Broccoli contains high levels of bioactive molecules and is considered a functional food. In this study, postharvest treatments to enhance the concentration of glucosinolates and phenolic compounds were evaluated. Broccoli whole heads were wounded to obtain florets and wounded florets (florets cut into four even pieces) and stored for 24 h at 20 °C with or without exogenous ethylene (ET, 1000 ppm) or methyl jasmonate (MeJA, 250 ppm). Whole heads were used as a control for wounding treatments. Regarding glucosinolate accumulation, ET selectively induced the 4-hydroxylation of glucobrassicin in whole heads, resulting in ∼223% higher 4-hydroxyglucobrassicin than time 0 h samples. Additionally, glucoraphanin was increased by ∼53% in whole heads treated with ET, while neoglucobrassicin was greatly accumulated in wounded florets treated with ET or MeJA, showing increases of ∼193 and ∼286%, respectively. On the other hand, although only whole heads stored without phytohormones showed higher concentrations of phenolic compounds, which was reflected in ∼33, ∼30, and ∼46% higher levels of 1,2,2-trisinapoylgentiobose, 1,2-diferulolylgentiobiose, and 1,2-disinapoyl-2-ferulolylgentiobiose, respectively; broccoli florets stored under air control conditions showed enhanced concentrations of 3-O-caffeoylquinic acid, 1,2-disinapoylgentiobiose, and 1,2-disinapoyl-2-ferulolylgentiobiose (∼22, ∼185, and ∼65% more, respectively). Furthermore, exogenous ET and MeJA impeded individual phenolics accumulation. Results allowed the elucidation of simple and effective postharvest treatment to enhance the content of individual glucosinolates and phenolic compounds in broccoli. The stressed-broccoli tissue could be subjected to downstream processing in order to extract and purify bioactive molecules with applications in the dietary supplements, agrochemical and cosmetics markets.

(2015) Effects of different defrosting methods on the stability of bioactive compounds and consumer acceptability of frozen broccoli, CyTA -Journal of Food, 13:2, 312-320, DOI: 10.1080DOI: 10. /19476337.2014 To link to this article: https://doi.org/10. 1080/19476337.2014 Broccoli (Brassica oleracea var. italica) is an excellent source of bioactive compounds. Frequently, it is commercialized frozen, though it has to be thawed before consumption. However, defrosting methods can affect the nutritional and sensory properties of broccoli. Therefore, the effect of defrosting (microwaving and boiling) for serving broccoli either cold or hot on the content of bioactive compounds (vitamin C, carotenoids, phenolic compounds, and glucosinolates) and sensory acceptability of frozen broccoli was studied. Marked losses of hydrosoluble compounds were observed after boiling. Carotenoids increased after short-time boiling (~20%) but dramatically decreased after microwave-defrosting (between 30% and 40% less). Nevertheless, short defrosting using microwave showed the less overall losses. Moreover, microwave-based methods were preferred by consumers. Microwave-defrosting of broccoli for a short period of time may be the method of choice for better retention of bioactive compounds and organoleptic properties.Keywords: Brassica oleracea var. italica; glucosinolates; vitamin C; carotenoids; phenolic compounds El brócoli (Brassica oleracea var. italica) es una excelente fuente de compuestos bioactivos. Frecuentemente, es comercializado congelado, aunque debe ser descongelado antes de ser consumido. No obstante, los métodos de descongelación pueden afectar las propiedades nutritivas y sensoriales del brócoli congelado. Por consiguiente, el efecto del descongelamiento (microondas y hervido) para servir brócoli frío o caliente en el contenido de compuestos bioactivos (vitamina C, carotenoides, compuestos fenólicos y glucosinolatos) y la aceptabilidad sensorial del brócoli congelado fue estudiado. Pérdidas marcadas de compuestos hidrosolubles fueron observadas después de hervir. Los carotenoides incrementaron después de hervir por tiempo corto (~20%) pero decrecieron después de la descongelación por microondas (entre 30% y 40% menos). Sin embargo, el descogelamiento corto utilizando microondas mostró las menores pérdidas globales. Además, los métodos por microondas fueron preferidos por los consumidores. El descongelamiento corto por microondas puede ser el método de elección para una mejor retención de nutracéuticos y propiedades organolépticas del brócoli congelado.