Resumen En esta investigación se evaluó el efecto de la aplicación de ciclos sucesivos de autoclaveado/enfriamiento y lintnerización (hidrólisis ácida) en almidones nativos de maíz (NCS), manzana (NAS) y malanga (NMS) sobre la formación de almidón resistente (AR) y se estudiaron las propiedades fisicoquímicas y digestibilidad in vitro de los almidones obtenidos. El almidón de malanga autoclaveado (AMS) presentó el mayor contenido de AR (14 %) en comparación con todos los almidones analizados. La hidrólisis enzimática de los almidones nativos y modificados indicó que el tratamiento de autoclave/enfriamiento disminuyó la amilólisis (≈ 24 - 41 %); mientras que con el tratamiento de lintnerización, la reducción fue menor (≈ 3 - 21 %), ambos resultados comparados con sus contrapartes nativas. Los tratamientos por autoclaveado y lintnerización redujeron el contenido de amilosa aparente en ≈ 5 %, produciendo amilosas con menores pesos moleculares (≈ 80 - 87 kDa) para los almidones autoclaveados, y ≈ 92 - 101 kDa para los almidones lintnerizados. La luminosidad disminuyó por el tratamiento en autoclave y no por el proceso de lintnerización. Estos resultados sugieren que el almidón de malanga sometido a ciclos de autoclaveado/enfriamiento podría aprovecharse en aplicaciones de panificación donde se desea aumentar el contenido de AR sin afectar las características sensoriales de color.

Abstract In this research, the effect of the application of successive autoclaving/cooling and lintnerization (acid hydrolysis) cycles in native starches of corn (NCS), apple (NAS), and malanga (NMS) on the formation of resistant starch (RS) was evaluated, and the physicochemical properties and in vitro digestibility of the obtained starches were studied. Autoclaved malanga starch (AMS) presented the highest RS content (14 %) compared to all analyzed starches. Enzymatic hydrolysis of native and modified starches indicated that autoclaving/cooling decreased amylolysis (≈ 24 - 41 %), while with the lintnerization treatment, the reduction was lower (≈ 3 - 21 %), both results compared to their native counterparts. Autoclaving and lintnerization treatments reduced the apparent amylose content by ≈ 5 %, producing amylose with lower molecular weights (≈ 80 - 87 kDa) for autoclaved starches, and ≈ 92 - 101 kDa for lintnerized starches. The luminosity decreased due to the autoclaving treatment and not to the lintnerization process. These results suggest that malanga starch subjected to autoclaving/cooling cycles could be used in baking applications where an increase of the RS content without affecting the sensory color characteristics is desired.

Abstract This study consisted of determining the effect of Bacillus strains inoculated alone or in combination with phytopathogenic fungi on the production of human health-related compounds and volatile organic compounds (VOCs) in tomato fruits. Seedlings were cultivated under greenhouse conditions and inoculated with B. amyloliquefaciens, B. methylotrophicus and B. subtilis alone or in combination with Alternaria solani, Fusarium oxysporum and Phytophthora infestans. Fully ripe fruits were harvested and evaluated for carotenoid, phenol and VOCs contents. Lycopene was the most abundant carotenoid (46.4-167.62 µg/g), followed by β-carotene and lutein. Fruits from plants inoculated with Bacillus had the highest carotenoid content. In contrast, phytopathogens decreased the carotenoid contents, especially the lycopene content. The content of total phenols ranged from 0.42 to 0.90 mg GAE/g. The content of these compounds increased 1.5-fold in fruits from plants inoculated with Bacillus strains, especially those treated with B. methylotrophicus, but the greatest increase (1.9-fold) was observed in plants inoculated with phytopathogens. Both Bacillus strains and pathogens increased the antioxidant capacity, with a 2.8-fold increase compared to the control. Thirty-two VOCs were identified in the tested tomatoes. The Bacillus strains caused an increase in the concentration of VOCs, which could be associated with an increase in fruit quality.

Abstract Beans have been an essential food for mexicans since ancient times. In the past, beans were cooked in clay pots with spices (epazote or bay leaf) added. Today, pressure cookers have replaced clay cookers, and herbs are almost a lost tradition. To understand traditional cooking methods, the present work evaluated the effect of the addition of spices (laurel or epazote) and the cooking method (clay pot or pressure cooker), on antinutritional characteristics and bacterial inhibition. The results show that the traditional techniques, clay pot, spices addition (epazote and bay leaf), and soaking, considerably decrease the concentration of α-oligosaccharides. On the other hand, when cooking in a pressure cooker with previous soaking, the concentration of phytic acid decreases to a greater extent, and reduces the activity of trypsin inhibitor compounds. On the other hand, the use of spices inhibits microbial growth. A combination of traditional Mexican cuisine (soaking and herbs usage) and modern cuisine (pressure cooker) decreases antinutritional compounds and preserves the beans’ microbial quality. These results show the importance of studying and maintaining traditional Mexican cuisine.

Resumen El frijol ha sido un alimento importante para los mexicanos desde tiempos ancestrales. En el pasado, los frijoles eran cocinados en ollas de barro agregando especias (epazote o laurel). En la actualidad, las ollas de presión han remplazado a las de barro y el uso de especias es casi una tradición perdida. Para comprender los métodos tradicionales de cocción, el presente trabajo evaluó el efecto de la adición de especias (laurel o epazote) y del método de cocción (olla de barro o de presión), sobre las características antinutricionales y la inhibición bacteriana. Los resultados muestran que los métodos tradicionales, olla de barro, adición de epazote y laurel, así como el remojo, disminuyen considerablemente la concentración de α-oligosacáridos. Mientras que la cocción en olla de presión con previo remojo, disminuye en mayor proporción la concentración de ácido fítico y reduce la actividad de los compuestos inhibidores de tripsina. Por otro lado, el uso de especias inhibe el crecimiento microbiano. Una combinación de cocina tradicional mexicana (remojo y uso de especias) y cocina moderna (olla a presión) disminuye los compuestos antinutricionales y conserva la calidad microbiana de los frijoles. Estos resultados muestran la importancia de estudiar y preservar la cocina tradicional mexicana.

ABSTRACT Intensive horticultural crop production usually involves challenges from excessive application of fertilizer, mainly nitrogen (N). The effect of N fertilizer on the fruit quality and antioxidant status of two cherry tomato cultivars (Caballero and Victoria) under greenhouse conditions was performed. Nitrogen treatments were applied ranging from conditions comprising deficiency to toxicity (0, 15, 30, 45 and 60 mmol∙L-1). Yield, weight, diameter, fruit quality, phenols, flavonoids, lycopene, ascorbic acid and antioxidant capacity were measured at physiological maturity of the fresh tomato fruits. N treatment with 30 mmol∙L-1 produced the highest yield, fruit weight, firmness and diameter in both cultivars. However, increasing N from 30 to 60 mmol∙L-1 increased the concentration of phenolics, flavonoids, and antioxidant capacity by 50, 125 and 33% in ‘Caballero’ tomatoes and by 60, 95 and 24% in ‘Victoria’ tomatoes, respectively. Lycopene content increased with increasing N doses (45 and 60 mmol∙L-1) for ‘Caballero’ tomatoes, while vitamin C decreased as N concentration increased, suggesting that ascorbic acid acts by protecting against oxidative stress in tomato. The present work shows how N fertilization considerably influences yield and quality of tomatoes, as well as nutritional and healthy values.

Abstract In this investigation, it was determined the impact of different storage conditions on volatile aroma compounds. The “Red Delicious” apple volatile compounds (CV) were analyzed at the time of harvest and after 1, 3, 5, and 7 months’ storage at 1 °C in controlled atmosphere (3% CO2 and 2% O2) (AC), in air cooling (RA), and in AC plus 7 days of stabilization in RA (AC+RA). The storage AC caused a reduction in the biosynthesis of volatile compounds, in apple “Red Delicious”. The maximum CV production was reached after the first month of storage in RA and CA, and there were no statistical differences between the two. However, the results show that the CV profile of the stored apple AC was different from that of the apple stored in RA. The apples in RA mainly produce esters that have been described as “ethereal fruit” and “sweet fruit”, while apples stored in AC show high content of ethyl esters, which have been described “as a brandy”, “odor pungent”, in particular ethyl acetate, is an indicator of possible generation of undesirable flavors during storage in AC.

Resumen En ésta investigación, se determinó el impacto de diferentes condiciones de almacenamiento, en compuesto volátiles del aroma. Los compuesto volátiles (CV) de manzana “Red Delicious” fueron analizados al momento de la cosecha y después de 1, 3, 5, y 7 meses de almacenamiento a 1 °C en atmósfera controlada (3% CO2 CO2 y 2% O2) (AC), en refrigeración en aire (RA), y en AC más 7 días de estabilización en RA (AC+RA). El almacenamiento AC causó una reducción en la biosíntesis de compuestos volátiles, en manzana “Red Delicious”. La producción máxima de CV se alcanzó después del primer mes de almacenamiento en RA y CA, no hubpo diferencias entre ambos. Sin embargo, los resultados muestran que el perfil de CV de la manzana almacenada AC fue diferente a la manzana almacenada en RA. Las manzanas en RA producen ésteres que han sido descritos como “frutales etéreos” y “fruta dulce”, mientras que las almacenadas en AC muestran alto contenido de ésteres de etilo, los cuales han sido descritos “como a brandi”, “olor pungente”, en particular el acetato de etilo, es un indicador de posible generación de sabores no deseados durante almacenamiento en AC.

Three strains of Candida oleophila and their combination were evaluated for nutrient competition as a mode of action for the biocontrol of Penicillium expansum and Botrytis cinerea. C. oleophila treatments reduced germination of conidia of both pathogens when challenged on 1% 'Golden Delicious' apple juice. P. expansum conidia germination was 1x10(7) mL-1 and B. cinerea conidia germination was 5x10(5) mL-1. C. oleophila treatments lowered conidia germination from 2-7x10(4) mL-1 for P. expansum and from 1-4x10(4) for B. cinerea. C. oleophila treatments reduced conidia germination on an average of 99% for P. expansum and 96% for B. cinerea. Sugar consumption for L07 rugose was of 0.026 mg mL-1 against B. cinerea and of 0.056 mg mL¹ against P. expansum. Sugar consumption supports conidia germination reduction. P. expansum consumed 1.69 μg L-1 of proteins, while L07 rugose consumed the greatest amount with 47.95 μg L-1. B. cinerea consumed 8.95 μg L-1 and L06 consumed 36.89 μg L-1, which was statistically equal to that of L07 rugose with 27.96 μg L-1. C. oleophila strains biocontrol B. cinerea and P. expansum, in part, by nutrient competition.

Tres cepas de Candida oleophila y su combinación, se evaluaron para determinar la competencia por nutrientes, como modo de acción para el biocontrol de Penicillium expansum y Botrytis cinerea. Los tratamientos con C. oleophila redujeron la germinación de conidios de ambos patógenos, al ser enfrentadas en jugo de manzana 'Golden Delicious' al 1%. Conidios de P. expansum germinaron a 1x10(7) mL-1 y conidios de B. cinerea germinaron a 5x10(5) mL-1. Los tratamientos con C. oleophila disminuyeron la germinación de conidios de 2-7x10(4) mL-1 para P. expansum y de 1-4x10(4) para B. cinerea. Los tratamientos con C. oleophila redujeron la germinación de conidios con promedios de 99% para P. expansum y de 96% para B. cinerea. Los azúcares consumidos por L07 rugosa fueron de 0.026 mg mL-1 contra B. cinerea y de 0.056 mg mL-1 contra P. expansum. El consumo de azúcares corrobora la reducción de germinación de conidios. P. expansum consumió 1.69 μg L-1 de proteínas, mientras que L07 rugosa consumió la mayor cantidad con 47.95 μg L-1. B. cinerea consumió 8.95 μg L-1 y L06 36.89 μg L-1, que fue estadísticamente igual al de L07 rugosa con 27.96 μg L-1. Las cepas de C. oleophila, ejercieron un biocontrol de B. cinerea y P. expansum, en parte, por competencia de nutrientes.