Academic literature on the topic 'Baby spinach'

Master of Science<br>Food Science<br>Kelly J.K. Getty<br>James L. Marsden<br>Escherichia coli O157:H7 outbreaks have been linked to leafy green produce and bagged spinach. The objective of this study was to evaluate a Photohydroionization (PHI) panel (novel advanced oxidation technology) and varying concentrations of lactic acid washes for controlling E. coli O157:H7 on baby spinach. Leaves were dip inoculated with a five-strain cocktail of E. coli O157:H7 inoculum having a concentration between 5-6 log CFU/ml. Leaves were submerged in inoculum for 30 s and dried for 1 h. Non-inoculated and inoculated leaves were washed for 30 s in food grade lactic acid diluted to concentrations of 0.5, 1.0, or 2.0% and allowed to dry for 10 min. For PHI treatment, leaves were placed under the PHI panel and treated for 1, 2, or 5 min on both sides for total treatment times of 2, 4 or 10 min. Following treatments, leaves were either sealed in low-density polyethylene bags or enumerated. Samples were enumerated at 0, 3, 7, 10, and 14 days following inoculation. Ten gram samples were diluted with sterile peptone and stomached for one min, and then 0.1 ml was plated onto sorbitol MacConkey agar with cefixime and tellurite plates that were incubated at 37°C for 24 h. For lactic acid treatments, E. coli O157:H7 populations were different (P < 0.05) compared to the control. There was no difference (P > 0.05) due to sampling time so sampling times where pooled together for each lactic acid concentration of 0.5, 1.0, and 2.0% and resulted in 2.01, 2.78, and 3.67 log CFU/g reductions, respectively. Leaves treated with 1.0% and 2.0% lactic acid had color degradation and were organoleptically unacceptable by day 14. When leaves were treated with PHI for 1, 2, or 5 min per side, E. coli O157:H7 populations were reduced 1.6, 1.49, or 1.95 log CFU/g, respectively. Leaves treated with PHI were not different from one another, but were different (P < 0.05) from the positive control. No color change occurred in leaves treated with PHI. The PHI panel and lactic acid washes of 0.5% or higher are effective in reducing E. coli O157:H7 in baby spinach.

Memoria para optar al título profesional de: Ingeniera Agrónoma<br>La industria de las hortalizas mínimamente procesadas en fresco (MPF) utiliza comúnmente lavados con hipoclorito de sodio (NaClO) para disminuir la carga microbiana del producto; sin embargo, éste puede generar subproductos perjudiciales para la salud, por lo que surge la necesidad de encontrar tecnologías nuevas y sustentables como la radiación UV-C. El objetivo de este estudio fue evaluar el efecto de la radiación UV-C sobre las características microbiológicas, funcionales y sensoriales en hojas de espinacas “baby” envasadas en atmósfera modificada. Se realizaron 2 ensayos, en el primer ensayo las espinacas fueron inoculadas con Escherichia coli y se trataron con dosis de radiación UV-C de 0, 5, 10, 15 y 20 kJ m-2 y almacenadas por 10 días a 5 °C en atmósfera con alto oxígeno (80%). En el ensayo 2 se utilizaron las 2 mejores dosis de radiación UV-C obtenidas del ensayo 1 además de dos tratamientos adicionales, un testigo sin solución sanitizante y otro con solución sanitizante de hipoclorito de sodio (100 mg L-1). Se evaluó la tasa respiratoria, composición gaseosa al interior de los envases, análisis microbiológico, color, calidad sensorial, concentración de fenoles totales y capacidad antioxidante. Las dosis de 10 y 15 kJ m-2 fueron efectivas en disminuir los recuentos de Escherichia coli sin afectar la apariencia y el color durante todo el periodo de conservación. El uso de radiación UV-C en dosis de 10 y 15 kJ m-2 fueron efectivas en conservar el nivel de compuestos fenólicos y capacidad antioxidante en concentraciones superiores que aquellas muestras no tratadas. Los tratamientos con UV-C y NaClO fueron efectivos en la reducción de microorganismos (aerobios mesófilos, enterobacterias, psicrótrofos y hongos y levaduras). Se observó que la radiación no tuvo un efecto significativo en la intensidad de color, sin embargo, dosis de 10 y 15 kJ m-2 afectaron la apariencia de las hojas de espinacas tipo “baby”.<br>The industry of the minimally processed fresh vegetables (MPF) usually washes with sodium hypochlorite (NaClO) in order to reduce the microbial load. However, it generates harmful to health by-products. Therefore, it is necessary to study new emerging and sustainable technologies such as the UV-C radiation. The aim of this study was to evaluate the effect of UV-C radiation on the microbiological, functional and sensory qualities of spinach “baby” leaves packed in modified atmosphere. Two essays were performed, on the first essay the spinach were inoculated with Escherichia coli and treated using 0, 5, 10, 15, 20 kJ m-2 UV-C radiation doses, stored for 10 days and 5 °C in high oxygen atmosphere (80%). The second essay used the 2 best doses of UV-C radiation selected from essay 1, with two additional treatments, one of them without sanitizing solution, and the other with sanitizing solution of sodium hypochlorite (100 mg L-1). The respiration rate, gas composition into the package, microbiological analysis, color, sensory qualities, total phenol concentration and antioxidant capacity were determined. The 10 and 15 kJ m-2 doses were effective in reducing Escherichia coli counts without affecting the appearance and color over the whole conservation period. The UV-C radiation used at 10 and 15 kJ m-2 doses were effective in kept the level of phenols and antioxidant capacity in superior concentrations than the untreated sample. Treatments with UV-C and NaClO were effective in reducing microorganisms (mesophilic aerobes, enterobacteria, psychrotrophic and mold and yeasts). It was observed that UV-C radiation did not have significant effect on the intensity of color; nevertheless, 10 and 15 kJ m-2 doses affected spinach “baby” leaves appearance.

Memoria de Título para optar al título profesional de Ingeniero Agrónomo<br>La espinaca es una hortaliza de hoja, la cual en el último tiempo se está produciendo de forma “baby leaf”, es decir, hojas de un largo de 8 a 12 cm. Estas hojas “baby” se utilizan para la industria de los productos mínimamente procesados. Dentro de las características que hace atractiva ésta hortaliza se encuentra su sabor agradable y su alto valor nutritivo. A pesar de sus cualidades, la espinaca acumula grandes cantidades de nitratos en sus hojas, lo que puede producir problemas a la salud como; metahemoglobinemia, cáncer gástrico o esofágico. Por ésta razón el comité científico de la Unión Europea, estableció un consumo diario de nitratos, con un de máximo de 3,7 mg de nitratos por kilo de peso corporal. Además realizó un reglamento (CE N°194/97) para la concentración máxima de nitratos en hojas de espinacas fresca, la cual es de 3.500 mg kg-1 de materia fresca.

Baby spinach is a relatively new crop in South Africa with both commercial significance and reputed health benefits. It is known to assist in combating degenerative conditions associated with ageing, such as heart disease, cardiovascular disease, Alzheimer’s disease, cataracts and several forms of cancer. Three parallel NPK trials were conducted to investigate the effects of nitrogen (N), phosphorus (P) and potassium (K) on the growth and development of baby spinach. N and P treatments were arranged as (0, 45, 75, 105, 120 kg.ha -1 N and P), and K treatments were arranged as (0, 63, 85, 127, 148 kg.ha -1) in a randomised complete block designed with four replicates. Results showed that yield, dry matter, chlorophyll content and Leaf Area Index (LAI) were significantly increased by increasing the N application, while K had a significant effect on the LAI but not on yield, dry matter, chlorophyll content or stomatal conductance. Nitrogen treatments quadrupled fresh yield, dry matter and chlorophyll content, reaching maximum impact at 75 kg.ha-1 N. Phosphorus application showed significantly increased yields, dry matter and chlorophyll content, reaching maximum impact at 75 kg.ha-1 P. Therefore, to achieve optimum growth with N and P, 75 kg.ha-1 is recommended. The optimum rates of N, P and K were then used to formulate a NPK combined trial which was arranged as 0, 30:30:40, 45:45:60, 60:60:70, 75:75:90 kg.ha-1 in a randomised complete block design with three replicates. The results showed that maximum impact on yield, chlorophyll content, fresh and dry matter was achieved when combined NPK was applied at 45:45:60<br>Agriculture and  Animal Health<br>M. Sc. (Agriculture)

Baby spinach (Spinacia oleracea L.) is considered to be the one of the extremely nutritious vegetables, rich both in phytochemicals and core nutrients. Nowadays, phytochemicals in plants are raising interest in consumers for their roles in the maintenance of human health. Variation in content of bioactive compounds and core nutrients is the main concern in vegetable production. Factors such as cultural practices specially fertilization, may affect the nutritional and medicinal properties of the plants Therefore, three parallel trials for NPK to investigate the response of baby spinach leaves to nitrogen (N), phosphorus (P) and potassium (K) on chemical composition were conducted, with treatments arranged as follows: 0, 45, 75, 105, 120 kg·ha-1 N and P and 0, 60, 85, 106, 127, 148 kg·ha-1 K in a randomized complete block design (RCBD) with four replications. The results demonstrated that, application of nitrogenous, phosphorus, potassium fertilizers significantly increased the total phenolic content, total antioxidant activity, total flavonoid content and vitamin C while magnesium, iron, zinc and selenium did not exhibit significant response to all treatments applied. The increase in concentrations on total phenolic content, total antioxidant activity, total flavonoid content and vitamin C was observed, reaching maximum at 45 kg·ha-1 N, 75 kg·ha-1 P and 85 kg·ha-1 K. The optimum rates of 45 kg·ha-1 N, 75 kg·ha-1 P, 85 kg·ha−1 K were then used to formulate the NPK treatment combinations as follows: 0, 30: 30: 40, 45:45:60, 60:60:70, 75:75:90 kg·ha-1, arranged in a RCBD with three replicates. The results showed that total phenolic content, total antioxidant activity , total flavonoid content and vitamin C reached maximum in baby spinach leaves at N45:P45:K60 kg·ha-1.<br>Agriculture and  Animal Health<br>M. Sc. (Agriculture)

Baby spinach (Spinacia oleracea L.) is considered to be the one of the extremely nutritious vegetables, rich both in phytochemicals and core nutrients. Nowadays, phytochemicals in plants are raising interest in consumers for their roles in the maintenance of human health. Variation in content of bioactive compounds and core nutrients is the main concern in vegetable production. Factors such as cultural practices specially fertilization, may affect the nutritional and medicinal properties of the plants Therefore, three parallel trials for NPK to investigate the response of baby spinach leaves to nitrogen (N), phosphorus (P) and potassium (K) on chemical composition were conducted, with treatments arranged as follows: 0, 45, 75, 105, 120 kg·ha-1 N and P and 0, 60, 85, 106, 127, 148 kg·ha-1 K in a randomized complete block design (RCBD) with four replications. The results demonstrated that, application of nitrogenous, phosphorus, potassium fertilizers significantly increased the total phenolic content, total antioxidant activity, total flavonoid content and vitamin C while magnesium, iron, zinc and selenium did not exhibit significant response to all treatments applied. The increase in concentrations on total phenolic content, total antioxidant activity, total flavonoid content and vitamin C was observed, reaching maximum at 45 kg·ha-1 N, 75 kg·ha-1 P and 85 kg·ha-1 K. The optimum rates of 45 kg·ha-1 N, 75 kg·ha-1 P, 85 kg·ha−1 K were then used to formulate the NPK treatment combinations as follows: 0, 30: 30: 40, 45:45:60, 60:60:70, 75:75:90 kg·ha-1, arranged in a RCBD with three replicates. The results showed that total phenolic content, total antioxidant activity , total flavonoid content and vitamin C reached maximum in baby spinach leaves at N45:P45:K60 kg·ha-1<br>Agriculture,  Animal Health & Human Ecology<br>M.Sc. (Agriculture)