压加工制成具有明显组织化结构的素肉制品技术以及蛋白组织化结构形成机制越来越受到学者的关注.近几年的研究表明大豆蛋白微观结构的变化对大豆素肉的宏观组织化结构具有至关重要的作用.本文对挤压过程中大豆蛋白构象及其对组织化结构影响的研究进行综述,概述大豆蛋白分子构成,并总结了挤压对...     

双螺杆挤压机工艺参数对组织蛋白的影响

本文采用新型双螺杆食品挤压机,进行了挤压加工大豆组织蛋白和工程内制品的试验研究,获得了螺杆转速,含水量和温度对挤压过程和产品组织化质量的影响规律,研究表明,螺杆转速在80r/min,100r/min之间,含水量在38％－44％之间,大豆组织蛋白的挤压组织化质量良好,螺杆转速在60r/min,80r/min这间,含水量在60％－65％之间,工程内制品的挤压组织化质量良好,优化的机筒温度和机头温度分布为：30℃－45℃－80℃100℃－130℃－150℃－100℃。     

Nutrient-based Corn and Soy Products by Twin-screw Extrusion

Blends were developed to provide 20% protein, 12% fat, 68% carbohydrate and 8% moisture. High protein soy products (full fat flakes, protein isolate and/or concentrate) were formulated with corn meal and soybean oil to provide high protein and fat. The blends were extruded to provide pre-cooked foods that could be reconstituted at 40°C to a porridge or gruel, eliminating prolonged cooking or degradation of heat labile nutrients. Two types of soy isolate and concentrate were evaluated under extrusion temperatures from 100 to 130°C and feed moistures 8.5 to 18%. The extrusion of lower valued concentrates at 100 to 115°C with moisture from 12 to 18% produced a precooked mix that was high in nutrients and contained the most available lysine.     

Rheological Properties of Extruded Milk Powders

Whey protein concentrate, whey protein isolate, and nonfat dry milk may be processed through a twin-screw extruder to produce ingredients for protein-fortified food. The products ranged from rigid to flexible to soft, and small amplitude oscillatory shear measurements showed that these properties varied with extrusion temperature and moisture content. The whey proteins showed different effects than nonfat dry milk due to the type and amount of protein present. The characteristics of extruded milk powders can be manipulated through processing parameters to obtain texturized products with the desired rheological properties.     

Dynamic mechanical properties and fractal analysis of texturized soybean protein/wheat gluten composite produced by high moisture extrusion

Texturized soybean protein (TSP) and wheat gluten were prepared at high moisture using a twin-screw extruder. Effects of feed moisture content, extrusion temperature and wheat gluten content on the dynamic mechanical properties, microstructures and fractal analysis of texturized soybean protein/wheat gluten composite were investigated. All extruded samples were well fitted with Burger's model in creep-recovery tests (R² ≥ 0.978). The creep-recovery rate decreased with an increasing extrusion temperature. The addition of wheat gluten increased the resistance to creep and the unrecoverable deformation of TSP samples. The extrusion parameters affected the microstructure and morphology of extruded products. The fractal dimension of TSP products decreased with an increase in moisture content and wheat gluten content. Texturized soybean protein (TSP) and wheat gluten composite could form well-structure products.     

Twin-Screw Extrusion Texturization of Acid and Alkali Denatured Soy Proteins

Effect of pH on functional characteristics of soy protein was investigated by modifying soy flour through acid (HCl) or alkali (NaOH) addition. Acid- and alkali-treated proteins were evaluated and texturized by twin-screw extrusion. Products were analyzed by rheological, functional, and ultrastructural methods. Acid-modified texturized protein had little expansion, increased peak force, increased work of shearing, and a nonoriented fiber arrangement. Slightly alkaline extrudates had increased rehydration but poorer texture. Stronger alkaline treatment resulted in denser products with high peak force measurements, which disintegrated when extrudates were rehydrated. The physicochemical state of soy protein, particularly conformation and protein-water interactions as affected by pH, may influence expansion of textured products and development of plexilamellar structure.     

高水分组织化花生蛋白产品干燥和复水特性研究

采用双螺杆挤压机研制的高水分组织化花生蛋白产品中(HM-TPP)蛋白质含量高,具有与动物肌肉类似的纤维状结构和口感,可作为食品原料和配料。文中主要分析了高水分组织化花生蛋白产品的干燥和复水特性。干燥试验结果表明:随干燥温度的增加制品中水分含量达到10%以下所需干燥时间明显缩短,在40、50和60℃下,分别需干燥4.5、7和13 h。其中,60℃下的干燥速率明显高于50℃和40℃下的干燥速率。干制HM- TPP产品的复水试验结果显示:在复水前期(1 h),水温40℃和60℃时的复水速率明显高于20℃的,但40℃和60℃的复水速率无明显区别。复水2.5～3.5 h后,复水产品中水分含量基本达到饱和状态。所得复水产品质地柔韧、表面光滑,富有弹性,基本可以恢复到新鲜产品的品质特性。     

双螺杆挤压对大豆蛋白体外消化率的影响

采用双螺杆挤压技术,研究了挤压工艺参数对大豆蛋白体外消化率的影响,并采用二次通用旋转组合设计,建立了大豆蛋白体外消化率与物料含水量、挤压温度、喂料速度、螺杆转速的二次回归方程,并利用该方程探讨了各因子对消化率的影响.结果表明,各因子对大豆蛋白体外消化率的影响顺序为:挤压温度>物料含水量>螺杆转速>喂料速度,物料含水量与挤压温度交互作用显著.利用统计优选法寻优,确定了大豆蛋白消化率的最佳挤压工艺条件:物料含水量35%,挤压温度155℃,喂料速度0.4 kg·min-1,螺杆转速150r·min-1,大豆蛋白体外消化率最高值为95.83%.     

Physical and Functional Properties of Arrowroot Starch Extrudates

ABSTRACT:  Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 °C) were used for extrusion. The physical properties—bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower ( P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food.     

高水分挤压组织化植物蛋白品质调控及评价研究进展

高水分挤压组织化技术具有高效、低耗、低成本的特点,是目前最有前景的食品加工技术之一。利用高水分挤压技术获得的高水分组织化植物蛋白具有类似动物肌肉的纤维结构,无需复水、可直接食用,可被应用于肉制品、速冻食品以及休闲食品等。本文综述了挤压参数对高水分挤压组织化植物蛋白品质调控的研究进展,重点论述了高水分组织化植物蛋白的品质评价方法,并对高水分挤压组织蛋白的应用前景进行了展望。     

Functional properties of corn and corn–lentil extrudates

Functional properties of corn and corn–lentil extrudates were investigated as a result of extrusion conditions, including feed rate (2.5–6.8 kg/h), feed moisture (13–19% wet basis) and extrusion temperature (170–230 °C). Lentil was used in mixtures with corn flour at a ratio of 10–50% (legume/corn). The water absorption index of extrudates increased with extrusion temperature and feed moisture content and decreased with feed rate and lentil/corn ratio. The water solubility index of extrudates increased with temperature, but decreased with feed moisture content and feed rate. The oil absorption index of extrudates increased with extrusion temperature and decreased with feed rate, feed moisture content and lentil/corn ratio. Generally, the use of lentil flour led to products with lower values for functional properties. Principal component analysis of functional properties discriminated samples with appropriate functionality based on industrial use.     

Extrusion parameters and consumer acceptability of a peanut-based meat analogue

Despite its high protein content and low cost, defatted peanut flour (DPF) remains underutilised in human foods. The objectives of this study were to: (1) determine the best extrusion parameters for a peanut-based textured meat analogue (TMA); (2) develop new TMA products from DPF and (3) evaluate their consumer acceptability. Preliminary runs using a wide range of extrusion parameters were conducted. A central composite RSM design was used to determine the optimal extrusion conditions within the best ranges revealed by the preliminary runs. Three levels of moisture, screw-speed and barrel temperature were used in 31 runs. Expansion ratio, bulk density, texture profile, water absorption/solubility indexes of the extrudates were determined and used as indicators of product quality. Peanut-based TMAs produced at optimal extrusion conditions were flavoured with beef flavour and evaluated by a 60-member sensory panel for flavour, texture, and overall liking, using a 9-point hedonic scale. Optimisation studies revealed that the most important extrusion conditions are in descending order: protein content, temperature, moisture and screw-speed. Extrusion conditions that produced the best TMA were 60–65% protein, 50–55% moisture, 160–165 °C and 80–90 r.p.m. Sensory acceptability of snacks incorporating peanut-based TMAs was similar or better than those containing soya-based TMAs in terms of flavour, texture, off-flavour and overall liking. TMA produced from inexpensive DPF has the potential to compete with commercial meat analogues, thereby adding value to the peanut industry.     

植物蛋白高水分挤压组织化过程中水分和冷却温度对流变特性的影响

植物蛋白挤压过程的顺利进行和最终产品的特性受挤压过程中水分、温度和剪切机械力等因素的重要影响。本研究以大豆分离蛋白、豌豆蛋白和谷朊粉为混合植物蛋白原料,采用双螺杆挤压机进行挤压,考察水分和冷却温度对植物蛋白肉产品流变特性的影响。结果表明：植物蛋白肉产品的流变特性受挤压过程中水分和冷却温度的影响,在一定范围内,水分和冷却温度的升高有利于改善挤压组织化产品的流变特性。     

High moisture food extrusion

Summary Extrusion at higher moisture contents (> 40%), also known as wet extrusion, is relatively less investigated compared to low and intermediate moisture extrusion. Literature on high moisture food extrusion has been reviewed. Wet extrusion applications utilise twin screw extruders due to their efficient conveying capabilities. Extruders can be used as bioreactors for starch hydrolysis using thermally stable enzymes. This process is usually followed by saccharification inside or outside an extruder to produce a high DE (dextrose equivalent) syrup. Starch-based high moisture extrusion research also reports a few modelling studies. The rheological properties, torque and energy requirements of high moisture extrusion systems are different from those of low and intermediate systems. Other research reviewed includes the extrusion of low-cost plant and animal proteins to manufacture nutritious food products that imitate the texture, flavour, and mouthfeel of meat.     

脱脂花生粉特性对其挤压产品结构的影响

以低温脱脂花生粉为原料,采用DSE-25型双螺杆挤压实验室工作站,在花生粉高水分挤压组织化工艺优化的基础上,研究了原料特性(粒度、pH值和油脂含量)对挤压组织化产品结构的影响规律。结果表明,原料特性对脱脂花生粉挤压组织化产品的质量和结构有明显影响。粒径在0.2~0.3mm范围内的原料,其挤压产品既可保持适当的硬度和咀嚼度,又有较好的组织化结构,其微观结构细致,气腔小且分布均匀。原料的pH值对产品的流变学性质和微观结构影响较大;在花生蛋白等电点附近(pH值4.5),挤压产品的硬度和咀嚼度最高,具有较致密的组织结构;在接近中性时,组织化度最高;偏碱性条件不利于产品组织化结构的形成。随原料中油脂含量的增加,挤压产品的硬度、咀嚼度和剪切力均明显下降,扭矩显著降低;综合挤压产品的感官质量和质构分析结果,认为原料中油脂含量在3%~6%范围内,有利于挤压产品组织结构的改善和感官质量的提高。     

挤压膨化对脱脂花生粕组织化度的影响

以脱脂花生粕为原料,采用双螺杆挤压技术,以组织化度为考核指标,分析了组织化度随喂料速度、物料湿度、机筒温度、螺杆转速的变化规律。在单因素基础上,采用Box-Behnken设计,对脱脂花生粕挤压组织化工艺条件进行优化。结果表明,脱脂花生粕最佳工艺条件为:喂料速度0.3004kg/min,物料湿度30.8%,机筒温度142.2℃,螺杆转速155r/min。在此条件下,花生粕组织化度为1.606791。     

挤压蒸煮对豆粕体外消化率的影响

以脱脂豆粕为原料,采用双螺杆挤压技术,研究了喂料速度、物料含水量、螺杆转速、挤压温度对蛋白质消化率的影响,在单因素试验的基础上,通过正交试验确定出了豆粕最佳的挤压工艺条件。结果表明:影响消化率的主要因素是挤压温度和物料含水量,而喂料速度与螺杆转速影响较小。豆粕挤压蒸煮的最佳工艺条件是:喂料速度0.35 kg/min、物料含水量33%、螺杆转速130 r/min、挤压温度150℃,在该工艺条件下,消化率达到95.7%,比原始豆粕消化率提高12.1%。     

醇法大豆浓缩蛋白（SPC）挤压组织化机理（Ⅱ）──蛋白质变性热力学的差示扫描量热分析法

采用差示扫描量热法分析大豆蛋白的变性热力学性质。在热变性过程中，醇法大豆浓缩蛋白的结构刚性大、次级键断裂程度低。水对蛋白质的热变性具有一定的促进作用。随着蛋白质水分含量的提高，其热变性温度（Ｔｄｅ）降低。根据这些性质，经调整醇法大豆浓缩蛋白的ｐＨ值使其热变性焓差（ΔＨｄ）增大，可实现其挤压组织化。所得挤出物的物理性质及其流变特性均有明显改善。     

Modelling the effects of peanut flour, feed moisture content, and extrusion temperature on physical properties of an extruded snack product

A mixture experimental design was used to evaluate the combined effects of non-fermented (PDPF) and fermented (F-PDPF) peanut flours, added feed moisture content, and extrusion temperature on physical properties of extruded cornstarch-peanut flour-based snacks. Moisture content, expansion ratio, bulk density, modified Kramer compression-shear force and colour of extrudates were significantly affected by the amount of PDPF and F-PDPF in the formulation. Oil absorption by extrudates was only influenced by the type of peanut flour. Within the range of (per 1-kg batch) 0.30–0.34 g g⁻¹ added water, 0.16–0.20 g g⁻¹ PDPF and/or F-PDPF, and extrusion temperatures of 125 to 150°C, extrudates with a wide range of functional characteristics can be produced.