Inulin

The aims of the current research were to evaluate and to compare the antioxidant activity and the content of total phenolic, flavonoids and fructan content in infusions and microwave-assisted extracts from eight herbs: rosehip (Rosa canina L.), peppermint (Mentha piperita L.), thyme (Thymus vulgaris L.), coltsfoot (Tussilago farfara L.), dandelion (Taraxacum officinale Web.), elecampane (Inula helenium L.), great burdock (Arctium lappa L.) and echinacea (Echinacea purpurea Moench.). The total phenolic contents, total flavonoids and antioxidant activity were evaluated by Folin-Ciocalteau, Al(NO3)3 methods and DPPH assays. The total fructans and sugars were determined by resorcinol and HPLC-RID methods. Infusion and microwave-assisted extraction (MAE) were evaluated as efficient methods for preparation of herbal drinks. The highest values of biologically active substances and antioxidant activity were found in MAE herbal extracts. Coltsfoot, thyme and great burdock extracts demonstrated the highest content of total phenolic and flavonoids. Coltsfoot and thyme extracts showed the highest antioxidant activity (334 mM TEg-1 and 287 mM TEg-1 dw, respectively). Fructans were found in coltsfoot (4.6%) and echinacea (3.9 %) leaves, in great burdock, dandelion and elecampane roots-14 %, 34% and 44% dw, respectively. Elecampane and dandelion roots were evaluated as sources of prebiotic inulin.

Abstract The inulin-type fructans, inulin and fructooligosaccharies (FOS), are part of dietary fibers for production of functional foods with improved health benefits. The increasing application of these components in food technology needs reliable methods for their analysis and control. The aim of the current review is to present and compare the main analytical methods for inulin determination in food products. This study summarizes not only the common applied spectrophotometric and enzymatic methods, but also describes in details chromatographic techniques-HPLC, GC and TLC, IR-FT and real time 1 H NMR spectroscopy. Some of suggested analytical assays, especially spectrophotometric, enzymatic and HPLC-RID methods are applied for routine analysis in analytical practice for monitoring of some process in food technology and control in food labeling. Special attention has been paid to nondestructive IR-FT spectroscopy that reveals the potential to identify the presence of inulin by typical for β-→1 glycosidic bond. Some typical shifts are shown for structure elucidation or hydrolysis of inulin by NMR spectroscopy.

The current research aimed to present the evaluation of the underground parts of two widespread plants in Bulgaria - prickly lettuce (Lactuca serriola L.) and annual sow thistle (Sonchus oleraceus L.) as a source of inulin-type fructans. The sequential ethanol and water extractions from their dry taproots were carried out. The amount of extracted fructans was defined by the resorcinol assay. The fructooligosacharides and inulin contents of the obtained extracts were analyzed by TLC and HPLC-RID methods. The total fructan content in the weed plant Sonchus oleraceus L. (19.6% dw) is higher than the fructan level in the roots of Lactuca serriola L (9.56% dw). In the ethanol extracts were observed the presence of monosaccharide glucose and fructose, high level of sucrose and trisaccharides 1-kestose. In the result of the carried analysis, we can conclude that the roots are rich source of fructans as the fructoligosacharides fraction dominates in ethanolic extracts. These plants could not only be consider as weeds, but it have to pay attention to their future possibility to be used as a potential source of fructooligosacharides with prebiotic effect in nutrition formula for animals and human.

Elecampane (Inula helenium L.) is herb from the Compositae family known as a rich source of biologically active compounds, especially inulin and eudesmane-type sesquiterpene lactones. Until now no detailed characteristics of inulin obtained from this plant have been done. The current research aimed to obtain this polysaccharide form elecampane dry roots by application of ultrasound-assisted extraction procedure and to elucidate its structure and physico-chemical properties. The isolated substance presented white tasteless powder with the melting point 178.5-181 °C, the angle of optical rotation (c=0.5; H2O), fructose content 93.3 % and reducing groups 2.9 %. Elecampane inulin was characterized as high molecular with average degree of polymerization (DP) 30 - 33 and the molecular weigh 5 kDa. The protein content in the polysaccharide fraction was below 1 %. The IR-FT spectra were characterized with typical bands for inulin structure - 817, 873 and 933 cm-1 that showed the presence of β 2→1 glycoside bond.

The carbohydrate composition (inulin and sugars) and antioxidant potential of 95% ethanol and subsequent water extracts from flower
heads of Carduus acanthoides L. and Onopordum tauricum Willd. grown in Bulgaria were investigated. The total fructans content in both
thistle species was analyzed by ketose-specific assay, while individual inulin and sugars content was defined by HPLC-RID method. The
total phenolic content and the antioxidant capacity of the studied extracts were also examined as the antioxidant potential was determined
by four in vitro assays (DPPH, ABTS, FRAP and CUPRAC). O. tauricum Willd. flower heads were evaluated for the first time as a rich
source of prebiotics and total phenols. Higher fructans content was found in the water extracts, while the ethanol extracts possessed
better antioxidant activity.

Inulin-type fructans are not digested and reach the human colon intact, where they are selectively fermented by the colon microbiota, in particular bifidobacteria. As a result, they are converted, directly or indirectly, to short-chain fatty acids and other organic acids, as well as gases, and lead to both bifidogenic and butyrogenic health-promoting effects. Bifidobacteria display phenotypic variation on strain level as to their capacity to degrade inulin-type fructans. Also, different chain lengths of inulin-type fructans may stimulate different subgroups within the bifidobacterial population. The end-metabolites of inulin-type fructan degradation by bifidobacteria reflect their growth rates on these polymers. Other colon bacteria are also able to degrade inulin-type fructans, as is the case for lactobacilli, Bacteroides, certain enterobacteria, and butyrate producers. Bacterial cross-feeding mechanisms in the colon lay at the basis of overall butyrate production, a functional characteristic of several colon bacteria that is always accompanied by gas production. Finally, specificity of polysaccharide use by the colon microbiota may determine diet-induced alterations in the microbiota and consequent metabolic effects.

Chicory (Cichorium intybus) belongs to plants of the Compositae family accumulating energy in the form of inulin fructan. Chicory, a prebiotic, is a fermentable oligosaccharide and oligofructose that may affect the intestinal mucosal architecture and the electrophysiological parameters. Therefore, this study was conducted to evaluate the effectiveness of adding chicory fructans in feed on the intestinal morphology and electrogenic transport of glucose in broilers. Four hundred, 1 day old broiler chicks were randomly divided into two groups (200 bird per group) for 5 weeks. The dietary treatments were (i) control, (ii) basal diets supplemented with the dried, grinded ground chicory pulp containing inulin (1 kg of chicory/ton of the starter and grower diets). In duodenum, dietary chicory increased the villus height and villus width and villus height to crypt depth ratio (p < 0.05), but the duodenal crypt depth remained unaffected (p > 0.05). However, in jejunum, the villus height, crypt depth and villus height to crypt depth ratio were decreased by dietary chicory compared with control birds (p < 0.05). In ileum, the villus height and villus crypt depth was decreased by dietary chicory supplementation compared with control (p < 0.05), but, the villus height to crypt depth ratio was increased (p < 0.05). Moreover, dietary chicory relatively affected the electrophysiological parameters of the intestine but did not reach significance. The amount of ΔIsc after d-glucose addition to the jejunal mucosa was numerically higher for chicory fed birds (19 μA/cm2) than control birds (10 μA/cm2). The percentage of increase in the Isc after d-glucose addition (ΔIsc %) was higher for chicory group upto (90%) of the control group. In colon, the actual Isc value and Isc after d-glucose addition was numerically higher for chicory fed birds than control birds (p > 0.05). Moreover, the conductance of jejunal and colonic tissues after d-glucose addition remained unaffected by the dietary chicory. In conclusion, addition of chicory to broilers diet increased the duodenal villus height, villus width and villus height to crypt depth ratio and decreased the villus height and crypt depth in both jejenum and ileum. Furthermore, dietary chicory relatively modified the small intestinal electrogenic transport of glucose in broilers.

Objective: The aim of the current study was to evaluate the black salsify (Scorzonera hispanica L.) as a potential source of inulin and to characterize the physicochemical properties of isolated polysaccharide. Methods: The carbohydrate content in its roots and leaves was analyzed by high-performance liquid chromatography with refractive index detection (HPLC-RID) method. Microwave-assisted extraction was performed for isolation of inulin from black salsify roots. The obtained polysaccharide was characterized by HPLC-RID method, HPLC size-exclusion chromatography, and Fourier transformed-infrared spectroscopy. Functional properties as swelling capacity, solubility, and water-holding and oil-holding capacities (OHCs) were also evaluated. Results: Black salsify (S. hispanica L.) roots were evaluated as a rich source of inulin (22% dw) and 1-kestose (6.25 g/100 g dw). The isolated inulin (yield 20%) was characterized with average degree of polymerization 17, with polydispersity index (1.04) that was near to medium-chained inulin. This polysaccharide showed better OHC than water-holding capacity, and it was characterized with swelling capacity 0.5 ml/g sample. Conclusion: For the first time, inulin was isolated from black salsify roots. The chemical characterization of inulin reveals the potential of this plant to be used as a valuable source of this polysaccharide for future application in food technology and pharmaceutical industry for dietary fibers, stabilizer, and coating agent.

Cupuassu is an acidic fruit that has a characteristic aroma, flavor, and texture; its fiber-rich pulp can provide a different consistency than other fruit pulps. Goat milk is an excellent source of amino acids, fatty acids, and minerals, and is widely used for processing fermented milks, such as yogurt. However, compared with cow milk yogurts, it is difficult to make goat milk yogurts with a good consistency. Therefore, it is necessary to use certain technological strategies. This study was carried out to investigate the possibility of adding cupuassu pulp, probiotic (Lactobacillus acidophilus LA-5), and prebiotic (inulin) to improve the texture of goat milk yogurt. A total of 6 treatments were performed: natural (N), probiotic (Pro), prebiotic (Pre), synbiotic (S), cupuassu (C), and probiotic with cupuassu (PC). The viability of probiotic in yogurts (Pro, S, and PC) was evaluated. In addition, instrumental analyses (pH, color, apparent viscosity, and texture) were performed to eval...

The in vitro fermentability of oligofructose and inulin was compared with a range of reference carbohydrates by measuring bacterial end-product formation in batch culture. Short chain fatty acid and gas formation indicated that these substrates, which occur naturally in the diet and reach the colon in a largely intact form, were utilized by mixed populations of gut bacteria. Bacterial growth data showed that oligofructose and inulin exerted a preferential stimulatory effect on numbers of the health-promoting genus Bifidobacterium, whilst maintaining populations of potential pathogens (Escherichia coli, Clostridium) at relatively low levels. Pure culture studies confirmed the enhanced ability of bifidobacteria to utilize these substrates in comparison with glucose. Batch culture experiments demonstrated that the growth of Bifidobacterium infantis had an inhibitory effect towards E. coli and Clostridium perfringens. Potentially, an increase in the concentration of these substrates in the diet may therefore improve the composition of the large intestinal microflora and have positive effects on the quality of the Western diet.

Polysaccharide inulin was isolated by different methods comprised conventional, accelerate solvent extraction (ASE), ultrasound – assisted extraction (UAE), and microwave extraction (MWE) from Helianthus tuberosus L. tubers. The resulting carbohydrate presented tasteless, white, dry powder. The isolated inulin was characterized in terms of yield, degree of polymerization (DP), melting point, water activity (aw), reducing groups and total fructose content. The structure of polysaccharide was confirmed by IR-FT spectroscopy. The yield varied in range of 12-24%, as the highest was obtained by MWE (da se promeni !!!). The highest DP was evaluated to be 45, as reducing groups not exceeded 1,8 %. Melting point was established in the range of 178-182 oC. The IR-FT spectra revealed the presence of typical bands for inulin structure - 817, 873 and 937cm-1 with terminated α-D-glucose residue.