00:02 Theory of the Analytical Procedure
02:07 Kit Description
03:12 Preparation of Reagent Solutions/Suspensions
05:30 Samples Containing 0–12% Fructan
07:55 Samples Containing 12–100% Fructan
10:07 Analysis of Fructan Content: a. Hydrolysis of Sucrose & Low DP Maltosaccharides
12:39 Analysis of Fructan Content: b. Hydrolysis of Fructan
14:16 Analysis of Fructan Content: c. Measurement of Fructan
17:14 Calculation of Fructan Content
50 assays per kit
Prices exclude VAT
Available for shipping
|Content:||50 assays per kit|
|Storage Temperature:|| Short term stability: 2-8oC, |
Long term stability: See individual component labels
|Stability:||> 1 year under recommended storage conditions|
|Linear Range:||4 to 80 µg of D-glucose, D-fructose or sucrose per assay|
|Limit of Detection:||1 g/100 g|
|Total Assay Time:||~ 30 min|
|Application examples:||Flours, plant materials (e.g. onion), food products and other materials|
The Fructan HK test kit is suitable for the specific measurement and analysis of all fructo-oligosaccharides (reducing and non-reducing) and of fructan polysaccharides but is not suitable for the analysis of samples containing high levels of D-glucose, D-fructose, sucrose or maltose.
View our full range of assay kits for polysaccharides.
- Very cost effective
- All reagents stable for > 12 months after preparation
- Fructan kits are available only from Megazyme
- Simple format
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
McCleary, B. V., Charnock, S. J., Rossiter, P. C., O’Shea, M. F., Power, A. M. & Lloyd, R. M. (2006). Journal of the Science of Food and Agriculture, 86(11), 1648-1661.
Procedures for the measurement of starch, starch damage (gelatinised starch), resistant starch and the amylose/amylopectin content of starch, β-glucan, fructan, glucomannan and galactosyl-sucrose oligosaccharides (raffinose, stachyose and verbascose) in plant material, animal feeds and foods are described. Most of these methods have been successfully subjected to interlaboratory evaluation. All methods are based on the use of enzymes either purified by conventional chromatography or produced using molecular biology techniques. Such methods allow specific, accurate and reliable quantification of a particular component. Problems in calculating the actual weight of galactosyl-sucrose oligosaccharides in test samples are discussed in detail.Hide Abstract
Measurement of total fructan in foods by enzymatic/spectrophotometric method: Collaborative study.
McCleary, B. V., Murphy, A. & Mugford, D. C. (2000). Journal of AOAC International, 83(2), 356-364.
An AOAC collaborative study was conducted to evaluate the accuracy and reliability of an enzyme assay kit procedure for measuring oligofructans and fructan polysaccharide (inulins) in mixed materials and food products. The sample is extracted with hot water, and an aliquot is treated with a mixture of sucrase (a specific sucrose-degrading enzyme), α-amylase, pullulanase, and maltase to hydrolyze sucrose to glucose and fructose, and starch to glucose. These reducing sugars are then reduced to sugar alcohols by treatment with alkaline borohydride solution. The solution is neutralized, and excess borohydride is removed with dilute acetic acid. The fructan is hydrolyzed to fructose and glucose using a mixture of purified exo- and endo-inulinanases (fructanase mixture). The reducing sugars produced (fructose and glucose) are measured with a spectrophotometer after reaction with para-hydroxybenzoic acid hydrazide. The samples analyzed included pure fructan, chocolate, low-fat spread, milk powder, vitamin tablets, onion powder, Jerusalem artichoke flour, wheat stalks, and a sucrose/cellulose control flour. Repeatability relative standard deviations ranged from 2.3 to 7.3%; reproducibility relative standard deviations ranged from 5.0 to 10.8%.Hide Abstract
Measurement of inulin and oligofructan.
McCleary, B. V. & Blakeney, A. B. (1999). Cereal Foods World, 44, 398-406.
Fructans are defined as any compound in which one or more fructosyl-fructose linkages constitute a majority of the linkages (1). This refers to polymeric material as well as to oligomers as small as disaccharide inulobiose. Fructans are widely distributed in the plant kingdom. They are present in monocotyledons, dicotyledons, and green algae. Fructans differ in molecular structure and in molecular weight. They may be classified into three main types, the inulin type, the levan (previously called phlein) type, and the graminan type (2). The inulin group consists of material that has mostly of exclusively the (2-1) fructosly-fructose linkage. Levan is material that contains mostly or exclusively the (2-6) fructosyl-fructose linkage. The graminan (or branched) type has both (2-1) and (2-6) fructosly-fructose linkages in significant amounts (e.g. graminan from Gramineae). The distribution of fructans in nature, and the production of fructooligosaccharides, such as neosugar, using fructosyltransferase, has been reviewed in a monograph (3). In the context of this article and the analytical procedure described, the term fructan relates only to inulin and graminan. The current analytical procedure has not been evaluated on levan.Hide Abstract
Measurement of inulin and inulin-degrading enzymes.
McCleary, B. V. (1998). “Proceedings of the Seventh Seminar on Inulin”, (A. Fuchs and A. Van Laere, Eds.), European Fructan Association, pp. 36-45.
A non-instrumental method for the measurement of fructan is described. The method simplifies fructan analysis, is easy to perform, uses standard laboratory equipment, and is accurate, reproducible and specific. The procedure employs highly purified and specific enzymes to hydrolyse sucrose, starch and fructans (inulins and graminan).Hide Abstract
Fructans - Analytical approaches to a fibre that ferments.
Blakeney, A. B., McCleary, B. V. & Mugford, D. C. (1997). Chemistry in Australia, 17-19.
Fructans are defined as any compound where one or more fructosyl-fructose linkages constitute a majority of the linkages. This refers to polymeric material as well as oligomers as small as the diasaccharide inulobiose. Material included in this definition may or may not contain attached glucose. The terms oligomer and polymer are used by fructan researchers to distinguish between materials that can be specifically characterised and those that can not. Fructans are widely distributed in the plant kingdom. They are present in monocotyledons, dicotyledons and in green algae.Hide Abstract
McCleary, B. V., Gibson, T. S. & Mugford, D. C. (1997). Journal of AOAC International, 80, 571-579.
An American Association of Cereal Chemists/AOAC collaborative study was conducted to evaluate the accuracy and reliability of an enzyme assay kit procedure for measurement of total starch in a range of cereal grains and products. The flour sample is incubated at 95 degrees C with thermostable alpha-amylase to catalyze the hydrolysis of starch to maltodextrins, the pH of the slurry is adjusted, and the slurry is treated with a highly purified amyloglucosidase to quantitatively hydrolyze the dextrins to glucose. Glucose is measured with glucose oxidase-peroxidase reagent. Thirty-two collaborators were sent 16 homogeneous test samples as 8 blind duplicates. These samples included chicken feed pellets, white bread, green peas, high-amylose maize starch, white wheat flour, wheat starch, oat bran, and spaghetti. All samples were analyzed by the standard procedure as detailed above; 4 samples (high-amylose maize starch and wheat starch) were also analyzed by a method that requires the samples to be cooked first in dimethyl sulfoxide (DMSO). Relative standard deviations for repeatability (RSD(r)) ranged from 2.1 to 3.9%, and relative standard deviations for reproducibility (RSD(R)) ranged from 2.9 to 5.7%. The RSD(R) value for high amylose maize starch analyzed by the standard (non-DMSO) procedure was 5.7%; the value was reduced to 2.9% when the DMSO procedure was used, and the determined starch values increased from 86.9 to 97.2%.Hide Abstract
McCleary, B. V. (1994). “Methods in Carbohydrate Chemistry”, Vol. X, (J. N. BeMiller, D. J. Manners and R. J. Sturgeon, Eds.), John Wiley & Sons Inc., pp. 175-182.
A number of methods have been described for the analysis of the fine structure of galactomannans, i.e., the distribution of D-galactosyl units along the D-mannan backbone (1). Such studies include the analysis of x-ray diffraction data of stretched fibers of galactomannans (2,3), 1H- and 13C-nmr (nuclear magnetic resonance) of native and partially depolymerized galacto¬mannans (4) and a range of chemical procedures (5-7), including those employing a detailed theoretical analysis of the kinetics of reaction (8). An alternative approach involves the characterization and quantification of the oligosaccharides produced on hydrolysis of galactomannans by highly purified and well-characterized β-mannanases (EC 220.127.116.11) (9,10). The β-mannanases employed were purified to homogeneity by affinity chromatography on gIucornannan-AH-Sepharose 4B. They were characterized by a range of physicochemicai procedures by determining the kinetics of their action on β-mannooligosaccharides, and by characterizing the structures of oligosaccharides produced on hydrolysis of galactomannans and glucomannans (11). From these studies, a basic model describing the subsite binding requirements of all the β-mannanases examined was proposed (Fig. 1). This model was then modified to account for the slight differences noted in the types of oligosaccharides produced by β-mannanases from different sources. The β-mannanases which differ most significantly in their action patterns on galactomannans are those from Aspergillus niger culture filtrates and from germinated guar seed.Hide Abstract
FODMAP modulation as a dietary therapy for IBS: Scientific and market perspective.
Ispiryan, L., Zannini, E. & Arendt, E. K. (2022). Comprehensive Reviews in Food Science and Food Safety, 21(2), 1491-1516.
A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) is a promising therapeutic approach to reduce gastrointestinal symptoms associated with irritable bowel syndrome (IBS). However, a shift toward a more sustainable, healthy diet with higher inclusion of whole-grain cereals (i.e., wheat, rye, barley) and pulses, naturally rich in FODMAPs, poses a severe challenge for susceptible individuals. Dietary restriction of fermentable carbohydrates (commonly called the "low FODMAP diet") has received significant consideration. Hence, the development of functional low FODMAP products is emerging in food science and the food industry. In this review, we evaluate the most promising yet neglected (bio)-technological strategies adopted for modulating the FODMAP contents in complex food systems and the extent of their uptake in the global food market. We extensively investigated the global low FODMAP market, contrasted with the status quo in food science and discussed the key principles and concomitant challenges of targeted FODMAP reduction strategies. Powerful tools are available which are based either on the use of ingredients where FODMAPs have been physically removed (e.g., by membrane filtration) or biotechnologically reduced during the food processing, mediated by added enzymes, microbial enzymes during a fermentation process, and seed endogenous enzymes. However, <10% of the small market of functional products with a low FODMAP claim (total ~800 products) used any of the targeted FODMAP reduction techniques. The global market is currently dominated by gluten-free products, which are naturally low in FODMAPs and characterized by inferior sensory attributes.Hide Abstract
Tritordeum breads are well tolerated with preference over gluten‐free breads in non‐celiac wheat‐sensitive patients and its consumption induce changes in gut bacteria.
Sánchez‐León, S., Haro, C., Villatoro, M., Vaquero, L., Comino, I., González‐Amigo, A. B., Vivas, S., Pastor, J., Sousa, C., Landa, B. B. & Barro, F. (2021). Journal of the Science of Food and Agriculture, 101(8), 3508-3517.
Background: The ingestion of wheat and other cereals are related to several gut disorders. The specific components responsible for non-celiac wheat-sensitivity (NCWS) may include gluten and other compounds. Tritordeum is a new cereal derived from crossing durum wheat with a wild barley species, which differs from bread wheat in its gluten composition. In the present work, we examined the response of NCWS patients to tritordeum bread Gastrointestinal symptoms as well as tritordeum acceptability, gluten immunogenic peptides excretion, and the composition and structure of the intestinal microbiota were evaluated. Results: Gastrointestinal symptoms of the subjects showed no significant change between the gluten-free bread and the tritordeum bread. Participating subjects rated tritordeum bread higher than the gluten-free bread. Analysis of the bacterial gut microbiota indicated that tritordeum consumption does not alter the global structure and composition of the intestinal microbiota, and only a few changes in some butyrate-producing bacteria were observed. Conclusions: All the results derived from acceptability, biochemical and microbiological tests suggest that tritordeum may be tolerated by a sub-set of NCWS sufferers who do not require strict exclusion of gluten from their diet.Hide Abstract
Reducing FODMAPs and improving bread quality using type II sourdough with selected starter cultures.
Menezes, L. A. A., De Marco, I., Neves Oliveira dos Santos, N., Costa Nunes, C., Leite Cartabiano, C. E., Molognoni, L., de Melo Pereira, G. V., Daguer, H. & De Dea Lindner, J. (2021). International Journal of Food Sciences and Nutrition, 1-11.
This study focussed on lactic acid bacteria (LAB) screening for sourdough type II elaboration and evaluating the effects of sourdough fermentation in bread making, focussing mainly on reducing FODMAPs. After a technological performance screening, six strains (Levilactobacillus brevis, Weissella minor, Lactiplantibacillus plantarum, Leuconostoc citreum, Limosilactobacillus fermentum, and Companilactobacillus farciminis) were selected for sourdough preparation. Total titratable acidity, pH, specific volume, and enumeration of microorganisms were carried out on sourdoughs, doughs, and breads. Breads were subjected to texture profile and colour analysis, moulds and yeast enumeration, and total fructans (main group of FODMAPs) quantification. Breads produced with sourdough showed a significant reduction of fructans, greater acidity, volume, and better performance during storage when compared to fermentation using only baker's yeast. Including specific cultures as starters in sourdough reduced fructans content by >92%, thereby producing a low FODMAP bread suitable for Irritable Bowel Syndrome patients with improved nutritional and technological properties.Hide Abstract
β-fructosidase FosE activity in Lactobacillus paracasei regulates fructan degradation during sourdough fermentation and total FODMAP levels in steamed bread.
Fang, S., Yan, B., Tian, F., Lian, H., Zhao, J., Zhang, H., Chen, W. & Fan, D. (2021). LWT, 145, 111294.
Low fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs) have been previously shown to effectively relieve symptoms of irritable bowel syndrome (IBS) patients. This study aimed to evaluate the effect of lactobacilli on the FODMAPs degradation during sourdough fermentation, especially on fructan. Phylogenomic analysis of lactobacilli revealed that the gene coding for β-fructosidase FosE are present in Lactobacillus paracasei. L. paracasei FJSSZ3L1 was selected to effectively degrade fructans, with a degradation percentage of 86.57 ± 2.88%. The β-fructosidase FosE activity with substrate specificity was detected in the supernatant and cell wall extract, and the location of enzyme activity was related to the growth time of the strain. Fructan content decreased during sourdough fermentation with L. paracasei. According to high-efficiency anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) analysis, the rapid hydrolyzation of higher degree of polymerization (DP) fructans resulted in a transient increase in DP 3 content after 24 h of fermentation. The fructan and FODMAPs content of steamed bread with sourdough fermented by L. paracasei FJSSZ3L1 were 0.19 ± 0.01 g/100 g and 0.31 ± 0.01 g/100 g, respectively, which are significantly lower than the critical intake standards for IBS patients.Hide Abstract
Nutritional profile of rodent diets impacts experimental reproducibility in microbiome preclinical research.
Tuck, C. J., De Palma, G., Takami, K., Brant, B., Caminero, A., Reed, D. E., Muir, J. G., Gibson, P. R., Winterborn, A., Verdu, E. F., Bercik, P. & Vanner, S. (2020). Scientific Reports, 10(1), 1-13.
The lack of reproducibility of animal experimental results between laboratories, particularly in studies investigating the microbiota, has raised concern among the scientific community. Factors such as environment, stress and sex have been identified as contributors, whereas dietary composition has received less attention. This study firstly evaluated the use of commercially available rodent diets across research institutions, with 28 different diets reported by 45 survey respondents. Secondly, highly variable ingredient, FODMAP (Fermentable Oligo-, Di-, Mono-saccharides And Polyols) and gluten content was found between different commercially available rodent diets. Finally, 40 mice were randomized to four groups, each receiving a different commercially available rodent diet, and the dietary impact on cecal microbiota, short- and branched-chain fatty acid profiles was evaluated. The gut microbiota composition differed significantly between diets and sexes, with significantly different clusters in β-diversity. Total BCFA were highest (p = 0.01) and SCFA were lowest (p = 0.03) in mice fed a diet lower in FODMAPs and gluten. These results suggest that nutritional composition of commercially available rodent diets impact gut microbiota profiles and fermentation patterns, with major implications for the reproducibility of results across laboratories. However, further studies are required to elucidate the specific dietary factors driving these changes.Hide Abstract
Influence of drying method on qualities of Jerusalem artichoke (Helianthus tuberosus L.) tuber harvested in Northeastern Thailand.
Puyanda, I. R., Uriyapongson, S. & Uriyapongson, J. (2020). Songklanakarin Journal of Science & Technology, 42(6), 1279-1285.
The aim of this study was to determine the effect of two drying methods, greenhouse solar drier and oven drier, on qualities of Jerusalem artichoke (Helianthus tuberosus L.) tuber (JAT). The quality characteristics were determined in term of physical and chemical qualities as well as microbial safety in the final samples. The results showed that protein, fat, ash, carbohydrate and total fiber content were not significantly different between solar drying and oven drying (p>0.05). However, inulin, total phenolic content (TPC) and antioxidant activity (AOA) in solar dried JAT was significantly (p≤0.05) higher than oven dried sample. Moreover, the color of JAT powder produced by solar displayed brighter than oven drying. Both drying methods were effective to reduce water content in dried products and had the total plate count and total yeast mold count with the acceptable level.Hide Abstract
Agave: A promising feedstock for biofuels in the water-energy-food-environment (WEFE) nexus.
Yan, X., Corbin, K. R., Burton, R. A. & Tan, D. K. (2020). Journal of Cleaner Production, 261, 121283.
The aim of this study was to conduct the first comprehensive life cycle assessment and economic analysis on ethanol produced from agave. Compositional and field data from a field experiment in Queensland, Australia was used. Our study shows that ethanol yields from agave (7414 L/ha/year) are comparable to Brazilian sugarcane (9900/L/ha/year) and higher than US corn ethanol (3800/L/ha/year). Furthermore, agave outperforms current first generation biofuel crops in water-related impacts, including Freshwater Eutrophication (96% lower than corn and 88% lower than sugarcane), Marine Ecotoxicity (59% lower than corn and 53% lower than sugarcane) and Water Consumption (46% lower than corn and 69% lower than sugarcane). The life cycle fossil energy use (Fossil Resource Scarcity) for agave is 58% lower than corn and 6% higher than sugarcane. The Global Warming impact for agave is also 62% and 30% lower than that of corn and sugarcane, respectively. Although its Land Use impact, measured by land occupied per unit ethanol output, is 98% higher than corn and 2% higher than sugarcane, agave can be grown on arid land that is not suitable for food crops. The economic analysis suggests that first generation ethanol production from agave is not commercially viable without government support. Overall, the results show that agave is promising for biofuel production in the water-energy-food-environment context.Hide Abstract
A biorefinery concept using forced chicory roots for the production of biogas, hydrochar, and platform chemicals.
Stökle, K., Hülsemann, B., Steinbach, D., Cao, Z., Oechsner, H. & Kruse, A. (2019). Biomass Conversion and Biorefinery, 1-11.
Chicory roots (Cichorium intybus L.) are an agricultural residue from salad production. After forcing, the roots contain ingredients from which further products can be obtained. Thus, forced chicory roots can still be considered as a low-cost feedstock for the production of valuable products. Sugars can be extracted and then be used for the production of platform chemicals like 5-hydroxymethylfurfural. Remaining sugars and other components can be degraded during hydrothermal carbonization, where a carbon-enriched hydrochar and a process water enriched in organic components are produced. The process water can be anaerobically digested to produce biogas. In this paper, a cascaded utilization of chicory roots was investigated. Of the initial sugars in the roots, 67.5 wt.% were extracted in a batch extraction with hot water. During hydrothermal carbonization in batch autoclaves, hydrochar yields of up to 66.2 wt.% were achieved. A methane potential of 255 L CH4/kg COD was determined from process water after carbonization. With this additional anaerobic digestion of the process water, a complete utilization of the forced chicory root is achieved. Therefore, in this work, a biorefinery concept for forced chicory roots combining sugar extraction, hydrothermal carbonization, and anaerobic digestion was investigated to elongate the value chain of chicory and to enable an optimum usage of the biomass. The carbon efficiency of this cascaded utilization was 96% whereas the state of the art process only showed 40%.Hide Abstract
Smallanthus sonchifolius roots ameliorate non-alcoholic fatty liver disease by reducing redox imbalance and hepatocyte damage in rats fed with a high fructose diet.
Alemán, M. N., Sánchez, S. S. & Honoré, S. M. (2019). Asian Pacific Journal of Tropical Biomedicine, 9(9), 365.
Objective: To evaluate the potential of Smallanthus sonchifolius (S. sonchifolius) roots in ameliorating hepatic damage of rats fed with a high fructose diet. Methods: The effect of S. sonchifolius roots on energy intake, body weight, fat and liver mass was determined in male rats fed with a high-fructose diet. Plasma glucose, triglycerides, total cholesterol, lipoproteins and aspartate aminotransferase and alanine aminotransferase were analyzed. Histological changes of the livers were evaluated by electronic microscopy and apoptosis was examined using the TUNEL method. The levels of malondialdehyde, reduced-glutathione and antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, glutathione S-transferase) activities were also determined. Results: S. sonchifolius roots significantly decreased energy intake, body weight, fat and liver mass (P < 0.05). S. sonchifolius roots ameliorated liver steatosis and mitochondrial morphology, avoiding cellular apoptosis and normalizing transaminase activity in the liver of rats fed with high fructose. Enzymatic assays revealed that S. sonchifolius roots had a modulatory effect on the oxidative stress induced by fructose-feeding by reducing lipid peroxidation (P < 0.05) and antioxidant enzyme activities (P < 0.05) in liver. Conclusions: S. sonchifolius roots can ameliorate non-alcoholic fatty liver disease by improving oxidative stress and liver injury.Hide Abstract
Dietary fibers, starch fractions and nutritional composition of finger millet varieties cultivated in Sri Lanka.
Jayawardana, S. A. S., Samarasekera, J. K. R. R., Hettiarachchi, G. H. C. M., Gooneratne, J., Mazumdar, S. D. & Banerjee, R. (2019). Journal of Food Composition and Analysis, 82, 103249.
Soluble, insoluble and total dietary fiber contents, rapidly and slowly digestible starch contents, arabinoxylans, β-glucans, fructans, resistant starch, amylose and total sugar contents, minerals and trace elements compositions and proximate compositions of three finger millet varieties, namely Ravi, Rawana and Oshadha, were evaluated using standard protocols. There were no significant differences (P ≥ 0.05) among the rapidly digestible starch, arabinoxylans, β-glucans, fructans, amylose, total sugar, protein, crude fat and crude fiber contents of Ravi, Rawana and Oshadha varieties. Total dietary fiber contents varied between 13.01% (Ravi) and 13.79% (Oshadha). Slowly digestible starch contents ranged from 43.38% (Ravi) to 49.15% (Oshadha) and resistant starch contents ranged from 3.75% (Ravi) to 4.58% (Oshadha). Ash content of Ravi (3.22%) was significantly higher (P < 0.05) than ash contents of other two varieties. Average sodium, magnesium, potassium, calcium, iron, zinc and phosphorous contents of three finger millet varieties were 12.04, 141.78, 407.15, 345.62, 3.49, 1.89 and 331.07 mg/100 g, respectively. Findings of the present study indicated that studied finger millet varieties were good sources of dietary fibers (including resistant starch) as well as minerals and trace elements (especially potassium, calcium, phosphorous and iron) when compared to commonly consumed cereals such as rice and wheat.Hide Abstract
Effects of a diet based on inulin-rich vegetables on gut health and nutritional behavior in healthy humans.
Hiel, S., Bindels, L. B., Pachikian, B. D., Kalala, G., Broers, V., Zamariola, G., Chang, B. P. I., Kambashi, B., Rodriguez, J., Cani, P. D., Neyrinck, A. M., Thissen, J., Luminet, O., Jérôme Bindelle, J. & Delzenne, N. M. (2019). The American Journal of Clinical Nutrition, 109(6), 1683-1695.
Background: Inulin-type fructans (ITFs) are a type of fermentable dietary fiber that can confer beneficial health effects through changes in the gut microbiota. However, their effect on gut sensitivity and nutritional behavior is a matter of debate. Objective: We evaluated the impact of consuming ITF-rich vegetables daily on gut microbiota, gastro-intestinal symptoms, and food-related behavior in healthy individuals. Methods: A single group-design trial was conducted in 26 healthy individuals. During 2 wk, the participants were instructed to adhere to a controlled diet based on ITF-rich vegetables (providing a mean intake of 15 g ITF/d). Three test days were organized: before and after the nutritional intervention and 3 wk after returning to their usual diet. We assessed nutrient intake, food-related behavior, fecal microbiota composition, microbial fermentation, and gastrointestinal symptoms. Results: The major microbial modifications during the intervention were an increased proportion of the Bifidobacterium genus, a decreased level of unclassified Clostridiales, and a tendency to decrease Oxalobacteraceae. These changes were reversed 3 wk after the intervention. The volunteers showed greater satiety, a reduced desire to eat sweet, salty, and fatty food, and a trend to increase hedonic attitudes towards some inulin-rich vegetables. Only flatulence episodes were reported during the dietary intervention, whereas intestinal discomfort, inversely associated with Clostridium cluster IV and Ruminococcus callidus, was improved at the end of the intervention. Conclusions: A higher consumption of ITF-rich vegetables allows a substantial increase in well-tolerated dietary fiber, which may in turn improve food-related behavior. Moreover, it leads to beneficial modifications of the gut microbiota composition and function. This trial is registered at clinicaltrial.gov as NCT03540550.Hide Abstract
Extraction of sugars from forced chicory roots.
Stökle, K. & Kruse, A. (2019). Biomass Conversion and Biorefinery, 9(4), 699-708.
The extraction of fructan and sugars from chicory roots is promising with regard to the production of 5-hydroxymethylfurfural. In this study, the extraction of chicory roots after the salad production was investigated for the first time in order to determine the extraction kinetics. Chicory roots were cut into different shapes (juliennes, slices, and cubes) and were extracted at different temperatures (T = 65°C; T = 80°C; T = 90°C) and with different solid-to-liquid ratios (1:5; 1:10; 1:20) in batch experiments. Maximum extraction yields (90.15% of extracted sugars) were achieved for T = 80°C and chicory roots that were cut into julienne shape. A solid-to-liquid ratio of 1:10 should be maintained in order to keep the process economical. Regarding the subsequent use of the extract for 5-hydroxymethylfurfural production, 89.5% of initial fructose and 89.8% of initial fructan were extracted at 80°C. According to this, the sugar-containing extracts could be used in the future in decentralized biorefineries to produce 5-hydroxymethylfurfural directly from chicory roots as an agricultural residue.Hide Abstract
Inulin enrichment of gluten free breads: Interaction between inulin and yeast.
Morreale, F., Benavent-Gil, Y. & Rosell, C. M. (2019). Food Chemistry, 278, 545-551.
Inulin can improve the nutritional quality of gluten free (GF) bread and have a prebiotic activity. However, breadmaking might frustrate the enrichments efforts due to inulin loss. In this study we aimed at studying the inulin enrichment of GF bread. Two different yeasts [having normal (Y1) or reduced (Y2) invertase activity] were used to leaven the breads enriched with five marketed inulins, which differed for the degree of polymerization (DP) and the manufacturer. Inulin replaced 10% of the rice flour and had low, intermediate or high DP, which ranged from 2 to 20; ≈20; ≥20, respectively. Fructan hydrolysis occurred during leavening of Y1-GF breads, reaching losses up to 40% after baking, depending on the diverse DP of the inulin-forming fructans. Inulin loss was less relevant in Y2-GF breads (up to 5% after baking) than Y1-GF breads. Crumb texture was not negatively influenced by inulin presence, even if this was high (e.g., Y2-GF breads). Information collected within this study may provide further insight to better optimize a GF bread formulation in view of inulin enrichment.Hide Abstract