Thursday, October 15, 2009

Brilliant research - you can make healthier meals

Ever so often a brilliant scientific study comes up. Today a paper like this was published in Food Control. The study looked at meals produced by a bulk catering company. Thing hospital kitchen or boarding school kitchen. They followed vegetables through the process, measuring vitamin C at the various stages. As expected there were a few critical steps that if not done right lead to large drops in vitamin C level of the food. Thus there were able to focus on these few steps and as a result reduce the vitamin C loses. The improvements are shown in the graph below:


The darker columns are the original reduction, and after improvements the were made the results are the lighter column. So you can see massive improvements of 20-30% across all vegetables except for white cabbage and tomatoes.

This is fantastic news. What this means that changing how we obtain and process foods before they appear on the table we can increase their vitamin retention. So what were the key issues. They were unsurprisingly the length of time that the vegetables were at room temperature (eg not in the fridge). Reduction in cleaning and cooking temperature, time and total water volume.

So applying this to the home situation, the following points should be followed as much as possible:
  • Choosing produce that has not warmed up to shop temperature. This is done by never choosing the produce that is at the top of the pile as this has had a chance to warm up. So go for the colder stuff below.
  • Keep all colder foods together eg produce and dairy products
  • Minimize the time that the produce sits in the car / kitchen before going into fridge
  • Keep produce in the fridge as long as possible before serving. And if it is made in advance keep things in the fridge 
  • Try not to peel or prep things that need to sit in water before you cook them. For instance peeling potatoes and putting them in water so they don't brown enables the vitamin C to be leached out into the water. 
  • Reduce the time you spend washing your vegetables 
  • Reduce the time you cook and temperature that the produce is cooked at.
  • Steaming instead of boiling. 
Lets hope there is more and more research looking at how we can decrease the lose of nutrient until we eat them.

Reference: Rodrigues, C., Control of vitamin C losses in vegetables prepared at a food servic. Food Control vol 21, 2010 pg 254-271

No comments:

Post a Comment