Jose Alvarez-Ramirez

Metropolitan Autonomous University | UAM · Departamento de Ingeniería de Procesos e Hidráulica

This work explores the use of singular value decomposition (SVD) entropy to characterize the complexity of stride interval sequences from gait dynamics. The computation of the approximate (ApEn) and sample (SampEn) entropies require the specification of the length of the scrutinized patterns (m) and the pattern similarity tolerance (r). In contrast...

The complexity in time series of two-phase flow is associate with the interaction of gas bubbles and liquid phase, this interaction shows characteristic that depend on different condition such as low rate, physical properties phases, geometry, and tube inclination, etc. This work uses singular value decomposition (SVD) entropy and rescaled range an...

The analysis of complex patterns in human gait dynamics typically relies on measuring stride intervals. Several studies have revealed that the dynamics of stride intervals exhibit fractal characteristics that depend on health, age, and task conditions. However, with current measurement devices, other gait parameters such as the swing and stance int...

This work examined the informational efficiency of the European CO 2 emission trading market for the different implementation phases in the period 2008–2022:Q3. The approach is based on a bootstrap singular value decomposition (SVD) approach and the analysis was conducted for a rolling window to assess the time-varying efficiency and over different...

Huauzontle is an undervalued and little‐studied pseudocereal crop whose seeds contain relatively high starch contents. There is scarce information on the structural, physicochemical, functional, and nutritional characteristics of native huauzontle starch (HS), and its modification has not been documented until today. HS is modified with citric acid...

Ionic gelation of alginate has become one of the most widely used encapsulation techniques, with the main drawback that alginate hydrogels exhibit highly porous structural networks, which promotes high rates of release of encapsulated core materials. To retard the diffusion and loss of oil, and in turn to develop new alternatives as wall materials,...

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 for reincorporate food waste still useful and safe, into the production chain of food for human consumption. This work aims to contribute to study the feasibility of recycling sta...

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 o...

Semolina pasta with improved nutritional properties is increasingly demanded by consumers. High protein content and low starch digestibility are features desired for a functional pasta. In this work, amaranth flour was used for 50% supplementation of semolina in pasta preparation. Raw amaranth flour increased protein from 11.7 g/100 g to about 14.0...

The formulation of semolina pasta with reduced starch digestibility is of prime importance to deal with the adverse effects of the intake of rapidly digested carbohydrates on human health. This work focused on the effects of the production method (extrusion and lamination) and the addition of commercial Type 2 resistant starch (RS) on the molecular...

Hybrid gels (HG) were prepared using candelilla wax (CW, 5 g), canola oil (CO,100 g), native corn starch (N, in 20:80, 40:60, 60:40 weight ratio respect CW), and water (W, 45:1 weight ratio respect N). In method M1 CW/CO/N were heated (90 °C, 15 min) and then mixed with W. N gelatinization was incipient. In method M2, by separate CW/CO and N/W were...

This work explored the use of pregelatinised amaranth flour (PAF) as an oil substitute in the preparation of amaranth cakes. Amaranth flour was extruded to achieve approximately 50% gelatinisation, ground and sieved. The PAF was used to replace the oil in the cake preparation at levels 33, 66% and 100%. FTIR analysis of the cake formulations showed...

Bixin and norbixin are extracted from annatto seeds, and the residual seed waste can be used as a potential source of annatto starch (AS), contributing to the circular economy of the regional communities where the resource is grown/processed. To assess AS suitability as a food ingredient, its physicochemical, antioxidant, microstructural, and funct...

Normal corn starch (∼26% amylose content) was subjected to different degrees of extrusion-based pregelatiniza-tion (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 in-frared analysi...

This work examined the information efficiency of the European CO 2 trading market for the period 2008-2021. The analysis is based on the singular value decomposition (SVD) approach and the task is to test whether the dynamics of logarithmic price differences are consistent with a random process. The results showed that the information efficiency ch...

The power reactor is routinely measured and has been widely used for characterization of the reactor core dynamics. This signal exhibits complex dynamics, including a combination of large- and small-amplitude fluctuations. This work proposed a method based on singular value decomposition (SVD) to quantify the complexity of the power signal. The und...

Native amaranth protein (APN) is a nutritional ingredient with potential applications for the structuration and functionalization of food products. However, its solubility is poor, which limits its use in the food industry. The effect of ultrasonication (US) at 50% amplitude for 10 min (APUS), pH-shifting at pH 2 and 12 (APpH2 and APpH12), and the...

This work proposed an approach to test the efficient market hypothesis (EMH) based on the singular value decomposition (SVD) entropy. The entropy is computed from the singular value distribution of a matrix formed by lagged returns up to a scale n. To decide whether a time series is predictable, the estimated SVD entropy was compared with a referen...

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 ti...

High-power ultrasound (HPU) is a non-thermal processing method that has been researched and used in the last years. The application of ultrasound can modify and improve some technologically important compounds such as starch. This research aimed to examine the effect of ultrasound treatment on yield, physicochemical, and functional properties of ly...

High-power ultrasound (HPU) is a non-thermal processing method that has been researched and used in the last years. The application of ultrasound can modify and improve some technologically important compounds such as starch. This research aimed to examine the effect of ultrasound treatment on yield, physicochemical and functional properties of lyc...

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...

Non-conventional flours from unripe fruits and pseudocereals have potential as functional ingredients given their high protein contents and antioxidant activity. Pregelatinized starch and flours are increasingly used in gluten-free foods and as fat substitutes. The present work aimed to address the effect of extruding pregelatinization in the visco...

White, red, and black quinoa (Chenopodium quinoa W.) and kiwicha (Amaranthus caudatus) are increasingly consumed as specialty foods worldwide. Starch was extracted from these Andean grains and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry, and enzymatic hydrolysis. A...

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 β-sheet structures (∼50% to ∼68%). The...

The objective of the work was to evaluate OSA-esterified taro starch as wall material to encapsulate avocado oil as lipophilic bioactive compounds, using spray drying for encapsulation. It was found that OSA-esterification decreased the amylose content (8.93–6.13%), %C (33.29–31.88%), and thermal properties of gelatinization (Tp: 86.1 to 80.7 °C, a...

Chickpea flour contains large fractions of protein and dietary fiber, which offer benefits for human health. This work studied the characteristics and in vitro starch digestibility of pastas with blends of semolina and chickpea flour. Texture analysis showed that chickpea flour induced significant reductions in hardness and elasticity of cooked pas...

Native corn starch is subjected to dual heat moisture (30 g per 100 g d.b.)/lactic acid (10 g per 100 g d.b.) treatment (HMLAx) at different temperatures (x = 90, 110, 130, and 150 °C), and is compared with heat moisture (HMx) treatment alone. Neither HMLAx nor HMx change the crystallinity type (A‐type) of the corn starch, but the relative crystall...

Maize starch dispersions (5 g/100 mL water) are treated with Ca(OH)2 (0.2 g/100 g starch), emulating the traditional nixtamalization process, and with CaCl2 or Ca(CO)3 (1.0g/100 g starch) salts, emulating ecological nixtamalization processes. The effect of these calcium compounds upon the in vitro digestibility of maize starch is evaluated in compa...

A hedonistic black color was imparted to bread by adding activated vegetable charcoal (AC; 0, 0.5, 1, 2 and 4 g/100 g wheat flour). The addition of AC had a significant effect on dough rheology and on bread specific volume, color, texture, and in vitro starch digestibility. The apparent viscosity and the viscoelastic moduli of dough were enhanced....

Identified in December 2019, the 2019-nCoV emerged in Wuhan, China, and its spread increased rapidly, with cases arising across Mainland China and several other countries. By January 2020, the potential risks imposed by 2019-nCoV in human health and economical activity were promptly highlighted. Considerable efforts have been devoted for understand...

This work studied the physicochemical, molecular, and emulsification properties of Oxalis tuberosa (oca) starch modified with octenyl succinic anhydride (OSA). Freshly harvested oca tubers were washed and selected, and starch was extracted by tuber size reductions and successive washes. Modifications were performed with OSA for 6 h at pH 8.5‐9. Mea...

Emulsions are widely used in food, drug, and cosmetic products. Due to the small size, starch nanocrystals have been proposed to stabilize Pickering emulsions However, this application is effective when starch nanocrystals offer a strong amphipathic character. Waxy maize and amaranth starch nanocrystals were treated chemically with octenyl succinic...

This paper is aimed at designing a class of model based extremum-seeking feedback controllers (ESC) for the on-line optimization of biomethane production rate in continuous Anaerobic Digestion (AD) processes. The ESC scheme is based on the modelling error compensation approach coupled with a first-order gradient estimator. The feedback control law...

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 oxid...

Spaghetti pasta was prepared with semolina and whole unripe plantain flour (WUPF) as dietary fiber source at three different fractions (0.15, 0.25 and 0.35 w/w). Hi‐Maize® 260 (HM) was used as commercial dietary fiber to compare the results. It was obtained that HM produced pasta with cooking parameters similar to pasta containing only semolina. Ho...

Backgound: Maize tortilla staling is a major drawback that affects its commercialization and consumption, so novel methods for retarding staling are continuously explored. In this work 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...

The role of endogenous protein in the formation of spray‐dried taro starch spherical aggregates is studied in this work. Taro starch dispersions (30 g per 100 mL water) are added with different protease concentrations (0.0, 1.0, and 5.0 × 103 IU protease per g starch) for degrading the surface protein of the starch granules. Protease treatment has...

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...

This paper is aimed at the design of a gradient based extremum-seeking feedback controller (ESC) for the on-line optimization of methane production in continuous Anaerobic Digestion processes (AD). The ESC technique is based on the modelling-error compensation approach coupled with a first-order gradient estimator. The feedback control law is able...

Octenyl succinic starch esters were prepared from three corn starches with different amylose content; namely, waxy (5.43%), normal (25.16%) and Hylon VII (65.84%). The degree of substitution varies from 0.0103 for waxy starch to 0.0125 for Hylon VII, meaning that the degree of substitution is positively correlated with the amylose content. Scanning...

The Monod equation has been extensively used for modeling microbial growth, but has no mechanistic basis and its derivation is purely empirical. In this work an approach was developed for deriving the Monod equation based on a simple kinetics scheme. The microbial growth process considered involved two consecutive steps, i.e., (i) the formation of...

This paper is focused on the design of a robust model based extremum-seeking controller (ESC) aimedat the online optimization of a class of uncertain nonlinear systems. The ESC scheme is based on themodeling-error compensation approach using a robust input–output linearizing control law coupledwith a first-order gradient estimator. The feedback con...

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,...

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...

The functional properties of starch are determined to a large extent by the molecular structure. The starch solubilization is dependent on the procedure and solvent. Structural parameters, like weight average molar mass and radius of gyration, can be calculated by the analysis of solubilized polymers using HPSEC-MAL-RI and AF4-MALS-RI systems. The...

Maltodextrin is commonly used as wall material for protection of bioactive compounds. This work explored the OSA modification of maltodextrin to improve the stability of microcapsules obtained by spray drying process. OSA maltodextrin showed a degree of substitution of 0.020 with OS groups by weight of about 2.49%. OSA maltodextrin exhibited improv...

There is a growing demand in the food industry for natural food products to replace synthetic ingredients. Motivated by this fact, the present work studied the extraction of coloring compounds from Bougainvillea spectabilis under aqueous and ethanolic conditions, and the encapsulation of the extract in alginate beads. Ethanolic extraction was more...

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...

High density polyethylene (HDPE), linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) are blended, and compared against a similar mixture but functionalized LDPE with maleic anhydride (MAh), HDPE‐LLDPE‐LDPE‐g‐MAh. In order to obtain nanocomposites from these polymer blends, a modified bentonite was added by incorporating l‐l...

Starch is an abundant renewable resource and is the raw material for the production of a wide range of products, many of which are obtained by hydrolysis. While the hydrolysis of starch by enzymes and acids has been extensively investigated, there are scant studies with respect to the use of solid acid catalysts for this purpose. In this work we ex...

The Butler-Volmer equation is commonly used to describe heterogeneous reaction mechanisms (e.g., charge transfer) involved on electrochemical systems. Under the application of an oscillatory exciting potential, the frequency response (i.e., electrochemical impedance spectroscopy) of the net current on the electrode is extensively quantified to char...

The present study proposes a complete (pMPS8) and partial (pMPS8-co-PEGDMA) functionalization of poly(poly(ethyleneglycol) methyl ether methacrylate (pPEGMA) with zwitterionic pendant groups to improve the mobility of polymer chains and ion-ion associations during Li+ conduction (weak electrolyte). Structural, thermal and electrochemical characteri...

Pectin was extracted from cacao pod husks (CPHP) wastes, having a methylesterification degree of 83.22%, acetylation degree of 10.20%, and protein content of 3.68%. The adsorption dynamics of CPHP at the canola oil-water interface were studied, and diffusion (k diff), penetration (k pen) and rearrangement (k rea) rate constants were determined. Can...

Background: Staling of maize tortilla is a major drawback affecting their manufacture, commercialization and consumption. The development of methods that may help retard staling of maize tortilla is an ongoing research topic. In this work a novel, simple, economic and effective method is proposed, based on adding completely gelatinized nixtamalize...

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 signific...

Pectin was extracted from cacao pod husks (CPHP) wastes, having a methylesterification degree of 83.22%, acetylation degree of 10.20%, and protein content of 3.68%. The adsorption dynamics of CPHP at the canola oil-water interface were studied, and diffusion (kdiff), penetration (kpen) and rearrangement (krea) rate constants were determined. Canola...

Acid hydrolysis of waxy maize and amaranth starches was achieved for nanocrystal production. Both starches are of the waxy type with an A-type crystallinity pattern. The mean granule sizes were ∼1–2 μm for amaranth starch and ∼15–18 μm for waxy maize. The starches (15 g dry basis) were subjected to acid hydrolysis with 100 mL of 3.16 M H2SO4 at 40...

Starch functional properties are largely determined by the molecular structure. The weight average molar mass and radius of gyration can be calculated by the analysis of solubilized polymers using AF4-MALLS-DRI systems. The chain length distribution can be determined by analysing debranched starches by gel permeation chromatography (GPC) and high p...

In a previous work gelatinized corn starch dispersions (GSD) contained different (∼ 7-59.6%) ghost phase fractions (GPF), i.e., insoluble amylopectin-rich remnants, were added glycerol as plasticizer, casted and dried for obtaining films. GPF had both positive and negative effects on films properties, but GPF of around 20-30%, provided films with g...

The electrocatalytic behavior of " inactive " (Boron Doped Diamond (BDD), SnO2-Sb and PbO 2) anodes toward the oxygen evolution reaction (OER) is evaluated using dc and ac techniques, under controlled experimental conditions (e.g. air bubbling, ohmic drop correction). Tafel slopes estimated from anodic polarization curves for all catalysts are loca...

Ultrasound technologies are increasingly used for the production of modified starches. An accurate understanding of the effects of ultrasound treatment on the morphological and functional properties of starch granules and dispersions is still under progress. This work studied the digestibility of corn starch as affected by ultrasound treatment (24...

Resistant starch (RS) from raw plantain flour (RPF) is destroyed after cooking, thus losing its nutraceutical benefits. The objective of this work was to obtain esterified flours from RPF and evaluate starch fractions, and physicochemical, structural and morphological properties. RPF was esterified with citric acid (40 g/100 g dry flour, pH 3.5) at...

Tamarind seed mucilage was isolated and dried with spray dryer. Functional properties and physicochemical characteristics of the extracted mucilage were evaluated. Functional properties showed that the solubility, water holding capacity and oil holding capacity increased with temperature. The swelling index was determined at different temperatures...

Adsorption isotherms for spray-dried tamarind seed mucilage were determined at 20, 30 and 40 °C and fitted to GAB and Caurie sorption models. The sorption properties were estimated using Kelvin and Helsey equations and the values found for the bound water were of 15.98, 11.33 and 9.87% and specific surface areas of 142.29, 133.97 and 133.14 m²/g at...

Mexico City is a megalopolis with severe pollution problems caused by vehicles and industrial activity. This condition imposes important risks to human health and economic activity. Based on hourly-sampled data during the last decade, in a recent work (Meraz et al., 2015) we showed that the pollutant dynamics in Mexico City exhibits long-term and s...

Microencapsulation is a process oriented to protect substances that are susceptible to decomposition or reduction of their functionality due to different degradation reactions (i.e., oxidation, hydrolysis, etc). Diverse wall materials, including some carbohydrates, preserve substances against adverse temperature, pH, humidity, oxygen, and other com...

This work presents results of the morphology and rheological properties of xanthan gum (XG)-based hydrogels reinforced by montmorillonite (MMT) particles. The results show that hydrogels exhibit self-supporting characteristics when a critical MTT concentration of approximately 2.0% w/w is used. Wide-angle, small-angle X-ray diffraction patterns and...

Films were made by blending either unripe banana or rice flour with sodium montmorillonite (MMT) by means of the casting method. Structural characterization by X-ray diffraction was performed to explain the interactions of the components between MMT and flour components. The effects of storage time on structure and mechanical properties of the film...

The effects of the amylose content and the preparation sequence in physicochemical properties of starch/montmorillonite (MMT) composites were studied in this work. Native (30%) and high amylose Hylon VII (70%) starches were considered for assessing the effects of amylose content. Glycerol and MMT were used as additives to evaluate the effects of th...

In many instances, the fluctuation function obtained from detrended fluctuation analysis (DFA) cannot be described by a uniform power-law function along scales. In fact, the manifestation of crossover scales may reflect the simultaneous action of different stochastic mechanisms displayed predominantly within certain scale ranges. This note proposes...

Native corn starch (NCS) dispersions (3% w/v) were inoculated with native (i.e., not genetically modified) Saccharomyces cerevisiae (2�107 cellsmL�1), fermented for 0, 12, 24, 48, 72, 96, 120, and 168 h at 38°C. It was found that glucoamylases, the amylolytic enzymes produced by native S. cerevisiae, produced morphological changes in the fermented...

In this paper, an adaptive extremum seeking control scheme for continuous stirred tank bioreactors is presented. Unknown growth kinetics without considering an explicit mathematical expression is assumed. An adaptive learning technique based on modeling error estimation coupled with a proportional compensation is used to construct a feedback contro...

Highlights • Numerical solutions of fractional RD systems are given using Green's function formulations. • The scheme proposed exhibit global approximation orders of O(h α). • Proposed scheme exhibit better numerical approximation than traditional schemes. Abstract Reaction–diffusion equations with spatial fractional derivatives are increasingly us...

Sonication (25 kHz) was applied to plantain (large granule size) and taro (small granule size) starches for two treatment durations (20 and 50 minutes) using a flow-cell at controlled temperature of 4 ± 0.1 °C. The granule size distribution of starches was only slightly affected by the ultrasound treatment. Ultrasound affected the granule surface m...

This work considered the Langmuir–Hinshelwood (LH) scheme for a single reactant. In a first step, the validity of the quasi-steady state approximation (QSSA) was revised in terms of nonlinear relaxation processes. It was found that the LH equation obtained from the QSSA is not valid most of the times, except for example in the case of high reactant...

The weak-form of the efficient market hypothesis (EMH) establishes that price returns behave as a pure random process and so their outcomes cannot be forecasted. The detrended fluctuation analysis (DFA) has been widely used to test the weak-form of the EMH by showing that time series of price returns are serially uncorrelated. In this case, the DFA...

By mid-1940s, Jackson Pollock, one of the most influential artists in the twentieth century plastic art, developed a unique painting technique (pouring and dripping) to generate complex non-figurative patterns. It has been argued that methods from fractality theory are suitable for characterizing these complex patterns. In fact, recent studies have...