Bioactive Compounds of Broccoli, Tomatoes Explored

Anaheim, CAFood scientists have isolated what is good for you in broccoli and these organic compounds are known as glucosinolates. Now the focus is on coming up with even more concentrated glucosinolates to enhance health.
Glucosinolates are the biologically active components in broccoli that are highly touted as antioxidants, boosting immune health, respiratory health, and cardiovascular health. They are an example of the so-called bioactive compounds in produce that are good for consumers. According to Howard Constant, president of Seminis Vegetable Seeds, Woodland, CA, companies like his are making strides in breeding new plant varieties that will deliver more concentrated amounts of bioactives to the consumer.
Were looking at opportunities beyond the seed, Constant said at the Institute of Food Technologists (IFT) Annual Meeting and Food Expo®. A produce industry that has traditionally been driven by population growth is now also being driven by crop innovation and the addition of value-added products with an extra boost of the healthy stuff.
This is only part of the research being conducted on bioactive compounds such as glucosinolates and lycopene. Lycopene is a substance in tomatoes that is high in beneficial carotene. Diane M. Barrett, University of California, Davis, CA, is looking at the quality of bioactives in produce during and after processing. Nutrients can be drastically affected, depending on type of harvest, washing, cooling, packing, sorting, processing, and transportation.
At every point here you have the potential for changes in these bioactive compounds, Barrett said. For example, bioactives can diminish with an increase in the distance your food travels to your table.
Storage temperature can have a large effect on bioactives, Barrett said, with refrigeration slowing enzyme activity that breaks down cells containing bioactives. Cell integrity can be lost through heat or high pressure processing. Growers, packers, transporters and retailers all have a role in making sure the consumers glucosinolates arrive in good shape.
There are many things that can affect the bioactives in foods, said Alyson Mitchell, Barretts colleague at the University of California, Davis. That includes farming procedures from production to harvest.
The importance of this is illustrated with tomatoes. Tomatoes are the second most consumed produce item in North America, 71 pounds per capita per year. They are loaded with vitamins and minerals, carotenoids, potassium, flavonoids, phenolic acids, and glycoalkaloids.
Another scientist at the University of California, Davis, Jean-Xavier Guinard, is testing the sensory properties of bioactives in vegetables. He said that increased bioactivity can come with severe drawbacks, including that they may not taste or smell very good in more concentrated forms.
Bioctive properties in vegetables present a lot of challenges, Guinard said. They may be bitter or astringent, and that could get worse with aging and cooking. A lot needs to be done when delivering glucosinolates and lycopenes to the dinner table.