Native and modified chayotextle flour effect on functional property and cooking quality of spaghetti

The objective of this research was to study the effect of partially substituting semolina flour by native (NCHF) and modified chayotextle (CHFMD) flours, on the physicochemical properties and cooking quality of spaghetti. Spaghetti was obtained by replacing semolina flour (control) with five different concentrations of NCHF and CHFMD flours (10%, 17.5%, 25%, 32.5% and 40%). The proximal composition of the flours showed that both NCHF and CHFMD flours lower content of protein and fat but higher content of ash and resistant starch (RS). Moreover, the RS content increased due to thermal modification (TM) and that RS remained high, even after the cooking process. Pasting properties such as peak viscosity, breakdown, setback and final viscosity were influenced by NCHF and CHFMD concentrations. Brightness (ΔL^*) was significantly reduced by inclusion of increasing CHFMD levels. True density and water absorption values increased with addition of NCHF and CHFMD, compared to the control spaghetti. The results obtained in this study demonstrated the possibility for producing spaghetti containing up to 40% CHFMD flour, with acceptable quality and functional properties.     

Gluten‐free pasta: effect of green plantain flour addition and influence of starch modification on the functional properties and resistant starch content

Green plantain flour (GPF) is rich in indigestible carbohydrates, especially in resistant starch (RS). The objective of this study was to improve the functional pasta properties and RS content by producing gluten‐free (GF) pasta based on rice flour with different amounts of GPF addition (15–60% of total flour blend). Egg albumen (3.5–6.0% of total flour) and dough moisture (36–40%, dough humidity%), at constant emulsifier (0.5% of total flour) addition, were optimised in the first trials. The results showed that an addition up to 30% GPF with higher amount of egg albumen (6%) at dough moisture of 38% provided pasta with acceptable cooking quality and high RS content. Some qualities and/or RS content of GF pasta samples was further improved by adding 30% pregelatinised flours from the native GPF or drum‐dried green banana flour (DDGBF) in combination with applying varied steps of cooking and/or cooling, which were applied after pasta extrusion prior to drying them. The study suggests that GPF, in its native form, but particularly when pregelatinised, is a promising ingredient to be used for the production of GF pasta.     

Improvement of resistant starch content and baking quality of cross-linked soft rice flour

Food Science and Biotechnology - To increase resistant starch (RS) content of rice flour, soft and normal rice flours were cross-linked with different flour concentrations (40, 50%). RS contents,...     

Effect of hydrothermal treatment of runner bean (Phaseolus coccineus) seeds and starch isolation on starch digestibility

The study investigated the effect of traditional soaking and cooking, storage after cooking and freezing (? 18 °C, 21 days) and autoclaving of two varieties of runner bean on starch digestibility. Results achieved were compared with digestibility of isolated starch subjected to similar treatments. The digestibility of native starch from Nata var. seeds was lower after isolation than in raw flour. This starch was characterized by a higher content of fat and lower values of swelling power (SP) and amylose leaching (AML). After the thermal treatment, a significantly higher content of rapidly digestible starch (RDS) was observed both in seeds and starch. It was accompanied by reduced contents of resistant starch (RS) and slowly digestible starch (SDS). In flours from cooked seeds, the content of RDS was observed to be higher than in flours from autoclaved seeds, despite similar changes in contents of other constituents (ash and protein). It was probably due to better starch gelatinization owing to the long-lasting soaking of seeds. This resulted in a greater decrease of amylose content of starch compared to the other flours. Differences in SP, AML and thermal properties between starches isolated from two bean varieties had no influence on their digestibility after cooking. The storage of starch pastes at a temperature of ? 18 °C, unlike that of seeds, resulted in a significant increase in RS content, which shows the importance of other flour components in the process of starch retrogradation.     

In vitro starch digestibility,expected glycemic index,and thermal and pasting properties of flours from pea,lentil and chickpea cultivars

In vitro starch digestibility, expected glycemic index (eGI), and thermal and pasting properties of flours from pea, lentil and chickpea grown in Canada under identical environmental conditions were investigated. The protein content and gelatinization transition temperatures of lentil flour were higher than those of pea and chickpea flours. Chickpea flour showed a lower amylose content (10.8–13.5%) but higher free lipid content (6.5–7.1%) and amylose–lipid complex melting enthalpy (0.7–0.8 J/g). Significant differences among cultivars within the same species were observed with respect to swelling power, gelatinization properties, pasting properties and in vitro starch digestibility, especially chickpea flour from desi (Myles) and kabuli type (FLIP 97-101C and 97-Indian2-11). Lentil flour was hydrolyzed more slowly and to a lesser extent than pea and chickpea flours. The amount of slowly digestible starch (SDS) in chickpea flour was the highest among the pulse flours, but the resistant starch (RS) content was the lowest. The eGI of lentil flour was the lowest among the pulse flours.     

干燥方法对山药粉性质的影响

通过真空干燥、冷冻真空干燥和喷雾干燥制备山药生/熟粉,研究其流变特性、糊化特性和消化性质,初步探究其变化机制。结果表明,山药生粉具有较高的成糊温度,山药熟粉中冷冻真空干燥山药熟粉的峰值黏度最高(3619.50 cP)。不同干燥方法干燥的山药粉均呈非牛顿流体特性,冷冻真空干燥的山药熟粉的粘弹性最高;山药生粉呈现完整的淀粉颗粒形态,山药熟粉的颗粒形貌差异较大。熟化处理使山药粉抗性淀粉含量显著降低(P<0.05)。熟粉中真空干燥山药熟粉的抗性淀粉含量最高(56.11%)。三种干燥方法中,冷冻真空干燥能较好的保留山药粉的原有理化特性。     

Compositional changes in whole grain flours as a result of solvent washing and their effect on starch amylolysis

Whole grain flour is used most often as raw material for fuel alcohol production. However, the dry-milling process and the non-starch components of flours may impact the enzymatic hydrolysis of starch to glucose. The particle size distributions of flours prepared from whole grain triticale, barley, wheat and corn were determined and the effects of pre-washing with water, hexane, 100% ethanol or 50% ethanol on flour composition and the amylolysis of starch were studied. Scanning electron microscopy of the flours revealed that grinding grain to pass a sieve with an aperture size of 0.5 mm effectively released starch granules from endosperm cells. Pre-washing with water or 50% ethanol decreased the protein, phytic acid and total free phenolic contents of flours and, except for corn flour, increased starch content. Pre-washing with water reduced the ash contents of all flours, and reduced the ??-glucan content of barley flour by 98%. Pre-washing with hexane or 100% ethanol removed much of the lipid from the flours. Pentosan content was affected only slightly by any of the pre-washing treatments. Each of the pre-washings was associated with a significant change, positive or negative, in the extent of ??-amylolysis for one or more of the flours. The degree of ??-amylolysis in unwashed flours ranged from 22.4 to 26.1%, and from 21.6 to 28.1% in pre-washed flours, varying with flour source and solvent treatment. Pre-washing of flours increased the degree of hydrolysis achieved with sequential ??-amylase/amyloglucosidase treatment, with values ranging from 61.4 to 72.8% in pre-washed flours compared to 56.2-57.8% in unwashed flours. The highest degrees of hydrolysis were achieved with 50% ethanol pre-washing (72.4 and 72.8% for triticale and barley flours, respectively). The degree of ??-amylase/amyloglucosidase hydrolysis obtained for isolated starches ranged from 83.7 to 93.0%. This study demonstrated clearly that the partial removal of non-starch components from whole grain flours by solvent pre-washing enhanced the degree of amylolysis of starch.     

Nutritional value of broad bean seeds. Part 3: Changes of dietary fibre and starch in the production of commercial flours

We report on the impact of flour production from small- and large-seed varieties of broad bean on the quantitative and qualitative distribution of dietary fibre and starch. The experimental material consisted of the seeds of small-seed varieties of broad bean: Gobik and Goral, large-seed varieties of broad bean: Windsor Bialy and Bartom, and pea seeds of Albatros, Karat and Miko varieties (for comparison). The seeds were at full physiological maturity. Soaking and hydrothermal processing were shown to cause multidirectional, statistically significant changes in dietary fibre and starch, depending on both parameters of the process and type of the seeds. The flours of both small-seed broad bean varieties contained 20.15%-28.31%, flours of the large-seed broad bean 23.10%-27.50%, and those from pea seeds 20.13%-22.81% total dietary fibre. Attention should be paid to the considerable, approximately 2-fold increase in the soluble dietary fibre (SDF) content, compared to the raw material. The processing of seeds caused significant changes also with reference to starch. The most considerable changes were observed when the variant with the longest times of soaking (18 h) and heating (45 min) was applied. In the broad bean flours, the content of analytically available starch decreased by 22.94-30.60% and its digestibility was observed to decrease up to 30.25%. The pea flours, however, were characterised by an increased concentration of both forms of starch, especially significant for the digestible starch. The calculated content of resistant starch (RS) differentiated, to a high extent, the flours obtained. Under the same processing conditions, the flours of small-seed Gobik and Goral varieties of broad bean were characterised by a significantly higher RS content than those obtained from the large-seed varieties. A decrease in the starch digestibility rate index (SDRI) values, especially high for the small-seed varieties, should also be emphasised. The results obtained indicate that the nutritional value of flours can be determined by controlled processing parameters.     

In vitro starch digestibility changes during storage of maize flour tortillas

Nixtamalized maize flours elaborated by four factories in Mexico were used for tortilla preparation. Samples were stored at 4 degrees C for up to 72 h and their in vitro starch digestibility features were evaluated. Moisture content was different between flour and tortilla but no evident relation could be established. Protein and lipid levels were lower in tortillas than in flour but ash content was not different in both samples. A decrease in available starch content was observed upon 48 h cold storage (4 degrees C), changes that were concomitant with increased total resistant starch (RS) levels. These changes were due mainly to retrogradation, as suggested by the increased retrograded resistant starch (RRS) levels recorded in stored tortillas; in some samples, RRS represented up to 100% of total RS. The digestion (alpha-amylolysis) rate (DR) of freshly prepared tortillas differed for the various samples. Although the amylolysis patterns for fresh and 72 h-stored tortillas were similar, lower DR values were shown for the stored materials. The differences found among the various tortilla samples may be due to variations in processing conditions during commercial maize flour preparation, and to the use of different maize varieties.     

湿热及酶解处理对糯米粉体外消化特性和血糖生成指数的影响

目的 研究酶解处理、湿热处理和湿热复合酶解处理对糯米粉体外消化特性和血糖生成指数(glycemic index, GI)的影响。方法 采用体外消化法测定了不同处理糯米粉的水解度和血糖生成指数值, 并通过X-射线衍射和激光共焦拉曼光谱实验测定了不同处理糯米的淀粉晶体结构。结果 3种处理的水解度和抗性淀粉(resistant starch, RS)相对含量增加, 慢消化淀粉(slowly digestible starch, SDS)相对含量降低; 其中湿热复合酶解处理条件下, RS相对含量最高, 为71.31%; 酶解处理条件下, RS相对含量最低, 为67.66%。酶解处理、湿热处理和湿热复合酶解处理的GI值分别为79.1、76.0和70.6。3种处理后糯米淀粉的晶体结构发生改变, 3种处理均使分子短程有序度与结晶度增加, 其中湿热复合酶解处理条件下, 结晶度最高, 为34.41%。 结论 湿热复合酶解处理后的糯米粉抗消化特性增强且GI值降低, 湿热复合酶解工艺可能通过影响糯米粉的体外消化率来降低GI值。     

挤压和酶解挤压对豌豆粉淀粉体外消化率、蛋白质结构和流变特性的影响

目的:研究挤压和酶解挤压处理对豌豆粉理化性质的影响.方法:采用挤压和酶解挤压的方法改性豌豆粉,利用扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱、快速黏度分析仪、流变仪分析原料、挤出物和酶解物3种样品的结构变化,并测定体外淀粉消化特性.结果:挤压处理能部分破坏豌豆的结构,表现为相对结晶度下降,I1045cm-1/I1...     

Effect of seed treatments on the chemical composition and properties of two amaranth species: starch and protein

The seeds of two Amaranth species were studied. The starch contents were 543 and 623 g kg^?1 while crude protein contents were 154 and 169 g kg^?1 for Amaranthus caudatus and Amaranthus cruentus seeds, respectively. The effect of several treatments, including cooking, popping and germination and flour air classification on the protein and starch properties were studied. Air classification decreased the starch content and increased the protein content, while heating increased the protein but did not affect the starch content. Germination decreased both starch and protein contents. Amylose content was increased by air classification and heating, but was not affected by germination. It was found that all treatments increased the starch swelling power and reduced the falling number. The resistant starch content was increased in the high protein flour (HPF) fraction and germinated flour compared with the raw flour, while its content decreased in the heat treated seed flours. These processes also affected the starch gelatinization temperature and peak viscosity. The thermal properties of the starch flour were not affected by air classification while gelatinization energy was decreased significantly (by 52.0 and 90.0% and by 70.0 and 95.0%) in cooked and popped A caudatus and A cruentus seed flours, respectively. The gelatinization energy was highest in germinated seeds dried at 90 °C with values of 2.67 and 3.87 J g^?1. Air classification reduced the level of all protein fractions. Thermal treatment decreased the water‐soluble fraction (albumins + globulins) and alcohol‐soluble fraction (prolamins) in both species. The levels of all fractions except the water‐soluble fraction (albumins + globulins) were reduced significantly in both species by germination, which mainly increased the amount of aspartic acid, serine and alanine, while the amounts of threonine, arginine and tyrosine decreased in both species. The polypeptide bands of the HPF in both species were unchanged compared with the raw seed flours, but more intensive coloured bands were observed. Thermal treatments eliminated major and minor bands above 35.0 KDa in both species. Copyright © 2004 Society of Chemical Industry     

Physicochemical and digestion characteristics of flour and starch from eight Canadian red and green lentils

Physicochemical and nutritional properties of flour and isolated starch from eight Canadian lentil cultivars were assessed to identify unique samples and key factors affecting starch digestion. The results showed that nearly half of apparent amylose in lentil flours was underestimated because it was complexed and embedded within the flour matrix, which led to slower starch digestion of cooked flour. Cooked red lentil flours showed significantly higher resistant starch content (11.0%) than flours from green lentils (6.8%) (P < 0.05). Among green lentils, Asterix and Greenland were unique for their high slowly digestible starch content after cooking, possibly owing to their high phenolic content and α‐glucosidase inhibitory activity. Long‐ and short‐range ordering in starch was more indicative of low starch digestion for raw or cooked lentil flour rather than for isolated starch. The results suggest the flour matrix protects the starch ordered structure from enzyme hydrolysis.     

Preparation and properties of RS III from waxy maize starch with pullulanase

Waxy maize starch was treated by pullulanase debranching and retrogradation at room temperature to produce resistant starch (RS). Physicochemical properties, crystalline structure and in-vitro digestibility of starch samples with different RS content were investigated. Compared with native starch, apparent amylose content of RS products increased. Based on Gel Permeation Chromatography (GPC) the Molecular Weight Distribution (MWD) of resistant starches significantly changed. Scanning Electron Microscopy (SEM) showed that upon pullulanase debranching and retrogradation treatment the granular structure of native starch was destroyed and all RS samples exhibited irregular shaped fragments. Crystal structure of samples changed from A–type to a mixture of B and V–type. The crystallinity of resistant starch also improved as compared with native starch. Moreover, samples with higher resistant starch showed higher relative crystallinity. Differential Scanning Calorimetry (DSC) determination showed that To、Tp、Tc and ΔH all increased which was in agreement with RS content. The resistance of waxy maize starch with Pullulanase treatment to α-amylase digestibility also increased, while the in-vitro digestibility of products decreased.     

Effects of high hydrostatic pressure on the RS content of amaranth,quinoa and wheat starch

RS exerts a range of beneficial effects on human health. Therefore, ways to increase the RS content in processed food products are looked for. The effects of high hydrostatic pressure treatments on the RS content of wheat, quinoa and amaranth starch were analysed in this study. A 2³ factorial screening design of experiments was used. Experimental factors were pressure (100–600 MPa), temperature (40–60°C) and time (10–30 min). RS in wheat starch increased with increasing pressure by a factor of up to 10 to a value of 4%. In detail, RS content increased significantly at pressures higher than 100 MPa in wheat starch, whereas in quinoa starch significant changes occurred at pressures above 350 MPa (up to 3.3% RS compared to 0.2% in native quinoa starch). Contrary, in amaranth starch the RS content of all pressure treated samples (about 0.5%) was lower than that of the native starch (1.3%). Wheat starch granules swelled to a maximum of 3.67 times their original size and quinoa starch up to 3.36 times. The extent of swelling (2.90) was lowest in amaranth starch.     

Effect of processing and storage time on in vitro digestibility and resistant starch content of two bean (Phaseolus vulgaris L) varieties

Seeds from two commercial bean varieties were cooked and stored for different times and analysed for chemical composition and in vitro starch digestibility. Parallel portions of cooked seeds were dried at 55 °C, milled and stored as flours. In general, protein and ash contents in both samples did not change with storage time, but statistical differences were shown between the two varieties (p < 0.05). Available starch (AS) contents in flours from the ‘negro’ variety did not change (p < 0.05) with storage time and, in general, were higher than in ‘flor de mayo’ samples, whose AS levels decreased during storage. The lower AS in ‘flor de mayo’ flour could be the consequence of formation of resistant starch due to retrogradation. Samples of whole ‘negro’ seeds did not show differences in AS content at 0, 24 and 48 h of storage compared with the corresponding flours, but at 72 and 96 h the AS increased in the whole samples. ‘Flor de mayo’ showed a similar pattern in flour and whole samples, with slightly higher values in the whole seeds. In general, total resistant starch (RS) content in the two varieties was higher in the flours than in ‘whole’ seeds, a fact that is not easy to explain at present. ‘Negro’ flour presented an RS content around 65.0 g kg^?1, and approximately 55.0 g kg^?1 was recorded in ‘flor de mayo’, with slight changes when storage time increased. Whole ‘flor de mayo’ showed significant levels of the retrograded portion of resistant starch (RRS), which did not change with storage time (p < 0.05). However, values were lower than in the flours. A pattern similar to that of the ‘negro’ variety was obtained for ‘flor de mayo’, since the flour exhibited higher amounts of RRS; however, in this variety, the RRS content in ‘whole’ samples decreased after prolonged storage. Flours presented higher amylolysis rates than whole samples, and the ease of digestion increased with storage time. Copyright © 2003 Society of Chemical Industry     

Effect of Chlorine Treatment on Wheat Flour and Starch: Measurement of Thermal Properties by Differential Scanning Calorimetry

Differential scanning calorimetry (DSC) was used to study the effect of chlorine treatment of wheat flour on the heat of gelatinization of the wheat flour and starch. The DSC thermograms were corrected for heat capacity changes and thermal lag. An endothermic transition occurred in both flours and starches at a temperature commonly associated with starch gelatinization. The enthalpy (ΔH) for the starches was concentration dependent. The chlorine treatment did not affect significantly the transition temperatures nor enthalpies of either the flour or the starch isolated from it. Addition of sucrose delayed the onset of gelatinization and increased the ΔH for both treated and untreated wheat flours and starches.     

Texture properties of rice cakes made of rice flours treated with 4-α-glucanotransferase and their relationship with structural characteristics

Rice flours were treated using a thermostable 4-α-glucanotransferase (GTase) from Thermus aquaticus for 1, 3, and 48 h. Molecular weight of modified rice starch rapidly decreased within 1 h of reaction, then slowed down. As the reaction proceeded, the proportions of short (<DP 11) and long (>DP 30) branched chains of modified starch increased, whereas the proportion of medium chains decreased. Rice cakes were prepared with native and GTase-treated rice flours (substitution at 5%) and kept for 3 and 21 h. Texture profile analysis indicated significantly increased hardness, adhesiveness, chewiness, and resilience in rice cakes containing treated rice flours. Sensory analysis revealed that the rice cakes containing 48 h-treated flour had significantly increased springiness, hardness, toughness, and adhesiveness during both storage periods. Meanwhile, it displayed the lowest starch-like attribute and crumbliness. These results suggested that the substitution for 48 h GTase-treated rice flour could retard the retrogradation of rice cakes.     

Slowly digestible sweetpotato flour: Preparation by heat-moisture treatment and characterization of physicochemical properties

The preparation and physicochemical characteristics of sweetpotato flour with increased slowly digestible starch (SDS) fraction were investigated under various heat-moisture treatment (HMT) conditions. The optimum conditions for preparing slowly digestible sweetpotato flour established using response surface methodology were moisture content of 22%, temperature of 103°C, and treatment time of 5.8 h. The highest SDS content in heat-moisture treated sweetpotato flour was 57.6%. The relative crystallinity of heat-moisture treated sweetpotato flour decreased, but the X-ray diffraction pattern maintained the A-type. The DSC of the heatmoisture treated flour showed a decreased gelatinization temperature range and gelatinization enthalpy compared with native one. The viscosity profiles and values changed significantly with HMT, resulting in a higher pasting temperature, decrease of the viscosity values, and no breakdown. It indicates that heat-moisture treated sweetpotato flour is more stable at high temperatures and shear rates than native one.     

Production of Resistant Starch by Extrusion Cooking of Acid-Modified Normal-Maize Starch

ABSTRACT:  The objective of this study was to utilize extrusion cooking and hydrothermal treatment to produce resistant starch (RS) as an economical alternative to a batch-cooking process. A hydrothermal treatment (110 °C, 3 d) of batch-cooked and extruded starch samples facilitated propagation of heat-stable starch crystallites and increased the RS contents from 2.1% to 7.7% up to 17.4% determined using AOAC Method 991.43 for total dietary fiber. When starch samples were batch cooked and hydrothermally treated at a moisture content below 70%, acid-modified normal-maize starch (AMMS) produced a greater RS content than did native normal-maize starch (NMS). This was attributed to the partially hydrolyzed, smaller molecules in the AMMS, which had greater mobility and freedom than the larger molecules in the NMS. The RS contents of the batch-cooked and extruded AMMS products after the hydrothermal treatment were similar. A freezing treatment of the AMMS samples at −20 °C prior to the hydrothermal treatment did not increase the RS content. The DSC thermograms and the X-ray diffractograms showed that retrograded amylose and crystalline starch–lipid complex, which had melting temperatures above 100 °C, accounted for the RS contents.