The increase in the use of bioactive compounds from purple corn in the food and pharmaceutical industries has led to the investigation of nonconventional extraction technologies that allow one to obtain more of these compounds. In this context, nonconventional techniques, known as emerging technologies, use more efficient processes that are safe for the environment, in addition to obtaining products with better functional characteristics as compared to those obtained by conventional technologies. This review aims to provide information on different nonconventional techniques used in the extraction of bioactive compounds from purple corn.

RESUMENEfecto de las altas presiones hidrostáticas respecto a la pasteurización térmica en los aspectos microbioló-gicos, sensoriales y estabilidad oxidativa de un paté de aceituna.En el presente trabajo se valoró el efecto del procesado por altas presiones hidrostáticas (APH) como método alternativo al tratamiento térmico de pasteurización para la conservación del paté de aceituna y su estabilidad durante el almacenamiento en refrigeración, mediante la caracterización de los aspectos microbiológicos, físico-químicos y sensoriales. El paté de aceituna fue elaborado partiendo de aceituna de mesa verde deshuesada y envasada en salmuera, a la cual, previo lavado con agua, se le adiciona zumo de naranja natural, aceite de oliva virgen, especias y sorbato potásico. Para evaluar el efecto del procesado, se aplicaron cuatro tratamientos de APH (450 y 600MPa durante 5 y 10min) y otro de pasteurización térmica (80 °C durante 20min), comparán-dose con el producto no procesado. Las muestras tratadas con APH presentaron, frente a las tratadas por pasteurización térmica, una reducción en la presencia de microorganismos, un aumento de su estabilidad oxidativa, una mayor aceptación sensorial; y respecto a las coordenadas colorimé-tricas mayor claridad y menor pardeamiento. El estudio de la vida útil del producto en refrigeración, indicaría la viabilidad de la aplicación de la tecnología de APH para obtener alimentos con vida útil similar a la obtenida con el tratamiento tradicional de pasteurización, pero con mejor calidad sensorial. PALABRAS CLAVE: Altas presiones hidrostáticas (APH) -Análisis sensorial -Estabilidad oxidativa -Microbiológico -Pasteurización térmica -Paté de aceituna. SUMMARYEffect of high hydrostatic pressure versus thermal pasteurization on the microbiological, sensory aspects and oxidative stability of olive pate.The present study examines the effect of high hydrostatic pressure processing (HHP) as an alternative to thermal pasteurization treatments for the conservation of olive pate and its stability during refrigerated storage, through the characterization of microbiological, physico-chemical and sensory aspects. The olive pate was made with green, pitted table olives packed in brine. Orange juice, olive oil, spices and potassium sorbate were added to the olives after being washed in water. To evaluate the effects of processing, four treatments of APH (450 and 600MPa for 5 and 10 min) and a thermal pasteurization (80 °C for 20 min) were applied to compare them with the unprocessed product. APH-treated samples showed a further reduction in the presence of microorganisms, an increase in oxidative stability, a higher sensory acceptance, greater clarity and less browning regarding the colorimetric coordinates, in comparison with those treated by thermal pasteurization. The study of the shelf life of the product in refrigeration would indicate the feasibility to implement APH technology in order to obtain food with a similar shelf life to foods obtained through the traditional thermal pasteurization treatment,...

RESUMEN Efecto de las altas presiones hidrostáticas y el tratamiento térmico tradicional en las características físico-químicas, microbiológicas y análisis sensorial de una mermelada de aceitunaEn el presente trabajo se valoró el efecto del procesado por altas presiones hidrostáticas (HPP) como método alternativo al tratamiento térmico de pasteurización en la mermelada de aceitunas. Para ello se comparó el efecto de ambos tratamientos sobre el producto procesado y se evaluó su estabilidad durante el almacenamiento en refrigeración, mediante la caracterización de los aspectos físico-químicos, microbiológicos, y sensoriales. Para evaluar el efecto del procesado, se aplicaron dos tratamientos de HPP (450 y 600MPa) y otro de pasteurización térmica (80 °C durante 20 min), comparándose con el producto no procesado. Las muestras tratadas con HPP 600MPa presentaron, frente al resto de tratamientos una reducción en la presencia de microorganismos, mayor claridad y menor pardeamiento, y una mayor aceptación sensorial. El estudio de la vida útil del producto en refrigeración, indicaría la viabilidad de la aplicación de la tecnología de HPP para obtener alimentos con vida útil similar a la obtenida con el tratamiento tradicional de pasteurización, pero con mejor calidad sensorial. PALABRAS CLAVES: Altas Presiones Hidrostáticas (HPP) -Análisis sensorial -Mermelada de aceituna -Microbiología -Pasteurización térmica. SUMMARY Comparative effect of high pressure processing and traditional thermal treatment on the physicochemical, microbiology, and sensory analysis of olive jamIn the present work the effect of the processing by high hydrostatic pressures (HPP) was assessed as an alternative to the thermal treatment of pasteurization in olive jam. The effects of both treatments on the product after processing were compared and stability during storage under refrigeration was assessed through the characterization of physicochemical, microbiological and sensory aspects. To assess the effect of processing, two HPP treatments (450 and 600MPa) and thermal pasteurization (80 °C for 20 min) were applied, comparing them with the unprocessed product. HPP 600MPa versus the rest of treatments showed a reduction in microorganisms, greater clarity and less browning, and sensory acceptance. The shelf-life of the refrigerated product would indicate the feasibility of the application of the HPP technology for food with similar shelf-life to that obtained with the traditional treatment of pasteurization, but with a better sensory quality.

The purple corn cob is an agro-industrial by-product that contains high-value bioactive compounds, which makes its use attractive for the development of extraction processes. The aim of this research was to extract the bioactive compounds from the purple corn cob by high isostatic pressure at different processing temperatures. Pressures of 0.01 MPa, 250 MPa, 450 MPa and 650 MPa for 3 minutes and at temperatures of 25 °C, 45 °C and 65 °C were used. High pressure extraction was compared with conventional extraction (2.5 h at 25°C). The purple corn cob extract obtained by isostatic processing at 650 MPa and 65 °C presented high antioxidant activity and content of bioactive compounds, unlike the conventional extraction of 2.5 h and 65 °C (p < 0.05). However, it did not show a significant difference with the extract obtained at 450 MPa and 45 °C (p > 0.05). Seven different anthocyanins were identified by liquid chromatography in the extracts obtained by high isostatic pressure (650 MPa at 65 °C) and hydroalcoholic maceration (2.5 h at 65 °C), mainly cyanidin-3-glucoside, pelargonidin-3-glucoside and peonidin-3-glucoside, and their respective malonyl derivatives. The high isostatic pressure increased the extraction of bioactive compounds by more than 50% and obtained them in shorter times, thus appearing as a new alternative, and eco-friendly method for the extraction of bioactive compounds from plant tissues.