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1.
The effect of different conditions of pea germination on dietary fiber (DF) composition was studied. Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) were subjected to acid hydrolysis, and the resultant neutral sugars, uronic acids, and Klason lignin were quantified. Germinated peas exhibited significantly higher contents of total dietary fiber (TDF) than the raw sample, due to the increases of both DF fractions. Under darkness conditions, germination exhibited the highest contents of IDF and SDF. Decreasing IDF/SDF ratios showed that the carbohydrate changes did not take place to the same extent during germination, the SDF fraction being the most affected. The detailed chemical composition of fiber fractions reveals increases of cellulose in the IDF of germinated samples, whereas SDF exhibits a decrease of pectic polysaccharides and also increases of polysaccharides rich in glucose and mannose. The DF results were corroborated by a comparative examination of the cell wall carbohydrate composition.  相似文献   

2.
Onion tissues of three varieties were evaluated for dietary fiber (DF) composition. Insoluble (IDF) and soluble (SDF) dietary fibers were subjected to acid hydrolysis, and the resultant neutral sugars, uronic acids, and Klason lignin were quantified. Brown skin exhibited the highest total dietary fiber (TDF) content (65.8%) on a dry matter basis, followed by top (48.5%) and bottom (38.6%), IDF being the main fraction found. The SDF:IDF ratio decreased from inner to outer tissues. Brown skin and outer leaves byproducts appear to be the most suitable sources of DF that might be used in food product supplementation. The chemical composition reveals that cellulose and pectic polysaccharides were the main components of onion DF in all tissues, although differences between them were noticed. An increase in the uronic acids/neutral sugars ratio from inner to outer tissues was found, suggesting that the galactan side chain shows a DF solubilization role.  相似文献   

3.
A collaborative study was conducted to determine the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), and total dietary fiber (TDF) content of food and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that developed for TDF only, which was adopted official final action by AOAC, except for changing the concentration of buffer and base and substituting hydrochloric acid for phosphoric acid. These changes were made to improve the robustness of the method. Duplicate blind samples of soy isolate, white wheat flour, rye bread, potatoes, rice, corn bran, oats, Fabulous Fiber, wheat bran, and a high fiber cereal were analyzed by 13 collaborators. Dietary fiber values (IDF, SDF, and TDF) were calculated as the weight of residue minus the weight of protein and ash. The coefficients of variation (CVs) of both the independent TDF determination and the sum of IDF and SDF were better than 15 and 18%, respectively, with the exception of rice and soy isolate. These 2 foods, however, contained only about 1% TDF. The CVs of the IDF were equally good, except for Fabulous Fiber, for which filtration problems occurred. The CVs for the SDF were somewhat high, but these products had very low SDF content. There was excellent agreement between the TDF determined independently and the TDF determined by summing the IDF and SDF. The method for separate determination of IDF and SDF requires further study. The modifications (changes in concentration of buffer and base and the use of hydrochloric acid instead of phosphoric acid) to the official final action method for TDF have been adopted.  相似文献   

4.
The effects of soaking, cooking, and industrial dehydration treatments on soluble carbohydrates, including raffinose family oligosaccharides (RFOs), and also on total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble (SDF) dietary fiber fractions were studied in legumes (lentil and chickpea). Ciceritol and stachyose were the main alpha-galactosides for chickpea and lentil, respectively. The processing involved a drastic reduction of soluble carbohydrates of these legumes, 85% in the case of lentil and 57% in the case of chickpea. The processed legume flours presented low residual levels of alpha-galactosides, which are advisable for people with digestive problems. Processing of legumes involved changes in dietary fiber fractions. A general increase of IDF (27-36%) due to the increase of glucose and Klason lignin was observed. However, a different behavior of SDF was exhibited during thermal dehydration, this fraction increasing in the case of chickpea (32%) and decreasing in the case of lentil (27%). This is probably caused by the different structures and compositions of the cell wall networks of the legumes.  相似文献   

5.
This study was undertaken to evaluate the lipidemic response of rice bran and the possible enhancement of its healthful properties by using raw or processed white or brown rice in place of corn starch. All diets contained 10% total dietary fiber, 15% fat, and 0.5% cholesterol. Weanling male golden Syrian hamsters were fed cellulose control (CC), processed corn starch (PCS), cellulose with processed brown rice (CPBR), rice bran (RB), RB with white rice (RBWR), RB with processed white rice (RBPWR), RB with brown rice (RBBR), and RB with processed brown rice (RBPBR) diets. After three weeks, the PCS diet significantly lowered total plasma cholesterol (TC) compared with the CC, CPBR, RBWR, and RBPBR diets. RB and RBBR diets significantly lowered TC and LDL‐C compared with CPBR diet. All the RB‐containing and PCS diets significantly lowered liver cholesterol and liver lipid content. Processing white rice increased TDF content 240% and insoluble dietary fiber (IDF) 360%, whereas soluble dietary fiber (SDF) decreased by 25%. Uncooked brown rice contained 7 times as much TDF as uncooked white rice. Processing brown rice decreased its TDF, IDF and SDF contents by 12, 6, and 42%, respectively. The data suggest that a possible mechanism for cholesterol‐lowering by rice bran, with or without added raw or processed rice (white or brown), is by decreasing lipid digestibility and increasing neutral sterol excretion, whereas cholesterol‐lowering by processed corn starch is mediated through other mechanisms.  相似文献   

6.
The proximate composition of sclerotia of Pleurotus tuber-regium, Polyporus rhinoceros, and Wolfiporia cocos, together with the yield, purity, monosaccharide profile, and microstructure of their insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) fractions prepared from AOAC enzymatic-gravimetric methods were investigated and compared. All three sclerotia were typical carbohydrate rich sclerotia [ranging from 90.5 to 98.1% dry matter (DM)] with an exceptionally low amount of crude lipid content (ranging from 0.02 to 0.14% DM). Besides, all three sclerotia possessed substantial amounts of IDF (ranging from 77.4 to 94.6% DM) with notably high levels of nonstarch polysaccharides (NSP) (89.9-92.2% DM) in which glucose was the predominant sugar residue (90.6-97.2% of NSP DM). On the contrary, both the yield (only ranging from 1.45 to 2.50% DM) and the amount of NSP (ranging from 22.4 to 29.6% DM) of the three sclerotial SDF fractions were very low. Scanning electron micrographs showed fragments of interwoven hyphae and insoluble materials in the three sclerotial IDF fractions, but only an amorphous structure of soluble materials was observed in the SDF fractions. The potential use of these fiber preparations was discussed.  相似文献   

7.
为明确玉米籽粒营养成分的分布差异及不同部位富集特征,应用快速缓苏、微量着水半湿法分层破胚剥皮技术,结合靶向代谢组学方法,对郑单958玉米不同部位的营养成分及基础代谢物质进行分析与比较。结果表明玉米籽粒不同部位的淀粉、脂肪、矿物元素和膳食纤维等营养物质含量存在显著差异（P<0.05）。该研究中的玉米内皮层可能主要由种皮、糊粉层及部分外胚乳构成,该部位营养成分的种类及含量均较为丰富,其中水溶性膳食纤维含量显著高于其他部位（P<0.05）,可作为玉米水溶性膳食纤维的提取分离来源。K、P和Mg元素是玉米中含量最高的矿物元素,主要存在于胚芽中,Fe、Zn、Mn和Cu元素在胚芽和玉米皮层中均有较多分布,精制加工会导致这些矿物元素的损失。玉米胚芽中水解氨基酸种类较其他部位丰富且含量较高（P<0.05）,甜味氨基酸占总游离氨基酸含量的24.49%,高于玉米皮层部位、显著高于胚乳部位。研究结果为玉米营养健康食品的创制、玉米精深加工及相关专用装备的研发提供参考。  相似文献   

8.
Nutritionists recommend increasing the intake of soluble dietary fiber (SDF), which is very low in most cereal-based products. Conversion of insoluble DF (IDF) into SDF can be achieved by chemical treatments, but this affects the sensorial properties of the products. In this study, the possibility of getting a substantial increase of SDF from cereal products using a tailored preparation of Trichoderma enzymes is reported. Enzymes were produced cultivating Trichoderma using durum wheat fiber (DWF) and barley spent grain (BSG) as unique carbon sources. Many Trichoderma strains were screened, and the hydrolysis conditions able to increase by enzymatic treatment the amount of SDF in DWF and BSG were determined. Results demonstrate in both products that it is possible to triple the amount of SDF without a marked decrease of total DF. The enzymatic treatment also causes the release of hydroxycinnamic acids, mainly ferulic acid, that are linked to the polysaccharides chains. This increases the free phenolic concentration, the water-soluble antioxidant activity, and, in turn, the phenol compounds bioavailability.  相似文献   

9.
Preparation of three novel dietary fibers (DFs) from mushroom sclerotia, namely, Pleurotus tuberregium, Polyporous rhinocerus, and Wolfiporia cocos, by a scale-up modified AOAC procedure using industrial enzymes was investigated. A remarkably high level of total dietary fiber (TDF) ranging from 81.7 to 96.3% sample dry matter (DM), in which a content of nonstarch polysaccharide (NSP) ranging from 86.6 to 94.3% sclerotial TDF DM, was obtained from the three sclerotia. All sclerotial DFs were rich in beta-glucan (the glucose residue ranged from 89.7 to 94.5% NSP DM) with a very low level of resistant glycogen (ranged from 3.77 to 3.94% sclerotial TDF DM). All three novel sclerotial DFs also exhibited similar, if not better, physicochemical and functional properties (pH, color, water binding capacity, oil holding capacity, and emulsifying properties) as those of barely DF control and commercial DF-rich ingredients. The potential use of the three mushroom sclerotial DFs as a new beta-glucan type DF-rich ingredient in the food industry was discussed.  相似文献   

10.
提高大豆渣膳食纤维中可溶性成分的方法研究   总被引：4，自引：2，他引：2  
以大豆渣为原料,采用微生物发酵、微射流均质机高压均质处理和高温蒸煮的方法来提高大豆膳食纤维中可溶性成分含量,研究不同发酵时间、不同处理压力和蒸煮温度以及蒸煮时间对提高豆渣可溶性膳食纤维（SDF）含量的影响。结果表明：利用发酵法可提高可溶性膳食纤维的含量达15%之多,并且在发酵的前6天,SDF含量增长很快,6 d后SDF的含量变化较少;而高压均质处理法提高可溶性膳食纤维含量的幅度在10%～28%之间,并随着处理压力的升高而增大;高温蒸煮法能提高可溶性膳食纤维的含量20%,121℃,20 min为较理想的蒸煮条件。  相似文献   

11.
为探究米根霉发酵米糠的最佳条件,本研究采用过热蒸汽对米糠作稳定化处理,以米根霉为菌种发酵稳定化米糠,以米糠可溶性膳食纤维(SDF)得率为指标,并对此条件下发酵米糠的体外益生活性进行评价。结果表明,过热蒸汽稳定米糠最佳条件为160℃、2 min,此条件下脂肪酶失活率为88.01%;甜香型米根霉发酵米糠的最佳条件为:以甜香型米根霉为发酵菌种,料液比1:2.25、接种量0.7%、发酵温度35℃、发酵时间24 h,此条件下SDF得率为5.83%,比未发酵米糠提高了近一半;与未发酵米糠相比,经甜香型米根霉发酵后的米糠,可有效促进双歧杆菌(对数值6.85)和乳酸杆菌(对数值5.23)的增殖;总短链脂肪酸含量提高37.30%,肠道益生活性显著增强(P<0.05)。本研究结果为改善米糠功能特性提供了依据,对今后米糠在发酵方面的应用具有一定的指导意义。  相似文献   

12.
The in vitro bile acid binding by rice bran, oat bran, dehulled barley, and β‐glucan enriched barley was determined using a mixture of bile acids at a duodenal physiological pH of 6.3. Six treatments and two blank incubations were conducted testing substrates on an equal protein basis. The relative in vitro bile acid binding of the cereal brans on an equal total dietary fiber (TDF) and insoluble dietary fiber (IDF) basis considering cholestyramine as 100% bound was rice bran 45 and 49%; oat bran 23 and 30%; dehulled barley 33 and 57%; and β‐glucan enriched barley 20 and 40%, respectively. Bile acid bindings on equal protein basis for the respective cereals were 68, 26, 41, and 49%. Bile acid binding by rice bran may account to a great extent for its cholesterol‐lowering properties, while bile acid binding by oat bran suggests that the primary mechanism of cholesterol lowering by oat bran is not due to the bile acid binding by its soluble fiber. Bile acid binding was not proportional to the soluble fiber content of the cereal brans tested. Except for dehulled barley, bile acid binding for rice bran, oat bran, and β‐glucan enriched barley appear to be related to their IDF content. Highest relative bile acid binding values for rice bran and β‐glucan enriched barley were observed on an equal protein basis, whereas highest values for dehulled barley were based on IDF. Data suggest that of all four cereals tested, bile acid binding may be related to IDF or protein anionic, cationic, physical and chemical structure, composition, metabolites, or their interaction with active binding sites.  相似文献   

13.
Of the two major brands of baby foods in Canada, one reports lower dietary fiber values than the other, although the products appear to be similar. To investigate the reasons for this discrepancy, seven selected samples of baby foods from both brands were analyzed for total dietary fiber (TDF) according to the Mongeau (rapid Health Protection Branch; HPB) method. Two cereals were also analyzed by using the Prosky and the Englyst (nonstarch polysaccharide; NSP) methods as an internal check on the methodology as well as a means of investigating the reasons for the discrepancies. The sampling included at least four different lots of each product (cereals, fruits, vegetables, and legumes). Each lot was analyzed individually. The TDF values determined using the rapid HPB method were in agreement with those obtained by other dietary fiber methods. Comparison between manufacturer-reported and measured values showed that the low values reported in brand A products were due, in part, to under-reporting of TDF content: measured TDF values were significantly higher than manufacturer-reported values. For brand B products, the manufacturer-reported and measured TDF values were in general agreement. This shows that a large part of the discrepancy between the two brands was due to methodological problems associated with measuring TDF in brand A. Differences in TDF content were also apparent as shown by the fact that brand A TDF values were consistently lower than those of brand B when both were measured by the same method. The differences in TDF content were not explained by differences in the polysaccharide composition of the fiber residues or by differences in water content. Although the limited number of samples does not allow any general conclusion about the TDF content of specific brands, the results show that formulation and/or manufacturing differences may influence TDF values in processed baby foods.  相似文献   

14.
Dietary fiber (DF) is one of the main dietary factors contributing to consumers' well-being. In this work the possibility of using the roasted coffee silverskin (CS), a byproduct of roasted coffee beans, as a DF-rich ingredient has been evaluated. The results of our investigation showed that this material has 60% total DF, with a relevant component (14%) of soluble DF. Although a small amount of free phenol compounds is present in CS, it has a marked antioxidative activity, which can be attributed to the huge amount of Maillard reaction products, the melanoidins. Static batch culture fermentation experiments showed that CS induces preferential growth of bifidobacteria rather than clostridia and Bacteroides spp. CS can be proposed as a new potential functional ingredient in consideration of the high content of soluble DF, the marked antioxidant activity, and the potential prebiotic activity.  相似文献   

15.
The objective of this study was to evaluate the chemical, physicochemical, and functional properties of agrowastes derived from okara ( Glycine max), corn cob ( Zea mays sp.), wheat straw ( Triticum sp.), and rice husk ( Oryza sativa) for potential applications in foods. The fibrous materials (FM) were treated with alkali to yield fibrous residues (FR). Rice husk contained the highest ash content (FM, 8.56%; FR, 9.04%) and lowest lightness in color (FM, 67.63; FR, 63.46), possibly due to the abundance of mineral constituents. Corn cob contained the highest amount of soluble dietary fiber (SDF), whereas okara had the highest total dietary fiber (TDF). The high dietary fiber fractions of corn cob and okara also contributed to the highest water- and oil-holding capacities, emulsifying activities, and emulsion stabilities for both FM and FR samples. These results indicate that these agrowastes could be utilized as functional ingredients in foods.  相似文献   

16.
为获得发酵性能优良的菌株,生产优质的发酵叶用芥菜,本研究从自然发酵的芥菜中分离发酵用菌株,通过测定乳酸菌的生长、产酸和亚硝酸盐降解能力以及酵母菌的产气、产酯能力和蛋白酶活性等发酵特性进行筛选,并对筛选获得的优良发酵菌加以应用。结果表明,筛选获得的2株乳酸菌L8短乳杆菌(Lactobacillus brevis)、L9植物乳杆菌(Lactobacillus plantarum)和1株酵母菌Y9酿酒酵母菌(Saccharomyces cerevisiae)在腌制叶用芥菜中的发酵性能优良。与自然发酵的叶用芥菜相比,接菌发酵叶用芥菜的pH值和亚硝酸盐含量分别减少了2.22%和88.13%;总酸含量、氨基酸态氮含量分别增加了9.02%和28.09%。接菌发酵提高了腌制芥菜的营养品质和安全性。本研究丰富了叶用芥菜的发酵菌种,为蔬菜发酵加工产业奠定了技术基础。  相似文献   

17.
为提高甘薯淀粉加工副产物的高值化利用水平,本试验以植物乳杆菌(Lp)、干酪乳杆菌(Lc)、保加利亚乳杆菌(Lb)、戊糖片球菌(Pp)、嗜热链球菌(St)、商业植物乳杆菌(SZ)6种乳酸菌分别对甘薯渣进行发酵,系统分析不同发酵产物的pH值、总酸含量及营养功能成分,并采用灰色理论加权关联度对甘薯渣发酵产物进行综合营养评价,筛选适宜发酵甘薯渣的乳酸菌菌种。结果表明,6种乳酸菌的发酵能力存在显著差异,其中Lb组pH值最低(3.15),Lc组总酸含量最高(27.90);同时,不同乳酸菌对发酵产物中营养功能成分的影响存在显著差异,其中Lb组乳酸含量最高(11.60 mg·mL-1),SZ组乙酸含量最高(66.99μg·mL-1),Lb组可溶性膳食纤维含量最高(0.74 g·100 mL-1),St组总酚含量最高(146.87μg GAE·mL-1)。与未发酵样品相比,Lc组游离氨基酸总量提高了3.71倍;所有发酵产物中的Mg、Ca、Fe、Zn、Se等矿物质元素含量均显著提高。进一步通过灰色理论加权关联度分析发现...  相似文献   

18.
龙眼果浆复合乳酸菌发酵工艺优化   总被引：1，自引：1，他引：0  
为筛选出适合龙眼发酵的复合乳酸菌,优化建立其发酵工艺,比较分析了7种不同的乳酸菌发酵龙眼的降糖能力和释放结合态酚类物质的能力,发现明串珠菌降糖能力最强,植物乳杆菌释放结合态酚能力最强。利用植物乳杆菌和明串珠菌复合发酵龙眼果肉,以游离酚质量分数和还原糖质量分数结合的综合模糊评判值为指标,通过Box-benhnken中心组合试验设计,确定复合乳酸菌发酵龙眼的最佳工艺条件。结果表明,各因素对复合乳酸菌发酵龙眼果浆的模糊评判值影响程度从强到弱依次为:发酵时间发酵温度接种量料液比。复合乳酸菌发酵龙眼的最佳工艺为:料液比为1∶7(g/m L),发酵温度为37℃,发酵时间为53 h,接种量为1.4%,菌种配比为1∶1。在最佳工艺条件下,发酵龙眼果浆的游离酚质量分数为(161.77±3.93)mg/(100 g),还原糖质量分数为(122.80±3.64)mg/g。该研究为开发低糖含量,且适合糖尿病、肥胖症等病人食用的龙眼乳酸菌发酵饮料新产品提供参考。  相似文献   

19.
乳酸菌发酵作为果蔬汁的一种绿色加工技术,不仅可以赋予产品独特的风味,还可以转化其中的活性物质,提高产品的营养价值和保健功效。该研究以湖北杂交枸杞为原料,使用6种乳酸菌(植物乳杆菌、嗜热链球菌、嗜酸乳杆菌、鼠李糖乳杆菌、干酪乳杆菌及发酵乳杆菌)进行发酵,研究发酵前后枸杞果汁理化特性、主要活性成分及体外抗氧化变化,并利用主成分分析进行综合评价优选出理想的发酵菌株。结果表明,6种乳酸菌在枸杞果汁中生长良好,活菌数均能达到10.0 lg CFU/mL以上。发酵后的枸杞果汁中总糖和还原糖含量显著降低(P0.05),且植物乳杆菌和嗜热链球菌产酸能力更强,发酵后总酸含量达6.74、6.07g/kg。与未发酵枸杞果汁相比,经植物乳杆菌、嗜热链球菌、鼠李糖乳杆菌和发酵乳杆菌发酵的枸杞果汁中总酚含量增加了13.76%～28.07%,而嗜酸乳杆菌和干酪乳杆菌发酵后无显著性差异(P0.05)。6种乳酸菌发酵后枸杞果汁中总黄酮含量增加了55.80%～161.97%。发酵枸杞果汁的抗氧化活性与发酵前相比均有显著提高(P0.05)。基于主成分分析的综合评价函数显示经植物乳杆菌、发酵乳杆菌发酵的枸杞果汁品质更优,适宜作为开发枸杞高值化绿色加工饮品的发酵剂。  相似文献   

20.
Rye bran and aleurone, wheat bran and aleurone, and oat bran and cell wall concentrate were compared in their in vitro gut fermentation patterns of individual phenolic acids and short-chain fatty acids, preceded by enzymatic in vitro digestion mimicking small intestinal events. The formation of phenolic metabolites was the most pronounced from the wheat aleurone fraction. Phenylpropionic acids, presumably derived from ferulic acid (FA), were the major phenyl metabolites formed from all bran preparations. The processed rye, wheat, and oat bran fractions contained more water-extractable dietary fiber (DF) and had smaller particle sizes and were thus more easily fermentable than the corresponding brans. Rye aleurone and bran had the highest fermentation rate and extent probably due to high fructan and water-extractable arabinoxylan content. Oat samples also had a high content of water-extractable DF, β-glucan, but their fermentation rate was lower. Enzymatic digestion prior to in vitro colon fermentation changed the structure of oat cell walls as visualized by microscopy and increased the particle size, which is suggested to have retarded the fermentability of oat samples. Wheat bran was the most slowly fermentable among the studied samples, presumably due to the high proportion of water-unextractable DF. The in vitro digestion reduced the fructan content of wheat samples, thus also decreasing their fermentability. Among the studied short-chain fatty acids, acetate dominated the profiles. The highest and lowest production of propionate was from the oat and wheat samples, respectively. Interestingly, wheat aleurone generated similar amounts of butyrate as the rye fractions even without rapid gas production.  相似文献   

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