挤压膨化处理对婴幼儿米粉理化和体外消化特性的影响

为探讨婴幼儿米粉基料干法制造过程中挤压膨化处理对米粉特性的影响规律,对不同品种大米经挤压膨化得到米粉的理化和消化特性差异进行比较分析,结果表明:在相同挤压膨化条件下,不同大米之间淀粉组成差异明显,导致膨化度、吸水指数和水溶性指数差异显著(P<0.05);处理后由淀粉体外消化特性得出:早籼米中抗性淀粉含量最高,接近15%;糯米快速消化淀粉含量最低,小于75%。蛋白质消化特性结果显示,糯米制品的胃蛋白酶消化率和蛋白质总消化率均低于其它3种米粉,这可能是因糯米中蛋白质的结构和组成不同所致。研究结果为挤压膨化技术在米粉生产中的应用及对不同品种大米米粉的性能影响提供理论依据。     

Physicochemical,antioxidant properties and in vitro digestibility of wheat–purple rice flour mixtures

The physicochemical characteristics, antioxidant properties and in vitro digestibility of high‐antioxidant content flours made from different combinations of Thai purple rice flour and refined wheat flour from 25%, 50% to 75% (w/w) were investigated and these were compared with whole flour from purple rice and refined wheat flour. The increase in substitution levels of purple rice flour affected all the functional properties of flours, at the same time the levels of dietary fibre, protein digestibility and antioxidant compositions were also changed. The purple rice flour exerted a particularly strong effect on starch digestibility as the purple rice increased to 50% in the mixture. Moreover, purple rice flour showed lower amounts of rapidly digested starch (RDS), whereas slowly digested starch (SDS) of whole flour from purple rice and 75% substitution purple rice flour was found to be the highest for all samples. The in vitro starch digestibility of all samples also showed a positive correlation between dietary fibre and antioxidant compounds. Overall, the addition of purple rice flour improved the final nutritional properties, notably a lower predicted glycaemic index, and a higher antioxidant potential, which are two important nutritional properties for human health.     

Physical,chemical and nutritional characteristics of puffed quinoa

Puffed quinoa can be used as ready-to-eat breakfast food or as an ingredient in snack formulations. In this study, puffed quinoa products with and without starch–chitosan coating were developed by gun, extrusion and microwave puffing at different process conditions (pressure, power, moisture content and energy consumption). Size, bulk density, colour, expansion index, water absorption and solubility, microstructure, mechanical and thermal properties, chemical composition and in vitro digestibility of organic matter and proteins of popped quinoa were assessed. Optimal process conditions for gun puffing were maximum 1.31 MPa after 780 s, 500 r.p.m. and 180 s for extrusion puffing and 1200 W for 60 s applying microwave puffing at 18–20% moisture contents. Gun and extrusion puffing yielded high-quality popped quinoa with a biological availability of organic matter between 84–88% and 79–90% for proteins. Extrusion and gun puffing are the most promising processes to prepare quinoa snacks.     

Assessment of the techno-functionality,starch digestion rates and protein quality of rice flour–whey protein instant powders produced in a twin extruder

Whey protein concentrate (WPC) is an important raw material for the production of instant beverages due to its protein properties. A central composite design was devised to analyse the effects of thermoplastic extrusion of 2:1 rice flour:WPC blends in physical, chemical–nutritional and functional properties. Three main factors were selected, screw speed (225–375 r.p.m.), conditioning moisture (17%–23%) and temperature (120–180 °C) to evaluate effects on water absorption (WAI) and solubility (WSI) indexes, viscoamylograph cold and final viscosities, in vitro protein and starch digestibilities and starch hydrolysis indexes (HI). A second-order model showed that linear parameters were significant for all variables studies. Conditioning moisture affected properties more significantly than temperature and screws speed. The best treatment (16% moisture conditioning, 180 °C last barrel zone and screws rotating at 350 r.p.m.) in terms of water solubility had high starch in vitro digestibility and excellent protein quality determined in vitro and in vivo with weanling rats.     

预酶解-挤压膨化对全谷物糙米粉品质特性的影响

以3 种糙米（普通糙米、红色糙米、黑色糙米）为原料,预酶解-挤压膨化制备实验组糙米粉,未经预酶解处理直接挤压膨化制备对照组糙米粉,分别测定其水溶性指数、吸水性指数、结块率、分散时间、米糊黏度、色度、糊化度、感官评分以及淀粉、还原糖、蛋白质含量等指标,并对淀粉和蛋白质进行体外模拟消化,比较并分析预酶解-挤压膨化对糙米粉品质特性的影响。结果表明：与直接挤压膨化相比,预酶解-挤压膨化处理使普通糙米、红色糙米、黑色糙米3 种糙米粉的水溶性指数分别提高了2.04、1.35 倍和1.71 倍;吸水性指数分别降低了67.87%、60.96%和62.17%;结块率分别提高了5.44、6.27 倍和3.07 倍;分散时间分别缩短了66.61%、61.79%和64.30%;米糊黏度降低,黏度曲线趋于平直,剪切稀释效应减弱;淀粉含量分别降低了29.22%、28.71%和26.70%,糊化度分别降低了19.53%、8.94%和13.13%;可溶性蛋白含量分别提高了1.50、2.87 倍和2.27 倍;差异均达显著水平（P＜0.05）。同时,亮度值略有升高,色差值分别为3.01、4.66、3.28;快消化淀粉比例降低,慢消化淀粉和抗性淀粉比例升高;蛋白质体外消化速率加快,消化率升高;综合感官评分显著升高（P＜0.05）。实验结果表明预酶解-挤压膨化处理提高了糙米粉的冲调分散性、降低了米糊黏度,提高了感官评分和蛋白质体外消化性能,对糙米粉品质具有提升作用。为拓宽糙米的加工利用途径、促进预酶解-挤压膨化技术在谷物加工领域中的应用提供了理论指导。     

Effects of the addition of wild legumes (Lathyrus annuus and Lathyrus clymenum) on the physical and nutritional properties of extruded products based on whole corn and brown rice

The effects of the addition of wild legumes (Lathyrus) from the South of Spain on the physical and nutritional properties of extruded products based on whole corn and brown rice were studied. Samples were obtained with a Brabender single screw extruder. The physical characterisation of the expanded products was performed by the measurement of density, expansion, solubility and specific mechanical energy consumption (SMEC). Chemical composition, amino acids content, protein digestibility, total polyphenol content and potential availability of iron and zinc were determined.     

脱酰胺处理对不同谷物蛋白体外消化率的影响

脱酰胺处理是蛋白质改性一种方式,经脱酰胺后,蛋白的理化性质和营养性质都会发生改变。本实验研究了酸法脱酰胺处理对大米、小麦、玉米蛋白体外消化率的影响,并从蛋白质的溶解度、表面疏水性、巯基和二硫键含量以及超微结构等理化性质方面来探究脱酰胺影响体外消化率的作用机理。试验结果表明:随着脱酰胺程度的加大,大米蛋白、小麦蛋白和玉米蛋白质巯基和二硫键之间的相互转化不明显(P0.05),两者的含量基本维持不变;三种谷物蛋白的溶解度在胃蛋白酶最适p H 1.5和胰蛋白酶最适p H 7的条件下逐渐增大;蛋白质的表面疏水性随脱酰胺度的增加逐渐减小;体外消化率也分别从原来的66.5%、79.5%和78.5%提高到了79.5%、89.0%、和89.2%,超微结构从原来的致密聚集变得多孔疏松,更利于蛋白质的消化。     

Effect of lactic fermentation and extrusion of bean and pea seeds on nutritional and functional properties

Controlled lactic acid fermentation of „Bomba”︁ bean and „Opal”︁ pea was used to improved their nutritional and functional properties. The modified legumes were used as a source for extrusion process to obtain snack-type foods. Milled legume seeds were fermented by different population of Lactobacillus plantarum with different moisture content in plant material to estimate the influence of this two parameters on the dynamics of lactic fermentation. Quantitative and qualitative changes in carbohydrates and nitrogen compounds of modified seeds were analyzed (e.g . mono- and oligosaccharides, "in vitro" starch and protein digestibility). In the new snack-type products, functional properties: water solubility index (WSI), water absorption index (WAI), expansion index, bulk density and texture explained as a shearing stress were recorded. Results showed a distinct decrease in raffinose, verbascose and stachyose contents even up to 80 - 90% after fermentation and extrusion process. Lactic fermentation and extrusion of bean and pea seeds contributes to a significant (a ≤ 0,05) increase of "in vitro" protein and starch digestibility. Observations of changes in functional properties of extruderates (e. g., expansion, shearing stress, WSI, WAI) allowed to choose the most efficient model of fermentation pretreatment to obtain the best improvement of nutritional and functional features of the product.     

Molecular rearrangements in extrusion processes for the production of amaranth-enriched,gluten-free rice pasta

Gluten-free pasta represents a challenge for food technologists and nutritionists since gluten-free materials used in conventional formulations have poor functional and nutritional properties. A novel extrusion-cooking process was set up to improve the textural characteristics of rice-based pasta, and to enrich it with amaranth. Mineral and fiber content, and protein digestibility were improved by amaranth enrichment. Extrusion-cooking of a 75/25 mixture of rice flour and amaranth prior to pasta-making gave the best results as for the textural characteristics of the final product. The firmness of cooked pasta increased due to the extrusion-cooking process, that also decreased protein solubility in the amaranth-enriched pasta. The content in accessible thiols also decreased in amaranth-enriched pastas, indicating that amaranth proteins may be involved in forming disulphide bonds during the pasta-making process. Our results suggest that starch in rice flour interacts best with amaranth proteins when starch gelatinization occurs simultaneously to protein denaturation in the extrusion-cooking process.     

基于灰色关联分析法综合评价不同干燥方式对山药脆片品质的影响

为了比较真空冷冻干燥、变温压差膨化干燥、真空干燥、热风干燥四种干燥方式对山药脆片物理特性、营养成分、微观结构、感官品质的影响,结合变异系数法和灰色关联分析对不同干燥方式山药脆片进行综合评价。结果表明:四种不同干燥方式下的山药脆片的物理特性和营养成分的保留均有明显差异,真空冷冻干燥和变温压差膨化干燥能产生较好的物理特性,并且较好的保留了营养成分。扫描电镜结果显示,真空冷冻干燥产品结构最完整;变温压差膨化干燥产品感官评分最高。综合评价结果:变温压差膨化干燥 > 真空冷冻干燥 > 真空干燥 > 热风干燥。综合多方面考虑,变温压差膨化干燥是最适合山药脆片加工的干燥方式。     

Changes in the quality and in vitro digestibility of brown rice noodles with the addition of ultrasound-assisted enzyme-treated red lentil protein

The effects of red lentil protein with ultrasound-assisted enzymatic treatment on the quality of brown rice noodles were investigated. The thermostability and anti-retrogradation ability of brown rice flour decreased significantly (P < 0.05), while the elastic and viscous modulus increased after adding untreated red lentil protein. Meanwhile, the cooking loss rate of brown rice noodles increased from 4.41% to 5.68%. When the red lentil protein was treated with ultrasound and enzyme, the protein–starch interaction was enhanced, and the negative effects of protein on brown rice flour and noodles were weakened. Moreover, the rice noodles with ultrasound-assisted enzyme-treated red lentil protein showed a lower starch digestibility than brown rice noodles, and its protein digestibility was significantly higher than that of rice noodles with ultrasound or enzyme-treated protein. Therefore, the addition of ultrasound-assisted enzyme-treated red lentil protein could effectively decrease predicted glycaemic index value, improve nutritional value and produce high-quality brown rice noodles.     

Enhancement of Attributes of Cereals by Germination and Fermentation: A Review

The nutritional quality of cereals and the sensorial properties of their products are sometimes inferior as compared to other sources of food which is due to the lower protein content and starch availability, the presence of determined antinutrients (phytic acid, tannins, and polyphenols) and the coarse nature of the grains. To ameliorate the nutritional qualities of cereals, they are processed in a number of ways. This review summarizes the enhancement in the nutritional value as well as the functional characteristics of cereals due to germination and fermentation treatment. The protein concentration increases and the amino acid profile is balanced by germination and fermentation. The antinutritional factors are reduced increasing the mineral availability from the cereals. Germination enhances the quality of nutrients and bioactive compounds of cereals thereby increasing the content in proteins, amino acids, sugars, and vitamins. The functional properties of cereals is enhanced due to generation of biofunctional substances, increase in protein solubility, in vitro protein digestibility and lowering of glycemic index.     

预糊化时间对即食冲调米粉品质的影响

以碎米为主要原料,采用湿热方法对原料进行预糊化,再应用滚筒干燥制备成即食冲调米粉,通过分析即食冲调米粉的吸水性指数、水溶性指数、流变特性、微观结构、消化特性,研究预糊化时间对样品的影响.结果表明:预糊化处理后的米粉冲调特性和消化性质得到显著改善,相对于未进行预糊化处理组样品,经过30min预糊化后,吸水性指数和水溶性指...     

Nixtamalised flour and tortillas from transgenic maize (Zea mays L.) expressing amarantin: Technological and nutritional properties

Nixtamalised flour from transgenic maize (genetically modified maize with the cDNA of amarantin) and its tortillas were evaluated for some technological and nutritional properties and compared to the commercial brand MASECA^™. Nixtamalised transgenic maize flour (NTMF) showed higher protein content, total colour difference, pH, water solubility index, essential amino acids content and lower Hunter “L” value, water absorption index, resistant starch and retrograded resistant starch than MASECA^™ flour. Tortillas from NTMF had higher protein content (12.64% vs 8.93%, db), essential amino acids content and calculated protein efficiency ratio (C-PER; 2.05 vs 1.04) than tortillas from MASECA^™. Tortillas from both nixtamalised transgenic maize and MASECA^™ flours showed similar sensory properties (puffing and acceptability). The use of transgenic maize for flour and tortilla preparation may have a positive impact on the nutritional status of people from countries where maize is the basic staple food.     

Effect of hydrocolloids on physicochemical,sensory and textural properties of reconstructed rice grain by extrusion cooking technology

Cracked or broken rice grains followed by lower rice efficiency during processing and milling of rice paddy are a major challenge contributing to the reduced economic productivity of this branch of industry. Therefore, the extrusion process for turning flour from broken rice or wastes into complete rice grains can bring about value-added for producers. In addition, an optimized formulation can improve product diversity and nutritional value. In this study, the effect of addition of Guar and Arabic gums on physicochemical, texture and sensory profiles of extruded rice grains was analyzed. Both gums were used in four concentrations (0.1, 0.2, 0.3 and 0.4 w/w %, d.b), and the effect of their different levels on properties of extruded rice was studied. Results from physicochemical tests on extruded rice samples showed that moisture content, water solubility index, water absorption index and bulk density were increased in samples containing higher concentration of Guar than Arabic gum and initial moisture content of 30% compared to no-gum samples, whereas lateral expansion, cooking loss, and total color change (ΔE) were reduced. Furthermore, results showed that higher levels of Guar than Arabic gum led to an improvement in sensory and textural properties.     

Functional,biochemical and pasting properties of extruded bean (Phaseolus vulgaris) cotyledons

Response surface methodology was used to investigate the effects of extrusion conditions – namely moisture content (12.3–23.7 g 100 g^?1) and temperature (150–178 °C) – on physicochemical, antinutritional compounds, functional and pasting properties of extruded bean cotyledons. Results indicated that extrusion cooking did not change the chemical composition of bean flours, but completely eliminated the activity of the trypsin and α‐amylase inhibitors and haemagglutinins. The extrusion significantly improved starch and protein digestibility, water solubility and absorption of bean cotyledon. In addition, extrusion conditions significantly affected pasting properties, resulting in extrudate flours with different peaks and final viscosity values. From the results obtained in this work, it is possible to design a product with specific physicochemical, functional and nutritional properties using the appropriate moisture and temperature during extrusion.     

速熟黑豆理化性质的研究

为研究速熟黑豆的理化性质,考察其与原料黑豆之间的差异,分析了黑豆的营养成分、氨基酸组成及体外消化性,同时利用扫描电子显微镜、傅里叶红外光谱扫描及差示扫描量热分析方法研究了黑豆的理化性质。结果表明,速熟黑豆与原料黑豆相比,淀粉含量增加9.13%,粗蛋白、粗脂肪含量稍有减少,氨基酸总量略有减少,蛋白溶解性变差,而消化性明显提高;速熟黑豆粉微颗粒间聚集成块状,尺寸变大;与原料黑豆相比成分变化不大,但速熟黑豆蛋白分子聚集,其蛋白溶解性变差;热分析过程中,速熟黑豆的蛋白没有吸热峰出现,表明速熟黑豆蛋白热变性完全。      

茯苓复配谷物挤压重组米的物性变化

以茯苓分别与薏米、红米、大米、苦荞四种谷物进行复配,采用双螺杆挤压技术制备成重组米,研究其物性变化。结果表明,相比薏米、红米、大米、苦荞四种谷物原料,复配茯苓的重组米糊化度分别增大了230. 8%、202. 1%、206. 8%、215. 7%,复水时间分别缩短了1. 04倍、0. 76倍、0. 83倍、0. 82倍,复水率分别增大了15. 88%、19. 45%、17. 97%、19. 94%,四种谷物消化性和复水性得以改善。相比四种全谷物重组米,复配茯苓的重组米色泽较好,但硬度增大,咀嚼性、弹性、黏附性及内聚性有所下降;水分以结合水和不易流动水的形式存在,自由水为0;淀粉回生度增大,V型晶体的衍射峰强度增强。     

不同干燥方式对金针菇菇根粉物理性质的影响

采用热风干燥、微波真空干燥、变温压差膨化干燥及真空冷冻干燥技术制备金针菇菇根粉,研究不同干燥方式对金针菇菇根粉物理性质的影响。结果表明:真空冷冻干燥粉体色泽保持最好,其次是微波真空干燥和变温压差膨化干燥;真空冷冻干燥和微波真空干燥粉体粒度和跨度较小,且粒度更均匀。热风干燥和变温压差膨化干燥粉体流动性及压片成型性较好;微波真空干燥和真空冷冻干燥粉体持水能力较强,真空冷冻干燥粉体持油力最强,达1.8 g/g;热风干燥和变温压差膨化干燥粉体水溶性较强,微波真空干燥最弱。真空冷冻干燥和微波真空干燥金针菇菇根粉适宜作为功能原料添加到食品中或吸附在食品表面。热风干燥和变温压差膨化干燥菇根粉适宜压制片剂及进行可溶性成分提取。      

膨化方式对发芽糙米主要生理活性物质的影响

以发芽糙米为原料,比较微波膨化和挤压膨化对发芽糙米色泽、水溶指数、吸水指数及主要生理活性物质的影响。结果表明,微波膨化和挤压膨化均提高了发芽糙米的吸水指数,分别是原料发芽糙米的1.84倍、2.81倍;L^*值分别降低了9.29%、4.41%。微波、挤压膨化的γ-氨基丁酸含量分别减少了40.42%和24.49%;植酸降解率为6.98%和14.17%;微波膨化能显著提高发芽糙米中谷维素的含量(p<0.05),是原料的1.44倍,而挤压膨化则降低了谷维素的含量,减少了89.2%。微波膨化处理后,γ-氨基丁酸和植酸虽有损失,但与挤压膨化的损失相差不多,且谷维素含量有所提高,因此,微波膨化能较大限度的保留生理活性物质。