Purple sprouting broccoli has come back into fashion over the past few years. It was initially cultivated by the Romans but fell out of favour compared to green broccoli.
All broccoli varieties are an excellent source of vitamin C and provide good amounts of vitamin A, iron and calcium. However of particular notability is broccoli’s antioxidant properties. Broccoli contains a mixture of both water and fat soluble antioxidants which have been proven to be particularly effective when working together. Whilst the antioxidant content of broccoli varies significantly between subspecies, growth conditions and storage conditions, purple-sprouting broccoli generally has a higher content of antioxidant compounds compared to green broccoli. Much of the difference is due to what gives purple sprouting broccoli it’s colour – anthocyanins, a particularly potent antioxidant.
But what happens to the antioxidant compounds when broccoli is cooked? A study by Yvette Porter, Antioxidant Properties of Green Broccoli and Purple-sprouting Broccoli Under Different Cooking Conditions in 2012 found that antioxidant activity initially increases with cooking then decreases (see table below). It was observed that whilst purple sprouting broccoli in it’s raw form has higher antioxidant activity it is more sensitive to heat and more soluble in water causing leaching of antioxidant compounds. However using cooking water for other uses such as soups and gravies would reclaim some of the antioxidants. Other studies have found that steaming broccoli initially increases antioxidant activity but there is a slower decline in activity therefore is a preferable cooking method over boiling.
However for people with Parkinson’s other factors have to be considered and well cooked vegetables are easier to chew and swallow. But even after boiling broccoli for 20 minutes there is still some goodness left making it well worth eating. And right now is the season to do it!