Agave Fructans Research Articles

Fructans from Agave tequilana with a Lower Degree of Polymerization Prevent Weight Gain, Hyperglycemia and Liver Steatosis in High-Fat Diet-Induced Obese Mice.

Fructans from agave have received specific attention because of their highly branched fructan content. We have previously reported that the degree of polymerization (dp) influences their biological activity. Therefore, the aim of this study was to investigate the effect of unfractionated and fractionated fructans (higher and lower dps) from Agave tequilana in high-fat diet-induced (HFD) obese mice. Fructans with a lower dp (HFD+ScF) decreased weight gain by 30 %, body fat mass by 51 %, hyperglycemia by 25 % and liver steatosis by 40 %. Interestingly, unfractionated fructans (HFD+F) decreased glucose and triglycerides (TG), whereas fractionated fructans with a higher dp (HFD+LcF) decreased TG but not glucose; in contrast, HFD+ScF decreased glucose but not TG. Our findings suggest that both higher and lower dp agave fructans have complementary effects in metabolic disorders related to obesity. These findings may contribute to the development of improved food supplements with a specific ratio combination of fructans with different dps.Electronic supplementary materialThe online version of this article (doi:10.1007/s11130-016-0578-x) contains supplementary material, which is available to authorized users.

Development of reduced‐fat cheeses with the addition of Agave fructans

Cheeses containing Agave fructans were compared with both full‐fat and reduced‐fat samples without fructans. Microstructure results showed that the cheeses obtained were very similar to the control samples (without fructans), even the full‐fat control sample, demonstrating the texturing role of the carbohydrates. Regarding the composition, a moisture content of 47.96 ± 1.45 and a good protein retention with a low‐fat content were found. Therefore, the cheese yield was not adversely affected, and no significant differences were observed in sensory aspects. Considering the health benefits of fructans and their abundance, this development could represent an innovation for dairy industry.

Effect of Spray Drying of Agave Fructans, Nopal Mucilage and Aloe Vera Juice

The effect of inlet air temperature on the physicochemical properties and stability of agave fructans, mucilage of cactus and aloe juice were evaluated. Temperatures employed for inlet air was 70–110C in 10C increments. The best temperature for the inlet air and agave fructans cactus mucilage, where yields obtained were 40–93%, moisture content 1.71–4.10% and bulk density 0.40–0.58 g/mL, was 100 and 110C, respectively. For aloe juice, the inlet air temperature showed no significant effect on yield, water activity and bulk density, but it did for moisture content, hygroscopicity index, glass transition temperature and solubility time in the powder. Agave fructans presented desirable physicochemical stability characteristics with potential use as the carrier agent. Practical Applications Agave fructans, nopal mucilage and aloe vera juice can be considered as food ingredients from natural sources. These ingredients can help to thicken various types of food. The ingredients from natural sources in powders improve the stability and transportation characteristics of the ingredients in juices or extracts. Finding the better spray drying conditions provides better physicochemical, stability, chemical and microbiological quality in the powder. Agave fructan, nopal mucilage and aloe vera powders have beneficial properties for health and present a potential use as nutraceutical food.

Functional characterization of a novel β-fructofuranosidase from Bifidobacterium longum subsp. infantis ATCC 15697 on structurally diverse fructans.

In this study, we describe the isolation of a gene encoding a novel β-fructofuranosidase from Bifidobacterium longum subsp. infantis ATCC 15697, and the characterization of the enzyme, the second one found in this strain, significantly different in primary sequence to the already reported bifidobacterial β-fructofuranosidases. The gene, found through genome-mining was expressed in Escherichia coli C41(DE3). The recombinant enzyme (B.longum_l1) has a molecular weight of 75kDa, with optimal activity at 50°C, pH 6·0-6·5, and a remarkable stability with a half-life of 75·5h at 50°C. B.longum_l1 has a wide specificity for fructans, hydrolysing all substrates through an exo-type mechanism, including Oligofructose P95 (β2-1 fructooligosaccharides (FOS), DP 2-8), Raftilose Synergy 1(β2-1 FOS & inulin, DP 2-60), Raftiline HP (inulin, DP 2-60), bacterial inulin (3000kDa) and levan (8·3 & 3500kDa), Agave fructans (mixed fructans, DP 3-29) and levan-type FOS (β2-6 FOS, DP 2-8), with the highest relative activity and turnover number found for levan-type FOS. The apparent affinity of the enzyme for levan-type FOS and Oligofructose P95 was found to be 9·2 and 4·6mmoll(-1) (Km ) with a specific activity of 908 and 725μmolmin(-1) mg(-1) of protein (k2 ), respectively, more than twice the activity for sucrose. B.longum_l1 is a wide substrate specificity enzyme, which may contribute to the competitiveness and persistence of this strain in the colon. The bifidobacterial β-fructofuranosidase activity was evaluated with a wide variety of substrates including noncommercial fructans, such as levan-type and mixed agave fructans. Its activity on these substrates certainly strengthens their commercial prebiotic character and contributes to the understanding of bifidobacteria stimulation by structurally diverse fructans.

Effect of Spray Drying Temperature and Agave Fructans Concentration as Carrier Agent on the Quality Properties of Blackberry Powder

Abstract The agave fructans as carrier agent can be an alternative to increase quality properties of blackberry. The aim of this study was to evaluate the effect of agave fructans concentration and inlet air temperature on quality properties of blackberry powder. Agave fructans concentrations were 50, 75 and 100 % (in base the total soluble solids percentage of blackberry extract), and the inlet air temperatures were 70–110 °C. A pilot-scale spray dryer was employed. Drying yield ranged from 58 to 94 % dry base. Encapsulation efficiency values varied between 48 and 100 % of anthocyanin concentration. The lower agave fructans concentration showed the best quality characteristics as lower water activity of 0.28, high anthocyanin retention of 98 %, high bulk density of 0.80 g/ml and the higher agave fructans concentrations showed the best stability properties as lower hygroscopicity of 0.013 gH20/gsolids and low particle temperature of 38 °C. The agave fructans improves good physicochemical and stability characteristics in blackberry powders.

Effect of agave fructans on bulk and surface properties of sodium caseinate in aqueous media

Aqueous systems of agave fructans and sodium caseinate were studied to identify the physical and physicochemical properties of the individual macromolecules and their mixtures. Bulk behavior of agave fructans alone and in mixtures with sodium caseinate systems was similar to that of the density and rheology of monosaccharide solutions. A synergistic surface activity effect was found and attributed to the tendency of agave fructans to associate with sodium caseinate, as was confirmed by the viscosity, zeta potential values and particle size distribution. Their mixture developed properties that make them appealing for applications in foods that are dispersed systems (emulsions and foams) where a large increase in viscosity is not desirable.

Synthesis and emulsifying properties of carbohydrate fatty acid esters produced from Agave tequilana fructans by enzymatic acylation

Carbohydrate fatty acid esters are non-ionic surfactants with a broad spectrum of applications. These molecules are generally synthesized using short carbohydrates or linear fructans; however in this research carbohydrate fatty acid esters were produced for the first time with branched fructans from Agave tequilana. Using immobilized lipases we successfully acylated A. tequilana fructans with vinyl laurate, obtaining products with different degrees of polymerization (DP). Lipozyme 435 was the most efficient lipase to catalyze the transesterification reaction. HPLC and ESI-MS analysis proved the presence of a mixture of acylated products as a result of the chemical complexity of fructans in the A. tequilana. The ESI-MS spectra showed a molecular mass shift between 183 and 366g/mol for fructooligosaccharides with a DP lower than 6, which indicated the presence of Agave fructans that had been mono- and diacylated with lauric acid. The carbohydrate fatty acid esters (CFAE) obtained showed good emulsifying properties in W/O emulsions.

Application of a Box–Behnken design for optimizing the extraction process of agave fructans (Agave tequilana Weber var. Azul)

Agave (Agave tequilana Weber var. Azul) is an industrially important crop in México since it is the only raw material appropriate to produce tequila, an alcoholic beverage. Nowadays, however, these plants have also a nutritional interest as a source of functional food ingredients, owing to the prebiotic potential of agave fructans. In this study, a Box-Behnken design was employed to determine the influence of temperature, liquid:solid ratio and time in a maceration process for agave fructan extraction and optimization. The developed regression model indicates that the selected study variables were statistical determinants for the extraction yield, and the optimal conditions for maximum extraction were a temperature of 60 °C, a liquid:solid ratio of 10:1 (v/w) and a time of 26.7 min, corresponding to a predicted extraction yield of 37.84%. Through selective separation via precipitation with ethanol, fructans with a degree of polymerization of 29.1 were obtained. Box-Behnken designs are useful statistical methods for optimizing the extraction process of agave fructans. A mixture of carbohydrates was obtained from agave powder. This optimized method can be used to obtain fructans for use as prebiotics or as raw material for obtaining functional oligosaccharides. © 2015 Society of Chemical Industry.

The effect of agave fructan products on the activity and composition of the microbiota determined in a dynamic in vitro model of the human proximal large intestine

Inulin and trans-galactooligosaccharides have so far fully met the criteria for prebiotics. This study shows the effect of putative prebiotics Metlos and Metlin (short and medium chain branched fructans from agave) on the activity and composition of the gut microbiota compared to the effects of two linear inulin type fructans (Synergy1 and Actilight) in order to evaluate their possible application as functional food. The method used was a dynamic in vitro model of the large intestine. With Synergy1 and Actilight, bifidobacteria and lactobacilli increased, whereas with Metlin and Metlos, primarily lactobacilli increased. With all four substrates, the butyrate production was increased which may have a beneficial impact on health. The production of the potentially harmful putrefactive metabolites was reduced by all substrates. Based on the definition of prebiotics and the results of this study, Metlos and Metlin should be considered as potential prebiotics.

Dehydrated apple matrix supplemented with agave fructans, inulin, and oligofructose

The objective of this study was to determine the effect of supplemented prebiotics: inulin (I), oligofructose (O), agave fructans (A) and their mixtures in three levels, 20, 40 and 60 g prebiotics/kg puree on the physicochemical and sensorial properties of a dehydrated apple matrix (DAM), fruit leather type. A simplex-centroid design was used to formulate the different mixtures. After that, fructans were identified in the matrices using thin-layer chromatography and high-performance anion-exchange chromatography with pulsed amperometric detection and enzymatic kits. A descriptive quantitative method was used to determine sensory profile of the matrices. The sensory acceptability was measured by a 7-point hedonic scale. Matrices supplemented with solely A and O, were significantly smoother and more qualified in acceptability compared to the control. The behavior of DAM with inulin was different; it increased hardness and decreased acceptability. In general, mixtures of prebiotics had a synergistic effect on matrices hardness. The optimum formulation corresponded to the DAM supplemented with agave fructans, indicating that it is possible to obtain a fruit leather type product with prebiotic potential.

A randomised, double- blind, cross-over study investigating the prebiotic effect of agave fructans in healthy human subjects.

This placebo-controlled, randomised, double-blind, cross-over human feeding study aimed to determine the prebiotic effect of agave fructans. A total of thirty-eight volunteers completed this trial. The treatment consisted of 3 weeks' supplementation with 5g/d of prebiotic agave fructan (Predilife) or equivalent placebo (maltodextrin), followed by a 2-week washout period following which subjects were crossed over to alternate the treatment arm for 3 weeks followed by a 2-week washout. Faecal samples were collected at baseline, on the last day of treatment (days 22 and 58) and washout (days 36 and 72), respectively. Changes in faecal bacterial populations, SCFA and secretory IgA were assessed using fluorescent in situ hybridisation, GC and ELISA, respectively. Bowel movements, stool consistencies, abdominal comfort and mood changes were evaluated by a recorded daily questionnaire. In parallel, the effect of agave fructans on different regions of the colon using a three-stage continuous culture simulator was studied. Predilife significantly increased faecal bifidobacteria (log10 9·6 (sd 0·4)) and lactobacilli (log10 7·7 (sd 0·8)) compared with placebo (log10 9·2 (sd 0·4); P=0·00) (log10 7·4 (sd 0·7); P =0·000), respectively. No change was observed for other bacterial groups tested, SCFA, secretory IgA, and PGE2 concentrations between the treatment and placebo. Denaturing gradient gel electrophoresis analysis indicated that bacterial communities were randomly dispersed and no significant differences were observed between Predilife and placebo treatments. The in vitro models showed similar increases in bifidobacterial and lactobacilli populations to that observed with the in vivo trial. To conclude, agave fructans are well tolerated in healthy human subjects and increased bifidobacteria and lactobacilli numbers in vitro and in vivo but did not influence other products of fermentation.

Production of fructanase by a wild strain of Saccharomyces cerevisiae on tequila agave fructan.

A new wild strain of Saccharomyces cerevisiae (CF3) isolated from tequila must was evaluated for production of fructanase on Agave tequilana Weber fructan (FT). Fructanase activity (F) was assessed by a 3(3) factorial design (substrate, temperature and pH). High enzymatic activity (31.1U/ml) was found at 30°C, pH 5, using FT (10g/l) as substrate. The effect of initial substrate concentration on F (FT0, 5.7-66g/l) was studied and it was found that F was highest (44.8U/ml) at FT0 25g/l. A 2(2) factorial experimental design with five central points was utilized to study the effect of stirring and aeration on fructanase activity; stirring exhibited a stronger effect on F. The ratio fructanase to invertase (F/S) was 0.57, which confirms that the enzymes are fructanase. Crude fructanase reached high substrate hydrolysis (48wt%) in 10h. It is shown that S. cerevisiae CF3 was able to produce large amounts of fructanase by growing it on fructan from A. tequilana.

In vitro colonic fermentation of food ingredients isolated from Agave tequilana Weber var. azul applied on granola bars

The stem of Agave tequilana Weber is used to obtain fructans. Reports on the potential prebiotic activity of agave fructans as ingredients are scarce. The aim of this study was to evaluate the indigestible fraction (IF) content and the short chain fatty acid production (SCFA) from in vitro fermentation of: Native-agave-fructans (NAF), agave-dietary-fiber (ADF), high-performance-fructans (HPF), both separately and as part of a composite granola bar. Agave ingredients and the IF of the agave granola bar were compared using an in vitro enzymatic digestion process followed by 24-h pH-controlled anaerobic batch cultures inoculated with human gut flora (fecal inoculum). Fermentation of agave ingredients resulted in a noticeable increase in SCFA production and the metabolite production profile varied with the fermentation time. Addition of NAF and ADF to granola modified the fermentation profiles, increasing propionate and butyrate molar ratios. Agave ingredients are good sources of fermentable dietary fiber with the ability to yield high concentrations of SCFA.

Agave fructans: their effect on mineral absorption and bone mineral content.

In this study we investigate the effect that Agave fructans as new prebiotics have on mineral absorption improvement. Forty-eight 12-week-old C57BL/6J mice were used in this study. Forty mice were ovariectomized and eight were sham-operated controls. Mice were fed standard diets or diets supplemented with 10% Agave fructans or 10% inulin fructans. Calcium and magnesium were evaluated as well as their excretion in feces. Osteocalcin levels were also measured; femur structure was studied by scanning electron microscopy. Other parameters, such as food intake, body weight, glucose, and short-chain fatty acid content, were recorded. Calcium in plasma and bone increased in Agave fructan groups (from 53.1 to 56 and 85 mg/L and from 0.402 to 0.474 and 0.478 g/g, respectively) and osteocalcin increased in all fructan groups (>50%). Scanning electron microscopy showed that fructans were able to mitigate bone loss. In conclusion, we demonstrated that supplementation with Agave fructans prevents bone loss and improves bone formation.

Effect of inulin and agave fructans addition on the rheological, microstructural and sensory properties of reduced-fat stirred yogurt

The effect of medium chain inulin (IN) and agave fructans (FR) at concentrations of 20, 40, and 60 g L−1 on the microstructural, rheological and sensory properties of reduced milk-fat (RIN or RFR, 13 g of milk fat L−1) stirred yogurts were investigated in comparison with those of a full-fat control (FC, 26 g of milk fat L−1) yogurt. Scanning electron micrographs revealed that RIN and RFR showed different protein network arrangements than FC. FR tended to cover the casein micelles, while IN formed secondary gelled structures. RIN40 and RFR60 exhibited sensory characteristics (viscosity, creaminess, flavour and overall acceptability) that were deemed superior than those of FC. The loss tangent values in the linear and the stress values corresponding to the crossover point between the storage and loss moduli in the non-linear viscoelastic regions provided indicators that closely agreed with sensory evaluation perceptions.

Assessment of agave fructans as lyoprotectants of bovine plasma proteins concentrated by ultrafiltration

The effectiveness of fructans as protectant agent to prevent protein denaturation was evaluated during freeze-drying and storage. Native agave fructans and two fractions obtained by ultrafiltration were assessed as protective agents. Since the protein denaturation during freeze-drying can alter the functional properties of proteins, the evaluation of bovine plasma protein properties was performed with different concentration of fructans, pH and freezing temperatures. The results showed that the incorporation of fructans as lyoprotectants improved functional properties, due to the reduction of protein denaturation with maximum stabilization of plasma bovine protein at a fructan concentration between 5% and 10% (w/v) for native fructans and 10% (w/v) for the fractions of fructans at −40°C. Moreover, when freezing at −4°C, fructans fraction at 15% (w/v) prevented protein denaturation while native fructans exerted no acceptable protection (P<0.001). This behavior could be explained by a microstructure study of fructans, where the higher heterogeneity in size of native fructans may be the reason for the lower protective effect. Furthermore, the higher heterogeneity of the samples affected the extent of non-enzymatic browning in the range of the temperatures assessed. The shelf life of freeze-dried proteins was improved from 1.7months for the control sample to 7–11, depending on the saccharide considered. Taking into account the health benefits of fructans, since they are categorized as prebiotic, the protein–saccharide mixture may be valuable functional ingredients for food formulations.

Granola bars prepared with Agave tequilana ingredients: Chemical composition and in vitro starch hydrolysis

The stem of Agave tequilana is used to obtain: agave syrup (AS) and native agave fructans (NAF). Ground-agave-fiber is the by-product from fructans production. These ingredients were used to design a food ingredient: agave dietary fiber (ADF), containing NAF (30 g/100 g) as soluble dietary fiber (DF) and ground-agave-fiber (70 g/100 g) as an insoluble DF. The objective of this work was to evaluate the effect of the incorporation of A. tequilana ingredients (AS, NAF, ADF) on the proximate composition, in vitro starch hydrolysis (HI) and predicted glycemic index (pGI) of oat-based granola bars. Total DF (82.03 g/100 g) was the main component in ADF, with 22.8 g/100 g soluble DF. Granola bars were prepared by substituting honey and wheat flour by AS and ADF. A sensory test was used to select the level of sugar substitution by NAF, where 62 g NAF/100 g was the preferred one. The effect of each ingredient on the chemical composition was evaluated using a 23−1 fractional design. Soluble DF in a granola bar containing a combination of three agave ingredients (AS, NAF and ADF) was 23.35 g/100 g, with HI and pGI values of 74 and 72%, respectively, pointing this product as a moderate GI food.

In vitro assessment of agave fructans (Agave salmiana) as prebiotics and immune system activators

The prebiotic effect of agave fructans (Agave salmiana) was evaluated through the growth of two lactic acid bacterial (LAB) strains (Lactobacillus casei and Bifidobacterium lactis). The immune system was activated through the stimulation of peripheral blood mononuclear cells (PBMC) of healthy subjects testing fructans, LAB or a mixture of these compounds at different concentrations. Immune responses, such as early cell activation (CD69), cell cycle progression, nitric oxide (NO) production and the expression of transcription factors for lymphocyte differentiation, were analyzed. Compared with other fructans, the extracted agave fructans showed the highest prebiotic activity and increased levels of CD69 expression, proliferative activity and NO production when administered with the probiotic L. casei. The Th1 lymphocyte differentiation produced through LAB stimulation was greatly diminished after the incorporation of agave fructans. In conclusion, these types of fructans (A. salmiana) are involved in the activation and selective differentiation of cells of the immune system through interactions with probiotics. Thus, agave fructans represent a novel immunomodulator that might benefit the functional food industry.

An exploratory study into the putative prebiotic activity of fructans isolated from Agave angustifolia and the associated anticancer activity

Linear inulin-type fructan (ITF) prebiotics have a putative role in the prevention of colorectal cancer, whereas relatively little is known about branched fructans. This study aims to investigate the fermentation properties and potential prebiotic activity of branched fructans derived from Agave angustifolia Haw, using the Simulator of Human Intestinal Microbial Ecosystem (SHIME) model. The proximal, transverse and distal vessels were used to investigate fructan fermentation throughout the colon and to assess the alterations of the microbial composition and fermentation metabolites (short chain fatty acids and ammonia). The influence on bioactivity of the fermentation supernatant was assessed by MTT, Comet and transepithelial electrical resistance (TER), respectively. Addition of Agave fructan to the SHIME model significantly increased (P < 0.05), bifidobacteria populations (proximal and transverse), SCFA concentrations (proximal, transverse and distal) and decreased ammonia concentrations in the distal vessel. Furthermore, the fermentation supernatant significantly (P < 0.05) increased the TER of a Caco-2 cell monolayer (%) and decreased fluorescein-based paracellular flux, suggesting enhanced barrier function and reduced epithelial barrier permeability (proximal and distal vessel). While cytotoxicity and genotoxicity remained unaltered in response to the presence of Agave fructans. To conclude, branched Agave fructans show indications of prebiotic activity, particularly in relation to colon health by exerting a positive influence on gut barrier function, an important aspect of colon carcinogenesis.

Effects of Agave tequilana fructans with different degree of polymerization profiles on the body weight, blood lipids and count of fecal Lactobacilli/Bifidobacteria in obese mice

Fructans are dietary fibers with beneficial effects on the gastrointestinal physiology and offer a promising approach for the treatment of some metabolic disorders associated with obesity. In vitro and in vivo studies were developed to test the safety of fructans obtained from Agave tequilana Weber var. azul. Additionally, an in vivo experiment using a diet-induced obesity model was performed to compare the effect of agave fructans with different degree of polymerization (DP) profiles: agave fructans with DP > 10 (LcF), agave FOS with DP < 10 (ScF), and agave fructans with and without demineralization (dTF, TF) versus commercial chicory fructans (OraftiSynergy1™) on the body weight change, fat, total cholesterol, triglycerides and count of fecal Lactobacillus spp. and Bifidobacterium spp. Results showed that A. tequilana fructans were not mutagenic and were safe even at a dose of 5 g per kg b.w. Obese mice that received ScF showed a significant decrease in body weight gain, fat tissue and total cholesterol without increasing the count of fecal Bifidobacteria. Whereas, obese mice that received LcF and TF showed decreased triglycerides and an increased count of fecal Bifidobacteria. Interestingly, although obese mice that received dTF did not show changes in body weight gain, fat tissue, total cholesterol or triglycerides, they showed an increase in the count of Bifidobacteria. These results demonstrate that both the degree of polymerization and the demineralization process can influence the biological activity of agave fructans.