RESUMEN
To reduce membrane fouling during the processing of highly pulpy fruit juices into clarified beverages, a crossflow Sono-Microfiltration (SMF) system was employed, strategically equipped with an ultrasonic probe for the direct application of low-frequency ultrasound (LFUS) to the juice just before the entrance to the ceramic membrane. Operating conditions were standardized, and the application of LFUS pulses in both corrective and preventive modes was investigated. The effect of SMF on the physicochemical properties and the total soluble phenol (TSP) content of the clarified juice was also evaluated. The distance of ultrasonic energy irradiation guided the selection of the LFUS probe. Amplitude conditions and ultrasonic pulses were more effective in the preventive mode and did not cause membrane damage, reducing the operation time of jackfruit juice by up to 50% and increasing permeability by up to 81%. The SMF did not alter the physicochemical parameters of the clarified juice, and the measured LFUS energy ranges did not affect the TSP concentration during the process. This study is the first to apply LFUS directly to the feed stream in a pilot-scale crossflow microfiltration system to reduce the fouling of ceramic membranes and maintain bioactive compounds in jackfruit juice.
RESUMEN
Resumen Introducción: México es de los principales países que enfrenta una problemática nutricional provocada por un déficit o exceso de nutrientes, que ocasiona desnutrición o sobrepeso en su población. Objetivo: Identificar los hábitos alimenticios entre tres distintos estratos sociales y compararlos con el perfil nutricional en un comedor social que brinda desayuno y comida en la Ciudad de Tepic, Nayarit. Materiales y métodos: Se realizaron encuestas en los diferentes estratos sociales que correspondieron a un recordatorio de un día de desayuno y comida con sus respectivos refrigerios y bebidas. Resultados: Se encontró consumos de proteína que excedían la ingesta recomendada diaria, bajo consumo de fibra dietética (asociado con la baja ingesta de frutas y verduras) y alta incidencia en consumo de bebidas carbonatadas. Además, la mayor ingesta calórica total fue en el estrato socioeconómico alto (atribuido a su mayor poder adquisitivo), seguido del comedor social; sin embargo, en ningún estrato, ni el comedor social se encontró una dieta balanceada. Conclusiones: El poder adquisitivo de los distintos estratos socioeconómicos no fue el principal factor que limita una adecuada alimentación, si no la falta de información y malos hábitos alimenticios de la población, debido a la pérdida de cultura alimentaria.
Abstract Introduction: Mexico is among the main countries that faces nutritional problems caused by a deficit or excess of nutrients, which is causing malnutrition or overweight in its population. Objective: To identify the eating habits of people belonging to three different socioeconomic strata and compare them to nutritional profiles of a community restaurant in the City of Tepic, Nayarit. Materials and methods: The participants were surveyed about what they ate for breakfast and lunch the day before. Results: Protein consumption was found to exceed the recommended daily intake. Also, there was a low ingestion of dietary fiber (associated with low intake of fruits and vegetables) and a high incidence of carbonated drink consumption. Finally, the largest total caloric intake was recorded in people from the highest SS (attributed to their higher income), followed by those who eat at the community restaurant. However, none of the participants followed a balanced diet. Conclusions: The purchasing power of people belonging to the different socioeconomic strata is not the main factor that limits a balanced diet, since additional factors are the lack of information and poor nutritional habits of the Mexican population due to the loss of their food culture.