Proteína inhibidora de la poligalacturonasa en manzana mexicana (Malus domestica Borkh)

La poligalacturonasa (PG) es una de las enzimas responsables de la pérdida de firmeza de la manzana. La determinación de la presencia y actividad de la proteína inhibidora de la poligalacturonasa (PIPG) es información de alta relevancia como base para otros trabajos, como los relacionados a la incidencia y severidad de enfermedades fungosas en poscosecha, como información básica para su control. Con esta finalidad, se determinó la presencia y actividad de la PIPG en frutos de manzana por medio de un análisis de difusión radial, determinando también índices de madurez y contenido de proteínas totales. Los 20 frutos de cada cultivar, provenientes de una huerta comercial en Cuauhtémoc, Chihuahua, se cosecharon por fecha, pizcando al  azar, bajo un diseño experimental completamente al azar.  ABSTRACT Polygalacturonase (PG) is one of the enzymes responsible for apple fruit firmness loss, therefore, the determination of the presence and activity of polygalacturonase inhibitor protein  (PGIP) is highly relevant information for those studies related to incidence and severity of postharvest fungal diseases and their control. PGIP presence and activity were determined on apple fruit by a radial diffusion analysis, maturity indexes and  total protein content were also quantified. Twenty apple fruits   of each cultivar were sampled from a commercial orchard in  Cuauhtemoc, Chihuahua, Mexico. Apple fruits were sampled  by date, picking them at random, under a completely randomized experimental design

Biofortificación con micronutrientes en cultivos agrícolas y su impacto en la nutrición y salud humana

Los seres humanos requieren de más de 22 elementos minerales para su desarrollo óptimo, los cuales pueden ser suplementados con una dieta balanceada. Las deficiencias de micronutrientes se han incrementado en las últimas décadas debido a la depreciación general de la calidad de la dieta de las poblaciones vulnerables, tanto en los países desarrollados y en desarrollo. Se estima que, de la población que padece malnutrición de micronutrientes, entre un 60 a 80% presenta deficiencia de hierro (Fe), más de 30% tiene deficiencia en zinc (Zn), 30% es deficiente en yodo (I) y alrededor del 15% es deficiente en selenio (Se). Las deficiencias de hierro (Fe) y zinc (Zn) son un problema crítico de salud pública en todo el mundo, con el impacto negativo en la salud, la esperanza de vida y la productividad. El proceso de biofortificación es un enfoque agrícola que puede mejorar la nutrición humana a nivel mundial. La biofortificación agronómica se considera a corto plazo y como una estrategia complementaria. Los análisis económicos sugieren que la biofortificación genética es la estrategia más eficaz para aumentar la dieta la ingesta de Fe y Zn de las poblaciones vulnerables. El enriquecimiento de micronutrientes esenciales de los granos de cereales mediante el mejoramiento genético es un área de alta prioridad de la investigación, y una estrategia eficaz entre otros enfoques, por ejemplo, el enriquecimiento, la suplementación y la diversificación de los alimentos. El presente manuscrito pretende dar a conocer la problemática de la deficiencia de micronutrientes a nivel mundial y cómo afecta a la nutrición y salud humana. Así mismo, se plantean algunas soluciones a este problema, como es el caso de la estrategia de biofortificación de micronutrientes en cultivos agrícolas. Abstract Humans require more than 22 mineral elements for optimum growth, which can be supplemented with a balanced diet. Micronutrient deficiencies have increased over recent decades due to the general depreciation of the quality of the diet of vulnerable populations, both in developed and developing countries. It is estimated that the population suffering from micronutrient malnutrition, between 60-80% of the population are deficient in iron (Fe), over 30% are deficient in zinc (Zn), 30% are deficient in iodine (I) and about 15% are deficient in selenium. Deficiencies of iron (Fe) and zinc (Zn) are a critical public health problem worldwide, with negative impact on health, lifespan and productivity. Biofortification process is an agricultural approach that can improve human nutrition worldwide. Agronomic biofortification is considered a short-term and as a complementary strategy, but economic analyses suggest that genetic biofortification is the most effective strategy for increasing dietary intake of Fe and Zn of vulnerable populations. Enrichment of cereal grains by breeding is a high-priority area of research, and an effective strategy among other approaches, such as fortification, supplementation and food diversification. This manuscript seeks to highlight the problem of micronutrient deficiency in the world and how it affects the human health and nutrition. Also, some solutions to this problem arise, as in the case of the strategy of micronutrient biofortification in agricultural crops. Keywords: biofortification, micronutrient deficiencies, nutrition, human health

Effects of native and modified starches on the physicochemical and textural properties of rainbow trout (Oncorhynchus mykiss) fish burgers

Native and modified starches of chayotextle and potato were mixed with rainbow trout meat, and the resistant starch content, pH, water-holding capacity (WHC), malonaldehyde content, sensorial properties and texture profile of the rainbow trout fish burger (RTB) were investigated during 21 days of storage at 0°C. The addition of acid-modified starches (AMS) to RTB resulted in a high content of resistant starch (RS). The RTB with added native and modified starches showed a better stability of pH, WHC and texture profile values during the 21 days of storage. The lipid oxidation values of the RTB control showed higher values than the RTB with added native and modified starches. In the sensory evaluation test, the RTB supplemented with AMS have the highest score regarding acceptability. The result confirmed the potential of modified starches as a prebiotic food ingredient, since they improve the physicochemical and sensorial properties of RTB

Caracterización fisicoquímica, reológica y funcional de harina de avena (Avena sativa L. cv Bachíniva) cultivada en la región de Cuauhtémoc, Chihuahua

En el presente trabajo se obtuvo una harina a partir del cereal de avena (Avena sativa L.) de la variedad Bachíniva, el cual representa una de las principales fuentes de ingresos para la región de Cuauhtémoc, Chihuahua. La harina se caracterizó fisicoquímica- mente mediante la evaluación de color, poder de hinchamiento/ solubilidad y análisis químico proximal. Se determinaron sus propiedades térmicas, moleculares, de formación de pastas (perfil amilográfico) y reológicas. Los resultados mostraron que la harina de esta avena es alta en proteínas y lípidos (6 y 8%, respectivamente) lo cual es adecuado para regímenes alimenticios en donde se requieren una alta cantidad de estos nutrientes. La temperatura y la entalpia de gelatinización (62 °C y 8 J/g) fueron comparables con los valores reportados en otras variedades de avenas. El perfil amilográfico, la viscosidad y las propiedades funcionales indicaron una posible interacción entre los compuestos no amiláceos y el almidón, lo cual se corroboró con el análisis molecular. Los resultados indicaron que este harina, por sus características fisicoquímicas, reológicas y funcionales puede ser empleada en la industria alimentaria para la producción de pudines, formulaciones infantiles y panes para enfermos celiacos. Abstract In this work It was obtained a flour made out of cereal oat (Avena sativa L.) cv Bachiniva, which represents one of major source of income for the region of Cuauhtemoc, Chihuahua. The flour was physicochemically characterized by evaluating color, swelling power/solubility and proximate chemical analysis. Thermal, molecular, formation of pastes (amilographic profile) and rheological properties were determined. The results showed that this oat meal is high in protein and lipid (6 and 8%, respectively) which is suitable for feeding regimes where high amounts of these nutrients are required. The temperature and enthalpy of gelatinization (62 °C and 8 J/g) were comparable to those reported in other varieties of oats. The amylographic profile, viscosity and functional properties indicated a possible interaction between non-starch compounds and starch which was corroborated by molecular analysis. The results indicated that this flour for their physicochemical, rheological and functional properties can be used in the food industry for the production of puddings, infant formula and breads for celiac patients. Keywords: flour, swelling power, solubility, Fourier transform infrared spectroscopy, amylographic profile, thermal properties

Physicochemical, Structural, Thermal and Rheological Properties of Flour and Starch Isolated from Avocado Seeds of Landrace and Hass Cultivars

The objective of this study was to obtain and characterize flours and starches from the avocado seeds of Hass and landrace cultivars. The morphological, physical-chemical, structural, thermal and rheological characteristics were evaluated. The flour yield of the Hass and landrace cultivars was 41.56 to 46.86% (w/w), while for starch, it was 35.47 to 39.57% (w/w) (cv. Hass and landrace, respectively). Scanning electron microscopy (SEM) revealed the presence of oval starch granules and other particles in flour, in contrast to flours, starches showed lower ash, proteins and lipids content. However, the amylose content was higher in starches (42.25–48.2%). Flours showed a higher gelatinization temperature (Tp = 73.17–73.62 °C), and their starches presented greater gelatinization enthalpy (∆Hgel = 11.82–13.43 J/g). All samples showed a B-type diffraction pattern, and the crystallinity was higher in the flours. The rheological analysis (flow curves and viscoelastic tests) evidenced a pseudoplastic (n = 0.28–0.36) behavior in all samples analyzed, but the consistency index (k) was higher in starches. In general, the flours and starches from avocado seeds presented interesting proximal, thermal and functional properties for possible application in food systems, and these findings could contribute to the revaluation of this by-product

Physicochemical, thermal and rheological properties of three native corn starches

Abstract Native starch was isolated from two corn landraces (blue and white) and a hybrid variety and then characterized for its physicochemical, thermal and rheological properties. The hybrid variety showed the highest starch yield, with its starch showing the highest fat, moisture and protein content but the lowest onset temperature of gelatinization. The hybrid corn starch also showed the highest G’ and G” values. The tested starches showed similar Tp, Tc, and ΔH values. The amylose contents ranged from 21.5 to 22.4%, with starch from blue corn showing the highest amylose content. All starches were white, with L values ranging from 93.6 to 99.5. The light absorbance of the starch gels increased with storage time. The obtained results demonstrated that the physicochemical, thermal and rheological properties of corn starch are highly dependent on the corn type