Stale bread waste recycling as ingredient for fresh oven-baked white bread: effects on dough viscoelasticity, bread molecular organization, texture, and starch digestibility.

BACKGROUND: Wasted food produced for human consumption is estimated at 33% globally, and bread is the food product with the highest percentage. There is an ongoing drive to reincorporate food waste still useful and safe into the production chain of food for human consumption. This work aims to contribute to the study of the feasibility of recycling stale bread waste flour (BWF) into fresh oven-baked white bread, by replacing 0, 20, 40, 60, 80, and 100 g/100 g of the wheat flour with BWF. RESULTS: Storage and loss moduli increased as the BWF content increased. The baked loaf exhibited decreased lightness and yellowness but increased redness. Increasing BWF contents produced decreased loaf volume and hardness but increased moisture content. Fourier-transform infrared analysis showed that the BWF addition induced important changes in the water, protein, and starch molecular organization. Therefore, starch digestibility showed reductions in both rapidly and slowly digestible starch fractions. Principal component analysis revealed that replacements of up 20 g/100 g can produce white bread with textural, colour, and starch digestibility characteristics like that of the control bread. CONCLUSION: The fresh oven-baked white bread variation produced by replacing 20 g/100 g of the wheat flour with BWF exhibited comparable colour, volume, texture, and starch digestibility features as a control bread did made with 0 g/100 BWF. Higher replacement percentages of wheat flour by stale BWF produced unsuitable drawbacks in the white bread characteristics, but those might be deemed as convenient in other types of bakery products. © 2023 Society of Chemical Industry.

Impact of the droplet size of canola oil-in-water emulsions on the rheology and sensory acceptability of reduced-milk fat stirred yogurt.

A coarse canola oil-in-water (O/W) emulsion (dispersed mass fraction 0.1) was prepared by adding oil to whey protein hydrolysate (WPH)-citric pectin (CP) soluble complex (1% total biopolymer weight; WPH to CP mass ratio 6:1; pH 4.25) aqueous phase using a high shear homogenizer (4000 rpm, 2 min). The coarse O/W emulsion was further homogenized to obtain emulsions (Ex) with different mean droplet sizes (4000, 3000, 120 and 60 nm). A full-fat yogurt (YC; 26 ± 0.3 g milk fat L-1) was prepared from reconstituted whole milk powder (WMP, 3% milk fat) and skim milk powder (SMP, 0.01% milk fat). Reduced-milk fat yogurt (YEx 13 ± 0.3 g milk fat L-1) variations were prepared from WMP + SMP + Ex, where Ex substituted 50% of the milk-fat contained in YC. The viscosity and viscoelastic moduli were lower for YEx than for YC; the effect was more pronounced for E60 and E120. Aroma was non-significantly different between YC and YEx. A multivariate analysis showed that YEx overall acceptability was linked to taste and after taste attributes and to the viscosity perceived in mouth. The loss modulus showed anti-correlation directionality with the overall acceptance. The smaller mean droplet sized YEx exhibited the highest overall acceptability. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05573-3.

Causas de muerte de los fallecidos en hemodiálisis iterada

Introducción: La hemodiálisis es la terapia de remplazo renal más utilizada en Latinoamérica y en Cuba. Se calcula que para el año 2030 la cantidad de pacientes que inician el tratamiento de reemplazo renal a nivel mundial aumentará a más del 50 % con respecto al año 2010. Objetivo: Caracterizar los pacientes en tratamiento de hemodiálisis iterada. Métodos: Se realizó un estudio descriptivo, transversal, de todos los pacientes en tratamiento de HDI del Instituto de Nefrología "Dr. Abelardo Buch López" (INEF), fallecidos en el período 2013-2018. Los datos se obtuvieron del registro de fallecidos, del registro de pacientes en hemodiálisis y de la historia clínica. El procesamiento fue realizado de forma automatizada (IBM Spss 22.0). Se calcularon tasas brutas de mortalidad y fue utilizada la técnica de análisis de distribución de frecuencias. Resultados: La tasa de mortalidad del período resultó ser 20,3 por cada 100 pacientes. El 60,9 % de los pacientes fallecidos tenían entre 60 y 79 años de edad. La hipertensión arterial (HTA) fue la enfermedad de base más frecuente (55,5 %), y la comorbilidad predominante (87,3 %). El 53,6 % de los pacientes fallecidos empleaba catéter venoso central, y el 70 % tenía menos de 5 años en HD. La principal causa de muerte fue la enfermedad cardiovascular (46,4 %). Conclusiones: En el INEF la mortalidad en hemodiálisis se comportó de manera estable. Similar a otros reportes de servicios de hemodiálisis, los fallecidos se caracterizaron en su mayoría por tener catéter venoso central para hemodiálisis y menos de cinco años en el tratamiento. Las causas de muerte presentaron el mismo patrón que las reportadas en análisis nacionales e internacionales.

Introduction: Hemodialysis is the most used renal replacement therapy in Latin America and in Cuba. It is estimated that by the year 2030 the number of patients starting therapy worldwide will increase to more than 50% compared to 2010. Objectives: To characterize the patients undergoing iterated hemodialysis treatment. Methods: A descriptive, cross-sectional study of all patients undergoing repeated hemodialysis treatment, who deceased in the period 2013-2018 was carried out at Dr. Abelardo Buch López Institute of Nephrology. The processing was done in an automatically (IBM Spss 22.0). Gross mortality rates were calculated and the frequency distribution analysis technique was used. Results: The mortality rate for the period was 20.3 per 100 patients. 60.9% of the deceased patients were between 60 and 79 years of age. Arterial hypertension was the most frequent underlying disease (55.5%), and the predominant comorbidity (87.3%). 53.6% of the deceased patients used a central venous catheter, and 70% had been on hemodialysis for less than 5 years. The main cause of death was cardiovascular disease (46.4%). Conclusions: At Dr. Abelardo Buch López Institute of Nephrology mortality in hemodialysis behaved in a stable manner. Similar to other reports of hemodialysis services, the deceased were mostly characterized by having a central venous catheter for hemodialysis and less than five years in treatment. The causes of death showed the same pattern as those reported in national and international analyses.

Effects of leavening agent and time on bread texture and in vitro starch digestibility.

Wheat dough added with baking dried yeast (BDY, 5 g) or baking powder (BP, 5 g) was leavened for 0, 2, 4 and 6 h for producing white bread (BBDY or BBD, respectively). The specific volume of BBDY was higher than for BBP. FTIR analysis revealed that BBP reduced the short-range crystallinity of starch granules, an effect magnified by the leavening time. Hardness and cohesiveness were higher for BBDY than for BBP which had a fragile crust structure. Readily digestible starch content of BBDY decreased (16.1-10.8%), while that of BBD increased at (17.1-31.5%) with leavening time. The opposite trend was found for resistant starch which increased from 71.2 to 79.1% for BBDY, and decreased from 69.3 to 40.2% for BBD. The hydrolysis rate constant for bread made with BP (~ 4 min-1) was about twofold faster than for BBDY. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05206-1.

Effect of gelatinization degree on emulsification capacity of corn starch esterified with octenyl succinic acid.

Normal corn starch (∼26% amylose content) was subjected to different degrees of extrusion-based pregelatinization (55, 75, and 95%) to improve the efficiency of octenyl succinic anhydride (OSA) esterification. The partial disruption of the native semi-crystalline structure was verified with X-ray diffraction and Fourier transform infrared analysis. It was found that partial gelatinization (pregelatinization) reduced the relative crystallinity, which is an effect that was magnified by OSA esterification. Polarized and scanning electron microscopies revealed gradual destruction of the starch granules, yielding a fraction of insoluble remnants for high gelatinization degrees. The emulsification index showed a marked increase of about 18% by single extrusion treatment. However, fully stable emulsions (emulsification index = 1.0) were obtained by dual extrusion-esterification treatment. The hardness of hydrogels was reduced by pregelatinization. Principal component analysis revealed that most starch characteristics were mutually interdependent and that the impact of gelatinization degree was independent of the impact of OSA esterification.

Susceptibilidad antimicrobiana de bacterias aisladas en sepsis del acceso vascular. Instituto de Nefrología, 2019 / Antimicrobial susceptibility of bacteria isolated from vascular access sepsis. Institute of Nephrology, 2019

Introducción: El acceso vascular en hemodiálisis es esencial para el enfermo renal por su repercusión en la calidad de vida. La fístula arteriovenosa, los catéteres para hemodiálisis o las prótesis vasculares, aunque han evolucionado gradualmente hacia el perfeccionamiento, son proclives a las infecciones debidas fundamentalmente a bacterias de la microbiota de la piel y mucosas. Objetivo: Caracterizar la susceptibilidad antimicrobiana de las bacterias aisladas de pacientes con sepsis del acceso vascular en el servicio de hemodiálisis del Instituto de Nefrología. Material y Métodos: Estudio de corte transversal, en el período comprendido entre enero a diciembre de 2019. El universo estuvo constituido por 112 aislamientos obtenidos a partir de muestras de hemocultivos, secreciones y puntas de catéter de los pacientes con bacteriemias, sepsis o secreción en el sitio de inserción del catéter o acceso vascular. Resultados: El 72,3 por ciento de las muestras estudiadas fueron hemocultivos. Se obtuvo 38,3 % de aislamientos de Staphylococcus aureus, sensibles en su totalidad a la vancomicina. El 68,1 % de las cepas de Escherichia coli fueron productoras de betalactamasas de espectro extendido (BLEE) con sensibilidad superior a 60 % a aminoglucósidos y carbapenémicos; similar patrón de sensibilidad mostraron las cepas de Pseudomonas, no obstante, el 100% fue resistente a las cefalosporinas. Conclusiones: No se reportó resistencia a la vancomicina en el estudio. Los aislamientos de los gérmenes gramnegativos mostraron elevada resistencia a las cefalosporinas y una buena sensibilidad a aminoglucósidos y carbapenémicos(AU)

Introduction: The vascular access in hemodialysis is essential for the renal patient both for its associated morbidity and mortality as well as for its impact on quality of life. Although arteriovenous fistula, hemodialysis catheters or vascular prostheses have gradually evolved toward improvement, they are prone to infections primarily due to bacteria on the skin and mucosal microbiota. Objective: To characterize the antimicrobial susceptibility of bacteria isolated from patients with vascular access sepsis in the hemodialysis service of the Institute of Nephrology. Material and Methods: A cross-sectional study was conducted in the period January-December 2019. The universe consisted of all 112 isolates obtained from blood culture samples, secretions and catheter tips from patients with bacteremia, sepsis or discharge at the site of catheter insertion or vascular access. Results: The results show that 72.3% of the samples studied were blood cultures. Also, 38.3 percent of Staphylococcus aureus isolates, which were totally sensitive to vancomycin, were obtained. On the other hand, 68.1% of Escherichia coli strains were extended spectrum beta-lactamases (ESBL) producers with sensitivity to aminoglycosides and carbapenems greater than 60%. Pseudomonas strains exhibited a similar pattern of sensitivity, however, 100% were resistant to cephalosporins. Conclusions: No resistance to vancomycin was reported in this study. Gram-negative isolates showed high resistance to cephalosporins and good sensitivity to aminoglycosides and carbapenems(AU)

Influence of gelatinization degree and octenyl succinic anhydride esterification on the water sorption characteristics of corn starch.

The effects of gelatinization degree (GD) and octenyl succinic anhydride (OSA) esterification in the sorption-desorption characteristics of normal corn starch (NCS) were studied. NCS was subjected to different GD (53, 70, and 96%) with an extruder and lyophilized. FTIR analysis revealed that GD increased the hydrated (995/1022 ratio) and decreased the short-range ordered (1022/1047 ratio). The equilibrium sorption-desorption curve of starches was obtained for water activities up to 0.95 and fitted with the Guggenheim-Anderson-de Boer (GAB) model. Gelatinization of corn starch decreased its water sorption capacity, increased its sorption hysteresis and decreased its monolayer moisture content. OSA treatment of NCS reduced the water sorption capacity, hysteresis, and monolayer moisture content as reflected by slight variations of these parameters with the GD. A principal component analysis showed that GD and OSA esterification are mutually independent treatments, which can provide different effects on the water sorption characteristics of NCS.

Effects of mixing, sheeting, and cooking on the starch, protein, and water structures of durum wheat semolina and chickpea flour pasta.

The influence of the pasta preparation stages on starch, proteins, and water structures of semolina and chickpea pasta was studied. The hydrated starch structures (995/1022 FTIR ratio) increased in semolina and reduced in chickpea pasta. The processing stages in semolina pasta led to a significant increase of ß-sheet structures (~50% to ~68%). The ß-sheet structures content in chickpea pasta was lower (~52%), and was most affected by sheeting and cooking. The water structure was assessed by the analysis of the OH fingerprint FTIR region (3700-2800 cm-1) and showing that water molecules (~90%) are strongly and moderately bound. The chickpea pasta displayed the highest content of strongly bonded water (about 55%) in contrast to the semolina pasta (~48%). A principal component analysis showed that the molecular organization of semolina pasta was mostly affected by dough formation and cooking; the molecular organization of chickpea pasta was determined by the cooking stage.

Factores relacionados con la supervivencia de pacientes que inician tratamiento de hemodiálisis. Instituto de Nefrología / Factors related to the survival of patients who start receiving hemodialysis. Institute of Nephrology

Introducción: La enfermedad renal crónica constituye un problema de salud por su impacto sobre los individuos, la sociedad y la economía. Existe un insuficiente conocimiento de los factores relacionados con la supervivencia en los pacientes que inician hemodiálisis en nuestro medio. Objetivo: Identificar los factores relacionados con la supervivencia de los pacientes que iniciaron hemodiálisis. Material y Métodos: Se realizó un estudio descriptivo de corte retrospectivo, de pacientes que iniciaron hemodiálisis en el Instituto de Nefrología Dr. Abelardo Buch en el período del 1 de enero de 2011 al 31 de diciembre de 2016. Se analizaron variables sociodemográficas y clínicas, y se realizó una correlación de estas con la supervivencia en hemodiálisis. Para todas las pruebas realizadas se fijó un nivel de significación ɑ= 0.05. Resultados: Se estudiaron 81 pacientes, con edad media de 55 años y predominio del sexo masculino (61,7 por ciento) y la raza blanca (59,3 por ciento). Los resultados estadísticamente significativos fueron la desnutrición (Índice de Masa Corporal < 18.5 kg/m2), con una mediana de supervivencia de (7,6+-4,9; log Rank: 0,015), las cifras de albúmina sérica menores a 35 g/L, con (33.1 +-5.4; log Rank: 0.050) la falta de seguimiento nefrológico previo, con (21,5 +-2,6; log Rank: 0,041), y el empleo de catéter venoso central como acceso vascular, con (32,4+-3,5; log Rank: 0,038). Conclusiones: La desnutrición, la hipoalbuminemia, el empleo de catéter venoso central como acceso vascular y la falta de seguimiento nefrológico previo afectaron negativamente la supervivencia de los pacientes en hemodiálisis(AU)

Introduction: Chronic kidney disease is a health problem because of its impact on individuals, society and the economy. There is not enough knowledge of the factors related to survival in patients who start hemodialysis in our environment. Objective: To identify the factors related to the survival of patients who started receiving hemodialysis. Material and Methods: A descriptive retrospective study was conducted in 81 patients who started receiving hemodialysis in the Dr. Abelardo Buch Institute of Nephrology in the period between January 1, 2011 and December 31, 2016. Sociodemographic and clinical variables were analyzed. A correlation between these variables and survival was made. The level of significance in all the tests performed was determined to be ɑ= 0.05. Results: A total of 81 patients were studied. The mean age was 55 years. The male sex (61,7 percent) and the white race (59,3 percent) predominated in the study. The statistically significant variables were malnutrition (body mass index < 18.5 kg/m2) with a median survival of (7,6+-4,9; log rank: 0,015), serum albumin levels lower than 35 g/L, with (33.1 +-5.4; log rank: 0.050), lack of previous nephrological follow-up, with (21,5 +-2,6; log rank: 0,041) and the use of central venous catheter as vascular access with (32,4+-3,5; log rank: 0,038). Conclusions: Malnutrition, hypoalbuminemia, the use of central venous catheter as vascular access and previous nephrological follow-up negatively affected the survival of patients on hemodialysis (AU)

In vitro digestibility characteristics of octenyl succinic acid (OSA) modified starch with different amylose content.

The effect of amylose content in the in vitro digestibility of non-modified and OSA-modified corn starch was studied. Corn starches with different amylose content (waxy, normal and Hylon VII) were treated with 3% OSA solution. In vitro digestibility tests showed that OSA treatment reduced the fraction of fastly digestible starch, an effect that was more pronounced for cooked starch. The amylose content was negatively linked to the decrease of in vitro digestion. HPSEC analysis was conducted to gain insights on the effect of OSA-treatment on in vitro digestibility. The results showed an increase of the molecular weight of starch chains. Besides, the molecular weight increase was similar for amylose and amylopectin fractions. This suggests that OSA could be acting as a cross-linking agent between starch chains, reducing the susceptibility to amylolysis. Overall, OSA treatment induced the formation of more complex starch chains, offering more resistance for amylolytic reactions.

Canola oil/candelilla wax oleogel improves texture, retards staling and reduces in vitro starch digestibility of maize tortillas.

BACKGROUND: Maize tortilla staling is a major drawback that affects its commercialization and consumption, and so novel methods for retarding staling are continuously being explored. The present study evaluated the effect of adding a canola oil/candelilla wax oleogel (CWO; 0. 2, 4 and 6 g 100 g-1 ) to a basic masa formulation (water, 60 g 100 g-1 ; nixtamalized maize flour, 40 g 100 g-1 ) on the texture, staling and in vitro starch digestibility of maize tortillas made using a hot plate (200 °C). RESULTS: Textural analysis showed that CWO reduced hardness and increased the tensile strength of tortillas. Fourier transform infrared analysis indicated that the retrogradation of starch chains, quantified in terms of the intensity ratio 1047/1022, was reduced by oleogel incorporation. In vitro starch digestibility tests showed that tortillas containing CWO had lower readily digestible and slowly digestible starch fractions compared to the control tortilla without oleogel. CONCLUSION: The formation of amylose-lipid inclusion complexes and the formation of an oily physical barrier around starch granules were postulated as mechanisms underlying the reduced starch digestibility. © 2019 Society of Chemical Industry.

Microencapsulation of sesame seed oil by tamarind seed mucilage.

Tamarind seed mucilage (TSM) was evaluated as a novel wall material for microencapsulation of sesame oil (SO) by spray-drying method. Wall material:core ratios of 1:1 (M1) and 1:2 (M2) were considered, and the corresponding physical and flow properties, thermal stability, functional groups composition, morphology, encapsulation efficiency, and oxidative stability were evaluated. Powder of M1 and M2 microcapsules exhibited free-flowing characteristics. The particle size distribution for M1 microcapsules was monomodal with diameter in the range 1-50 µm. In contrast, Microcapsules M2 presented a bimodal distribution with diameter in the ranges 1-50 µm and 50-125 µm. M1 microcapsules were thermally stable until 227 °C and microcapsules M2 until 178 °C. Microcapsules M1 and M2 exhibited a dominant amorphous halo and external morphology almost spherical in shape. Encapsulation efficiency was 91.05% for M1 and 81.22% for M2. Peroxide formation reached values after six weeks was 14.65 and 16.51 mEq/kgOil for M1 and M2 respectively. Overall, the results led to the conclusion that tamarind mucilage is a viable material for high microencapsulation efficiency, while offering protection against oxidation mechanisms of SO.

Physicochemical, microstructural and digestibility analysis of gluten-free spaghetti of whole unripe plantain flour.

Plantain is a climacteric fruit having economic relevance in several tropical regions. Unripe plantain is an alternative source of indigestible carbohydrates (dietary fibre) and undigestible starch fraction. Unripe plantain flour was explored in this work as an alternative ingredient (whole and pulp) in spaghetti formulations. Chemical composition, cooking quality, texture analysis, and microstructure of spaghetti formulations were analyzed. The microstructure results showed that the presence of fiber in the food matrix helped the reduction of the starch granule swelling in the cooking process. Spaghetti made with whole plantain flour exhibited lower rapidly starch fraction, with increased resistant starch fractions. Overall, the whole unripe plantain flour exhibited good potential for gluten-free spaghetti having highest content of fiber and lower starch digestion rates.

Morphological, molecular evolution an in vitro digestibility of filamentous granules of banana starch during fruit development.

The development of starch granules of a banana cultivar (morado variety - Musa AAA subgroup Red dacca) from filamentous shape to semi-spherical and finally to oval shape, was studied. The purity of the extracted starch changed from 83.5% (6 weeks) to 95.4% (16 weeks). Impurities were ascribed to cellulosic and latex fractions responsible for the integrity of the pristine fruit. The amylose content was stabilized at about 29.6% after the 12th week. The thermal analysis showed that the gelatinization enthalpy increased from 5.0 to 11.2 J/g from the 6th to the 12th week, indicating an increased degree of internal molecular organization. The analysis of chain-length distribution and gel permeation chromatography, showing that the content of long chains (B1, B2, and B3+) increased with the development of the starch granule. Also, XRD analysis indicated that C- type X-ray diffraction pattern from early to later phases of development, although the relative crystallinity content increased from 19.3 to 23.5% after 16 weeks of development. FTIR revealed the formation of more ordered structures with the development time. In vitro digestion tests showed that the resistant starch fraction increased from 37.5% for week 6 to 55.5% for week 16.

Cooling rate, sorbitan and glyceryl monostearate gelators elicit different microstructural, viscoelastic and textural properties in chia seed oleogels.

Recently the structuring of liquid oils with low molecular weight organogelators has received much attention. Food products devoid of trans fats, with tailored rheological and textural properties can be designed for desired applications by properly selecting the organogelator and cooling rate used in their formation. Nevertheless, studies regarding these points are still scarce. In this work the effect of two different food-grade gelators (glyceryl monostearate, GM and sorbitan monostearate, SM) and different cooling rates (1, 3 and 9 °C/min) on the microstructural, viscoelastic and texture properties of chia seed oleogels (GMO and SMO, respectively) were evaluated. Gelator and chia seed oil (ChSO) were mixed in 1:10 mass ratio. SMO formed crystalline needle-like structures, with faster cooling rates producing smaller crystals (higher crystallinity index) and a more compact network. GMO showed an opposite crystallinity index dependence with cooling rate than SMO. GMO hardness higher than that of SMO, and increased while that of SMO decreased as cooling rate was faster. Both GMO and SMO showed a thixotropic dependence of the storage (G') and loss (G") moduli with forward-backward temperature ramp (5-80-5 °C). Both moduli values were higher for GMO than for SMO independently of cooling rate used. A thixotropic index was obtained, which reflected that GMO had a more thermo-reversible structure than SMO. The results of this study indicate that the formation mechanism of chia seed oleogels was affected by the cooling rate and the chemical nature of the gelator, and elicited completely different microstructural and mechanical responses.

High intensity ultrasound treatment of faba bean (Vicia faba L.) protein: Effect on surface properties, foaming ability and structural changes.

Response surface methodology was used for establishing the amplitude (72.67%) and time (17.29 min) high-intensity ultrasound (HIUS) conditions leading to an optimized faba bean protein isolate (OFPI) with lower interfacial tension, zeta potential and viscosity, and higher solubility than native faba bean protein isolate (NFPI). OFPI showed significantly higher adsorption dynamics at the air-water interface, and produced foam with significant smaller bubble diameter, higher overrun, stability and yield stress, and lower liquid drainage than NFPI. Fourier Transform Spectroscopy (FT-IR) revealed that the secondary structure of OFPI deferred from NFPI in terms of increases in ß conformations (6.61% ß-sheet, 19.6% ß-turn, 0.8% anti-parallel ß-sheet) and decreases in inter-molecular aggregates (43.54%). Multienzyme study pinpointed that the structural changes could have induced a decrease on the relative protein digestibility of OFPI respect that of NFPI. The results of this work demonstrate that HIUS technology improves the surface and foaming properties of faba bean protein isolate, which may favour the revalorisation of this crop.

A novel, simple, economic and effective method for retarding maize tortilla staling.

BACKGROUND: Staling of maize tortillas is a major drawback affecting their manufacture, commercialization and consumption. The development of methods that may help retard staling of maize tortillas is an ongoing research topic. In this work, a novel, simple, economic and effective method is proposed, based on adding completely gelatinized nixtamalized maize flour (GMF) dispersion to the basic masa formulation recipe (water, 600 g kg-1 ; nixtamalized maize flour, 400 g kg-1 ) in substitution of 50, 100 and 150 g kg-1 of water. RESULTS: Masa added with GMF showed increased water retention capacity, reduced freezable water content and improved flow and dynamic rheological properties and produced tortillas with decreased firmness. The infrared 1047/1022 cm-1 spectral ratio indicated that a more disordered starch granule arrangement was formed, while enthalpy peaks associated with starch retrogradation decreased. All the above indicators were more pronounced the higher was the GMF content. CONCLUSION: This work showed that GMF can play the role of a self-hydrocolloid anti-staling agent by retarding the retrogradation of maize starch and deterring the loss of water and rheological properties of masa and the increase in undesirable sensory characteristics of tortilla such as increased firmness. © 2018 Society of Chemical Industry.

Physicochemical, digestibility and structural characteristics of starch isolated from banana cultivars.

Banana starches from diverse varieties (Macho, Morado, Valery and Enano Gigante) were studied in their physicochemical, structural and digestibility features. X-ray diffraction indicated that the banana starches present a B-type crystallinity pattern, with slight difference in the crystallinity level. Macho and Enano Gigante starches showed the highest pasting temperatures (79 and 78°C, respectively), whilst Valery and Morado varieties presented a slight breakdown and higher setback than the formers. Morado starch presented the highest solubility value and Valery starch the lowest one. The swelling pattern of the banana starches was in agreement with their pasting profile. All banana starches showed a shear-thinning profile. The resistant starch (RS) fraction was the main fraction in the uncooked banana starches. Morado variety showed the highest amount of slowly digestible starch (SDS) and the lowest RS content reported until now in banana starches. Banana starch cooked samples presented an important amount of SDS and RS. Molecular weight and gyration radius of the four banana starches ranged between 2.88-3.14×10(8)g/mol and 286-302nm, respectively. The chain-length distributions of banana amylopectin showed that B1 chains (DP 13-24) is the main fraction, and an important amount of long chains (DP≥37) are present. The information generated from this study can be useful to determine banana varieties for starch isolation with specific functionality.

Diffusion and decay chain of radioisotopes in stagnant water in saturated porous media.

The analysis of the diffusion of radioisotopes in stagnant water in saturated porous media is important to validate the performance of barrier systems used in radioactive repositories. In this work a methodology is developed to determine the radioisotope concentration in a two-reservoir configuration: a saturated porous medium with stagnant water is surrounded by two reservoirs. The concentrations are obtained for all the radioisotopes of the decay chain using the concept of overvalued concentration. A methodology, based on the variable separation method, is proposed for the solution of the transport equation. The novelty of the proposed methodology involves the factorization of the overvalued concentration in two factors: one that describes the diffusion without decay and another one that describes the decay without diffusion. It is possible with the proposed methodology to determine the required time to obtain equal injective and diffusive concentrations in reservoirs. In fact, this time is inversely proportional to the diffusion coefficient. In addition, the proposed methodology allows finding the required time to get a linear and constant space distribution of the concentration in porous mediums. This time is inversely proportional to the diffusion coefficient. In order to validate the proposed methodology, the distributions in the radioisotope concentrations are compared with other experimental and numerical works.

Diffusion in two-dimensional conical varying width channels: comparison of analytical and numerical results.

This study is devoted to the unbiased motion of a point-like brownian particle in two-dimensional tilted asymmetric channels of varying width formed by straight walls. An effective one-dimensional description in terms of the generalized Fick-Jacobs equation is used to derive formulas that yield the particle's effective diffusion coefficient as a function of the geometric parameters of the channel. To such end, we use the formulas obtained by Bradley [Phys. Rev. E 80, 061142 (2009)] and by Dagdug and Pineda [J. Chem. Phys. 137, 024107 (2012)] to study two-dimensional diffusion in narrow and smoothly asymmetric channels of varying width. Comparison with brownian dynamics simulation results allows us to establish the domain of applicability of both the one-dimensional description and the effective diffusion coefficient formulas.