Simultaneous Determination of Melatonin, <Emphasis Type="SmallCaps">l</Emphasis>-Tryptophan,and two <Emphasis Type="SmallCaps">l</Emphasis>-Tryptophan-Derived Esters in Food by HPLC with Graphene Oxide/SiO<Subscript>2</Subscript> Nanocomposite as the Adsorbent

In this research, a dispersive solid-phase extraction (dSPE) with graphene oxide@SiO₂ (GO@SiO₂) nanocomposites as the adsorbent followed by high-performance liquid chromatography analysis was developed for simultaneous determination of melatonin, l-tryptophan, and two l-tryptophan-derived esters in food (black sesame seed (Sesamum indicum L.) was selected in this case). The GO@SiO₂ nanocomposite was prepared by one-pot aggregation in aqueous phase with sol-gel technique. The structure and morphology of the GO@SiO₂ were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform-infrared spectroscopy, and X-ray diffraction. The extraction conditions of dSPE including the ratio of material to liquid, adsorption and desorption time, desorption temperature, and desorption solvents were investigated, respectively. The detection limits of the developed method for the analysis of melatonin, l-tryptophan, l-tryptophan methyl ester, and l-tryptophan ethyl ester were achieved below 0.1 μg mL^?1. The established method was successfully applied to the analysis of the target analytes in black sesame seed, which provided a simple, low-cost, and sensitive approach for the determination of trace compounds in complex samples.     

Improvement of <Emphasis Type="Italic">Candida parapsilosis</Emphasis> by genome shuffling for the efficient production of arabitol from <Emphasis Type="SmallCaps">l</Emphasis>-arabinose

Arabitol is used in the food industry as a low-calorie sweetener. It is produced by yeasts during the biotransformation process of l-arabinose. Genome shuffling was performed in Candida parapsilosis DSM 70125, an efficient producer of arabitol, to obtain fusants with improved arabitol production ability. Four mutants from the parental library were used for the first round of genome shuffling. The best fusants, GSI-1 and GSI-10A, were subjected to a second round of genome shuffling. Finally, two fusants, GSII-3 and GSII-16, produced concentrations of arabitol that were 50% higher than that of the wild-type strain during selection culture. Under the optimal conditions established for C. parapsilosis, the two fusants produced 11.83 and 11.75 g/L of arabitol and were approximately 15–16% more efficient than the wild-type strain. Flow cytometry analysis showed that the ploidy of the new strains did not change.     

Effects of <Emphasis Type="SmallCaps">l</Emphasis>-lysine on thermal gelation properties of chicken breast actomyosin

The effects of l-lysine (l-Lys) on the water holding capacity (WHC) and texture of actomyosin (AM) gel and the possible mechanisms were investigated. l-Lys increased the WHC and hardness of the AM gel. These effects may be related to the even and continuous microstructure of the gel according to the scanning electron microscopy analysis. Furthermore, l-Lys increased the surface hydrophobic residues and the reactive sulfhydryl groups. l-Lys decreased the storage modulus at the first transition temperature but increased it at the second transition temperature and the third transition enthalpy. These results suggested that l-Lys varied the thermal behaviors and the microstructure of the AM gel by increasing the surface hydrophobicity and reactive sulfhydryl groups, ultimately contributing to the increased WHC and hardness. The changes in pH did not fully explain the results from the present study. The results were useful for understanding previous findings and may serve as a reference for the preparation of reduced-sodium and phosphate-free meat products.     

Evaluation of <Emphasis Type="Italic">eryC</Emphasis> as a Molecular Marker for the Quantitative Detection of <Emphasis Type="Italic">Brucella</Emphasis> Spp. by Real-Time PCR in Food Samples

We evaluated the capacity of the Brucella sp. eryC gene as a diagnostic marker for brucellosis by quantitative real-time PCR. eryC gene encodes the enzyme d-erythrulose-1-phosphate dehydrogenase that plays an important role in the erythritol metabolism and is related with the Brucella survival in the intracellular environment of the macrophage. The assay includes an internal amplification control (IAC) in order to avoid false negative results. It was 100% specific, with an analytical sensitivity of 1 genome equivalent (GE) in 43% of the reactions, being the quantification highly linear (R ² > 0.9953) and efficient (PCR efficiency >0.8820) over a 6-log dynamic range, down to 10 GE. Finally, the applicability of this assay was evaluated with artificially contaminated biological matrices implicated in the transmission of this bacterium such as sheep raw milk and pig blood. The eryC-IAC real-time PCR assay allowed detection of as few as ten Brucella cells per 25 ml of sheep raw milk or per 1 ml of pig blood. In conclusion, we present an alternative for the detection of Brucella genus and therefore facilitate the establishment of preventive and prophylactic measures in food and farm environments.     

A Novel Technological Process of Extracting <Emphasis Type="SmallCaps">l</Emphasis>-Tyrosine with Low Fluorine Content from Defatted Antarctic Krill (<Emphasis Type="Italic">Euphausia superba</Emphasis>) By-product by Enzymatic Hydrolysis

Antarctic krill (Euphausia superba) offers a high potential for development of innovative food products due to its large reserves and satisfied nutritional values. Defatted krill powder by-product generates from the process of krill oil, which is rich in various types of amino acids. This study aimed at recovering tyrosine from defatted krill by-product through enzymatic hydrolysis. Defatted krill by-product was hydrolyzed with three types of protease under optimum conditions with different incubation time. Free tyrosine dissociated from protein through hydrolysis by trypsin and was detected in the protein hydrolysates. Content of tyrosine increased with the increasing of incubation time till 5 h. Tyrosine extract contained 6.43 mg/kg fluorine and over 95 % of tyrosine, which demonstrated its high purity and safety. Tyrosine extract showed rod-shaped microstructure through scanning electron microscope analysis. Crystalline structure and thermal properties of tyrosine extract agreed well with those of l-tyrosine standard. During this process, both tyrosine of high purity and bioactive peptide products were obtained.     

Isolation of five proanthocyanidins from pear (<Emphasis Type="Italic">Pyrus pyrifolia</Emphasis> Nakai) fruit peels

Five proanthocyanidins, two B-type dimers and three A-type trimers, were purified and isolated from the fruit peels of Pyrus pyrifolia Nakai cv. Chuhwangbae. The isolated compounds were identified as (–)-epicatechin gallate-(4β → 8)-(–)-epicatechin (Hahashi et al. in Ann Biol Res 3:3200–3207, 2012), (–)-epicatechin-(4β → 8)-(–)-epicatechin (procyanidin B2) (Tanrioven and Eksi in Food Chem 93:89–93, 2005), (–)-epicatechin-(4β → 8, 2β → O-7)-(–)-epicatechin-(4β → 8)-(–)-epicatechin (cinnamtannins B1) (Salta et al. in J. Fun. Food 2: 153–157, 2010), (–)-epicatechin-(4β → 8)-(–)-epicatechin-(4β → 8, 2β → O-7)-(–)-epicatechin (aesculitannin A) (Challice and Westwood in Phytochemistry 11: 37–44, 1972), and (–)-epicatechin-(4β → 6)-(–)-epicatechin-(4β → 8, 2β → O→7)-(–)-epicatechin (Es-Safi et al. in J Agric Food Chem 54: 6969–6977, 2006). Their structures were determined by nuclear magnetic resonance and mass spectrometry. The three A-type proanthocyanidin trimers were identified for the first time from pear.     

Development and characterization of reconstituted hydrogel from <Emphasis Type="Italic">Aloe vera</Emphasis> (<Emphasis Type="Italic">Aloe barbadensis</Emphasis> Miller) powder

Structural and rheological characterization of reconstituted hydrogels developed from A. vera non-fibrous alcohol insoluble residue (NFAIR) powder using different methods [viz., shaking (S), heating-shaking (HS), and heating (H)] and concentrations (viz., 0.2–1.6 %, w/v) was carried out. Functional group distribution by FTIR spectroscopy and Congo red (CR) method revealed the presence of acetylated acemannan in A. vera powder. Dynamic oscillation studies of A. vera (NFAIR) fluids at all concentrations of 0.2–1.6 %, w/v, showed gel strength in the order of H > HS > S method. However, in H method, increase in concentration from 0.2 to 1.6 %, w/v showed the conformational transition from semi-diluted solution to weak gel nature. Rheological models described the effect of heating temperatures (HT); 30–90 °C, and times (Ht); 15–60 min on viscoelastic behavior in reconstituted A. vera fluids. The reconstituted A. vera hydrogel prepared with a concentration of 1.6 %, w/v using 50 °C (HT) and 30 min (Ht) condition showed a good agreement with the Power law (storage modulus, G′) and Weak gel model (complex modulus, G*) fitted data (R² > 0.94) resulting higher viscoelastic moduli intercepts; G′₀ (71.5 Pa s ^n′), G″₀ (33.5 Pa s ^n″), lower slopes; n′ (0.22), n″ (0.06), higher network strength (A _F , 121.3 Pa s^1/z ) and number of network (z, 5.3) values. The obtained results suggested that heating at 50 °C/30 min can develop aqueous weak gel networks of A. vera with enhanced gel strength which may be utilized as a novel gelling agent for wide variety of targeted applications in food and pharmaceutical sectors.     

Effect of heat-treated <Emphasis Type="Italic">Nuruk</Emphasis> on the quality characteristics of aged <Emphasis Type="Italic">Yakju</Emphasis>

Long-term aging of Yakju, a traditional Korean liquor made of rice and Nuruk (a fermentation agent), causes browning and odor and flavor development. This study investigated the effects of heat-treated Nuruk (50–80 °C, 30 min) on Yakju quality. The saccharogenic powers and glucoamylase, α-amylase, and carboxypeptidase activities were similar in non-heat-treated Nuruk and that treated at 50 °C. However, acidic protease and alcohol dehydrogenase decreased above 50 °C. The content of nitrogen-containing compounds was inversely proportional to the heat-treatment temperature. Compounds that cause off-flavors decreased at 50–60 °C, but increased at 70–80 °C, whereas compounds that provide fragrance increased at 50–60 °C. Sensory evaluation indicated that bad taste attributes were higher in Yakju produced using non-heat-treated Nuruk. Therefore, heat treatment of Nuruk at 50 °C can be adopted as a method for improving Yakju quality, as enzymatic activities that affect color, aroma, and taste are regulated.     

Properties of a fibrinolytic enzyme secreted by <Emphasis Type="Italic">Bacillus subtilis</Emphasis> JS2 isolated from saeu (small shrimp) <Emphasis Type="Italic">jeotgal</Emphasis>

Bacillus species were screened to be used as starters for jeotgals, salted and fermented Korean sea foods. A strain, JS2, showing strong fibrinolytic activity was isolated from saeu (small shrimp) jeotgal, and identified as Bacillus subtilis. Bacillus subtilis JS2 grew well at 20% (w/v) NaCl concentration. SDS-PAGE of culture supernatant from JS2 showed 3 major bands of 27, 29, and 60 kDa in size. Fibrin zymography showed that the 27 kDa band was the major fibrinolytic protein. The gene, aprEJS2, was cloned and introduced into B. subtilis WB600 using pHY300PLK. A B. subtilis transformant harboring pHYJS2 showed higher fibrinolytic activity than B. subtilis JS2. aprEJS2 was overexpressed in Escherichia coli BL21 (DE3). The optimum pH and temperature for AprEJS2 were pH 8.0 and 40 °C, respectively. Km and V_max values were determined. AprEJS2 has strong α-fibrinogenase activity and moderate β-fibrinogenase activity.     

Reversed-phase HPLC determination of mangiferin,isomangiferin and hesperidin in <Emphasis Type="Italic"> Cyclopia </Emphasis>and the effect of harvesting date on the phenolic composition of <Emphasis Type="Italic"> C. genistoides</Emphasis>

A reversed-phase HPLC method for separation of polyphenols in honeybush tea (Cyclopia spp.) is presented. Separation of eriodictyol, luteolin, medicagol, formononetin, mangiferin, isomangiferin, hesperetin and hesperidin was investigated. A C12 stationary phase was required to separate mangiferin and isomangiferin. The method was used to quantify the three major polyphenols (mangiferin, isomangiferin and hesperidin) in C. genistoides, C. intermedia, C. maculata and C. sessiliflora and to study the effect of harvesting date on these compounds in two types of C. genistoides. The highest levels of the xanthones, mangiferin (3.61 g/100 g) and isomangiferin (0.54 g/100 g), and the flavanone, hesperidin (1.74 g/100 g), were found for C. genistoides (both xanthones) and C. intermedia, respectively. Cyclopia sessiliflora contained the lowest levels of mangiferin (1.04 g/100 g) and hesperidin (0.29 g/100 g). The mangiferin content of both the Overberg and West Coast types decreased with harvesting date (P <0.05). The Overberg type contained more mangiferin, but hesperidin was more prominent in the West Coast type.     

Probe-Based Fluorescence Melting Curve Analysis for Differentiating <Emphasis Type="Italic">Larimichthys polyactis</Emphasis> and <Emphasis Type="Italic">Larimichthys crocea</Emphasis>

Larimichthys polyactis (redlip yellow croaker) and Larimichthys crocea (large yellow croaker) are commercially important fish species in East Asia with high differences in their market values. In Korea, consumers prefer L. polyactis to L. crocea, although it is difficult to distinguish them based on their morphological traits. The objective of this study was to develop an assay for differentiating L. polyactis and L. crocea using fluorescence melting curve analysis (FMCA) with a single locked nucleic acid (LNA) probe. Species-specific regions of the mitochondrial 16S rDNA were selected as LNA probes. The target sequences of L. polyactis and L. crocea had a 2-bp difference, and a single LNA probe was identified using melting temperature (Tm) shift. LNA probe was 100 % complementary to the target sequence of ten L. polyactis samples, giving a significantly higher Tm value (66 °C) than that of five L. crocea samples (42 °C). Overall, the developed LNA-based FMCA system had high efficiency, multiplexity, and simplicity, and could be effectively used for differentiating L. polyactis and L. crocea, and as a food analyzing method based on DNA sequence.     

Modeling the Inactivation of <Emphasis Type="Italic">Listeria innocua</Emphasis> and <Emphasis Type="Italic">Escherichia coli</Emphasis> in Fresh-Cut Tomato Treated with Pulsed Light

The effectiveness of pulsed light (PL) treatments to inhibit microorganisms on fresh-cut tomatoes (Lycopersicon esculentum Mill., cv. Daniela) was investigated. Tomato slices inoculated with Escherichia coli or Listeria innocua were exposed to PL treatments (4, 6, or 8 J cm^?2 fluence) and kept cold at 4 °C for 20 days. L. innocua and E. coli counts, gases in the headspace of the containers (O₂ and CO₂), pH, titratable acidity, and soluble solid content were monitored throughout the cold storage. The PL treatments reduced significantly (p < 0.05) initial loads of both microbes. The effect of the PL fluence on the survival number of microoganisms was described by a log-linear model (R ² = 0.849–0.999). At any fixed time within the cold storing, the microbial counts for untreated samples were always higher than those cut tomatoes that had been previously PL-treated. The behavior of L. innocua and E. coli during the storage were well adjusted (R ² > 0.930) by Gompertzian models; the studied microorganisms exhibited different patterns during the storage period. On the other hand, O₂ and CO₂ partial pressures in containers with fresh-cut tomatoes were also significantly affected by PL treatments (p < 0.05). The highest PL fluence caused the greatest changes of O₂ and CO₂ contents. In addition, the application of PL triggered an acceleration of the O₂ consumption during the cold stage. PL treatments might be used to effectively extend the safety of fresh-cut tomatoes over 12 days of storage against E. coli and L. innocua growth.     

Nutritional,functional, thermal and structural characteristics of <Emphasis Type="Italic">Citrullus lanatus</Emphasis> and <Emphasis Type="Italic">Limonia acidissima</Emphasis> seed flours

Seeds from fruits such as Citrullus (C.) lanatus (watermelon) and Limonia (L.) acidissima (wood apple) are not commonly utilized but could be suitable in numerous food formulations. It was shown that the protein content of defatted seed flours was 71.38 and 49.51 % and that these contained considerable amounts of minerals such as Na, Mn, Mg, K, Cu, Fe and Zn. The defatted L. acidissima seed flour was superior to C. lanatus in essential amino acids. The flours obtained from both seeds were also evaluated for functional properties and characterized by X-ray diffraction, differential scanning calorimeter and scanning electron microscope (SEM). Amorphous nature was observed in defatted C. lanatus and L. acidissima flours due to the low percentage of degree of crystallinity. Spherical morphologies were observed through SEM. The exothermic peak was recorded in defatted C. lanatus and L. acidissima flour.     

Antioxidant and emulsion properties of freshwater carps (<Emphasis Type="Italic">Catla catla</Emphasis>, <Emphasis Type="Italic">Labeo rohita</Emphasis>, <Emphasis Type="Italic">Cirrhinus mrigala</Emphasis>) protein hydrolysates prepared using flavorzyme

Fish protein hydrolysates (FPHs) were prepared from freshwater carps (Catla catla, Labeo rohita, and Cirrhinus mrigala) using flavorzyme at different degrees of hydrolysis (DHs) ranging from 5 to 20%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activity of the FPHs prepared from the three species were in the range of 50–82%; the ferric reducing power of the FPHs prepared from catla was the highest. The linoleic acid peroxidation inhibition activity of the prepared FPHs varied from 71 to 91%. The emulsion activity index of the FPHs prepared from catla and rohu decreased significantly with an increase in the DH (p < 0.05). The emulsion stability index of the FPHs prepared from the three species was the highest at 20% DH. FPHs prepared from freshwater carps possess good antioxidant and surface-active properties and are therefore suitable to be used as natural antioxidants in health-food formulation and as water-soluble antioxidants in the food-processing industry.     

A mathematical model for moisture movement during continous and intermittent drying of <Emphasis Type="Italic">Eucalyptus saligna</Emphasis>

A modified diffusion-based mathematical model is proposed to describe the moisture movement during continuous and intermittent drying of Eucalyptus saligna. This model includes the temperature change, the surface drying coefficient (β _n ) and 2 diffusion coefficients [from green to FSP (D _f ) and from FSP to dry condition (D _o )] as important parameters. The final model expression obtained was M?=?exp (??25 β _n ² D _t /l²) with the β _n used was 1.5807 kg m^?2 s^?1, the D _f was 2.26?×?10^?11 m² s^?1, and the D _o was 5.85?×?10^?12 m² s^?1. The range of temperature change between heating and non-heating phases in the intermittent drying regimes was from 24.9 to 31.8 °C. The R² values obtained when the model was fitted into the drying data of different intermittent regimes ranged from 71.5 to 85.9%. The R² value was 87.4% when the model was fitted into continuous trial data. The high values of R² indicate that the model can be used to understand the moisture reduction both in intermittent and continuous regimes.     

Partition Behaviors of Different Polar Anthocyanins in Aqueous Two-Phase Systems and Extraction of Anthocyanins from <Emphasis Type="Italic">Nitraria tangutorun</Emphasis> Bobr. and <Emphasis Type="Italic">Lycium ruthenicum</Emphasis> Murr.

This study aimed to investigate the partition behaviors of various polar anthocyanins in NaH₂PO₄/(NH₄)₂SO₄-ethanol aqueous two-phase systems (ATPS) and to extract anthocyanins from Nitraria tangutorun Bobr. and Lycium ruthenicum Murr. Anthocyanins in Hibiscus sabdariffa L., Morus atropurpurea Roxb., N. tangutorun, and L. ruthenicum were profiled using HPLC-ESI-MS/MS and HPLC-DAD, and the partition behaviors of total anthocyanins and main anthocyanins were studied. The partition coefficient of anthocyanins increased with increased hydrophobicity, and low-polarity anthocyanins exhibited a higher preference for the top phase in NaH₂PO₄/(NH₄)₂SO₄-ethanol ATPS. Additionally, the NaH₂PO₄-ethanol ATPS gave higher selectivity and total anthocyanin yield than the (NH₄)₂SO₄-ethanol system. Extraction at 65 °C for 45 min and at 45.5 °C for 45 min using 28% NaH₂PO₄ and 26% ethanol (w/w) led to the recovery of 98.91 ± 0.03% of N. tangutorun anthocyanins (3.62 ± 0.05 mg/g) and 99.84 ± 0.01% of L. ruthenicum anthocyanins (13.16 ± 0.29 mg/g) from raw material; more than 70% of total sugars were removed in a single step. NaH₂PO₄-ethanol aqueous two-phase extraction is a promising method for extracting anthocyanins from N. tangutorun and L. ruthenicum.     

Integrated Analytical Methods to Characterize Lipids from <Emphasis Type="Italic">Prosopis</Emphasis> spp. and <Emphasis Type="Italic">Ceratonia siliqua</Emphasis> Seed Germ Flour

Flour from seed germ of European carob (Ceratonia siliqua) and South American algarrobo (Prosopis spp.) is a potential ingredient for health-promoting baked products. Herein, lipids from germ of three Argentinean Prosopis (P. alba, P. nigra, and P. ruscifolia) and one European carob species were characterized in detail, exploiting an array of up-to-date analytical techniques. Total lipids ranged from 7.1 to 8.1% (w/w). Linoleic acid (C18:2, ω-6) predominated the GC flame ionization detector profiles of fatty acid in all samples (43.3–50.6%). Prosopis spp. contained 6–7% of C20–C24 fatty acids and, consistently, C56–C60 triacylglycerols, as detected by MALDI-TOF mass spectrometry (MS), which were practically missing in C. siliqua germ. Phospholipids were isolated by hydroxyapatite chromatography, characterized by MALDI-TOF MS and grossly quantified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Because of a relatively high content (9.5–11.8%, v/v), phospholipids might increase the antioxidant potential and improve the baking performances of flour fortified with carob and algarrobo seed germ.     

Comparative Study on the Inactivation and Photoreactivation Response of <Emphasis Type="Italic">Listeria monocytogenes</Emphasis> Seafood Isolates and a <Emphasis Type="Italic">Listeria innocua</Emphasis> Surrogate after Pulsed Light Treatment

The inactivation and photoreactivation response of six seafood-isolated Listeria monocytogenes and one Listeria innocua strain after pulsed light (PL) treatment was evaluated. The lower inactivation levels found after exposure of treated samples to daylight during the first 90 min of storage confirmed that both L. innocua and L. monocytogenes have the capability to photorepair PL-induced DNA damage upon appropriate conditions. Photoreactivation levels from 0.2 to 2.1 log CFU cm^?2 were observed depending on treatment intensity (fluence) and Listeria strain. Complete photorepair of PL-caused damage was not found even after treatments inducing low inactivation levels. Photoreactivation increased up to 2.1 log with the applied fluence up to a threshold able to cause between 2.4 and 5.4 log reductions under dark storage. Photorepair was not avoided but lower photoreactivation was observed after higher fluence inducing more than 6 log reductions under dark storage. Both L. innocua and L. monocytogenes serotype 1/2b exhibited the highest photoreactivation levels whereas serotypes 1/2a showed the lowest ones. The overall inactivation and photoreactivation responses of tested Listeria strains were comparable indicating that L. innocua may be a good surrogate for the safe evaluation, optimization and validation of PL technology to control L. monocytogenes in food products and food processing facilities.     

Effect of <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> Bauer and <Emphasis Type="Italic">Bifidobacterium animalis</Emphasis> ssp. <Emphasis Type="Italic">lactis</Emphasis> BB12 on proteolytic changes in dry-cured loins

The effect of the potentially probiotic bacteria strain of Lactobacillus acidophilus Bauer and probiotic bacteria Bifidobacterium animalis ssp. lactis BB12 on proteolytic changes of proteins in dry-cured loins during fermentation and cold storage was studied. Results of the conducted tests demonstrated that the use of probiotic bacteria for the production of dry-cured meats impacts the generation of products of protein proteolysis with high antioxidant activity. The highest antioxidant activity of peptides after fermentation and cold storage was observed in the loin with the strain B. animalis ssp. lactis BB12 and the loin with the mixture of strains L. acidophilus Bauer and B. animalis ssp. lactis BB12. Qualitative analysis of peptides demonstrated that peptides with weight below 3.5 kDa are characterized by the highest capacity of quenching the ABTS cation radical, including the peptides in loins with the strain B. animalis ssp. lactis BB12.     

Effect of Addition of Native Agave Fructans on Spray-Dried Chayote (<Emphasis Type="Italic">Sechium edule</Emphasis>) and Pineapple (<Emphasis Type="Italic">Ananas comosus</Emphasis>) Juices: Rheology,Microstructure, and Water Sorption

The effect of the combination of maltodextrin DE 10 (MD) and native agave fructans (FR) in concentrations of 0, 2, and 4% (w/v) on the rheological properties, microstructure, and water sorption of spray-dried chayote and pineapple powders was evaluated. A 10% (w/v) maltodextrin treatment was used as a control to compare treatments added with fructans. The scanning electron micrographs revealed spherical particles in a range from 16 to 105 μm with shrinkage, whereby greater caking and agglomeration occurred among particles in treatments with native agave fructans. The flow behavior of all juices can be described by the Bingham model with low plastic viscosities (0.0026 to 0.0030 Pa s^?1); the isotherms of the powders show a sigmoid shape pointing to the easy union of the fructans with water molecules. These types of isotherms are common for non-porous foods, and are indicative of physical adsorption in multi-layers where the adsorbate conserves its identity.