Inulin Ratio Research Articles

Limited enzymatically hydrolyzed pea protein-inulin interactions in gel systems.

Gelation of protein-polysaccharide mixtures can help create a variety of distinctive gel systems as compared to single polysaccharide or protein gels. The properties of these functional gels are heavily reliant upon the nature of protein-polysaccharides interactions, their gelling compatibility, and mechanism. Pea protein isolate dispersions (7.5%) were subjected to limited enzymatic hydrolysis using the enzyme Alcalase® at three hydrolysis times (0, 3, and 6min). Inulin was added according to three ratios (0, 1:4, and 2:4) with pea protein. Viscoelastic properties of the gels formed were measured using amplitude sweep and frequency sweep. Storage modulus (G') measurements from the amplitude sweep indicated that samples hydrolyzed for 3min with 1:4 ratio of inulin to pea protein had maximum gel strength, exhibiting G' values of ∼307Pa. G' values for samples hydrolyzed for 0 and 6min with different inulin ratios averaged ∼13 and ∼144Pa, respectively. Confocal laser scanning microscopy showed that gels developed by samples hydrolyzed for 3min showed a dense network as compared to an open network in gels formed by samples hydrolyzed for 6min, whereas large random aggregates were observed in gels formed by samples hydrolyzed for 0min. The study confirmed that inulin promotes noncovalent bond formation in samples hydrolyzed for 3min with a 1:4 inulin ratio, shown by an ∼18% increased protein solubility in urea. Additionally, collaboration between noncovalent bonds and disulfide linkages stabilized the gel structure, as indicated by further increase in solubility in combination of urea and Dithiothreitol. PRACTICAL APPLICATION: Plant proteins are gaining attention as alternatives to animal proteins. However, they have inferior functionality, which affects their applicability in food products. This investigation aimed to evaluate enzymatic hydrolysis to enhance the structural and functional properties of pea proteins, thus increasing their applicability in the food industry. Inulin is an oligosaccharide and soluble fiber, which promotes gut health. Thus, gels combining hydrolyzed pea protein and inulin can serve as a model mixed food system of interest to both the industry and consumers.

Development of Inulin-Enriched Honey Powder for Further Application in Prebiotic Biscuits

Maltodextrin has the drawback of increasing the glycemic index (GI), which is considered healthy during the digestion process. The incorporation of inulin, a prebiotic agent, addresses these issues while offering additional health benefits. This study aimed to characterize inulin-enriched honey powder produced via spray drying with varying ratios (100%, 75%, 50%, and 25%) of inulin and maltodextrin as carriers for potential application as a sugar substitute for prebiotic biscuit formulations. Chemical properties, including pH, moisture content, hydroxymethylfurfural (HMF) content, diastase activity, and the sugar profile, were analysed. The results revealed that formulations containing 50% inulin presented optimal characteristics, such as a balanced pH, minimal HMF levels, and favourable sugar profiles (e.g., glucose, maltose, fructose-to-glucose and glucose-to-moisture ratios). These findings suggest that inulin-enriched honey powder with balanced carrier ratios could serve as an innovative sugar substitute, contributing to the development of healthier prebiotic biscuits. Future studies should explore functional properties, including the prebiotic potential of inulin-enriched honey powder, which impacts biscuit rheology and consumer acceptability.

Impacts of cold-extrusion whey protein isolate synergized with inulin on physicochemical characteristics of fermented milk

Impacts of extruded whey protein isolate-inulin (EWPI-I) complexes with different inulin ratios (5%, 10%, and 15%) on the textural, sensory, and rheological characteristics of fermented milk were investigated in this work. The addition of inulin to both EWPI-I and WPI-I complexes in ratios of 0–15% resulted in a gradual increase in apparent viscosity, water holding capacity (WHC), viable counts, and consistency index K of fermented milk. However, these properties decreased during the storage period (P < 0.05). Rheology analysis revealed that the consistency index K of EWPI-I fermented milk was higher than that of WPI-I fermented milk within 14 days of storage due to the formation of high molecular WPI polymers induced by extrusion. Principal component analysis (PCA) showed that EWPI-15%I (inulin ratios of 15%) fermented milk exhibited the best characteristics among all fermented samples. Furthermore, hardness, adhesion, chewiness and WHC of EWPI-15%I fermented milk were 261.13%, 298.31%, 480.40% and 38.24% higher than those of untreated fermented milk. It was observed that on the first day of storage, the viability of S. thermophilus and L. bulgaricus in EWPI-15%I fermented milk increased by 2.99% and 3.14%, respectively, compared to untreated samples. The proliferation of S. thermophilus and L. bulgaricus was found to be more conducive with combination of EWPI and inulin. Therefore, EWPI-I complex could remarkably improve water holding capacity and rheological properties of fermented milk, which will be applied for developing fermented dairy products with high quality characteristics.

New insights on the effects of blend composition on the biodegradation and permeability of Inulin-Eudragit RS film coatings for colon drug delivery

Inulin has been applied in Inulin-Eudragit RS (Inu-ERS) coatings as the component responsible for degradation by human microbiota. However, studies on how bacterial enzymes can degrade polysaccharides like inulin imbedded in water insoluble polymers like Eudragit RS are still elusive. The present work aims at elucidating the complex process of enzyme triggered biodegradation of inulin with various molecular weights in isolated films with Eudragit RS. The ratio of inulin to Eudragit RS was varied to create films with different degree of hydrophilicity. The phase behavior study revealed that blends of inulin and Eudragit RS are phase separated systems. The film permeability was studied by determination of the permeability coefficient of caffeine and the fraction of inulin that was released from the films in a buffer solution with or without inulinase was quantified. Together with the morphology characterization of the Inu-ERS films with and without incubation in the enzyme solution, these results suggest that the action of the enzyme was only limited to the fraction of inulin released in the buffer solution. Inulin fully embedded in the Eudragit RS matrix was not degraded. The permeation of the model drug caffeine occurred in the phase-separated film as a result of pores formed as a consequence of inulin release. The inulin to Eudragit RS blend ratio and the molecular weight of inulin affected the percolation threshold, the release of inulin, the morphology of the film formed thereafter and the connectivity of the formed water channels, thus influencing the drug permeation properties.

Study of the sorptiondesorption of ecdysterone (20 E) as part of adaptogenic compositions with inulin and functional food ingredients based on spinach and quinoa

The main principle in the enrichment of food with minor bioactive compounds is the prediction and evaluation of possible chemical interactions of the components included in the matrix of the food. These interactions have a impact on the bioavailability of minor bioactive compounds. In our work, we studied the processes of sorption and desorption (release), the main processes affecting the bioavailability of the minor bioactive compound ecdysterone (20 E) in the composition of functional food ingredients obtained from spinach leaves (FFI-1) and quinoa grains (FFI-2) on hydrocolloid matrix - inulin. The objective of the research was to study the completeness of sorption-desorption processes of 20 E in adaptogenic compositions with inulin and functional food ingredients based on spinach and quinoa under the influence of hydrolytic enzymes of the gastrointestinal tract (GIT) in vitro. Material and methods. To obtain experimental compositions, containing FFI-1 and FFI-2 and the polysaccharide (inulin), a mechanical mixing method was used. To study the sorption properties, model solutions of the compositions were prepared. Using an in vitro enzymatic model, the ability of 20 E to be released from the matrix of the compositions was studied. The content of 20 E was determined by HPLC-MS/MS. Results. 6 compositions with different ratios of polysaccharide/FFI were obtained. At the first stage of the study, the maximum sorption of 20E in the model solution was observed for 4 compositions with the ratio of inulin : FFI = 2.50 or 3.75 g : 189.19 mg FFI-1 or 68.40 mg FFI-2. At the second stage of the study, when assessing the desorption of 20 E on the enzymatic GIT model, it was found that 20 E almost completely released only from 2 compositions, in other cases about 25% of 20 E remained in a bound state. Conclusion. The formulation of two compositions with the ratio of inulin (2.50 g) : FFI-1 (189.19 mg)/FFI-2 (68.40 mg) were obtained, which have the most optimal sorption / release parameters of 20 E under the influence of human gastrointestinal enzymes. These compositions can be considered promising for inclusion in the formulation of fortified foods.

Reformulation of traditional Iranian food (Doeeneh) using probiotics: Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus acidophilus LA-5, Lacticaseibacillus rhamnosus LGG, and inulin and its effect on diabetic and non-diabetic rats

Abstract Objectives The purposes of this study were to produce novel formulations of Doeeneh using three probiotic strains and different inulin ratios and to investigate the survival of probiotics. Likewise, the effect of Doeeneh on the biological properties of non-diabetic and diabetic rats was also evaluated. Materials and Methods Doeeneh, composed of milk and wheat bulgur, was enriched with different proportions of inulin and fermented by Bifidobacterium animalis subsp. lactis BB-12 (B), Lactobacillus acidophilus LA-5 (A), Lacticaseibacillus rhamnosus LGG (R), and their co-cultures. The physicochemical and sensory properties and probiotics viability were investigated for 14 d. Diabetes was induced in albino rats by administration of alloxan monohydrate (150 mg/kg i.p.). Changes in weight and blood glucose were measured weekly, and food and water consumption were measured daily; total cholesterol and triglycerides were measured after 35 d by a biochemical kit. Results The increased proportion of high-degree of polymerization inulin decreased pH and increased acidity. However, a higher concentration of inulin applied to Doeeneh resulted in a slower decrease in pH value. This result can show the buffering effect of inulin in Doeeneh as well; changes in pH were slow over time due to the presence of the buffering compounds. Therefore, the probiotics’ survival was in the standard range even in the inulin-free sample. Likewise, the Doeeneh sample containing 5% inulin (SABR3) considerably reduced the levels of blood glucose, total cholesterol, and triglyceride in diabetic rats. Moreover, the diabetic rats fed Doeeneh demonstrated less weight loss and food/water intake than the control. Conclusions Traditional foods and their preparation methods are a suitable target for the development of health-oriented products, and functional food with nutraceutical capabilities can be designed and produced based on them.

Determination of Calcium Levels with XRF and Literature Review of its Bioavailability in Vitro of Dahlia Tubers Syrop (Dahlia Pinnata Cav.)

Calcium bioavailability (Ca) states the ratio of available calcium to the amount of calcium consumed during metabolic processes. The bioavailability of Ca is calculated by the difference between the amount of Ca in the consumed food product and the excreted feces. In this research, calcium can be obtained from dahlia tuber syrup (Dahlia pinnata Cav.). The purpose of this study was to discuss the determination of Ca levels and a literature review of the Ca bioavailability of dahlia tuber syrup (Dahlia pinnata Cav.) in vitro. The content of Ca in dahlia tubers was determined experimentally using an XRF (X-Ray Fluorescence) instrument. The bioavailability of Ca was determined by predicting the ratio of inulin and Ca content. The results showed that the Ca content of dahlia tuber syrup was 197,57 ppm. The bioavailability of Ca in dahlia tuber syrup in vitro was predicted from a relatively high ratio of inulin content of around 65-86% and FOS levels from hydrolysis of 5% dahlia tuber inulin about 15,41-29,38% or an average of 22,395%, on Ca levels is 81,46-85,33%. The results of the study on the bioavailability of Ca in dahlia tuber syrup (Dahlia pinnata Cav.) have a fairly high level. The high bioavailability of Ca can increase calcium absorption in the body and have health effects, among others, for heart and bone health.

PRELIMINARY STUDY OF INSULIN DRY POWDER FORMULATION: CRITICAL PROCESS PARAMETERS ON SPRAY-FREEZE-DRYING AND CRITICAL MATERIAL ATTRIBUTE OF TREHALOSE AND INULIN AS STABILIZER

Objective: The aim of this study was to obtain recommendations about critical process parameters (CPP) and optimal ratio of trehalose and inulin as critical material attribute (CMA) on insulin dry powder formulation with spray-freeze-drying (SFD) method.&#x0D; Methods: Inulin dry powder was formulated with the SFD method, which consisted of an atomization process and freeze-drying (FD). SFD processes were optimized in order to obtain dry powder and CPP was analyzed. All seven variations of formulas proceeded with physicochemical characterization to obtain the optimal formula.&#x0D; Results: In the early optimization, there was a slight time lag between the atomization process and FD; as a result, some of the powder coagulated and crystallized. Another critical parameter was that the FD process should not be interrupted for at least 50 h of FD. Dry powder proceeded with physicochemical characterization, a formula without inulin showed semicrystalline properties, while six formulas had amorphous properties due to its combination. All formulas had a spherulite shape and rough surface. Five formulas with the combination of trehalose and inulin obtained dry powders with a diameter range of 30-43 μm, moisture content below 3.5% and high encapsulation efficiency (EE). Formula with the ratio of 1:1 (F4) showed optimal properties with moisture content and EE of 2.62% and 99.68%, respectively.&#x0D; Conclusion: This study concluded that there were two critical process parameters in the SFD method. There should be no time lag in SFD process and FD time which should not be interrupted. The optimal ratio for trehalose and inulin was shown by F4 with ratio of 1:1.

Effect of inulin/kefiran mixture on the rheological and structural properties of mozzarella cheese

The relationships between chemical, textural, rheological and microstructural properties of low fat mozzarella cheese incorporated with different ratios of inulin/kefiran mixture were studied. By increasing inulin content, the protein and moisture content was increased and as a result, the meltability was reduced. Although, textural properties of low-fat mozzarella was completely influenced by inulin incorporation and hardness was increased, but the lower springiness and higher cohesiveness of cheese was achieved at high level of inulin which may be related to the increase in moisture and protein. Rheological properties of low-fat mozzarella cheese confirmed its shear-thinning behavior in which the G' value was more than G″. Mechanical properties of cheese showed that inulin incorporation into cheese did not significantly change the rheological properties of the cheese matrix. Consequently, the formation of a more rigid and cross-linked protein structure which is less plasticized achieved at high inulin incorporation through keeping more water and protein and less fat content. SEM results indicated the sponge honeycomb structure of mozzarella cheese which clearly confirmed the textural and rheological properties and there was an interrelationship among chemical, textural, rheological and microstructural properties of low-fat mozzarella cheese incorporated at different ratios of inulin.

Preparation and Characterization of New Sol-Gel Hybrid Inulin-TEOS Adsorbent.

A new biopolymer–silica hybrid material consisting of inulin and tetraethoxysilane (TEOS) for use as an adsorbent was successfully synthesized via the sol–gel method in acidic conditions. The hydrolysis and condensation processes were attained in water/ethanol solution. Three molar ratios of inulin:TEOS (1:1, 1:2, and 2:1) were prepared and dried at various temperatures (50, 60, and 70 °C). The optimized molar ratio of 2:1 with a drying temperature of 70 °C was found to obtain the best morphology and characteristics for absorbent properties. Fourier transform infrared spectroscopy (FTIR) analysis showed a strong interaction between inulin and TEOS, which was also observed using energy dispersive X-ray spectroscopy (EDX). Field emission scanning electron microscopy (FESEM) images revealed the presence of nanoparticles on the rough surface of the hybrid sol–gel. X-ray diffractometer (XRD) analysis showed the amorphous state of the silica network where the inulin existed as an anhydrous crystalline phase. Brunauer–Emmet–Teller (BET) analysis confirmed that the composite was mesoporous, with 17.69 m2/g surface area and 34.06 Å pore size. According to thermogravimetric analysis (TGA) results, the hybrid inulin-TEOS adsorbent was thermally stable under a temperature of 200 °C.

Effect of inulin concentration on physicochemical properties and antioxidant activity of date powders obtained by hot-air tray dryer

In the present study, it was aimed to produce free-flowing date powders using various levels of inulin as drying-aid agent (10, 20, 30, 40, and 50%) through hot-air drying at 60°C for 24 h. Effects of different inulin ratios on physicochemical properties of date powders were investigated. This is the first report which evaluated the suitability of this prebiotic carbohydrate as drying-aid agent to fabricate date powders. Inulin addition yielded date powders with high flowability. On the other hand, contents of bioactive compounds including total phenolics, flavonoids, and condensed tannins of date powders decreased significantly (P&amp;lt;0.05) as the inulin concentration increased from 10% to 50% Accordingly, DPPH-radical inhibition capacities reduced in date powders containing higher levels of inulin. Furthermore, significant correlations were detected between bioactives contents and antioxidant activity of date samples. The results showed that free-flowing date powders with improved prebiotic content may be produced by incorporating inulin up to ratio of 50% and used as sugar substitute in different food products.

Comparative study of instrumental properties and sensory profiling of low-calorie chocolate containing hydrophobically modified inulin. Part II: Proton mobility, topological, tribological and dynamic sensory properties

The aim of the present work was to evaluate the changes in instrumental measurements and dynamic sensory properties of chocolate as affected by the partial and total substitution of sucrose by dodecenyl-succinylated inulin upon storage. The results of textural, surface topology, and tribological properties of non-stored chocolates were found to be a function of modified inulin replacement, where an increase in modified inulin ratio allowed an increase in hardness, roughness, and friction coefficient. Compared to non-stored samples, the deterioration of textural properties after storage was inhibited in chocolate containing higher levels of modified inulin. Higher modified inulin ratios did not also induce an important change in NMR proton mobility, roughness, and friction coefficient upon storage. Confocal Raman microscopy revealed modified inulin located around sucrose and cocoa particles dispersed in fat phase, especially at the higher ratios. Temporal Dominance of Sensations (TDS) curves of non-stored samples elucidated that firmness was a dominant perception at the beginning of mastication, followed by melting rate, while cocoa flavor was experienced at the end of evaluation. However, these attributes were not perceived in stored chocolate with the lowest modified inulin. A PCA was performed to compare TDS scores and instrumental readings, showing a high correlation between instrumental measurement of hardness, friction coefficient, and NMR relaxation times and TDS score of firmness, bitterness, astringency, and melting rate. This work shows a new perspective to use biopolymeric surfactant for producing low-calorie chocolate, considering that hydrophobically modified inulin can diminish production costs and facilitate low-calorie product development.

Comparative study of instrumental properties and sensory profiling of low-calorie chocolate containing hydrophobically modified inulin. Part 1: Rheological, thermal, structural and external preference mapping

Low-calorie chocolate was prepared using replacement of sucrose by hydrophobically modified inulin (dodecenyl succinylated inulin) as biopolymeric surfactant at different levels (100:0, 75:25, 50:50, 25:75, and 0:100%). The instrumental parameters of produced chocolates before and after storage were compared with their sensory evaluation. Morphological assay showed that the lowest modified inulin ratio allowed an increase in frequency of surface crystals upon storage with progress of blooming phenomenon. However, higher levels of modified inulin were more effective in enduring blooming. Replacement of lowest inulin ratio increased elastic modulus of stored chocolate, with a more solid-like behavior. However, viscoelastic parameters of stored chocolates with higher modified inulin contents remained similar to the levels obtained for non-stored samples. Thermal analysis revealed that enthalpy increased in stored chocolate containing lowest modified inulin content due to post crystallization, while substitution of modified inulin at higher levels seemed to slow down this process. Upon storage, V-type crystal was transformed to VI-type form in chocolate formulated with the lowest modified inulin proportion, while chocolates with higher inulin contents showed the slowest change in polymorphic transformation. Quantitative descriptive analysis revealed that increasing inulin content resulted in good textural and color appearance. Partial least squares showed that blooming, mass forming, cracking and powderiness attributes were responsible for lower consumer acceptance of chocolate.

Effects of dietary inulin as prebiotic on growth performance, immuno-haematological indices and ectoparasitic infection of fingerlings Nile tilapia, Oreochromis niloticus

Background: Prebiotics contain non-digestible ingredients, which beneficially affect to the host by selectively stimulating the growth of one or a limited number of bacteria at the colon. Inulin and oligofructose are the most commonly used as prebiotic food ingredients in aquaculture. Dietary supplemented of inulin has shown an enhancement on growth and health of fish. Aim of the Study: The current study aimed to assess the effects of varying doses of inulin as a natural prebiotic on the growth, nutrient utilization, liver histology, immune responses and ecotoparasitic infection of fingerlings Nile tilapia (Oreochromis niloticus). Materials and Methods: Eighteen full glass aquaria measuring (75×40×35cm) were distributed into six treatments and each treatment was represented in three replicates (25 fish in each aquarium with an initial body weight of 9.23±0.25g). Six diets were formulated by using two levels of sorghum (15 and 30%) and the inulin, which produced and imported from China was used in each level with three doses 2.5,5.0 and10.0g/kg diet. Fish samples of (blood, histological examination of liver and spleen, ectoparasitic infection and proximate composition of fish) were detected. Results: The results demonstrated that the highest growth performance and feed efficiency were obtained with dietary low inulin ratio (2.5 g/kg diet). White Blood Cell (WBC), Alternative Complement Pathway (ACP) and Superoxide Dismutase Activity (SOD) were affected significantly (P˂0.05) with increased dietary inulin doses. Results of histopathological examinations showed that the fish fed in low dose of inulin improve liver and spleen structures. Also, the ecoparasitic infection showed enhancement in resistance for ectoparasatic with all doses of inulin.Conclusion: The present results showed that inulin supplementation at low dose (2.5g/kg diet) in the two levels of sorghum inclusion (15 & 30%) in dietary Nile Tilapia, enhancing growth performance, immuno-haematological indices, parasitic infection and each of liver and spleen structure of Nile tilapia fingerlings.

Application of Simplex Lattice Design in Formulation Development of Lozenges Containing &lt;i&gt;Vernonia cinerea&lt;/i&gt; Extract for Smoking Cessation

The aim of this work was to apply the simplex lattice design in the formulation development of lozenges containing Vernonia cinerea extract. The different ratios of three diluents; milk powder, xylitol, and inulin were investigated. The preformulation parameters of powder mixtures were evaluated. The compressed lozenges were evaluated for their weight variation, thickness, hardness, friability, and disintegration time. Results showed that the ratios of the three diluents affected the preformulation parameters. The angle of repose data revealed that all 12 powder mixtures had excellent flow property. The formulation containing milk powder had the highest values of Carr’s index and Hausner ratio, indicating the poor compressibility. While formulation containing inulin had the best compressibility. A formulation containing xylitol had the lowest moisture content. The compressed lozenges had a weight variation of less than 5%, a diameter of 1.5 mm, a thickness of 5-6 mm, and a hardness of 2-12 kP. The 8 of 12 formulations had friability of less than 1%. Use of milk powder provided the longest disintegration time. The desired properties of developed lozenge achieved when the medium amount of xylitol and inulin and low amount of milk powder were used. The optimal diluent ratio providing the weight variation not more than 5%, the hardness of 5-8 kP, friability not more than 1%, and disintegration time not more than 30 min was an equal weight ratio of milk powder, xylitol, and inulin.

Influence of Fortification with Inulin and Hi-maize on Acidity and Viability of Starter Culture in Probiotic Yoghurt

In this study, the effect of fortification with inulin&#x0D; and resistant starch (Hi-maize) on yoghurt starter and probiotic bacteria&#x0D; survival, as well as acidity properties of set-type probiotic yoghurt&#x0D; containing Lactobacillus acidophilus&#x0D; were investigated. Milk was fortified with inulin or Hi-maize at 2% and 4%&#x0D; ratios whereas control group had no supplement. Samples fortified with Hi-maize&#x0D; had higher lactic acid value than those fortified with same ratio of inulin.&#x0D; Lactic acid percentages increased significantly in all probiotic yoghurts at&#x0D; the end of storage in comparison to the first day (p&amp;lt;0.05). The highest&#x0D; viable counts of Streptococcus&#x0D; thermophilus were&#x0D; enumerated in the sample fortified with 2% Hi-maize during 14 days of storage.&#x0D; The control sample had as high viable counts of Lactobacillus bulgaricus as the sample fortified with 4% Hi-maize,&#x0D; except first day of the storage. The highest viability of L. acidophilus was detected in control and the sample fortified&#x0D; with 4% Hi-maize on 7th and 14th day whereas the highest&#x0D; value was reported for the control sample at the end of the storage. L.acidophilus populations ranged from&#x0D; 6.30 to 7.95 log cfu/g in probiotic yoghurts during 21 days of refrigerated&#x0D; storage. Therefore, all experimental yoghurts presented probiotic viability&#x0D; above the minimum recommended level of 6 log cfu/g suggested for beneficial&#x0D; health effects.

High-level secretory expression of Aspergillus exo-inulinase and its use in the preparation of fructose syrup from inulin

Abstract Inulin is a type of fructose polymer that is commonly present in plants as a storage carbohydrate. Enzymatic hydrolysis of inulin via exo-inulinase to produce fructose is an efficient, green and state-of-the-art technique. To achieve the high-level secretory expression of inulinase and to realize enzymatic preparation of fructose syrup from inulin, an Aspergillus exo-inulinase gene inu was codon-optimized and co-expressed with the endoplasmic reticulum secretion protein in Pichia cells. After inducible expression in a 500-L pilot scale bioreactor, the inulinase activity of the recombinant strains reached 10,480 U/mL of cultivation broth. Next, according to the determined enzymatic characteristics of inulinase INU, we optimized the parameters for inulinase to hydrolyse inulin. Under the optimal condition of the enzyme/inulin ratio of 5000 U/g, 15% substrate and an incubation temperature of 50 °C for 4 h, the hydrolysis ratio of inulin reached 100%. The hydrolysis products of inulin contain two components, 95% fructose, and 5% glucose. This study has fulfilled the scaled-up production of inulinase and facilitated its industrial application for enzymatic preparation of fructose from inulin.

Identification of a recombinant inulin fructotransferase (difructose dianhydride III forming) from Arthrobacter sp. 161MFSha2.1 with high specific activity and remarkable thermostability.

Difructose dianhydride III (DFA III) is a functional carbohydrate produced from inulin by inulin fructotransferase (IFTase, EC 4.2.2.18). In this work, an IFTase gene from Arthrobacter sp. 161MFSha2.1 was cloned and expressed in Escherachia coli. The recombinant enzyme was purified by metal affinity chromatography. It showed significant inulin hydrolysis activity, and the produced main product from inulin was determined as DFA III by nuclear magnetic resonance analysis. The molecular mass of the purified protein was calculated to be 43 and 125 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively, suggesting the native enzyme might be a homotrimer. The recombinant enzyme showed maximal activity as 2391 units/mg at pH 6.5 and 55 °C. It displayed the highest thermostability among previously reported IFTases (DFA III forming) and was stable up to 80 °C for 4 h of incubation. The smallest substrate was determined as nystose. The conversion ratio of inulin to DFA III reached 81% when 100 g/L inulin was catalyzed by 80 nM recombinant enzyme for 20 min at pH 6.5 and 55 °C. All of these data indicated that the IFTase (DFA III forming) from Arthrobacter sp. 161MFSha2.1 had great potential for industrial DFA III production.

Mashed potatoes enriched with soy protein isolate and inulin: chemical, rheological and structural basis

Soy protein isolate is typical vegetable protein with health-enhancing activities. Inulin, a prebiotic no digestible carbohydrate, has functional properties. A mashed potato serving of 200 g with added soy protein isolate and/or inulin concentrations of 15-60 g/kg provides from 3 to 12 g of soy protein isolate and/or inulin, respectively. Currently, no information is available about the possible texture-modifying effect of this non-ionizable polar carbohydrate in different soy-based food systems. In this study, the effect of the addition of soy protein isolate and inulin blends at different soy protein isolate: inulin ratios on the degree of inulin polymerization and the rheological and structural properties of fresh mashed and frozen/thawed mashed potatoes were evaluated. The inulin chemical structure remained intact throughout the various treatments, and soy protein isolate did not affect inulin composition being a protein compatible with this fructan. Small-strain rheology showed that both ingredients behaved like soft fillers. In the frozen/thawed mashed potatoes samples, addition of 30 : 30 and 15 : 60 blend ratios significantly increased elasticity (G' value) compared with 0 : 0 control, consequently reducing the freeze/thaw stability conferred by the cryoprotectants. Inulin crystallites caused a significant strengthening effect on soy protein isolate gel. Micrographs revealed that soy protein isolate supports the inulin structure by building up a second fine-stranded network. Thereby, possibility of using soy protein isolate and inulin in combination with mashed potatoes to provide a highly nutritious and healthy product is promising.

Sensory and Texture Properties of Mashed Potato Incorporated with Inulin and Olive Oil Blends

The effect of adding different ratios of inulin and extra virgin olive oil blends, formulated without (MPA) and with cryoprotectants (MPB), on texture properties of fresh mashed potatoes and frozen/thawed mashed potatoes was studied. Inulin and extra virgin olive oil behaved like soft fillers, but inulin was associated with increased fibrousness and extra virgin olive oil with increased creaminess. In the total dataset and frozen mashed potatoes, frozen/thawed mashed potatoes, and MPA subgroups, component 1 was a contrast between mechanical and surface textural attributes, whereas in MPB samples component 1 was determined by geometrical attributes. Addition of inulin at 30 g/kg and extra virgin olive oil at 45 g/kg is recommended.