ABSTRACT
The influence of cooking methods on chlorophyl, carotenoids, polyamines, polyphenols contents and antioxidant capacity were analyzed in organic and conventional green beans. The initial raw material had a higher content of chlorophyl and total phenolics in conventional green beans, whereas organic cultive favored flavonoid content and antioxidant capacity. Polyamines and carotenoids were similar for the two crop systems. After the cooking process, carotenoids (ß-carotene, lutein and zeaxanthin) increased. Microwave heating favored the enhancement of some polar compounds, whereas pressure cooking favored carotenoids. When we used the estimation of the radical scavenging activity by electron spin resonance (ESR) spectroscopy, a reduction of the DPPH radical signal in the presence of green bean extracts was observed, regardless of the mode of cultivation. The highest reduction of the ESR signal ocurred for microwave cooking in organic and conventional green beans, indicating a higher availability of antioxidants with this type of heat treatment.
Subject(s)
Carotenoids/chemistry , Chlorophyll/chemistry , Cooking/methods , Phaseolus/chemistry , Polyamines/chemistry , Polyphenols/chemistry , Antioxidants/chemistry , Electron Spin Resonance Spectroscopy , Flavonoids/chemistry , Hot Temperature , WaterABSTRACT
Smoothies represent an excellent and convenient alternative to promote the daily consumption of fruit and vegetables in order to obtain their health-promoting benefits. Accordingly, a green fresh vegetables smoothie (77.2% cucumber, 12% broccoli and 6% spinach) rich in health-promoting compounds was developed. Soluble solids content, pH and titratable acidity of the smoothie were 4.3 ± 0.4°Bx, 4.49 ± 0.01 and 0.22 ± 0.02 mg citric acid 100-1 g fw, respectively. Two thermal treatments to reduce microbial loads and preserve quality were assayed: T1 (3 min at 80 â) and T2 (45 s at 90 â). Fresh blended unheated samples were used as control (CTRL). The smoothie presented a viscoelastic behaviour. T1 and T2 treatments reduced initial microbial loads by 1.3-2.4 and 1.4-3.1 log units, respectively. Samples were stored in darkness at 5 and 15 â. Colour and physicochemical changes were reduced in thermal-treated samples throughout storage, which were better preserved at 5 â rather than at 15 â. Vitamin C changes during storage were fitted with a Weibullian distribution. Total vitamin C losses of T1 and T2 samples during storage at 15 â were greatly reduced when they were stored at 5 â. Initial total phenolic content (151.1 ± 4.04 mg kg-1 fw) was 44 and 36% increased after T1 and T2 treatments, respectively. The 3-p-coumaroyl quinic and chlorogenic acids accounted the 84.7 and 7.1% relative abundance, respectively. Total antioxidant capacity (234.2 ± 20.3 mg Trolox equivalent kg-1 fw) remained constant after the thermal treatments and was better maintained during storage in thermal-treated samples. Glucobrassicin accounted the 81% of the initial total glucosinolates content (117.8 ± 22.2 mg kg-1 fw) of the smoothie. No glucosinolates losses were observed after T2 treatment being better preserved in thermal-treated samples. Conclusively, a short time-high temperature mild thermal treatment (T2) showed better quality and bioactive compounds retention in a green fresh vegetable smoothie during low temperature storage.
Subject(s)
Food Handling , Food Preservation , Phytochemicals/analysis , Vegetables/chemistry , Antioxidants/analysis , Ascorbic Acid/analysis , Beverages/analysis , Beverages/microbiology , Carotenoids/analysis , Chlorophyll/analysis , Cold Temperature , Color , Dietary Fiber/analysis , Food Analysis , Food Contamination/analysis , Food Microbiology , Food Storage , Fruit/chemistry , Fruit/microbiology , Hot Temperature , Hydrogen-Ion Concentration , Nutritive Value , Phenols/analysis , Rheology , Taste , Vegetables/microbiologyABSTRACT
O objetivo desse trabalho foi avaliar o efeito das concentrações de potássio aplicadas via fertirrigação em cobertura sobre o crescimento, a produção e composição química de berinjela 'Ciça' em um Latossolo vermelho distroférrico. Os tratamentos foram compostos por cinco concentrações de K2O (0; 36; 72; 108 e 144 kg ha-1 fornecidos via fertirrigação), sendo utilizado como fonte o cloreto de potássio, parcelado em seis aplicações. O sistema de irrigação foi do tipo localizada por gotejamento e o manejo da irrigação foi realizado via tanque evaporímetro "Classe A". As colheitas se iniciaram aos 62 Dias Após o Transplante (DAT) se prolongando por cinco meses e as variáveis avaliadas foram: altura de plantas, número de folhas, massa fresca dos frutos, além de número de frutos por planta, produção por planta, produtividade e classificação dos frutos de acordo com seu comprimento e diâmetro. Aos 85 DAT realizou-se a coleta de frutos para caracterização quanto à porcentagem de lipídeos, proteínas e fibras. Apesar da fertirrigação potássica em cobertura proporciona uma redução na produção e na produtividade, as concentrações de 36 kg ha-1 e 72 kg ha-1 de K2O aplicadas via fertirrigação, incrementaram as características físico-químicas dos frutos.
The objective of this study was to evaluate the effect of potassium applied through fertigation in coverage of the development, production and chemical composition of eggplant 'Ciça' in an Oxisol. The treatments consisted of five rates of K2O (0, 36, 72, 108 and 144 kg ha-¹ supplied by fertigation) and is used as source of potassium, in six installments topdressing applications. The irrigation system was of the type localized and drip irrigation was conducted via tank evaporimeter "Class A". The harvest began 62 Days After Transplanting (DAT) extending by five months, and the characteristics were evaluated: plant height, leaf number, average weight, average length and average fruit diameter, fruit number per plant, production per plant, yield and fruit classification according to their size. At 85 DAT was performed to collect fruit for characterization as to the percentage of lipids, protein and fiber. Spite of potassium fertigation provide coverage for a reduction in the production and yield, the concentrations 36 kg ha-1 and 72 kg ha-1 of K2O applied through fertigation, increased features physicochemical evaluations.
El objetivo de este trabajo fue evaluar el efecto de las concentraciones de potasio aplicadas via fertirrigación en áreas cubiertas sobre el crecimiento, la producción y la composición química de la berenjena 'Ciça' en un Oxisol. Los tratamientos consistieron en cinco concentraciones de K2O (0; 36; 72; 108 y 144 kg ha-1 suministrados via fertirrigación), siendo utilizado como fuente el cloruro de potasio, parcelado em seis aplicaciones. El sistema de riego fue de tipo localizado por goteamiento y el manejo de irrigación fue realizado mediante tanque evaporímetro "Clase A". Los cultivos comenzaron 62 Días Después del Trasplante (DAT) prolongándose por cinco meses y las variables evaluadas fueron: altura del planta, número de hojas, peso fresco de los frutos, además del número de frutos por planta, producción por planta, productividad y clasificación de los frutos de acuerdo con su longitud y diámetro. A los 85 DAT se realizó la recoleta de frutos para la caracterización del porcentaje de lípidos, proteínas y fibras. Aunque la fertirrigación potásica en cobiertas proporciona una reducción en la producción y la productividad, las concentraciones de 36 kg ha-1 y 72 kg ha-1 de K2O aplicadas via fertirrigación incrementaron las características físico-químicas de los frutos.
