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Edible films (EF) can be produced and developed for preservation of fruits and vegetables. Starch has been considered one of the biopolymers with the greatest potential to produce edible films by different processing techniques such as extrusion-casting. The objetive was to study the effect of calcium carbonate nanoparticles and plasticizers (sorbitol- glycerol (80-20%; w/w)) (by extrusion (EXT)-casting (CT) combination technologies to obtain EF with improved mechanical and barrier properties. Corn starch-plasticizers were processed in a twin screw extruder to produce thermoplastic starch modified followed by the addition of the calcium carbonate nanoparticles (CCNP) in casting to EF formation. A hybrid design (four factors; twenty one treatments) of surface response methodology was used to optimization process. The optimal EF was characterized mechanical and barrier properties and also characterized according to microstructural properties (X-ray diffraction, Scanning Electron Microscopy) to determine the damage caused in the starch during EXT and CT. In conclusion, it is possible to obtain EF with greater both Breaking Strength and Deformation, as well as, lower Water Vapor Permeability and Solubility (mechanical and barrier properties), through the use of CCNP and plasticizers, using EXT-CT combination processes.

X-ray diffractograms, optic and electronic microscopy were used to study the structural changes on extruded orange pulp using a Brabender® laboratory single-screw extruder (GNF 1014/2, 20:1, L/D). The results showed that most of the cellulose would be in the amorphous state, with small crystalline areas in the angular region of 2θ = 14.5°. The evaluated extrusion conditions did not affect the crystallinity of the raw cellulose, maintaining the size of the crystalline regions in the angular region of 2θ = 22.5°. Neutral detergent solubilized the crystalline areas of potassium citrate and cellulose, formed during the extrusion process. However, these conditions did not affect the crystallinity of the raw cellulose. In addition, no change was observed in the crystallinity of pectin. The electron microphotographs allowed for the estimation of the heterogeneity of orange pulp and assessment of the difference of resistance between the walls of the buds and juice vesicles. Thus, it was demonstrated that during the extrusion process most of the porosity and the cellular structure of the endocarp remained unaltered.

The aim of the present study was to obtain succinylated nanoparticles from high-amylose starch using a sequential method of extrusion and ultrasonic energy. Dynamic light scattering, degree of substitution, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy were employed to characterize the nanoparticles. The extrusion processing caused granular fragmentation and the succinylation of starch. Afterward, succinylated nanoparticles from the extruded starch were obtained with high yields using ultrasonication. Also, non-esterified nanoparticles were obtained to evaluate the succinylation effect. Succinylation increased hydrodynamic size (up to 329 nm) and ζ-potential values (up to − 62 mV) and improved the colloidal stability of succinylated nanoparticles compared to those of the non-esterified nanoparticles. Succinylated nanoparticles showed polyhedral morphologies, while non-esterified nanoparticles showed round-spherical and cubic morphologies. Moreover, all nanoparticulate systems showed a V61-type crystalline structure and an increased crystallinity. Using the sequential method of extrusion and ultrasonic energy made it possible to obtain succinylated nanoparticles from HAMS with size-controlled and desirable colloidal properties.

High-energy milling (HEM) was used to produce nixtamalized corn flours, the traditional nixtamalization process was used as a control. Four creole grains were stone-milled, adjusted to an appropriate moisture content and calcium hydroxide concentration and milled using HEM. The physicochemical, thermal, and rheological characteristics of the flours and corn masas were affected by the HEM process. Negritas and Ahualulco creole grains nixtamalized by HEM showed similar viscosity profiles as a control. HEM reduced the gelatinization enthalpy compared to control and raw flours. Diffractograms showed changes in the crystalline structures and FT-IR demonstrated different regions for lipids, proteins, and carbohydrates in all control and treated grains. The texture of corn masas revealed significant differences according to the grain type. ESEM analysis showed smaller particles of HEM flours compared to those of the control. HEM could be a faster, non-pollutant, energy-saving, alternative nixtamalization process.

This study aimed at evaluating the effect of high-energy milling (HEM) and traditional nixtamalization (TN) on bioactive compounds and antioxidant capacity in nixtamalized creole corn flours obtained from a maize genotype cultivated under rainy temporal conditions in the Mexican semidesert. Four creole grains, including San Jose de Gracia white and blue (WG and BG), Negritas (NG), and Ahualulco white corn grains (SG), were used. For HEM nixtamalization, corn grains were hammer-milled; then, two different conditions were evaluated: treatment H1, with raw flours with 14% moisture content and 1.1% Ca(OH)2, and treatment H2, with raw corn flours with a 23% moisture content and 1.4% Ca(OH)2. The TN process was utilized as a control. TN recorded significant losses in luminosity value L* (p

Normal and acetylated rice and waxy maize starches with a blend of nopal mucilage (Opuntia ficus-indica) and glycerol were used for the preparation of laminated and tubular films by extrusion and blown extrusion, respectively. The composition of the formulation was 70% starch (normal or acetylated), 20% glycerol, and 10% nopal mucilage ( w / w ). The degrees of substitution (DS) for acetylated rice starch (0.94) and waxy maize starch (0.76) present high potential for use as a polymeric matrix in packing materials. The use of nopal mucilage can improve the processability of extruded and tubular films by favoring the increase of some mechanical and functional properties. The films elaborated with nopal mucilage and glycerol present a homogeneous relief without breaking, adhesiveness, and contraction once formed. The elongation values of acetylated waxy maize starch films (33%) were higher than those of rice acetylated films (17%), while the blown films presented a 30% decrease in tensile strength, compared to the laminated films. Acetylation generated more hydrophobic material for the rice starch sample, which can be evidenced by a decreased solubility of the laminated films. Films of both sources of acetylated starch showed a significant decrease in water vapor permeability and showed a plasticized starch disposition-type layer without unmelted starch granules.

In this study, hard corn grains were nixtamalized (alkali-heat treatment) by a high-energy ball mill to investigate the effects on its physicochemical, textural, and microstructural properties. Ball milling modifies the structure and properties of cornstarch. The gelatinization peak of starch was evidenced and thermal and pasting properties were significantly affected. With regard to rheological properties, the viscosity peak increased from 2454 cP in traditional nixtamalized flour to 4294 cP in high-energy milling treatments with 1.4% of Ca(OH)2 and 20% moisture content, C1.4, while enthalpy ranged from 3.5 to 0.34 J/g, respectively. High-energy milling influenced the Fourier-Transform InfraRed Spectroscopic (FT-IR) patterns. All of the samples of the corn-grain starches presented the typical A-type X-ray diffraction pattern. The crystallinity of starch from CG showed a lower intensity in peaks 2θ ~ 15 and 23° compared with starch from WG and YG. The textural properties of the masas were influenced, adhesiveness was reduced, but cohesiveness was increased by the addition of Ca(OH)2. In the structural characterization by E-SEM, the control presented a greater amount of agglomerated starch granules, followed by the high-energy milling treatments. The results suggest that high-energy alkaline milling could be a potential physical and chemical method to modify corn-starch properties and obtain nixtamalized products.

In this study, succinylated nanoparticles from normal (NPS-N), high-amylose (NPS-H), and high-amylopectin corn starch (NPS-W) were synthesized, characterized, and studied for the nanoencapsulation of the Ardisia compressa anthocyanins. The nanoparticle‒anthocyanin interaction was also investigated. The succinylated starch nanoparticles (S-SNPs) had hydrodynamic sizes of 65-390 nm, degrees of substitution (DS) of 0.014-0.032, ζ-potential values of up to -34 mV and a nanocolloid behavior. NPS-N and NPS-W showed the highest (p0.05) encapsulation efficiencies (EE) (52 and 49 %, respectively) compared than NPS-H (45 %). Thereby, the lowest DS obtained, and the branched amylopectin structure favored the EE. The nanoparticle-anthocyanin interaction occurred through hydrophobic and electrostatic interactions and influenced significantly (p0.05) the hydrodynamic size and surface properties of the resulting nanocapsules. The relative crystallinity (RC) decreased significantly (p0.05) in the S-SNPs, but the nanocapsules mostly experimented a structural recrystallization and showed melting temperatures150 °C.

Phenolic compounds with antioxidant properties are highly sensitive molecules, which limits their application. In response, extruded esterified starch has been proposed as efficient encapsulating material. In this work, we aim to describe the encapsulation of red sorghum phenolic compounds by spray drying using extruded phosphorylated, acetylated and double esterified sorghum starch as wall material. Their respective encapsulation yields were 77.4, 67.4 and 56.8 %, and encapsulation efficiency 91.4, 89.7 and 84.6 %. Degree of substitution confirmed esterification of the sorghum starch and Fourier transform infrared spectroscopy showed the significant chemical and structural changes in the extruded esterified starch loaded with phenolic compounds. Microcapsules from phosphorylated sorghum starch showed the highest endothermic transition (173.89 °C) and provided a greater protection of the phenolic compounds during storage at 60 °C for 35 days than the other wall materials. Extruded esterified sorghum starch proved to be effective material for the protection of phenolic compounds due to its high encapsulation efficiency and stability during storage.

Betalains of pitaya (Stenocereus pruinosus) fruit can be used as natural pigment, but they are susceptible to deterioration by temperature, pH, and presence of sugars. In this work, a refined extract (Er) of betalains was obtained through aqueous two-phase extraction, which reduced significantly sugar and mucilage contents. In order to favor stability, the encapsulation of the refined extract was evaluated, with native potato starch that was modified through phosphorylation or succinylation and reactive extrusion. Starches were evaluated in terms of degree of substitution, Fourier transform infrared spectroscopy, scanning electron microscopy, and viscous behavior. Microcapsules were formed by spray drying and their stability was evaluated at 40 °C for 39 days and by using them as pigmenting agent of yogurt at 4 °C during 32 days. The behavior of modified starches during encapsulation was superior to that of commercial N-Lok® starch. Microcapsules based on modified starches showed better pigmenting potential and higher stability than Er and microcapsules based on N-Lok® starch. The separation of betalains from pitaya fruit may be a good alternative for adding value to this plant genetic resource.

The encapsulation by spray drying of maize anthocyanins was evaluated using two types of wall materials, consisting of normal and waxy maize starch, which were esterified with octenyl succinic anhydride. The X-ray diffraction analysis revealed that SWMS possessed a completely amorphous, while SNMS had a crystalline structure. SNMS showed peaks at 2θ = 13.1°, 19.8° and 22.4°. The results revealed that SNMS and SWMS had almost the same encapsulation productivity (EP); SNMS showed the best performance because its EP was higher (95%) than in SWMS (90%). The stability of microcapsules produced with SNMS showed the highest anthocyanin retention after storage in the water activity (a(w)) range of 0.11–0.94 at 40 °C.

Resistant starch type IV (RSIV) can be produced by chemical modifications (etherized or esterified) such as conversion, substitution, or cross-linking, which can prevent its digestion by blocking enzyme access and forming atypical linkages. In this research, the effects of barrel temperature (145.86–174.14 °C), the screw speed (42.93–57.07 Hz) and derivatization (esterification) in the formation of RSIV content of directly expanded snacks (second generation snacks) were studied. Potato starch was chemically modified by phosphorylation and succinylation, and expanded by using the extrusion cooking process. Snacks with phosphorylated starch showed expansion index from 2.57 to 3.23, bulk density from 306.19 to 479.00 kg/m3 and RSIV from 43.27 to 55.81%. Snacks with succinylated starch had expansion index from 3.52 to 3.82, bulk density from 99.85 to 134.51 kg/m3 and RSIV from 23.17 to 35.01%. The results found in this work showed that it is possible to manufacture extruded directly expanded snacks (second-generation snacks) such as a ready-to-eat (RTE) with good physicochemical properties and without substantial loss of extrusion functionality, which could bring a healthy benefit due to the presence of RSIV.

Samples of native gelatin and gelatin modified by acylation and esterification were processed by casting and thermoplastic extrusion to produce laminated and tubular films. Extruded films containing sorbitol showed homogeneity and flexibility. Thinner films were obtained with the addition of sorbitol to the formulation. Tubular films prepared from gelatin modified with stearic acid were easily processed, had reduced friction, and were able to withstand bubble formation without fracturing after preparation. Films prepared by casting or thermoplastic techniques showed a decrease in tensile strength with the addition of plasticizer, and this also resulted in a substantial increase in their elongation ratio. The stearic acid modified gelatin-based films processed by blown extrusion showed higher tensile strength. Films fabricated by casting were, in general, less soluble than those prepared by extrusion except the films modified with stearic acid with or without the addition of plasticizer.

The addition of flaxseed and amaranth on the physicochemical, functional and microstructural changes of instant-extruded cereals was evaluated. Six different mixtures were made with additions of amaranth (30%–50%) and flaxseed (10% and 15%) using maize grits and minor additives as supplementary ingredients and then extruded in a twin-screw extruder. The extrudates evaluated, had insoluble and soluble fiber contents increased with the proportion of amaranth and flaxseed. The mixture 4 (higher flaxseed content) presented highest soluble fiber percentage (1.9%). Extruded cereals had the lowest viscosity (

The addition of flaxseed and amaranth on the physicochemical, functional, and microstructural changes of instant-extruded products was evaluated. Six mixtures with different proportions of amaranth (18.7&ndash, 33.1%), flaxseed (6.6&ndash, 9.3%), maize grits (55.6&ndash, 67.3%) and minor ingredients (4.7%) were extruded in a twin-screw extruder. Insoluble and soluble fiber contents in extrudates increased as the proportions of amaranth and flaxseed increased. However, the highest flaxseed proportion had the highest soluble fiber content (1.9%). Extruded products with the highest proportion of flaxseed and amaranth resulted in the highest dietary fiber content and hardness values (5.2 N), which was correlated with the microstructural analysis where the crystallinity increased, resulting in larger, and more compact laminar structure. The extruded products with the highest maize grits proportion had the highest viscosity, expansion, and water absorption indexes, and the lowest water solubility index values. The mixtures with amaranth (18.7&ndash, 22.9%), flaxseed (8.6&ndash, 9.3%), and maize grits (63.8&ndash, 67.3%) resulted in extruded products with acceptable physicochemical and functional properties.

Fiber-reinforced starch-based biocomposites provide an environmentally friendly alternative to replace petroleum-based plastics. Nevertheless, these materials present structural stability problems owing to their hydrophilicity. Therefore, a chemical modification is usually necessary. Hence, the aim of this research is to obtain biocomposites based on acetylated corn starch (AS), acetylated sugarcane fiber (AcSF) and glycerol. Also, to assess the AcSF content (FC, 0.0–20.0%) and glycerol content (GC, 20.0–30.0%) on their physical, mechanical and microstructural properties. A single-screw extruder and central composite rotatable design were employed. Due to acetylation and possible interaction between matrix-fiber, there was an improvement in water resistance; while the mechanical properties were enhanced by increasing FC up to 12.0%. Biodegradability recorded a range of 24.2–39.3%. Microstructural analysis evidenced the extrusion process effect, chemical modification and new interactions formation. It was found that an optimum blend was of FC = 12.0% and GC = 24.0%. The acetylation of both sugarcane fiber and corn starch allowed us to obtain eco-friendly materials with good mechanical properties and water resistance.

Starch edible films (EFs) have been widely studied due to their potential in food preservation; however, their application is limited because of their poor mechanical and barrier properties. Because of that, the aim of this work was to use the extrusion technology (ExT) as a pretreatment of casting technique to change the starch structure in order to obtain EFs with improved physicochemical properties. To this, corn starch and a mixture of plasticizers (sorbitol and glycerol, in different ratios) were processed in a twin screw extruder to generate the starch modification and subsequently casting technique was used for EFs formation. The best conditions of the ExT and plasticizers concentration were obtained using response surface methodology. All the response variables evaluated, were affected significatively by the Plasticizers Ratio (Sorbitol:Glycerol) (PR (S:G)) and Extrusion Temperature (ET), while the Screw Speed (SS) did not show significant effect on any of these variables. The optimization study showed that the appropriate conditions to obtain EFs with the best mechanical and barrier properties were ET = 89 °C, SS = 66 rpm and PR (S:G) = 79.7:20.3. Once the best conditions were obtained, the optimal treatment was characterized according to its microstructural properties (X-ray diffraction, Scanning Electron Microscopy and Atomic Force Microscopy) to determine the damage caused in the starch during ExT and casting technique. In conclusion, with the combination of ExT and casting technique were obtained EFs with greater breaking strength and deformation, as well as lower water vapor permeability than those reported in the literature.

Phosphorylated starch was prepared and evaluated as an encapsulating agent for purple maize anthocyanins under several inlet air temperatures (130–170°C) and different concentrations (10–20%) of phosphorylated starch during the spray-drying process. Phosphorylation was carried out by reactive extrusion with 4% sodium tripolyphosphate as a crosslinking agent at pH 5. The derivatization resulted in the loss of crystallinity, low viscosity, and high solubility of the starch. A band at 1,569 cm−1 in the FTIR spectrum attributed to the purple maize anthocyanins was observed in the microcapsules. The drying process yield ranged from 25.67 to 49.11%. The highest drying yield (49.11%) with encapsulation productivity of 87.63% resulted with 20% solids at 170°C. The higher the concentration of phosphorylated starch, the better the anthocyanin protection during the spray-drying process was, in which smoother microcapsules were observed by scanning electron microscopy.

This work investigated the possibility of using hydrolyzed corn starch–gelatin as a base matrix and cellulose as reinforcement, to produce containers by extrusion blow molding. First, the compounds were characterized by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) to determine their viscoelastic behavior and thermal stability. The results showed that the most suitable processing temperature should be less than 120 °C to avoid degradation. Furthermore, the addition of cellulose decreased the viscosity of the starch–gelatin polymer matrix allowing the compounds to be processed at temperatures as low as 100 °C. Then, parisons were obtained by extrusion blow molding and presented suitable processing characteristics. Overall, the best containers were found to have 44% higher energy at break and better dimensional stability when cellulose was added.

A major challenge for the development of a ready-to-drink probiotic green tea beverage (RTD-PGT) is the undesired fermentation of the product by the probiotics and loss of polyphenolic compounds during shelf-life. Thus, the aim of this work was to evaluate the stability, cell survival and sensorial acceptability of a RTD-PGT formulated with Lactobacillus rhamnosus GG microencapsulated by spray drying in a matrix of whey protein isolate and modified huauzontle's starch, after refrigerated storage. Microcapsules contained 9.02 ± 0.3 log CFU/g, and for them to be incorporated to a RTD-PGT, ascorbic acid needed to be supplemented to prevent cellular loss. After 5 weeks of storage at 4 °C, the RTD-PGT showed a decrease of merely 0.44 log CFU/mL displaying final cell counts higher than the recommended 7 log CFU/mL, and no evidence of fermentation. Furthermore, 38.52 ± 0.72% of green tea polyphenols formed an insoluble complex most likely with at least one component of the microcapsules. No significant changes on the concentration of polyphenolic compounds or their antioxidant capacity were detected, and a minor change in color was quantified. The sensory shelf-life of the RTD-PGT was of at least 23 days at a 50% of consumer's rejection. In conclusion, a multipurpose encapsulation system was developed, generating a stable RTD-PGT.

In the present research work, esterified nanoparticles with 2-octen-1-ylsuccinic anhydride were synthesized from waxy corn starch, to our knowledge for the first time, in a single step of ultrasonic treatment. First, the ultrasound time to produce non-esterified nanoparticles was studied. The results showed that non-esterified nanoparticles had sizes ranging from 63 to 48 nm, as well as polydispersity indexes (PDI) ranging from 0.458 to 0.224 and ζ-potential values ranging from −16 to −24 mV in ultrasonication times ranging from 20 to 100 min. Succinylated nanoparticles were obtained at 80 min with two degrees of substitution i.e., 0.003 and 0.01, hydrodynamic sizes of 57 and 83 nm, PDI of 0.479 and 0.91, and ζ-potential values of −6.27 and −14.03 mV, respectively. The succinylation of nanoparticles was confirmed by FTIR spectroscopy, and it was possible to elucidate the conversion of amylopectin molecules into amylose blocks. The nanoparticles showed stability during storage in aqueous suspension at 4 °C. By means of the ultrasonic technology, destructuring of the waxy corn starch and, at the same time, the succinylation of the nanoparticles in a total time of 120 min was effectively achieved.

Extruded third-generation fiber enriched snacks can be made using type 4 resistant starch. The present study aimed to evaluate and optimize some extrusion conditions, namely the transition or intermediate barrel temperature and the feed moisture in the direct formation of third-generation snacks with type 4 resistant starch using the phosphorylation of sorghum starch. The physicochemical and sensory properties of the optimal snack were investigated. An increase in barrel temperature resulted in an increase in the resistant starch (13.1 ± 0.5 g/100 g) and the expansion index values, as long as the feed moisture was maintained above 28%. The optimal conditions with a desirability value of 0.932 were a barrel temperature of 136 °C and a feed moisture of 28.5%. The optimal third-generation snack had 17.1 ± 0.2 g/100 g of resistant starch and a desirable expansion index of 5.7 ± 0.4, as well as general sensory acceptability (“I like moderately”). Phosphorylated resistant starch of the optimal snack showed a degree of substitution and a percentage of phosphorus (0.02 ± 0.00 and 0.35 ± 0.15%, respectively) within the limits allowed in foods. This study showed that using optimal extrusion conditions, phosphorylation of sorghum starch was possible to produce resistant starch and simultaneously to obtain an extruded snack with acceptable physical and sensorial properties. Additionally, it showed that sorghum is a good alternative source of starch for the formulation of extruded snacks.

Betalains of pitaya (Stenocereus pruinosus) fruit can be used as natural pigment, but they are susceptible to deterioration by temperature, pH, and presence of sugars. In this work, a refined extract (Er) of betalains was obtained through aqueous two-phase extraction, which reduced significantly sugar and mucilage contents. In order to favor stability, the encapsulation of the refined extract was evaluated, with native potato starch that was modified through phosphorylation or succinylation and reactive extrusion. Starches were evaluated in terms of degree of substitution, Fourier transform infrared spectroscopy, scanning electron microscopy, and viscous behavior. Microcapsules were formed by spray drying and their stability was evaluated at 40 °C for 39 days and by using them as pigmenting agent of yogurt at 4 °C during 32 days. The behavior of modified starches during encapsulation was superior to that of commercial N-Lok(®) starch. Microcapsules based on modified starches showed better pigmenting potential and higher stability than Er and microcapsules based on N-Lok(®) starch. The separation of betalains from pitaya fruit may be a good alternative for adding value to this plant genetic resource.

The aim of this work was to evaluate the effect of the addition of huitlacoche paste to nixtamalized blue-corn flours (NBCF) on the physicochemical, thermal, and rheological properties of masas. Raw blue maize was nixtamalized (hydrothermal alkalinized process), then was wet-milled in a stone mill, masa was dehydrated, pulverized and sieved to obtain NBCF; commercial nixtamalized blue-corn flour (CNBCF) was used as a control. Huitlacoche paste in concentrations of 3, 6, 9, 12, 15, and 18% was added to nixtamalized flours. Characteristics of the blue grain showed its great effects on water absorption, viscosity, and masa cohesiveness; the addition of huitlacoche significantly influenced adhesiveness, water-absorption, color, and the rheological properties (p

Encapsulation by spray drying of purple maize anthocyanins was carried out using encapsulating agents produced from maize starch derivatives. Normal and waxy maize starches were hydrolyzed with hydrochloric acid and were esterified with acetic anhydride before extrusion process. The influence of different derivative starches as encapsulating agents were investigated regarding the morphology (SEM), encapsulation efficiency (EE), adsorption isotherms and anthocyanins retention (AR) after 30 days of storage at different a w (0.11–0.94) at 40 °C. SEM images showed spherical microparticles with rough surfaces. The values of EE were higher in starch derivatives with respect to hydrolyzed native normal and waxy maize starches. After storage, microparticles produced with acetylated normal maize starch had the highest AR in the range of 0.11–0.75 a w . It was found that the experimental data were well represented by means of the GAB and Peleg models.

The aim of this work was to produce and characterize particles obtained by ionic gelation with pectin or alginate and coated with egg white proteins, whey protein or a mixture of both; the ability of these particles to protect a model oil against lipid oxidation was also assessed. The zeta potentials of the protein solutions, the polysaccharide-oil emulsions and the particles were measured. The encapsulation efficiency, calcium content, size, solids, morphology and adsorbed protein of the particles were determined. High encapsulation efficiencies (91.70 and 95.50%) and average particle sizes (140 and 215 μm) for alginate and pectin particles, respectively, were obtained. Lower amounts of calcium were observed for particles of pectin (1.44 μmol Ca/mg of particle) than for particles of alginate (2.48 μmol Ca/mg of particle). After cross linking with calcium, the zeta potential of the particles was significantly lower than the zeta potential of their respective emulsions. More concentrated protein solutions resulted in increased amounts of adsorbed protein. The coated particles produced with alginate increased in size, whereas the coated particles produced with pectin decreased in size. The particles coated with protein were better able to protect the encapsulated oil against lipid oxidation than the uncoated particles. The highest protective capacity was observed for the particles made with pectin and coated with egg white proteins.

The aim of this work was to study the effect of the addition of passion fruit pulp (PFP: 0–7 %), the variation of barrel temperature in the third zone extruder (BT: 80–140 °C) and feed moisture (FM:16–30 %) in a blend of corn starch and passion fruit pulp on different physicochemical characteristics of directly expanded snacks by extrusion technology. Single-screw laboratory extruder and a central, composite, rotatable experimental design were used. Expansion index of extrudates ranged between 1.0 and 1.8. Decreasing of feed moisture (18 %), passion fruit pulp concentration (1.42 %) and the increasing of barrel temperature (127 °C) resulted in higher expansion index. The increasing of feed moisture and passion fruit pulp concentration resulted in higher penetration force values of extrudates. The passion fruit pulp concentration showed a highly significant effect (p ≤ 0.01) on the L *, a * and b * parameters. Passion fruit pulp has a reasonable source of β-carotene, proteins and dietary fibers that can be added to expanded snacks.

Extruded third-generation snack foods (TGS) can be produced adding materials rich in bioactive compounds, such as the bagasse of naranjita fruit (Citrus mitis B.). The aim of this work was to study the effect of extrusion temperature (ET; 89.8–140.2°C), moisture content (MC; 21.10–32.89%) and dehydrated naranjita bagasse (DNB) content (1.12–11.88%) on TGS properties, such as, carotenoids content, physical and sensory characteristics. For data analysis, response surface methodology was used. The highest expansion index and the lowest penetration force were presented at high ET and low MC, whereas the highest carotenoids content and ΔE were presented at high DNB. Also, the highest sensory acceptability was presented combining high ET and MC, and low DNB. The optimal processing conditions were ET = 125°C, MC = 23% and DNB = 8.03%. TGS with acceptable physical and sensory properties, in addition to important carotenoid levels, were obtained. Los alimentos botana de tercera generación (BTG) pueden ser producidos adicionando materiales ricos en compuestos bioactivos, tales como el bagazo del fruto de naranjita (Citrus mitis B.). El objetivo del presente trabajo fue estudiar el efecto de la temperatura de extrusión (TE; 89,8–140,2°C), contenido de humedad (CH; 21,10–32,89%) y contenido de bagazo deshidratado de naranjita (BDN; 1,12–11,88%) sobre propiedades de BTG, tales como, contenido de carotenoides, características físicas y sensoriales. Para el análisis de datos fue utilizada la metodología de superficie de respuesta. El mayor índice de expansión y la menor fuerza de penetración fueron presentados a TE altas y CH bajos, mientras que el mayor contenido de carotenoides y ΔE fueron presentados a contenidos de BDN altos. Asimismo, la mayor aceptabilidad sensorial fue presentada combinando TE y CH altos, y BDN bajos. Las condiciones óptimas de procesamiento fueron TE = 125°C, CH = 23% y BDN = 8,03%. Se obtuvieron BTG con aceptables propiedades físicas y sensoriales, además de importantes niveles de carotenoides.

In this study, extruded films of corn starch (CS) plasticized with coconut oil (CO) (as an alternative plasticizer to glycerol) in the presence of Yucca schidigera extract (YSE) as a surfactant were investigated. It was observed that corn starch films (CSF) plasticized with a lower concentration (15 wt%) of CO showed a better equilibrium of mechanical properties, a higher WVP (5.8 ± 0.2 × 10−9 g m−1 s−1 Pa−1) and percentage of elongation (8 ± 0.5), and a lower Young modulus (99 ± 8 MPa) than those with a higher amount of plasticizer. However, films with Yucca schidigera extract (YSE) as a surfactant showed a decrease in WVP (4.9 ± 0.2 × 10−9 g m−1 s−1 Pa−1), a lower Young modulus (61 ± 2 MPa) and an increase in the percentage of elongation (13 ± 0.4). In order to describe the viscoelastic properties before the extrusion processes in materials in water suspensions and after extrusion process in CSF, rheological and DMTA analysis were performed, showing consistent behaviors for both samples.

Bacillus thuringiensis (Bt) is one of the bioinsecticides used worldwide due to its specific toxicity against target pests in their larval stage. Despite this advantage, its use is limited because of their short persistence in field when exposed to ultra violet light and changing environmental conditions. In this work, microencapsulation has been evaluated as a promising method to improve Bt activity. The objective of this study was to develop and characterize native and modified amaranth starch granules and evaluate their potential application as wall materials in the microcapsulation of B thuringiensis serovar kurstaki HD-1 (Bt- HD1), produced by spray drying. Native amaranth starch granules were treated by hydrolyzation, high energy milling (HEM) and were chemically modified by phosphorylation and succinylation. The size of the Bt microcapsules varied from 12.99 to 17.14 μm adequate to protect the spores of Bt from ultraviolet radiation. The aw coefficient of the microcapsules produced by the modified starches after drying was low (0.14-1.88), which prevent microbial growth. Microcapsules prepared with phosphorylated amaranth starch presented the highest bacterial count and active material yield. Different concentrations of the encapsulated Bt formulation in phosphorylated amaranth starch showed a high level of insecticidal activity when tested on M. sexta larvae and has great potential to be developed as a bioinsecticide formulation, also, the level of toxicity is much higher than that found in some of the products commercially available.

The objective of this study was to develop with thermoplastic extrusion amaranth starch derivatives and to characterize and evaluate their functionality as encapsulating agents of Bifidobacterium breve ATCC 15700 and Lactobacillus casei ATCC 334 during spray drying. The survival of both probiotics during storage at different water activities and at two storage temperatures, their viability in a food model system, and their tolerance to a simulated gastrointestinal tract were determined. Native amaranth starch was chemically modified to obtain phosphorylated, acetylated, and succinylated starch. Starch derivatives were reduced in viscosity, and the solubility in water was increased. In general, the modified amaranth starches and control corn starch did not provide good protection to both probiotics during storage at 25°C. However, there was excellent viability during storage at 4°C for both probiotics. Microcapsules showed a uniform coverage of the cells. Storage for 35 days at 25°C of blends of o...

The stability of antioxidants in extruded and nixtamalized blue maize flours with calcium hydroxide [Ca(OH)2] and calcium lactate [C6H10O6Ca] were evaluated. Extruded blue maize flours batches were obtained by mixing blue maize flours separately with different Ca(OH)2 (0.1, 0.2 and 0.3 %) and C6H10O6Ca (0.3, 0.6 and 0.9 %) concentrations respectively and extruded to obtain the extruded flours. For nixtamalized flours, the maize grains were cooked at 1 % Ca(OH)2 and 2.95 % C6H10O6Ca concentrations respectively. Color, antioxidant activity, total phenolics, total anthocyanins and individual anthocyanins, contents were analyzed. Color, antioxidant activity, anthocyanins contents and total phenolics decreased as the calcium hydroxide concentration increased. In contrast, increasing the calcium lactate concentration on the extruded flours had the opposite effect. The extrusion process retained 57–47 %, 72–62 % and 79–65 % of the anthocyanins content, total phenolic content and antioxidant activity, respectively. These retention rates were higher than those of the nixtamalized flours using the same calcium sources. Cyanidin-3-glucoside and pelargonidin-3-glucoside were identified in the maize kernel and flours. Cyanidin-3-glucoside concentration was increased by both extrusion and nixtamalization processed with either of the two calcium sources. In contrast, pelargonidin-3-glucoside concentration decreased by both processes. Other anthocyanins were observed, but they were not identified.

Summary The effects of different concentrations of calcium hydroxide [Ca(OH)2] and calcium lactate [C6H10O6Ca] on the functional and physical properties of extruded (EF) and nixtamalised (NF) blue maize flours were evaluated. Calcium source and concentration showed no significant effects on the EF expansion index. The water absorption index (WAI) of EF decreased as the concentrations of both calcium sources increased, and NF with C6H10O6Ca had the lowest WAI. The thermal and pasting properties of NFs were higher than those of EF. NF with C6H10O6Ca showed the highest final viscosity (FinV), indicating less damage to the starch granules, and this was correlated with microscopic analysis. In contrast, the FinV of EFs was significantly affected by calcium source and concentration. Extrusion with 0.3% and nixtamalisation at 2.95% of C6H10O6Ca yielded high WAI value and the best rheological properties in maize flour, respectively. These results suggest the use of C6H10O6Ca in extrusion or nixtamalisation to produce blue maize flours for tortilla or snacks with antioxidants.