Comparative studies between the optimum dietary fibre sources of some substituted cookies

To realize the line of balance between utilization of dietary fibre sources level of substitution and maximum improvement or minimum reduction of in vitro protein digestibility in high dietary fibre cookies, the optimum level of substitution by corn bran, rice bran and barley husk were studied. Analysis for amino acids composition, infrared absorption spectroscopy and X-ray diffraction were carried out. Rice bran was the best fibre source for improving lysine content. Barley husk fulfilled two criteria viz. improvement in lysine content and minimum decrease in amino acids content.     

Semi-solid fibre syrup for sugar reduction in cookies

Since sugar reduction is a pillar of the international nutritional guideline, the food industry is constantly looking for new ingredients able to replace sugar technological functionality while satisfying the consumer's request for clean label. Based on corn (Zea mays) dextrin and seed coats of chickpeas (testa of Cicer arietinum seed), a fibre syrup was tested as bulking agent in cookies to reach 30% and 50% sugar reduction. Cookies were characterised for their physicochemical, rheological and sensorial attributes. Fibre syrup addition did neither hinder dough workability nor require changes in cookie production procedure. The use of the fibre syrup permitted to partially preserve the structural strength of cookies and increased their red colour index. Moreover, the fibre syrup use allowed to obtain sugar-reduced cookies qualified for ‘reduced in sugar’ and ‘high in fibre’ nutritional claims.     

Apparent digestibility of dietary fibre and other components in table olives

The apparent digestibility of the main components of the olive (Olea europaea arolensis) has been studied using young Wistar rats. An appreciable digestibility of fibre was found (of the order of 31% Neutral Detergent Fibre) and a high digestibility of fats (higher than 60%) and sugars (100% of glucose and 76% of fructose). Some 41% of the protein was digested, a relatively low value when compared with other products. If the diet is previously desalted, the digestibility of the components diminishes. There are significant differences in the digestibility of dry matter, fibre, cellulose and lignin, but not in proteins and fat.     

羧甲基化反应改善膳食纤维性能的研究

对大豆不溶性膳食纤维(IDF)进行改性,探讨了羧甲基改性方法对IDF持水力等性能的影响,通过正交实验优选出最佳改性条件,即:乙醇体积分数85%,NaOH总用量0.3 g(原料用量1.0 g),碱醚摩尔比2.1∶ 1,反应温度45 ℃,反应时间2.5 h.在此最佳条件下,改性IDF的持水力、膨胀力、持油力和阳离子交换容量比未改性产品分别提高了101.71%、147.00%、14.61%和19.35%.     

高纤维压缩饼干的研制

膳食纤维对人体有很多生理功能，本课题升对船员在航海中易发生便秘的问题，将麦麸，魔芋精粉等主要原料精制后添加到食品中，从而提高食品膳食纤维含量，并研制出一种适合船员在特殊环境下食用，有利用于预防和改善便秘的高纤维压缩饼干.     

Bread fortified with dietary fibre extracted from culinary banana bract: its quality attributes and in vitro starch digestibility

The effect of fortification of dietary fibre (DF) on dough rheology, quality characteristics and in vitro starch digestibility of bread was studied. Bread was prepared incorporating DF (2–4 g per 100 g of flour mixture). Rheological study of dough showed an increase in dough stiffness and elasticity with higher incorporation of the DF. The results of chemical composition revealed that addition of DF increased total DF (19.65 g per 100 g) content of bread. However, incorporation of 2 g per 100 g DF of flour mixture with 66 g per 100 g moisture showed higher water retention and specific volume of 86.76% and 5.83 cm³ g⁻¹, respectively, which was close to control bread. Improved textural property with acceptable sensory attributes was observed for bread fortified with 2 g per 100 g DF of flour mixture and 66 g per 100 g moisture content. Incorporation of DF (2–4 g per 100 g of flour mixture) showed a decrease in rapidly digestible starch (RDS) and an increase in slowly digestible starch (SDS) content with lower predicted glycaemic index (pGI) than control bread.     

菜籽蛋白的制备及其体外模拟消化

采用响应面法(RSM)优化了菜籽蛋白提取的3个影响因素(pH、温度、液料比).同时对大豆蛋白(SPI)、菜籽蛋白(PPI)及其12S组分(RP-12S)、2S组分(RP-2S)进行模拟体外消化,结合SDS-PAGE分析和可溶性氮释放量评价了菜籽蛋白消化率.结果表明,在 pH 12.0、液料比19:1、55.0 ℃下提取菜籽粕 30 min,重复2次,最大提取率可达 78.85%,酸沉 pH 为5.0.经胃蛋白酶、胰蛋白酶体系消化,PPI、RP-12S、RP-2S的可溶性氮释放量分别为 84.51%、78.33%、80.39%.均比 SPI 的可溶性氮释放量高.说明菜籽蛋白拥有比大豆蛋白更好的消化性,是适合人类食用的优质蛋白质.     

Effect of the insoluble dietary fibre from oil palm fat-free flour on digestibility in rats

This work shows the results of comparing the effects of the insoluble dietary fibre from oil palm fat-free flour and cellulose on the growth, weight, humidity and composition of faeces in adult rats (Sprague–Dawley). Five groups of rats were fed for 4 weeks. The control group was fed with a diet free of fibre, and the remaining four groups with diets containing 50 or 100 g of either oil palm fat-free flour or cellulose, respectively. The adaptation period was 4 days. The evolution of growth and food intake did not vary significantly p<0.05 regardless of the type of diet. On the other hand, faeces excretion increased by 3.3–4.7 g/day in the groups of rats fed with oil palm fat-free flour, while it increased by only 3.1–4 g/day in diets based on cellulose. A higher content of water was observed in the faeces of rats fed with insoluble dietetic fibre from oil palm fat-free flour. The apparent digestibility of the insoluble dietary fibre of oil palm fat-free flour was low (35%), showing resistance to fermentation. The digestibility of the protein tended to decrease more with the insoluble dietary fibre of oil palm than with the cellulose, which may be related. ©     

Variation in in vitro digestibility of barley protein.

In vitro digestibility of protein was measured with pepsin/pancreatin in 321 spring barley lines grown in the field. The variation in digestibility was far less than the variation in the protein content. A small environmental influence on the digestibility was found. Two entries had slightly impaired digestibilities; these findings were partially verified in a repeated field trial, but were not confirmed in vivo. In vitro digestibilities of barleys grown in pots at various N-levels were positively correlated with protein or hordein content. In vitro digestibility was negatively correlated with the fibre content in decortification fractions of Bomi and the high-lysine mutant Risø 1508. The digestibility was positively correlated with the hordein concentration for the Bomi fractions, but not for the 1508 fractions.     

In vitro digestibility of protein and amino acids in protein mixtures

Six protein sources, casein, field peas, peanut meal, wheat flour, rapeseed and soya bean concentrate and their blends (ratio 1:1) were subjected to in vitro enzymic digestion. Wheat flour had the lowest in vitro digestibility (30% in 6 h) while the other sources had similar digestibilities (40%). Basic and aromatic amino acids were the most readily liberated from these protein sources. Some protein combinations, such as a rapeseed/field pea blend, gave in vitro digestibilities higher than calculated from individual proteins. The type of response observed could not be predicted from either nitrogen digestibility or amino acid composition of the individual sources. The digestibility of some amino acids was modified and this could be due to varying affinity of digestive enzymes for the protein.     

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。     

Ileal amino acid digestibility of some novel dietary protein sources for growing chickens

The apparent ileal digestibility coefficients of amino acids in five high‐protein ingredients (casein, isolated soyprotein, maize gluten meal, spray‐dried bovine plasma (SBP) and spray‐dried porcine plasma (SPP)) and soybean meal were determined using 3‐week‐old broiler chickens. The amino acids in casein were highly digestible. Isolated soyprotein was also well digested by the birds, but the digestibility coefficients of all amino acids in isolated soyprotein were lower (P < 0.05) than those in casein. The amino acid digestibility coefficients in isolated soyprotein were greater (P < 0.05) than those in soybean meal, which may be reflective of reduced concentrations of anti‐nutritive factors, particularly indigestible oligosaccharides. The digestibilities of amino acids in maize gluten meal were higher (P < 0.05) than those in soybean meal, except for the digestibilities of arginine, histidine, threonine and aspartic acid, which were similar (P > 0.05) between the two protein sources. The ileal digestibilities of all indispensable amino acids in SBP and SPP were lower (P < 0.05) than those in casein and isolated soybean meal but higher (P < 0.05) than those in soybean meal. No differences (P > 0.05) were observed in the digestibility of amino acids between SBP and SPP. The overall mean amino acid digestibility coefficients of casein, isolated soyprotein, soybean meal, maize gluten meal, SBP and SPP were 0.955, 0.888, 0.823, 0.849, 0.860 and 0.856 respectively. Copyright © 2006 Society of Chemical Industry     

Factors affecting the in vitro protein digestibility of chickpea albumins

In vitro protein digestibility (IVPD) of chickpea albumins and its possible relationship to their structure and the presence of trypsin inhibitor activity (TIA) have been studied. Trypsin digestion of the albumin fraction under non‐reducing conditions was incomplete, while the reduction of inter‐ and intramolecular disulphide bonds caused an improvement in the accessibility of sites susceptible to trypsin digestion. Trypsin inhibitor activity in the chickpea albumin fraction was dependent upon both temperature and heating time. Although heating the albumin fraction at 100 °C for 30 min reduced the TIA by more than 50% with respect to the initial activity, an important TIA rate was attributable to heat‐resistant trypsin inhibitor. The TIA decrease was not related to an increase in the rate of IVPD. However, we observed a significant (P ≤ 0.05) increment in IVPD in the presence of β‐ME, confirming the essential role of disulphide bonds in stabilising the protein structure of the albumin fraction. © 2000 Society of Chemical Industry     

Incorporation of sugarcane bagasse in the development of high dietary fibre noodles

Sugarcane bagasse (SB) is one of the most abundant food wastes. In this research, SB was incorporated into the development of noodles at three different ratios, i.e. 5%, 10% and 15%. Total dietary fibre of noodles significantly increased from 3.39% (control noodles; – without SB) to 13.85% with 15% SB incorporation. All SB incorporated noodles (SBNs) were qualified to be labelled as ‘High in dietary fibre’. The 15% SBN had the highest fibre content and lowest dialyzable glucose, but the organoleptic properties were the lowest. Due to that, 5% SBN was deemed to be the most suitable ratio for noodles incorporation, as it had the closest value towards the commercial noodles in terms of colour, texture, fibre content and dialyzable glucose concentration of noodles samples. In terms of sensory evaluation, the 5% SBN had the highest overall acceptability, and the ratio was suitable for noodles development.     

决明子蛋白质提取工艺研究及其体外消化率的测定

目的:优选决明子蛋白质的最佳提取工艺及体外消化率测定.方法:采用正交试验法,以凯氏定氮法测得决明子蛋白质的含量和得率为考察指标,对提取过程中缓冲液浓度、pH值、固液比及提取时间4个工艺因素进行优化研究.并用胃蛋白酶-胰蛋白酶法测定体外消化率.结果:决明子蛋白质最佳提取工艺为KH2PO4-NaOH缓冲液浓度为50 mmol/L,pH值为8.0,液固液比为1:50,提取12h.影响决明子蛋白提取各因素的主次关系为:缓冲液浓度＞pH值＞固液比＞提取时间.其中缓冲液浓度和pH值的影响迭显著性水平.优化参数下提取的决明子粗蛋白含量为93.0%,提取率为94.2%,体外消化率为97.6%.结论:决明子是含蛋白质较高的植物种子,其蛋白质消化率较高,具有很好的开发前景.     

In vitro protein digestibility of legumes cooked with spices

The present study was planned to investigate the effect of spices on in vitro protein digestibility in decorticated forms of bengal gram (Cicer arietinum), black gram (Phaseolus mungo), green gram (Phaseolus radiatus) and red gram (Cajanus indicus). The spices used were chilli (Capsicum annum), pepper (Pepper nigrum L.), coriander (Coriander sativum) and a mixture of these. Legumes were pressure cooked with 5.0% of freshly powdered spices and in vitro protein digestibility determined using pepsin and pancreatin enzymes by standard techniques. Samples without spices served as controls. The results reveal that protein content of legumes ranged from 20.5 to 23.0 g/100 g. The percent protein hydrolysed for legumes without spices were 63.4 for bengal gram, 65.8 for black gram, 60.0 for green gram and 55.4 for red gram. Casein sample could be hydrolysed to the extent of 78.8%. Chilli powder decreased digestibility significantly by 50, 78, 73, 60 and 69% in casein, bengal gram, black gram, green gram and red gram, respectively. Pepper exhibited a variable effect of altering the digestibility to 93% in casein and red gram, 106% in black gram and green gram and 98% in bengal gram, which were not significant. Coriander also decreased digestibility by 48, 76, 87, 77 and 73% and mixture of spices by 74, 91, 96, 96 and 82% in casein, bengal gram, black gram, green gram and red gram, respectively. It can be concluded that spices do influence in vitro protein digestibility in legumes to varying extent.     

Storage stability of a high dietary fibre powder from orange by-products

The goal of this investigation was to evaluate the effects of storage time and conditions on the physicochemical and microbiological properties of a high dietary fibre powder (HDFP). HDFP for this study was manufactured from orange juice industry by-products. The storage period was 11 months and samples were stored under vacuum or air exposure and under dark or light exposure. The HDFP is a stable product (based on chemical, microbiological and physicochemical properties) with large amounts of dietary fibre (71.62 ± 0.24 g 100 g⁻¹ dry sample) and polyphenols content (40.67 ± 0.45 mg g⁻¹ dry sample). Hesperidin is the major compound identified in HDFP (higher than 50% of total phenolic compounds). The packaging material used protects the HDFP only up to 6 months. After this time, the increase in moisture content decreases the quality of the product. The best storage conditions are packaging under vacuum and darkness. Both conditions preserve the colour of the fibres probably by means of avoiding pigment degradation.     

琥珀酰化对玉米醇溶蛋白消化率的影响

酰化改性是现代食品蛋白质化学的改性方法之一。本研究通过对玉米醇溶蛋白琥珀酰化的改性研究发现,随着酰化试剂用量的增大,酰化程度不断提高,总体趋势是先快后慢。随酰化程度增大,玉米醇溶蛋白的含氮量降低,分子量减小,但是溶解度和消化率都有所提高,这表明琥珀酰化改变了玉米醇溶蛋白的结构,改善了其性质。     

Water recycling in processing orange peel to a high dietary fibre powder

Water recyling in fruit and vegetable processing may contribute to decreasing industrial waste and load. Water was recycled for washing orange peel to prepare a high dietary fibre powder using tap water washing as the standard. Total sugar (12.1–13.1%), total dietary fibre (70–71.5%), soluble dietary fibre (21–22%), yield (59–60%), water holding capacity (7.8–8.1  g water g⁻¹ dry matter), colour and microbiological quality of a dry product were not significantly affected when the liquors from pulping and pressing were recycled for washing peel. Recycling liquors from pulping and pressing gave the highest energy (43%) and water (33.4%) savings, respectively.