Identifying non-destructive growth and maturity indexes of Prickly pear (Opuntia albicarpa S. Var. Burrona) and evaluation of freeze-drying conditions

Around the world, prickly pear fruits are valued as a source of dietary functional compounds and ingredients for innovative foods. Growth and physicochemical changes of Opuntia albicarpa S. fruits were recorded from 0 to 132 days-after-flowering (DAF) to identify non-destructive maturity-indices. Optimum-ripened fruits were freeze-dried to study physicochemical and functional characteristics of dried and rehydrated pulp. Principal component analysis confirmed growth turned into fruit ripening in DAF 99, and it lasted until DAF 132. Changes in color parameters of the peel correlated with fruit texture and pulp sugar content and taste index (P < 0.01). During freeze-drying, plate temperature had more significant effects than the thickness (P < 0.05). At 30°C, color ΔE between dried and fresh slices augmented, but, texture Δ´s (medium force) between rehydrated and fresh pulp was lower. Color tests could be used to harvest commercially-ripened fruits. Freeze-drying at 30°C improves the rehydrated slices texture regarding thickness maintaining rehydration coefficients.Las tunas son apreciadas en todo el mundo como fuente de compuestos funcionales dietarios e ingredientes para alimentos innovadores. Para identificar índices de maduración no destructivos, se registraron cambios en el crecimiento y en los parámetros fisicoquímicos de frutos de Opuntia albicarpa S. entre los días después de la floración (DAF) 0 al 132. Frutos con maduración óptima fueron liofilizados para evaluar características fisicoquímicas y funcionales de pulpa seca y rehidratada. El análisis de componentes principales confirmo que el crecimiento dio lugar a la maduración en el DAF 99 y ésta prosiguió hasta el DAF 132. Los cambios en parámetros de color en cáscara correlacionaron con la textura del fruto, y en pulpa, con el contenido de azúcares y el índice de sabor (P< 0.01). Durante la liofilización, la temperatura de placa tiene más efectos significativos que el espesor (P≤ 0.05). A 30°C, el ΔE de color entre la pulpa seca y fresca aumentó, pero, el Δ de textura (fuerza media) fue menor entre la rehidratada y la fresca. Se pueden emplear evaluaciones de color para cosechar frutos en su madurez comercial, y liofilizar estos frutos a 30°C mejora la textura sin importar el espesor, manteniendo los coeficientes de rehidratación.This work was supported by the SIMORELOS program of CONACyT

Changes in the Antioxidant Properties of Extra Virgin Olive Oil after Cooking Typical Mediterranean Vegetables

Extra virgin olive oil (EVOO), water, and a water/oil mixture (W/O) were used for frying, boiling and saut&eacute;eing Mediterranean vegetables (potato, pumpkin, tomato and eggplant). Differences in antioxidant capacity (AC) (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric iron (FRAP), 2,2-azinobis-(3-ethylbensothiazoline)-6-sulphonic acid (ABTS)), total phenolic content (TPC) and individual phenols (high-performance liquid chromatography (HPLC)) in unused and used EVOO and water were determined. The water used to boil tomatoes showed the highest TPC value, whilst the lowest was found in the EVOO from the W/O used for boiling potatoes. After processing, the concentrations of phenols exclusive to EVOO diminished to different extents. There was a greater transfer of phenols from the vegetable to the oil when eggplant, tomato and pumpkin were cooked. W/O boiling enriched the water for most of the phenols analysed, such as chlorogenic acid and phenols exclusive to EVOO. The values of AC decreased or were maintained when fresh oil was used to cook the vegetables (raw &gt; frying &gt; saut&eacute;ing &gt; boiling). The water fraction was enriched in 6-hydroxy-2,5,7,8&ndash;tetramethyl-chroman-2-carboxylic acid (Trolox) equivalents following boiling, though to a greater extent when EVOO was added. Phenolic content and AC of EVOO decreased after cooking Mediterranean diet vegetables. Further, water was enriched after the boiling processes, particularly when oil was included

Influencia de las técnicas culinarias sobre el contenido de polifenoles y capacidad antioxidante en hortalizas de la dieta Mediterránea: minoría religiosas en Granada y su área metropolitana

Tesis Univ. Granada. Departamento de Nutrición y Bromatologí

Influence of temperature and time during malaxation on fatty acid profile and oxidation of centrifuged avocado oil

Abstract Virgin oil from avocados (Persea americana Mill.) is obtained by mechanical processes after pulp malaxation at temperatures that minimize oxidation and improve separation. The objective of this study was to assess the effect of time (0, 20, 30, 40, 60, 120 and 180 min) and temperature (40 and 50 °C) conditions during pulp malaxation on extraction yield, nutritional value (normalized fatty acid profile) and specific extintion (K232 and K270) of virgin oil extracted under laboratory conditions from avocados cultivated in southern Jalisco, Mexico. When pulp was malaxated for 120 min at 40 and 50 °C, a larger proportion of oil was extracted (82.9 ± 0.3% and 80.2 ± 0.8%, respectively). We observed that the normalized percentage of the fatty acids linoleic (18 ± 2%) and linolenic (1.2 ± 0.2%) decreased with mixing time, while that of palmitoleic (9 ± 1%), oleic (51.6 ± 1.2%) and stearic (0.5 ± 0.1%) remained without change. The ω-6:ω-3 ratio (15 ± 1) was higher than the recommended values but similar to those reported as favorable for health. Specific extinction (K232, 2.2 ± 0.3 and K270, 0.20 ± 0.03) indicate that the oxidation level remained low. Malaxation at 40 or 50 °C did not significantly alter the characteristics of the oil, but time significantly affected yield

Variation on the content of phytochemicals compounds in typical Mediterranean foods depending on the culinary technique used

El aceite de oliva virgen extra (AOVE) y la patata son alimentos característicos en la Dieta Mediterránea, a su consumo se asocian beneficios para la salud relacionados con fitoquímicos bioactivos como los antioxidantes polifenólicos. Las técnicas culinarias a las que son sometidos los alimentos previos a su consumo causan variaciones en la retención y distribución de la capacidad antioxidante (CA) y en el contenido de fenoles totales (CFT). El objetivo de este trabajo ha sido estudiar el contenido en polifenoles y la CA mediante los métodos ABTS y DPPH, antes y después del cocinado que sufre una hortaliza como la patata mediante cuatro técnicas culinarias diferentes (fritura, rehogado, cocción en agua y cocción en agua-aceite) donde los medios de transferencia de calor utilizados son el aceite o el agua. Siempre que se utiliza AOVE, ya sea como medio de transferencia de calor (fritura y rehogado) ya sea como ingrediente culinario (cocción en agua–aceite), se incrementa la CA de la patata. Por el contrario, e independientemente de la técnica culinaria seguida, el CFT disminuye en la patata. Ahora bien si se utiliza una mezcla de agua–aceite (A/A), como medio de transferencia de calor, el agua de cocción se incrementa en compuestos fenólicos. Posiblemente se tratan de fenoles hidrosolubles procedentes del aceite y que son extraídos del mismo por el propio agua de cocción. Por ello sería recomendable hervir las patatas en agua adicionada de un poco de aceite y consumir junto con estas hortalizas el propio agua de cocción para evitar perdidas en fenoles que se producirían si se deshechan las aguas de hervido. En general, la patata gana y el aceite pierde en CA (tanto por el método ABTS como por el método DPPH); las mayores pérdidas en la CA se producen en el aceite procedente del rehogado. Por el contrario, el mayor incremento en la CA se produce en la patata cocinada por esta técnica y cuando se aplica el método DPPH. Son también notables los incrementos obtenidos en la CA de la patata hervida con una mezcla de A/A. El aceite procedente de una primera fritura pierde contenido fenólico posiblemente debido a la oxidación térmica, polimerización e hidrólisis que dan lugar a productos de oxidación, pero su CA se aumenta cuando se analiza por el método ABTS. El método de cuantificación originó variaciones en la magnitud de la CA; sin embargo, la interpretación conjunta de la CA medida por ambos métodos facilita la comprensión del mecanismo antioxidante involucrado. La adecuada elección de los métodos y condiciones de elaboración culinaria maximizarán la CA y el aporte de polifenoles del AOVE y la patata a la dieta.Extra virgin olive oil (AOVE) and potatoes are Mediterranean diet typical food, health benefits linked with bioactive phytochemicals as polyphenolic antioxidants are associated to consumption. Before consumption, this food is processed by culinary techniques changing antioxidant capacity (AC) retention and distribution as total phenol content (TFC). The aim of this study has been to analyze the total polyphenol content and the AC by ABTS and DPPH methods, before and after cooking vegetables such as potato by four different culinary techniques (frying, fry lightly, cooked in water and cooking oil-water) using as heat transfers way oil or water. After using AOVE as heat transfer medium (fried and fry lightly) either as a culinary ingredient (water-oil cooking), increases the AC of the potato. Instead of and regarding less the culinary technique used the TFC decreases in potato. However if an oil-water mix (O / A) is used as a heat transfer way, the phenolic compounds increases in cooking water. Probably are water-soluble phenols from oil, which are extracted from the same cooking water. Would be suitable to boil the potatoes in oily added water and eat these vegetables with their own cooking water to avoid phenols losses, which would occur if boiling water is drop. Generally, potatoes wins and oil loses in AC (by ABTS and DPPH method), the majority AC losses occur in the oil from fry lightly. Instead of, the largest increase in AC happens in the potato cooked by this technique and when DPPH method is applied. When oil- water mix is used, there are important increments in the AC of the potato, The oil from first frying, loses phenolic content possibly due to thermal oxidation, polymerization and hydrolysis process, but the AC increase when is analyzed by ABTS method. Quantification method used originates AC variations, however AC interpretation by both methods facilitates the understanding of antioxidant mechanism involved. The suitable choice of one methods and culinary conditions applied in the cooking process will increase the AC total and total phenol contribution to the diet

Functional composition of avocado (Persea americana Mill. Var Hass) pulp, extra virgin oil, and residues is affected by fruit commercial classification

The avocado's quality classification criteria are based on the presence and extension of fruit shape defects and surface damages made during its growth or postharvest handling. This study aims to address the variations according to the commercial quality of Southern Jalisco avocado Hass fruits, focusing on some compositional and biofunctional compounds of the edible, inedible fractions, and the oil. Fresh fruits of four quality classifications were separated into the pulp, peel, and seed, and the extra virgin avocado oil (EVAO) was extracted to analyze for the fat, humidity, dry matter contents, total phenolic content (TPC), total carotenoid content (TCC), antioxidant capacity, fatty acids profiles, and phenolic compounds. Depending on the fraction, the lower-quality class (D) had a significantly (p < 0.001) highest total phenolic content (0.605–23.18 mg EAG/g FW), total carotenoid content (0.137–1.696 mg/100 g FW), ABTS antioxidant capacity (0.32–24.52 μmol TE/g FW), higher oleic acid (37.47–64.87%), and a lower saturated fatty acid content than the highest class (A). The principal component analysis made it possible to classify samples according to the fraction but not with the quality classification. The most important parameters for PC1 were DPPH, oleic acid, ABTS, linoleic acid, and TPC, while for PC2 were oleic acid, DPPH, erucic acid, TPC, and ABTS. However, the general discriminant analysis made it possible to discriminate 98% of the samples according to classes and 100% according to classes/fraction combinations by using 12 and 24 of the evaluated variables, respectively. It was demonstrated that quality classification has not only a cosmetic impact but also on functional compound composition. Lower-class fruits could be used for oil production instead of superior classes, and peels could be included in the extraction process

Migration of Avocado Virgin Oil Functional Compounds during Domestic Cooking of Eggplant

Avocado virgin oil (AVO) was used during eggplant deep-frying, boil, and boil in a water-oil mixture (W/O). There were measured the contents of moisture, dry matter, fat, total (TPC) and ten individual phenols, antioxidant activity (ABTS and DPPH), and total sterols; as well as the profiles of eight fatty acids and fourteen sterols/stanols. The values of raw and processed foods were compared and studied with multivariate analysis. The antioxidant capacity of AVO lowered after deep frying but augmented in eggplant and water after all treatments. The TPC was steady in AVO and raised in fried eggplant. Thermal treatments added to the initial profiles of the AVO, eggplant and water, nine, eight, and four phenols, respectively. Percentages of the main fatty acids (oleic, palmitic and linoleic), and sterols (β-sitosterol, campesterol, and Δ5-avenasterol), remained unchanged between the raw and treated AVO; and the lipidic fractions from processed eggplant. Cooking leads to the movement of hydrophilic and lipophilic functional compounds between AVO, eggplant and water. Migration of sterols and unsaturated fatty acids from AVO to eggplant during deep frying and W/O boiling improved the functional properties of eggplant by adding the high biological value lipophilic fraction to the naturally occurring polyphenols