RESUMEN
Different spices such as turmeric, oregano, and cinnamon were γ-irradiated at 1 and 10 kGy. The electron paramagnetic resonance (EPR) spectra of the nonirradiated samples were characterized by a single central signal (g = 2.006), the intensity of which was significantly enhanced upon irradiation. The EPR spectra of the irradiated spice samples were characterized by an additional triplet signal at g = 2.006 with a hyperfine coupling constant of 3 mT, associated with the cellulose radical. EPR analysis on various sample pretreatments in the irradiated spice samples demonstrated that the spectral features of the cellulose radical varied on the basis of the pretreatment protocol. Alcoholic extraction pretreatment produced considerable improvements of the EPR signals of the irradiated spice samples relative to the conventional oven and freeze-drying techniques. The alcoholic extraction process is therefore proposed as the most suitable sample pretreatment for unambiguous detection of irradiated spices by EPR spectroscopy.
Asunto(s)
Celulosa/química , Cinnamomum zeylanicum/química , Curcuma/química , Origanum/química , Especias/análisis , Cinnamomum zeylanicum/efectos de la radiación , Curcuma/efectos de la radiación , Espectroscopía de Resonancia por Spin del Electrón , Irradiación de Alimentos , Rayos gamma , Origanum/efectos de la radiación , Especias/efectos de la radiaciónRESUMEN
Food irradiation is a widely employed technology for food treatment. Since in several countries no regulations prevail, it is difficult to detect whether food has been irradiated or not. Among different analytical methods the study of the thermoluminescent (TL) emission of polymineral extracted from food is one of the most useful physical identification method. The aim of this work is to analyze the TL properties of inorganic polyminerals extracted from commercial clove (Syzygium aromaticum L.) and marjoram (Origanum majorana L.) spices exposed to (60)Co gamma radiation for detection purposes. The feasibility of using the TL method for irradiated food detection and absorbed dose determination is assessed.
Asunto(s)
Irradiación de Alimentos , Minerales/química , Origanum/efectos de la radiación , Syzygium/efectos de la radiación , Dosimetría Termoluminiscente/métodos , Silicatos de Aluminio/análisis , Rayos gamma , Origanum/química , Tamaño de la Partícula , Compuestos de Potasio/análisis , Cuarzo/análisis , Reproducibilidad de los Resultados , Especias/efectos de la radiación , Syzygium/químicaRESUMEN
The present study optimized the ultrasound assisted extraction (UAE) conditions to maximize the antioxidant activity [Ferric ion Reducing Antioxidant Power (FRAP)], total phenol content (TP) and content of individual polyphenols of extracts from marjoram. Optimal conditions with regard to amplitude of sonication (24.4-61.0 µm) and extraction temperature (15-35 °C) and extraction time (5-15 min) were identified using response surface methodology (RSM). The results showed that the combined treatment conditions of 61 µm, 35 °C and 15 min were optimal for maximizing TP, FRAP, rosmarinic acid, luteolin-7-O-glucoside, apigenin-7-O-glucoside, caffeic acid, carnosic acid and carnosol values of the extracts. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values with low average mean deviations (E%) ranging from 0.45% to 1.55%. The extraction yields of the optimal UAE were significantly (p < 0.05) higher than solid/liquid extracts. Predicted models were highly significant (p < 0.05) for all the parameters studied with high regression coefficients (R(2)) ranging from 0.58 to 0.989.
Asunto(s)
Antioxidantes/aislamiento & purificación , Antioxidantes/efectos de la radiación , Origanum/química , Origanum/efectos de la radiación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Sonicación/métodos , Antioxidantes/química , Técnicas Químicas Combinatorias/métodos , Ondas de Choque de Alta Energía , Extractos Vegetales/efectos de la radiación , Dosis de RadiaciónRESUMEN
Ionizing radiation is known to stimulate the generation of oxygen radicals which destabilize organic molecules resulting in a decrease of the system's antioxidant potential. The Salmonella typhimurium (TA102) reverse mutation assay, co-incubated with t-BOOH and H(2)O(2), was used to assess the effects of gamma-irradiation (dose: 10kGy) on the antioxidant properties of sage, thyme, and oregano in chloroform and methanol extracts as well as in their mixture. In addition, measurements of the trolox equivalent antioxidative capacity (TEAC), total polyphenol content (TPC), and tocopherol equivalent (TE) were performed. For the methanol and mixed extracts, antioxidative properties in the S. typhimurium reverse mutation assay were only found when using an exogenous metabolic activation system. Generally, the greatest inhibition of mutagenicity was observed in the chloroform fractions of irradiated and of non-irradiated herbs. The relative antioxidant activities for the different herbs were as follows: TA102/t-BOOH, TEAC, TPC: thyme approximately oregano>sage. TA102/H(2)O(2): thyme approximately oregano approximately sage. TE: sage>thyme>oregano. For the majority of the investigated samples the impact of irradiation was insignificant. Therefore, gamma-irradiation at the doses tested seems to have little, if any, effect on the antioxidative capacity of the tested herbs.
Asunto(s)
Conservación de Alimentos , Depuradores de Radicales Libres/efectos de la radiación , Extractos Vegetales/efectos de la radiación , Especias/efectos de la radiación , Animales , Combinación de Medicamentos , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Rayos gamma , Peróxido de Hidrógeno/farmacología , Origanum/química , Origanum/efectos de la radiación , Extractos Vegetales/química , Extractos Vegetales/farmacología , Ratas , Proteína Ribosómica S9 , Proteínas Ribosómicas , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Salvia officinalis/química , Salvia officinalis/efectos de la radiación , Especias/análisis , Thymus (Planta)/química , Thymus (Planta)/efectos de la radiación , terc-Butilhidroperóxido/farmacologíaRESUMEN
Nine spice and aromatic herb samples (i.e., basil, bird pepper, black pepper, cinnamon, nutmeg, oregano, parsley, rosemary, and sage) were gamma-irradiated at a dose of 10 kGy according to commercial practices. The effects of the disinfection treatment on the content of organic radicals and some nutrients (namely, vitamin C and carotenoids) in the samples were investigated by chromatographic and spectroscopic techniques. Irradiation resulted in a general increase of quinone radical content in all of the investigated samples, as revealed by electron paramagnetic resonance spectroscopy. The fate of these radicals after storage for 3 months was also investigated. The cellulose radical was clearly observed in a few samples. Significant losses of total ascorbate were found for black pepper, cinnamon, nutmeg, oregano, and sage, whereas a significant decrease of carotenoids content was observed for cinnamon, oregano, parsley, rosemary, bird pepper, and sage.