Composition and in vitro digestibility of raw versus cooked white- and colour-flowered peas

Ten pea cultivars (four white-flowered, Pisum sativum ssp. hortense, and six colour-flowered, Pisum sativum ssp. arvense) grown in Latvia were analyzed and tested in in vitro experiments, as raw and cooked seeds. The colour-flowered (CF) had a greater proportion of hulls and a higher acid detergent fibre (ADF) content than white-flowered (WF) pea seeds (10.7 vs. 8.2% and 92.2 vs. 84.5 g/kg dry matter (DM), respectively). Three out of six CF varieties had a significantly greater amount of protein bound to neutral detergent fibre (NDF) than WF peas. The tannin content was higher in CF than in WF peas (8.46 vs. 0.37 g/kg DM). In vitro protein and amino acid digestibility was about 8% higher in WF than in CF varieties. Cooking decreased the tannin content in CF peas (8.46 vs. 5.51 g/kg DM) but had no effect on in vitro protein digestibility. Heat treatment reduced significantly trypsin inhibitor activity and amount of protein bound to NDF in CF and WF varieties (from 6.50 to 0.52 and from 6.54 to 0.46 trypsin inhibitor units (TIU)/mg DM; from 1.250 to 0.831 and 0.761 to 0.209 g N/100 g NDF, respectively). However, the protein bound to NDF content in pea DM increased in CF and decreased in WF varieties (from 1.525 to 2.145 and from 0.913 to 0.502 g N/kg DM, respectively). Cooking resulted in an increased NDF content over two times in both CF and WF pea seeds (from 122 to 259 and from 120 to 262 g/kg DM, respectively). The results suggest that colour-flowered pea may be considered as an interesting dietary alternative to white-flowered pea since cooking removes trypsin inhibitor activity (TIA), decreases tannins, and increases dietary fibre contents.     

Effect of storage on resistant starch content and in vitro starch digestibility of some pressure‐cooked cereals and legumes commonly used in India

Resistant starch (RS) is that fraction of starch, which escapes enzymic hydrolysis in the small intestine and passes in the colon. Effect of storage time (12 and 24 h) and temperature (4 °C and 25 °C) was studied on RS content of the pressure‐cooked cereal and legume grains/seeds and their flours. RS content was observed to increase in the stored cereals and legumes, with more enhanced increase in the flour samples stored at refrigeration temperature for longer duration (41.4% in wheat flour and 85.4% in pea flour). Significant positive correlations were observed between RS content (4 °C, 24 h) and amylose (y = 0.388 × –5.948, r = 0.840, P ≤ 0.05, n = 7) as well as between % increase in insoluble dietary fibre content (4 °⁰C, 24 h) and amylose (y = 2.257 × –27.724, r = 0.971, P ≤ 0.05, n = 7). Reduced in vitro starch digestibility of the cooked/stored samples (4 °C, 24 h) was observed when compared to freshly cooked samples.     

Effect of variety and processing on nutrients and certain anti-nutrients in field peas (Pisum sativum)

The effect of variety and processing (soaking, cooking and dehulling) on nutrients and anti-nutrients in field peas (Pisum sativum) was investigated. Analysis of variance showed that variety had a significant effect on crude protein, starch, ash, soluble dietary fibre (SDF), insoluble dietary fibre (IDF), total dietary fibre (TDF), trypsin inhibitor activity (TIA), minerals, phytic acid, sucrose and oligosaccharides. Soaking and cooking increased protein content, IDF, TDF, Ca, Cu, Mn and P in peas whereas ash content, Fe, K, Mg, Zn, sucrose and oligosaccharides were reduced. TIA was increased by soaking but reduced by cooking. Cooking was more effective than soaking in reducing oligosaccharides. Dehulling increased crude protein, starch, K, P, phytic acid, stachyose and verbascose content but reduced SDF, IDF, TDF, Ca, Cu, Fe, Mg and Mn.     

马铃薯抗性淀粉结构特征及体外消化特性的研究

研究马铃薯抗性淀粉的结构特征与体外消化特性。方法 以马铃薯淀粉为对照, 采用红外光谱仪、XRD、DSC等手段研究了马铃薯抗性淀粉的碘吸收特性、颗粒形貌、晶型结构形态、热特性等。通过模拟体外消化评价了抗性淀粉的消化性能。结果 马铃薯淀粉和抗性淀粉碘吸收曲线最大吸收峰在580~600 nm,马铃薯抗性淀粉分子量分布更集中。马铃薯淀粉为B型结晶结构, 马铃薯抗性淀粉为C型结晶结构。SEM观察显示：马铃薯淀粉分子颗粒完整, 表面光滑, 整体呈不规则的椭圆形; 马铃薯抗性淀粉分子为不规则多面体, 分子表面粗糙、有凹陷, 且有少量的层状起伏; 红外光谱分析表明抗性淀粉未出现新的基团。DSC检测发现：马铃薯抗性淀粉的热稳定性更高; 马铃薯淀粉和抗性淀粉酶解前2 h内消化速率迅速增加, 酶解2 h后速率减慢, 消化速率逐渐趋于平缓, 血糖指数分别为70.42、40.50。结论 说明马铃薯抗性淀粉具有较致密的结晶结构和酶抗性, 抗消化性显著。     

湿热处理对芋头淀粉糊化和体外消化性能的影响

以荔浦芋为原料制备芋头淀粉,将不同水分含量（10% ~ 30%）的芋头淀粉在110℃条件下湿热处理2 h,研究湿热处理 (HMT) 后芋头淀粉糊化特性和体外消化性能的变化。结果表明,HMT对芋头淀粉颗粒形貌影响不显著,但颗粒之间发生聚集现象,且随HMT水分含量的升高聚集体积增大,粒度也随之增加。随着水分含量增加,HMT使芋头淀粉的溶胀力和溶解度降低,糊化温度升高,糊化焓值降低,淀粉糊黏度降低,但淀粉糊稳定性增加。HMT也改变了淀粉的体外消化性能,增加了慢消化淀粉和抗性淀粉含量。说明HMT可用于扩展芋头淀粉的应用范围,如制造需要在高温下加工的产品或制备低GI值食物。     

The impact of germination and dehulling on nutrients, antinutrients, in vitro iron and calcium bioavailability and in vitro starch and protein digestibility of some legume seeds

The content of nutrients (protein, starch, ash, calcium, iron, phosphorous and thiamin) and antinutritional components (dietary fiber fractions, phytic acid and tannin), and in vitro bioavailability of calcium and iron and in vitro digestibility of protein and starch were determined in control, germinated and dehulled green gram, cowpea, lentil and chickpea. Germination caused significant (P<0.05) increase in protein, thiamin, in vitro iron and calcium bioavailability and in vitro starch and protein digestibility contents of all the legume samples. Further increase in mentioned parameters was observed after dehulling the germinated legumes. Phytic acid and tannin were reduced by 18-21% and 20-38%, respectively, on germination and more reduction was observed in dehulled over germinated samples. There were negative correlations between nutrients bioavailability and digestibility with antinutritional factors.     

Preparation, physicochemical characterization and in vitro digestibility on solid complex of maize starches with quercetin

The objective of this study was to prepare and characterize solid complex of starch with quercetin. Starches with different content of quercetin were prepared and their formation was confirmed by the presence of the carbonyl signal around 1662 cm⁻¹ in the FT-IR spectra. Scanning electron microscopy (SEM) suggested most of the starch granules disintegrated with many visible fragments along with increasing quercetin content in the binary mixtures. X-ray diffraction (XRD) of quercetin-starch complexes revealed that the crystal structure of native starch was disappeared and new crystalline regions were formed. The thermal behavior of quercetin-starch was investigated using thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC). It was observed that the mass loss and thermal stability of complexes depend on the content of quercetin in the complexes. There were obvious differences between pregelatinized starch and quercetin-starch complexes in digestion rate. The digestion rate was drastically reduced as the quercetin was blended. The digestion rate was steady at about 37.3% for pregelatinized starch and 10.1% for quercetin-starch complex (2.5 g/100 g) after incubating 2 h. The residual starch of quercetin-starch complexes can be thought as resistant starch, the amounts of resistant starch were sharply increased in comparison with the pregelatinized starch.     

The determination of water‐soluble vitamins and in vitro digestibility of selected Czech cheeses

Water‐soluble vitamins, in vitro organic matter digestibility (OMD) and dry matter digestibility (DMD) values were determined in various different Czech cheeses. An HPLC method for the simultaneous determination of niacin, pantothenic acid and pyridoxine in cheese was established. Different hydrolysis conditions and enzymes were used to release these vitamins from their complex form. The cheeses contained on average 2.04 mg of niacin, 3.24 mg of pantothenic acid and 2.16 mg of pyridoxine per 100 g of fresh mass. An enzymatic method was applied for the evaluation of OMD and DMD in cheeses. In vitro digestibility values ranged from 83.29% to 99.99% for organic matter (OMD) and 83.33% to 99.87% for dry matter (DMD) after two different enzymatic digestions (pepsin, pancreatin). In addition, cheeses incubated with pepsin plus pancreatin, OMD and DMD were strongly digested (99.04–99.83%, 97.73–99.74%).     

Sensory,functional characteristics and in vitro digestibility of snacks supplemented with non-traditional ingredient raw and processed fenugreek

Fenugreek seeds were germinated, soaked and roasted and were evaluated for nutritional properties. Raw and processed fenugreek seeds were used to develop snack product. Snacks were examined for the sensorial, functional, antinutritional properties and in vitro digestibility. Using sensory analysis, 5% level of substitution of raw and processed fenugreek was accepted for the development of extruded snacks. Lateral expansion was highest for snacks prepared from processed fenugreek (163.0% to 206.1%) than raw fenugreek (162.5 to 168.7%), and vice versa for bulk density. The antioxidant activity and total phenolic content were highest for snacks prepared from germinated fenugreek (7.30% to 9.87% and 1.352 to 3.561 mg GAE g⁻¹ of sample) and lowest for snacks prepared from raw fenugreek (6.68% to 7.03% and 1.29 to 2.76 mg GAE g⁻¹ of sample). Not only extrusion but also processing such as soaking, roasting and germination reduced the antinutritional content of the snack product. Both in vitro digestibilities increased with extrusion cooking. In vitro digestibility was also found to be higher in snacks prepared from processed fenugreek than raw fenugreek. Therefore, development of such functional foods using processed fenugreek would raise the consumer demand and benefit the population by increasing the health status.     

Physicochemical,rheological, morphological,and in vitro digestibility properties of cross-linked starch from pearl millet cultivars

The effect of epichlorohydrin (0.5%) as a cross-linking agent on physicochemical, rheological, morphological, and in vitro digestion properties of pearl millet starches from different cultivars was studied. Degree of cross-linking (DC) ranged between 40.61% and 89.75%, lower values of DC were observed for cv.HC-10 and cv.HHB-67 whereas higher values were observed for cv.HHB-223 and cv.GHB-732. Cross-linked starch from cv.GHB-732 showed the lowest amylose content, swelling power, and solubility as compared to other cultivars. Rheological properties of starches during heating showed their elastic behaviour. G′ value was much higher than the G′′ value at all frequency values for starch pastes. Plots of shear stress (σ) versus shear rate (γ?) data for cross-linked starch pastes were fitted to Herschel-Bulkley model and yield stress (σ_o), flow behaviour index (n), and consistency index (K) were evaluated. Scanning electron micrographs (SEM) investigations revealed that cross-linked starch granules had slightly rough surfaceand grooves with slight fragmentations. Readily digestible starch (RDS) of cross-linked starches varied from 46.1% to 50.6%, cv.GHB-732 had the lowest value. Slowly digestible starch (SDS) and resistant starch (RS) content of cross-linked starches ranged from 34.5% to 36.4% and 13.6% to 19.4%, respectively. cv.HC-10 had the highest value for SDS content while the highest RS content was observed for cv.GHB-732. In comparison to native starches, cross-linked modification decreased SDS and RDS content whereas RS content was increased.     

体外模拟法测定婴儿奶粉中蛋白质的消化率

采用体外模拟的方法测定了婴儿奶粉中蛋白质的消化率。此法的重现性试验的相对标准偏差为1．73％，表明重现性较好。测定结果表明：各种不同原料间蛋白质的消化率差异显差。此法快速，简便，重现性好，可应用于婴儿食品质量的评定。     

环氧氯丙烷交联淀粉的制备及其体外消化性能的研究

以环氧氯丙烷为交联剂,制备土豆交联淀粉。用正交实验考察环氧氯丙烷用量、氢氧化钠用量、反应温度和反应时间四个因素对交联度的影响,确定最佳工艺条件,并对体外消化条件进行优化,对不同交联度淀粉的消化速度进行研究。体外淀粉消化条件的优化实验显示,消化产物测定的最佳条件为：波长485nm,显色温度100℃,显色时间30min,葡萄糖浓度范围0～80μg/mL,其回归方程为y=0.0044x-0.005,R2=0.9988,且样品溶液在2h内显色稳定。各因素对交联淀粉制备影响的重要性依次为环氧氯丙烷用量、氢氧化钠用量、温度及反应时间;最佳工艺条件为：以50g土豆淀粉计,环氧氯丙烷用量为1.00mL,氢氧化钠用量为0.75g,温度50℃,时间6h,土豆交联淀粉和交联前相比,消化性降低了13.7%～34.5%,且与交联度呈负相关。     

Relationship between proportion and composition of albumins,and in vitro protein digestibility of raw and cooked pea seeds (Pisum sativum L.)

BACKGROUND: Peas provide an excellent plant protein resource for human diets, but their proteins are less readily digestible than animal proteins. To identify the relationship between composition and in vitro digestibility of pea protein, eight pea varieties with a wide range of protein content (157.3–272.7 g kg^?1) were determined for the proportion of albumins and globulins, their compositions using sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and in vitro protein digestibility (IVPD) before and after heat treatment using a multi‐enzyme (trypsin, chymotrypsin and peptidase) method. RESULTS: The proportion of albumins based on total seed protein content decreased from 229 to 147 g kg^?1 as seed protein content increased from 157.3 to 272.7 g kg^?1, while the proportion of globulins increased from 483 to 590 g kg^?1. The IVPDs of eight raw pea seeds were 79.9–83.5%, with significant varietal variations, and those were improved to 85.9–86.8% by cooking. Albumins, including (pea albumins 2) PA2, trypsin inhibitor, lectin and lipoxygenase, were identified as proteolytic resistant proteins. Globulins were mostly digested by protease treatment after heating. CONCLUSION: The quantitative ratio of albumins and globulins, and the quantitative variations of albumin protein components, including lipoxygenase, PA2, lectins and trypsin inhibitors, appear to influence the protein digestibility of both raw and cooked pea seeds. Copyright © 2010 Society of Chemical Industry     

Amylose content,molecular structure,physicochemical properties and in vitro digestibility of starches from different mung bean (Vigna radiata L.) cultivars

Physicochemical and in vitro digestibility characteristics of starches isolated from six cultivars of mung bean (Vigna radiata L.) were studied. Significant differences (p < 0.05) were observed between the cultivars with respect to amylose content (29.9–33.6%), relative crystallinity (29.0 to 31.7%), particle diameter (16.2–17.1 µm) and molecular weight of amylopectin (260–289 × 10⁶ g/mol). The scanning electron micrographs revealed the presence of large oval to small round shape granules with average particle diameter of 16.2–17.1 µm. The X‐ray diffraction pattern was of the C‐type. The enthalpies of gelatinization and retrogradation were 8.9–10.3 and 4.6–6.3 J/g, respectively. The amounts of slowly digesting and resistant starch of mung bean followed the order: PBM‐1 > SML‐32 > ML‐613 > SML‐134 > ML‐267 > ML‐5 and ML‐5 > ML‐267 > SML‐134 > ML‐613 > SML‐32 > PBM‐1, respectively. The six starches exhibited significant (p < 0.05) differences in their pasting parameters. Correlation analysis showed that amylose content, granule diameter and relative crystallinity values were important in determining thermal, pasting and in vitro digestibility of starches.     

Effect of fructans-based fat replacer on chemical composition, starch digestibility and sensory acceptability of corn snacks

To develop a convenience healthy food snack the partially hydrogenated vegetable fat, used as the flavour fixative agent, was replaced by a non-fat-flavouring solution enriched with inulin and oligofructose. The effects of this replacement on chemical composition, in vitro rate of starch digestion and sensory acceptability were assessed. The new snack presented low-fat levels (0.1%) and around a sevenfold increase in dietary fibre (15.3% of dietary fibre, being 13.3% of fructans) when compared with the traditional ones. The enrichment with fructans reduced the predicted Glycaemic Index by 25%, thus indicating that this dietary fibre contributes effectively towards delaying the in vitro glycaemic response. Fructans-enriched snack presented overall acceptability score (6.6 ± 1.7) similar to the traditional one, flavoured with fatty fixative agent (7.4 ± 1.4). The healthy low-fat fibre-enriched snack produced presented the high sensory acceptability typical for this food product type.     

Influence of depigmentation of pearl millet (Pennisetum gluacum L.) on sensory attributes, nutrient composition and in vitro digestibility of biscuits

Presence of high concentration of pigments in the pericarp and endosperm regions of pearl millet imparts undesirable gray color to its products. This study attempts to improve the acceptability of pearl millet products through processing technique and to study its effect on nutritional composition of pearl millet product. Pearl millet grains were depigmented by soaking in 0.2 N HCl for 18 h followed by washing, blanching at 98°C for 30 s and sun drying. Three different types of biscuits were prepared from refined flour (Reference), native or unprocessed pearl millet (T-I) and depigmented pearl millet (T-II). Results indicated that depigmentation improved the sensory attributes especially the color of pearl millet biscuits (T-II). The protein, fat, ash and total dietary fiber of pearl millet based biscuits (T-I as well as T-II) were significantly (P?0.05) higher than the reference biscuits. Depigmentation significantly improved the in vitro starch digestibility, in vitro protein digestibility and the soluble dietary fiber content of pearl millet biscuits (T-II) by 14.50, 6.56 and 6.18%, respectively. On the other hand, a significant decrease of 6.73, 2.43 and 17.03 g/100 g in protein, starch and insoluble dietary fiber was detected in pearl millet biscuits (T-II) due to depigmentation.