Effects of different defrosting methods on the stability of bioactive compounds and consumer acceptability of frozen broccoli

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 (similar to 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.