Lauroylated, Acetylated, and Succinylated Agave tequilana Fructans Fractions: Structural Characterization, Prebiotic, Antibacterial Activity and Their Effect on Lactobacillus paracasei under Gastrointestinal Conditions

The effect of chemical modification of fractions of native agave fructans (NAF), high performance (HPAF), and a high degree of polymerization (HDPAF) by lauroylation, acetylation, and succinylation reactions on their prebiotic activity, antibacterial properties were evaluated and survival of L. paracasei in a simulated gastrointestinal system. The characterization of the reactions was confirmed by NMR and FTIR. The lauroylated and succinylated fructan fractions showed higher antibacterial activity against pathogenic bacteria such as Escherichia coli, Enterococcus faecalis and Staphylococcus aureus than the unmodified ones. Analyses with L. paracasei showed that the acetylated fructan fractions had a greater prebiotic effect, and simulated gastrointestinal tests demonstrated that the acetylated and succinylated fractions favored the survival of L. paracasei during the gastrointestinal phase. The effect of modifying the agave fructans fractions on the evaluated properties depended on the structure, size, and polarity of each incorporated functional group, as well as the degree of polymerization and substitution of each fraction. These results show that the chemical modification of the fructan fractions analyzed improves their functional properties, offering an alternative in the food and pharmaceutical industry.

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.

Physicochemical Composition and Apparent Degree of Polymerization of Fructans in Five Wild Agave Varieties: Potential Industrial Use

In this study, we characterize fructan extracts from five wild agave varieties at three ages to identify their potential use in the food industry. Physicochemical parameters (solids soluble total and pH), sugar content and fructan distribution profiles by high-performance anion-exchange chromatography (HPAEC) were evaluated. We found that the ages and variety influenced the carbohydrate content and also fructan dispersion. Two- to four-year-old plants exhibited the highest concentrations of free sugars and fructans, with a low apparent degree of polymerization (DPa) of ≤9 monomers, which highlights their potential use as prebiotics. Conversely, 10- to 12-year-old plants presented a low concentration of free sugars and fructans with a maximum DPa of 70 monomers, which can be used to obtain fractions with high, intermediate and low DPa. These fractions have a potential use in the food industry as prebiotic, soluble fibers, stabilizers and sweeteners, among others. The agave varieties Agave spp., Agave salmiana, and Agave atrovirens showed mainly fructooligosaccharides (FOSs). Due to the presence of these low molecular carbohydrates, prebiotics, fermented products and/or syrups could be obtained. A. salmiana spp. crassipina and Agave tequilana variety cenizo presented DPa ≤50 and DPa ≤70, respectively, which could be useful in the production of fructan fractions of different DPa. These fractions might be used as functional ingredients in the manufacture of a wide range of food products.

Use of Electrosprayed Agave Fructans as Nanoencapsulating Hydrocolloids for Bioactives

High degree of polymerization Agave fructans (HDPAF) are presented as a novel encapsulating material. Electrospraying coating (EC) was selected as the encapsulation technique and β-carotene as the model bioactive compound. For direct electrospraying, two encapsulation methodologies (solution and emulsion) were proposed to find the formulation which provided a suitable particle morphology and an adequate concentration of β-carotene encapsulated in the particles to provide a protective effect of β-carotene by the nanocapsules. Scanning electron microscopy (SEM) images showed spherical particles with sizes ranging from 440 nm to 880 nm depending on the concentration of HDPAF and processing parameters. FTIR analysis confirmed the interaction and encapsulation of β-carotene with HDPAF. The thermal stability of β-carotene encapsulated in HDPAF was evidenced by thermogravimetric analysis (TGA). The study showed that β-carotene encapsulated in HDPAF by the EC method remained stable for up to 50 h of exposure to ultraviolet (UV) light. Therefore, HDPAF is a viable option to formulate nanocapsules as a new encapsulating material. In addition, EC allowed for increases in the ratio of β-carotene:polymer, as well as its photostability.

Application of high hydrostatic pressure on Pacific white shrimp (Litopenaeus vannamei) pâté: Microbiological, physicochemical and consumer acceptance

The locally elaborated shrimp pâté is highly susceptible to microbial spoilage and deterioration during storage due to its content in nutrients. These conditions limit its commercialization in a larger scale. High hydrostatic pressure is an alternative to heat treatments technology used to inactivate microorganisms. The aim of this project was to evaluate the effect of high hydrostatic pressure on quality parameters and microbiological stability of Pacific white shrimp ( Litopenaeus vannamei) pâté during storage. Shrimp pâté was pressurized to 400, 500 and 600 MPa for 90 and 180 s. Samples were analysed for physicochemical, microbiological and flavour profile up to 21 days of storage at 4 ℃. A hedonic test was made to evaluate the acceptance of pâté. No microorganisms were detected at 600 MPa for 180 s and a shelf life of 14 days was reached. No relevant changes in pH or colour of pressurized samples were detected; flavour profile did not show any changes after being pressurized or during storage. Shrimp pâté treated with 600 MPa for 180 s presented good sensory acceptance. High hydrostatic pressure treatments could improve microbiological quality of shrimp pâté without a sensible modification of the physicochemical and sensorial qualities of this product.

Effect of maltodextrin reduction and native agave fructans addition on the physicochemical properties of spray-dried mango and pineapple juices

The effects of the partial replacement of maltodextrin by native agave fructans on the characteristics of spray-dried pineapple and mango powder were evaluated in this study. An experimental 3³ design, three concentrations of maltodextrin (5, 7, and 10%), three concentrations of native agave fructans (0, 2, and 4%), and three feed temperatures (110, 115, and 120  ℃) were used. The results using the treatment in which only maltodextrin was used as a reference indicated that an increment in the inlet temperature decreases the moisture content, a_w, and solubility. Likewise, an increase (more than 2%) in fructans concentration generates products with increased a_w, moisture, hygroscopicity, wettability, and greater solubility. Additionally, no modification of storage stability was observed. Mango and pineapple powder color were affected mainly by the inlet temperature, causing an increase in luminosity (L*) and a decrease in parameter ( a*). A scanning electron microscopy showed spherical powder particles with certain contractions; powder stability in treatments with native agave fructans was not modified in the treatment at 2%. Finally, the addition of 2% agave fructans as carrier material was able to reduce the maltodextrin concentration of the spray drying process.

Microencapsulation of Eugenia uniflora L. juice by spray drying using fructans with different degrees of polymerisation

The objective of this work was to microencapsulate pitanga (Eugenia uniflora L.) juice by spray drying, using High Performance Agave Fructans (HPAF) and High Degree of Polymerisation Agave Fructans (HDPAF) and maltodextrin (MD), respectively, as the wall materials. The physicochemical and antioxidant properties of the capsules during storage at various temperatures were evaluated. The microparticles developed using fructans HPAF and HDPAF, exhibited similar physicochemical and flow properties to those presented by the microparticles prepared with MD. The highest yield and concentration of anthocyanins after drying and during storage were found for a 1:6 core:wall material ratio. The total color change was a good indicator of the microcapsule stability. This study showed that both fructans fraction possess similar encapsulating properties to MD and that the HDPAF were more efficacious than MD at protecting the antioxidants during drying and storage.