Papers by Gonzalo Velazquez
Food Hydrocolloids, 2021
Lutein (LUT) is a natural colorant and antioxidant that is found in vegetable sources such as mar... more Lutein (LUT) is a natural colorant and antioxidant that is found in vegetable sources such as marigold flowers and green leaves. Due to its instability under some environmental conditions, carrier materials are desirable to protect and incorporate this natural colorant into food products. Whey protein isolate (WPI) and pectin have been studied as a well-known system to entrap active compounds. The first part of this study evaluated the effect of total concentration (0.2 and 0.4%) and biopolymer ratio (3:0, 3:1, 3:2, 3:3, 2:3, 1:3 and 0:3) of the WPI:low methoxyl pectin (LMP) nanocomplexes (NCs). Subsequently, the influence of the type of pectin, including LMP and high methoxyl pectin (HMP) for the optimization of NCs was studied at different concentrations of pectin at ratios of 4:0, 4:1, 4:2, 4:3, 4:4 and 0:4 (WPI:LMP/HMP). Moreover, the loading of LUT into the NCs was investigated to assess its effect on the particle and stabilization properties. All NCs showed a stable particle size at pH 5.0 and precipited at lower pH values. NCs loaded with LUT at a ratio of 4:1 (WPI:LMP) and pH 5.0 showed the most stable system with a particle size of 204 ± 5 nm after 30 days. The binding properties showed a maximum binding constant (Kq) of 5.35 × 10 13 M − 1 S − 1 at pH 7.0, which proves that this is the optimal pH condition to bind the LUT to the WPI.
El estudio cinético de la gelatinización del almidón es una herramienta poco explotada tecnológic... more El estudio cinético de la gelatinización del almidón es una herramienta poco explotada tecnológicamente en la industria alimentaria debido al bajo grado de confianza que proporcionan los métodos tradicionales que determinan la energía de activación como uno de los parámetros cinéticos importantes en los procesos. La importancia de este parámetro es que se utiliza para determinar el curso de esta reacción en función de la temperatura además de brindar información respecto al consumo energético. Con la finalidad definir una metodología para el estudio cinético y el cálculo de la energía de activación que sea aplicable a procesos de ingeniería, se propone un enfoque que considere la naturaleza química del almidón estudiando su mecanismo de reacción a nivel molecular y macroscópico, variando la temperatura de reacción, contenido de humedad y tiempo de reacción. Los resultados establecen las bases para establecer un método de aplicación robusta que permita calcular la energía de activaci...
Beef tenderness is an important trait in consumer satisfaction and has been considered as the mai... more Beef tenderness is an important trait in consumer satisfaction and has been considered as the main trait for palatability, for which reason it is important to evaluate its variability in dierent cattle breeds. An experiment was designed to evaluate the Warner Bratzler Shear Force (WBSF) of Red Brangus cattle rib eye steaks and consumer acceptance. The tenderness of beef rib eye steaks was evaluated by the WBSF. A consumer preference evaluation test was carried out to quantitatively estimate tenderness, juiciness, avor, doneness and general acceptance of the evaluated steaks. Mean WBSF was 5.03 kg ± 0.93 kg, theoretically indicating a tough beef. The distribution of the samples showed 21 % and 11 % of moderately tender and tender beef cuts, respectively. Cattle condition (bulls and steers) was not signicant for the WBSF (p > 0.5). All the traits evaluated in the hedonic evaluation had approximately 6 points of a total of 8 (8 was best). Tenderness, juiciness and avor presented a high and signicant correlation (p < 0.5). None of the subjective traits was correlated with total acceptance. Under theoretical criteria, tender Red Brangus beef cuts are infrequent; however the beef has a good acceptance. Characterization studies may be necessary and useful to create marketing niches specic for this and other cattle breeds.
Journal of Food Engineering, 2003
This paper describes the interaction of water with solid polymers. A portion of the water adsorbe... more This paper describes the interaction of water with solid polymers. A portion of the water adsorbed in hydrophilic materials is strongly bound to individual sites (bound water), while an additional amount is bound less firmly to the polymeric chain (free water). Both, free and bound water, have been the subject of many studies that have uncovered, in some cases, qualitative evidence of the presence of bound water. In this paper we report a method to quantify the fraction of water adsorbed in the first layer in contact with an hydrophilic material. The measurement was carried out on infrared spectroscopy data of methylcellulose films exposed to several humid environments. The quantification was based on the determination of the change in the natural vibration frequency brought about by the interaction of water molecules with the solid.
Food Research International, 2011
The aim of this work was to assess the influence of high hydrostatic pressure on antioxidant capa... more The aim of this work was to assess the influence of high hydrostatic pressure on antioxidant capacity, mineral and starch bioaccessibility of a non conventional food: "algarrobo" Prosopis chilensis seed. The algarrobo seed was pressurized at 500 MPa during 2, 4, 8 and 10 min. The antioxidant activity, mineral and starch content and bioaccessibility of algarrobo samples were significantly affected by the processing and digestion conditions. All treatments increased the bioaccessibility of the antioxidant activity (IC 50), minerals (dialysis and solubility) and starch (resistant and digestible) compared to the untreated sample. Bioaccessibility of calcium, iron and zinc in the treated sample for 500 MPA at 10 min, expressed as percentage solubility, was several-fold higher (three, three and five times, respectively) than in the untreated sample. Similar effect was observed in IC 50 value, algarrobo seed untreated sample exhibited the lowest antioxidant activity (0.11 ± 0.005 mg/ml), and followed by all treated samples (500 MPa at 2, 4, 8 and 10 min) which showed the strongest activity. In summary, the antioxidant capacity, mineral and starch content of the seed may be underestimated in the literature because the extraction solvents usually used do not allow a complete release of antioxidant compounds and, additionally, non-extractable polyphenols with a high antioxidant capacity are ignored. This correspondingly applies to the starch and mineral content. On the other hand, the analysis of in vitro digestive enzymatic extracts suggests that the antioxidant activity, minerals and starch of seed in the human gut may be higher than what might be expected from literature data based on measurements of aqueous-organic extracts.
Cereal Chemistry Journal, 2002
Characterization of functional properties of proteins from Ganxet beans (Phaseolus vulgaris L. va... more Characterization of functional properties of proteins from Ganxet beans (Phaseolus vulgaris L. var. Ganxet) isolated using an ultrasoundassisted methodology
Journal of Food Processing and Preservation, 2020
Films were obtained by casting a solution of succinated hydrolyzed corn starch homogenized using ... more Films were obtained by casting a solution of succinated hydrolyzed corn starch homogenized using an ultra turrax (UF). Glycerol was added as a plasticizer. Films obtained after homogenizing with a magnetic bar by the conventional method (CF) were used as a control. The physicochemical, thermomechanical, and hygroscopic properties were evaluated. UF resulted in a gray color change when heating at 65 °C during the mechanical homogenization process, while the CF remained white. The thermomechanical properties depended on the conditioning at different relative humidity values. Mechanical properties of the UF showed the lowest values of tensile strength (TS) and percentage of elongation (%E). The mechanical homogenization at high revolutions allowed changing the physicochemical and mechanical properties of the films obtained from dual modified starch, probably due to the dispersion, rearrangement, orientation and interaction of the macromolecular components of the modified polymers. These films could have a wide array of applications. Practical Applications These films have a wide array of applications in foods with low moisture content. Also providing new information for future research using doubly modified starch by homogenizing it at high revolutions, causing new molecular interactions and eventually physicochemical properties new.
Journal of Food Science and Technology, 2020
The aim of this study was to evaluate the effect of acid hydrolysis and succination upon single a... more The aim of this study was to evaluate the effect of acid hydrolysis and succination upon single and a combination of both of them as a dual modification on the morphological, structural, thermal, and pasting profile of the achira starch in order to expand its potential food applications. The surface of achira starch granules was eroded with acid hydrolysis, while the succination resulted in the formation of pores or cavities, having a slight impact on the crystallinity and the gelatinization enthalpy. Succinated starch presented the lowest transition temperatures (To = 60.29°C, Tp = 65.03°C and Te = 69.86°C) compared to other starches in this study. The succination increased the final viscosity (3808 cp) when compared with the native starch (3114 cp), while acid hydrolysis resulted in a decreased value (735 cp). These are desirable properties for its possible use as an additive in bakery industry processes.
International Journal of Food Properties, 2017
The structural properties of blends of waxy corn starch and potato starch at different proportion... more The structural properties of blends of waxy corn starch and potato starch at different proportions were evaluated at 20% solids content. The results from differential scanning calorimetry, wide-angle X-ray scattering, and small-angle X-ray scattering of the starch blends indicated that each starch gelatinized completely and independently. The setback viscosity values were higher in the blends compared with native starches, which suggested that the granular interactions had an important effect. The presence of waxy corn starch granules could have reinforced the network formed by amylose leached from potato starch granules. The intrinsic characteristics of waxy corn starch and potato starch determined the type of granular and molecular interactions that could be carried out during the processes of gelatinization and gel formation in starch blends.
Food and Bioprocess Technology
Tamaulipas ocupa el tercer lugar nacional en la captura de camarón, con un volumen promedio cerca... more Tamaulipas ocupa el tercer lugar nacional en la captura de camarón, con un volumen promedio cercano a las 15,000 toneladas anuales. La captura de este crustáceo está acompañada de una importante pesca incidental denominada Fauna de Acompañamiento del Camarón (FAc), que representa en promedio 3 veces el volumen del camarón y que se compone en un 60% de pescado. La mayor parte de estos peces mueren durante la captura y selección del camarón y son descartados y regresados al mar, lo que significa que anualmente se desaprovechan aproximadamente 27,000 toneladas de pescado que, por su valor nutritivo, puede utilizarse como materia prima para la elaboración de productos alimenticios. La ausencia de propuestas tecnológicas para el aprovechamiento de especies de bajo valor comercial ha frenado el desarrollo del sector pesquero, ya que el esfuerzo pesquero se ha enfocado tradicionalmente en especies de alto valor comercial en el mercado sin preocuparse por el aporte nutricional que represent...
Ciencia y Tecnologia Alimentaria, 2005
Ciencia y Tecnologia Alimentaria, 2007
Food and Bioprocess Technology, 2011
Meat Science, 2009
Beef proteins are considered non-setting proteins and usually gels obtained by adding of microbia... more Beef proteins are considered non-setting proteins and usually gels obtained by adding of microbial transglutaminase are obtained by cooking directly the solubilized paste. The aim of this work was to determine the effect of pre-heating treatments on the mechanical properties of restructured beef gels treated with microbial transglutaminase (MTG). The effect of cooling (cold binding) the solubilized pastes after the pre-heating treatments was also studied. The restructured beef gels were obtained by adding 0.3% MTG or 0% MTG (control). Three pre-heating temperatures (40, 50 or 60°C) for 30 or 60min were studied, followed by heating at 90°C for 15min. Control samples without pre-heating were also prepared. Cold binding was studied by holding pre-heated gels at 4°C for 12h before heating at 90°C for 15min. Changes in mechanical properties (texture profile analysis and puncture test), color attributes, expressible water and cooking loss were determined. Results indicated that the better mechanical properties can be obtained by pre-heating beef pastes at 50°C for 30min with minimal effect on color, expressible water and cooking loss when 0.3% of MTG is added. It was concluded that there were no practical advantages by pre-heating the gels for 60min. Cold binding did not improve the mechanical properties of beef gels.
Journal of the Science of Food and Agriculture, 2004
Commercial restructured fish are produced as heat-induced gels in the form of fish fingers and ba... more Commercial restructured fish are produced as heat-induced gels in the form of fish fingers and bars of kamaboko. Restructured fish products have been developed using vacuum tumbling and massaging to solubilize and extract myofibrillar proteins with salt to obtain sticky ...
Journal of the American Dietetic Association, 2007
The purpose of this study was to assess whether nutrients offered to border Mexican-American pres... more The purpose of this study was to assess whether nutrients offered to border Mexican-American preschool children met the Recommended Dietary Allowances. Nutrient contents of two dietary patterns were examined in this study, one composed exclusively of home foods and one containing a combination of both home and school foods. The sample consisted of 198 Mexican-American preschoolers living on the Texas-Mexico border, who were recruited using a convenience sampling technique. A self-administered, precoded 24-hour recall questionnaire was used. Nutrient values of home foods were collected during a weekend day, and nutrient values containing a combination of both home and school foods were collected during a weekday. Fisher's exact test or 2 test and t test were used for analyses. Mean nutrient contents of foods provided to the border Mexican-American children exceeded recommendations for total energy (PϽ0.001), total fat (PϽ0.001), saturated fat (PϽ0.001), carbohydrates (PϽ0.001), protein (PϽ0.001), sodium (PϽ0.001), and niacin (PϽ0.001). Foods offered were also significantly insufficient in fiber (PϽ0.001), vitamin A (PϽ0.001), and potassium (PϽ0.001). Nutrition interventions targeting low-income border Mexican-American families should emphasize the need and importance of providing children with diets that meet the Recommended Dietary Allowances.
Journal of Food Engineering, 2011
Monte Carlo procedures can be used to evaluate the uncertainty of food safety and quality estimat... more Monte Carlo procedures can be used to evaluate the uncertainty of food safety and quality estimations associated with the variability in the parameters for the calculation model used. Procedures for possible inclusion in an undergraduate process engineering course covering the assessment of uncertainty in thermal processing decisions were developed using spreadsheets and operations found in the Excel™ Analysis ToolPack. Published thermal decimal reduction time (D T , T = 110°C) and initial spore load (N o , spores/ container) level for Clostridium botulinum Type B in mushroom were used to estimate a thermal processing time (F T). For a survival probability (N) of 1 spore in 10 9 containers and using mean values for the parameters D T and log N o yielded F 110°C = 5.96 min. Unique combinations of D Ã T and N Ã o datasets generated assuming normal and lognormal distributions, respectively, were used to obtain the distribution for the spore survival probability and the associated percentage of under processing. Next, the coefficient of variation (CV) for the percentage of under processing based on 2-500 generated datasets was calculated and used as a criterion to determine that 100 was an acceptable minimum number of datasets to estimate a recommended thermal process (F 110°C = 9.6 min) considering the reported variability of the parameters D T and N o. This thermal process would yield a 10 À9 failure rate with a 95% confidence based on the frequency distribution for spore survival probability. The same procedures were used to assess the impact of lowering the standard deviation of both N o and D 110°C by 10%, 50%, and 90% yielding 8.6, 7.8, and 6.4 min, respectively, as a recommended thermal process at 110°C with 95% confidence.
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Papers by Gonzalo Velazquez