Agave Fructans Research Articles

Evaluation of biopolymers in the encapsulation by electrospraying of polyphenolic compounds extracted from blueberry (Vaccinium corymbosum L.) variety Biloxi

The Blueberry cv. Biloxi is characterized by its high phenolic compounds content, mainly anthocyanins, which are relevant for their application in the prevention of chronic degenerative diseases. In this study, we have demonstrated that the encapsulation of blueberry extracts is feasible using as a matrix a combination of biopolymers through the electrohydrodynamic process from aqueous solutions. Corn prolamin zein, whey protein concentrate and high polymerization grade agave fructans were used as polymers. The properties of the solution and the capacity of atomization with high voltage were evaluated by adding glycerol as an adjuvant. The results of this investigation showed that most of the solutions were within the recommended ranges to be electrospun. However, not all exhibited stability when the blueberry polyphenolic extract was added. The morphology of structures was characterized and then related to the properties of the solution. The corn prolamin zein was able to obtain capsules loaded with encapsulation efficiency of 52.65% of polyphenolic extract by electrospraying process with homogeneous morphology and smooth, as well as continuous nanofibers by electrospinning process.

Physicochemical and functional properties of native and modified agave fructans by acylation

Native agave fructans were modified by an acylation reaction with lauric acid. Native and modified fructans were characterized using NMR, FTIR and various physicochemical and functional properties at different pHs were evaluated. NMR and FTIR spectra demonstrated the incorporation of lauric acid in the molecular structure of fructans. Modified agave fructans exhibited a color, moisture and water activity similar to native fructans, but properties such as solubility, swelling capacity, emulsifying activity and foam capacity were significantly modified by the acylation reaction mainly when the samples were analyzed at different pHs. The thermogram of the acylated fructans evidenced significant changes in thermal properties when compared with native fructans and acylated fructans were able to form micellar aggregates. In general, modified fructans showed improved functional properties in comparison with native fructans representing an important opportunity to improve the functionality of the foods in which it is incorporated.

Microencapsulation of Lactobacillus plantarum by spray drying with mixtures of Aloe vera mucilage and agave fructans as wall materials

AbstractIn this work, a spray‐drying process is used to encapsulate a probiotic strain of Lactobacillus plantarum with mixtures of Aloe vera mucilage (AVM) (Aloe barbadensis Miller) and agave fructans of high degree of polymerization (AFHDP). Physicochemical properties of the powders reveal moisture contents lower than 10% and water activity between 0.195 and 0.3, suggesting stability during storage. A non‐Newtonian shear‐thinning behavior arises in the reconstituted powders under steady shear flow and viscosity is shown to depend on the concentration, pH, and temperature. A predominant viscous behavior is exhibited in the viscoelastic properties under small amplitude oscillatory flow with equal values of the elastic and viscous moduli at high frequencies (G´ = G´´), suggesting a random coil conformation. Scanning electron microscope observations reveal a spherical microcapsule morphology possessing homogeneous surfaces with modal particle‐size distribution (D [4,3] =21.3 μm). The addition of arabic gum to the AVM‐AFHDP mixtures induces a shift in the glass transition temperature (Tg) to 150°C. Preserved stability of the AVM‐AFHDP functional groups with the probiotic after spray drying reveals the effective encapsulation of the microorganism, as corroborated by transmission electron microscopy and Fourier‐transform infrared. Enhanced microorganism survival rate of 70% in the mixture is recorded, representing an alternative for probiotic encapsulation.PRACTICAL APPLICATIONSNowadays, the use of mixtures of prebiotic biopolymers as encapsulating wall materials is highly appreciated by the food and pharmaceutical industry. This research demonstrated that mixtures of Aloe vera mucilage and agave fructans are suitable for the microencapsulation of L. plantarum through studies on their rheological, morphological, and calorimetric properties. High survival rates and stable powders are obtained in samples subjected to spray drying. Results of this investigation may help to develop new delivery drug systems, which are able to protect bioactive compounds or probiotic cells through the gastrointestinal tract. Increasing health benefits, including probiotic and symbiotic effects, are expected with the intake of dietary fibers.

Agave fructans as fat and sugar replacers in ice cream: Sensory, thermal and texture properties

The principal aim of the present study was to investigate the feasibility of replacing fat and sugar with agave fructans to produce both low-fat, and low-fat and sugar ice cream. For this purpose, agave fructans (0–3.0%) were added to several ice cream formulations to explore relationships between their sensory perception, and their previously reported thermal and texture properties. Formulations with less than 1.2% of agave fructans contributed sensory attributes linked to the amount and size of ice crystals, such as crystallized (both texture and appearance), grainy and cold sensation. These were related to frozen water, ice fraction, enthalpy and maximum temperature, as well as hardness, melting rate and compression force. On the other hand, the samples with concentrations between 1.2 and 3.0% of agave fructans showed ice cream formulations with longer melting times, smooth, creamy and fluid texture, and with fatty sensation. These properties were directly related to low non-frozen water concentrations, high glass transition temperatures and ΔCp values, as well as textural properties, such as apparent viscosity and overrun. Even though consumers liked the samples with higher amounts of fat and sugar, all the samples showed liking values in a quite narrow range around the neutral point on the liking scale. Thus, agave fructans were able to enhance several sensory, thermal and textural properties, making them a feasible alternative as a fat and sugar replacer.

Applying Differential Neural Networks to Characterize Microbial Interactions in an Ex Vivo Gastrointestinal Gut Simulator

The structure of mixed microbial cultures—such as the human gut microbiota—is influenced by a complex interplay of interactions among its community members. The objective of this study was to propose a strategy to characterize microbial interactions between particular members of the community occurring in a simulator of the human gastrointestinal tract used as the experimental system. Four runs were carried out separately in the simulator: two of them were fed with a normal diet (control system), and two more had the same diet supplemented with agave fructans (fructan-supplemented system). The growth kinetics of Lactobacillus spp., Bifidobacterium spp., Salmonella spp., and Clostridium spp. were assessed in the different colon sections of the simulator for a nine-day period. The time series of microbial concentrations were used to estimate specific growth rates and pair-wise interaction coefficients as considered by the generalized Lotka-Volterra (gLV) model. A differential neural network (DNN) composed of a time-adaptive set of differential equations was applied for the nonparametric identification of the mixed microbial culture, and an optimization technique was used to determine the interaction parameters, considering the DNN identification results and the structure of the gLV model. The assessment of the fructan-supplemented system showed that microbial interactions changed significantly after prebiotics administration, demonstrating their modulating effect on microbial interactions. The strategy proposed here was applied satisfactorily to gain quantitative and qualitative knowledge of a broad spectrum of microbial interactions in the gut community, as described by the gLV model. In the future, it may be utilized to study microbial interactions within mixed cultures using other experimental approaches and other mathematical models (e.g., metabolic models), which will yield crucial information for optimizing mixed microbial cultures to perform certain processes—such as environmental bioremediation or modulation of gut microbiota—and to predict their dynamics.

Effects of Agave Fructans, Inulin, and Starch on Metabolic Syndrome Aspects in Healthy Wistar Rats.

Healthy Wistar rats were supplemented during 20 weeks with commercial inulin (I) and Agave tequilana fructans (CAT), experimental fructans from A. tequilana (EAT) and A. salmiana (AS) mature stems, rice starch 10% (RS), and standard feed for rodents (C). Feed intake was kept steady, but with I, body weight and abdominal adipose tissue (6.01 g) decreased at the end. Glucose (mg/dL) (C, 120.52; I, 110.69; CAT, 105.75; EAT, 115.48; AS, 101.63; and RS, 121.82), total cholesterol (C, 89.89; I, 64.48; CAT, 68.04; EAT, 68.74; AS, 68.04; and RS, 82), and triglycerides (C, 84.03; I, 59.52; CAT, 68.56; EAT, 59.08; AS, 75.27; and RS, 81.8) kept being normal and without differences between fructans. At the end, there was a significant increase in lactic acid bacteria when the I and AS groups were compared to the C group (C, 9.18; I, 10.64; CAT, 10.34; EAT, 10.36; AS, 10.49; and RS, 9.62 log 10 CFU/g of feces). In addition, with fructans, there was an accelerated process in feces emptiness, Lieberkühn crypts kept their morphology, and there was an increment of goblet cells.

Novel process to obtain agave sap (aguamiel) by directed enzymatic hydrolysis of agave juice fructans

Kluyveromyces marxianus and Saccharomyces paradoxus, which are the native microorganisms found in aguamiel, were used successfully for exo- and endo-fructanase synthesis to hydrolyze agave fructans important in agave sap production. We studied culture media for enzyme synthesis, as well as the physicochemical properties and enzyme activity, and we optimized the bioprocess parameters and the enzyme extract mixture to maximize agave fructan hydrolysis. The results showed that the best culture medium for fructanase synthesis contained 14.0, 20.0, and 1.0 (g-L−1) of sucrose, peptone, and K2HPO4, respectively. The best enzyme-to-substrate ratio for agave juice containing 90 g-L−1 of fructans was 10:1. Under constant operating conditions of 45.25 °C, 65.47 rpm, and pH 4.28, a product with 93.62 g-L−1of total reducing sugars (TRS) and fructooligosaccharides (FOS) with a polymerization degree (PD) from 3 to 10 hexose units was obtained using a mixture of 98.4% K. marxianus and 1.6% S. paradoxus enzyme extracts. The resulting agave sap preserves the natural flavor and tastes closest to natural agave sap (aguamiel); hence, the results show, for the first time, a resolution of the technical challenge for stable agave sap production and confirm the importance of using native strains to evolve from spontaneous to directed fermentation.

Changes in gut microbiota in predigested Hibiscus sabdariffa L calyces and Agave (Agave tequilana weber) fructans assessed in a dynamic in vitro model (TIM-2) of the human colon

Hibiscus sabdariffa (Hb) calyces are a source of dietary fiber (DF) and phenolic compounds. Agave fructans (AF) and oligofructans (OF) are considered as soluble DF. The aim of the study was to investigate changes in gut microbiota upon feeding predigested Hb, AF, OF or Mix (Hb/AF) to a dynamic, validated in vitro model of the human colon (TIM-2), using sequencing of the V3-V4 regions of the 16S rRNA gene. A pooled human fecal microbiota was used. Production of short-chain fatty acids (SCFAs), branched-chain fatty acids (BSCFAs) and ammonia was also assessed. Samples were taken after 0, 24, 48 and 72 h. Principal component (PC) analysis of fermentation metabolites and relative abundance of genera was carried out, and extracted factors were based on eigenvalues >1.0 and explained >60% of variance. Fermentation of samples resulted in different SCFAS concentrations. The highest butyric acid production was on AF and OF, while the molar ratio of SCFAS on Hb was 63:18:18 for acetic, propionic and butyric acid, respectively. BSCFAS were also produced upon feeding the studied substrates, but in much lower concentrations. About 45 bacteria genera were identified and 10 of these were the most abundant changing during the fermentation time, amongst which a high relative abundance in Bifidobacterium, Bacteroides and Catenibacterium, that changed during the fermentation time depending of substrate. Hb feeding after 48 h led to Bifidobacterium being the most abundant genus. Two PCs were identified: after 24 h of fermentation PC1 was highly influenced by Bifidobacterium and Prevotella, which was related with Hb and SIEM feeding. Evaluation of the changes in metabolites and gut microbiota composition during colonic fermentation in a validated in vitro model provides a complete and reliable view of the potential prebiotic effect of different dietary fibers.

Three-dimensional water mapping of succulent Agave victoriae-reginae leaves by terahertz imaging

While terahertz imaging has been used before for the determination of water content in vegetative tissue, most studies have either presented measurements of the temporal evolution of water content at a single-point of the plant or have presented two-dimensional images of leaves, demonstrating the potential of the technique, but relatively little of such information has been used to support biologically relevant conclusions. In this article we introduce terahertz time-domain spectroscopic imaging as a technique for the determination of the three-dimensional distribution of water in succulent plant tissues. We present the first three-dimensional water mapping of an agave leaf, which demonstrates an unprecedented capability to study the water retention mechanisms within succulent plants. We found that agave leaves are composed of a low-hydration outer tissue layer, defined by the outermost layer of vascular tissue that surrounds a high-hydration tissue, the carbohydrate rich hydrenchyma. The findings are supported by histological images and the correlation between the water content and carbohydrate presence is consistent with recently published findings of a remarkably large hydration shell associated with agave fructans.

Micro- and Nanostructures of Agave Fructans to Stabilize Compounds of High Biological Value via Electrohydrodynamic Processing.

This study focuses on the use of high degree of polymerization agave fructans (HDPAF) as a polymer matrix to encapsulate compounds of high biological value within micro- and nanostructures by electrohydrodynamic processing. In this work, β-carotene was selected as a model compound, due to its high sensitivity to temperature, light and oxygen. Ultrafine fibers from HDPAF were obtained via this technology. These fibers showed an increase in fiber diameter when containing β-carotene, an encapsulation efficiency (EE) of 95% and a loading efficiency (LE) of 85%. The thermogravimetric analysis (TGA) showed a 90 °C shift in the β-carotene decomposition temperature with respect to its independent analysis, evidencing the HDPAF thermoprotective effect. Concerning the HDPAF photoprotector effect, only 21% of encapsulated β-carotene was lost after 48 h, while non-encapsulated β-carotene oxidized completely after 24 h. Consequently, fructans could be a feasible alternative to replace synthetic polymers in the encapsulation of compounds of high biological value.

Hydrophobic agave fructans for sustained drug delivery to the human colon

Given their glycosidic β 2−1 and β 2−6 linkages, fructans from Agave tequilana Weber var. azul (AtF) may be employed for the design of drug carriers targeting the human colon. However, the high water solubility of AtF prevents their use for such a purpose. In this work, AtF were esterified with acetyl, lauroyl and palmitoyl groups with the aim to encapsulate ibuprofen as a model drug and characterize its enzymatic release in simulated colon conditions. It was found that efficiency of encapsulation increased from 0.8% (unmodified fructan) to 17 or 21.5% when AtF was esterified with acetyl groups at high degree of substitution (2.75 DS) or with a long acyl chain such as palmitoyl at low DS (0.18) respectively. Hydrophilic fructan based microspheres (AtF, and lauroyl fructan, 46 and 61.3° contact angle respectively) had poor encapsulation efficiency (0.8–1.5%) and lost most of their cargo (85%) at gastric conditions. In contrast, hydrophobic fructan based microspheres (acetyl and palmytoyl, 91–98° contact angle) showed high stability at gastric pH and were able to release the drug for long periods. These characteristics make hydrophobic fructans appropriate vehicles that show great potential for the delivery of drugs to the colon, allowing long drug bioavailability during its delivery and release.

Evaluación de la fermentación de fructanos de agave de cadena media y larga sobre el crecimiento de bacterias intestinales utilizando un simulador de tracto digestivo humano

The prebiotic activities of agave fructans are well documented; however, little is known about the effects of agave fructan fractions in particular. Some reports have demonstrated that different fructan chain lengths have different effects on the growth of intestinal microbiota bacterial communities. The aim of this study was to evaluate two agave fructan fractions on the growth of probiotic and pathogenic bacteria cultured in a gastrointestinal tract simulator. The growth was carried out by plate count using media selective for each different bacterial type. In addition, the metabolites generated via fructan metabolism were analyzed by ultra-high performance liquid chromatography. These results suggest that these fructan fractions possess prebiotic activities and have beneficial effects via inhibition of intestinal pathogen growth. These effects particularly depend on the length of the selected fructan fraction administration period. This knowledge is important for enhancing the selective use of prebiotics in functional foods.

Effect of Agave Fructans as Carrier on the Encapsulation of Blue Corn Anthocyanins by Spray Drying.

Effects of agave fructans as carrier agents on the encapsulation of blue corn anthocyanins using spray-drying were evaluated. Blue corn extract was mixed with 6%, 8%, 10%, and 12% (w/v) of agave fructans in duplicate and dried at 150 °C. The extract showed good contents of anthocyanins, polyphenols, and antioxidant activity. The increase of agave fructans in the encapsulated powders caused a significant increase (p < 0.05) in the humidity, water activity (aw), pH, bulk density, water solubility index (WSI), and color L* values. On the contrary, the agave fructan addition decreased the hygroscopicity, water absorption index (WAI), antioxidant activity, total anthocyanin, total polyphenol, and individual anthocyanin contents. The encapsulation of blue corn extract with 6% agave fructans (w/v) resulted in good physical, thermal, morphological, and high antioxidant properties. The results suggest that the use of agave fructans as wall material represents advantages in the conservation of anthocyanins and other bioactive compounds from blue corn extract during their encapsulation. The application of blue corn anthocyanin encapsulated powders as a food ingredient is promising for food pigmentation, representing additional advantages for their contribution as a soluble fiber that can benefit the health of consumers.

Technological and Structural Properties of Oat Cookies Incorporated with Fructans (Agave tequilana Weber)

The beneficial effect of agave fructans on health has been demonstrated gaining popularity as a new prebiotic and functional food ingredient, however, their role as an ingredient and their technological properties is scarcely reported. This work studied the structural and quality features of doughs and cookies added with agave fructans “AF” and compared to systems added with chicory fructans “CF” or without fructans (“WF”) added, to analyse the effect of the chemical structure due to the fructan-type added. For doughs, it was found that AF lowered the water adsorption, causing a short development time and the highest stability during kneading. The texture profile analysis and rheological tests revealed that AF increased springiness and cohesiveness. For cookies, the crumb and lightness were evaluated using a computer vision system. Among the samples, AF promoted a darker and shiny crust and a more homogeneous and compact microstructure. X-ray diffraction analysis demonstrated that AF had the highest values of crystallinity. In order to provide more information about the distribution of carbohydrates (aldoses and ketoses) and gluten proteins in the cookies, a method was developed to specifically stain these molecules, and it successfully described the effect of the fructans incorporated into doughs and cookies. Results from confocal laser scanning microscopy illustrated differences in the distribution of the biopolymers stained. This research provided an improved understanding of the AF addition on the technological properties and the structure–functionally relationship of doughs and cookies, beyond the nutraceutical applications attributed to the AF.

Dehydrated apple‐based snack supplemented with Agave fructans exerts prebiotic effect regulating the production of short‐chain fatty acid in mice

The effect of dehydrated apple-based snack supplemented with Agave fructans on short-chain fatty acids (SCFA) production in mice was evaluated. Animals were randomly divided into three groups (n = 8): Control group (CG), oligofructose (OG), and Agave fructans (AG). After 24 days of treatment (stage 1), AG and OG showed elevated levels of acetate (10 µmol/g for both treatments), propionate (2.4 µmol/g for both treatments), and butyrate (1.5 and 3.2 µmol/g for OG and AG, respectively) compared with the CG. After 42 days of treatment (stage 2), AG had higher concentrations of acetate (20.8 µmol/g), propionate (2.1 µmol/g), and butyrate (5.5 µmol/g); whereas, OG only exhibited higher levels of acetate (16.8 µmol/g) and butyrate (5.6 µmol/g) in comparison with the controls. Dehydrated apple-based snack supplemented with Agave fructans exhibits a prebiotic effect increasing SCFA production in mice. Practical applications Dehydrated fruit-based snacks are generally perceived by consumers as healthy products with acceptable sensory attributes. They have a prolonged shelf life and may be consumed directly or cut into small parts for use in confectionery and bakery. In addition, the products derived from fruits plus prebiotics can enhance the beneficial effect on health and increase their consumption. This study opens up some commercial potential and technical challenges of using prebiotic-based supplements.

A rheological study of chicory and agave tequilana fructans for use in foods

Fructans are biopolymers used as food additives to modify physical properties such as texture and viscosity, while providing health benefits. They are extracted from chicory roots and roots of other plants such as agavaceas. Fructans of the genus Agave have structural differences with respect to chicory inulin, in terms of their interaction with other components. The effect of concentration and temperature on the rheological properties of fructan solutions obtained from agave and inulin was studied. The intrinsic viscosity, critical concentration and capacity of gel formation were determined in conjunction with the effects of temperature on these properties. The samples exhibited similar values of intrinsic viscosity (0.060–0.072 dL g−1), showing a critical concentration (C *) between 170 and 180 g L−1. However, only inulin formed a viscoelastic solid (gel) at concentrations higher than C*. The apparent viscosity of the solutions of both agave fructans and the inulin decreased in relation to an increase in temperature. In the concentration range of 20–100 g L−1, both biopolymers showed no variation in viscosity. It is suggested that agave fructans can be used as food additives like those from chicory inulin in the concentration range of 20–100 g L−1.

Determination of Fructan (Inulin, FOS, Levan, and Branched Fructan) in Animal Food (Animal Feed, Pet Food, and Ingredients): Single-Laboratory Validation, First Action 2018.07.

Traditional enzyme-based methods for measurement of fructan were designed to measure just inulin and branched-type (agave) fructans. The enzymes employed, namely exo-inulinase and endo-inulinase, give incompletely hydrolysis of levan. Levan hydrolysis requires a third enzyme, endo-levanase. This paper describes a method and commercial test kit (Megazyme Fructan Assay Kit) for the determination of all types of fructan (inulin, levan, and branched) in a variety of animal feeds and pet foods. The method has been validated in a single laboratory for analysis of pure inulin, agave fructan, levan, and a range of fructan containing samples. Quantification is based on complete hydrolysis of fructan to fructose and glucose by a mixture of exo-inulinase, endo-inulinase, and endo-levanase, followed by measurement of these sugars using the PAHBAH reducing sugar method which gives the same color response with fructose and glucose. Before hydrolysis of fructan, interfering sucrose and starch in the sample are specifically hydrolyzed and removed by borohydride reduction. The single-laboratory validation (SLV) outlined in this document was performed on commercially available inulin (Raftiline) and agave fructan (Frutafit®), levan purified from Timothy grass, two grass samples, a sample of legume hay, two animal feeds and two barley flours, one of which (Barley MAX®) was genetically enriched in fructan through plant breeding. Parameters examined during the validation included working range, target selectivity, recovery, LOD, LOQ, trueness (bias), precision (repeatability and intermediate precision), robustness, and stability. The method is robust, quick, and simple.

Su1641 – Randomized Double Blind Controlled Trial to Assess the Efficacy of Agave Fructans (Tequilana Weber Blue Variety) Versus Psyllium Plantago in Patients with Chronic Functional Constipation

Su1641 – Randomized Double Blind Controlled Trial to Assess the Efficacy of Agave Fructans (Tequilana Weber Blue Variety) Versus Psyllium Plantago in Patients with Chronic Functional Constipation

Effect of Agave Fructans and Maltodextrin on Zn2+ Chlorophyll Microencapsulation by Spray Drying

Spray-drying technology is a suitable process for large-scale production of various advanced materials. This study describes the effect of the concentration (0.5, 1.0, and 1.5%) of novel carrier agents, agave fructans (FOS) and maltodextrin (MD), in a chlorophyll extract spray-drying process on colour, antioxidant activity, and stability. A pilot plant was employed with a spray-dryer feed flow rate of 13% and an atomisation level of 28000 rpm. The air inlet and outlet temperatures were 180 and 80°C, respectively. A MD concentration of 0.5% was enough to obtain a chemically and physiochemically stable encapsulated chlorophyll powder. High inlet air temperatures reduced the chlorophyll content from 18 to 6 mg/g; high concentrations of the carrier agent also decreased the chlorophyll content. The results showed that, under conditions of low inlet temperature and concentration, both wall materials were efficient in microencapsulating chlorophyll for potential use in the food industry.

Hydration shells of carbohydrate polymers studied by calorimetry and terahertz spectroscopy

We present a study of the hydration shells of some carbohydrate polymers of commercial and biological importance, namely, agave fructans, inulin, and maltodextrin, employing terahertz time-domain spectroscopy and differential scanning calorimetry. We observe that the hydration numbers calculated using terahertz spectroscopy are marginally higher than those of the calorimetric values. We attribute this discrepancy to the definition of hydration number, which in a way correlates with the physical process used to quantify it. The aqueous solutions show a non-proportional increase in the absorption coefficient and the hydration number, with a decrease in the carbohydrate concentration. We demonstrate that this behavior is consistent with the “chaotropic” or “structure breaking” model of the hydration shell around the carbohydrates. In addition, the study reveals that agave fructans and inulin have good hydration ability. Given the high glass transition temperature and good hydration ability, these carbohydrates may behave as good bio-protectants and hydrating additives for food and beverages.