Fresh, Frozen or Canned: Which is Really Best?
By Paris Owen BSc (Nutrition) Nutrition & Dietetics Student
It’s the great debate. In terms of getting the most nutrition out of your fruit and veggies, is fresh, frozen or canned the best? I’m sure many of us would instantly guess fresh- right? But it’s actually a bit more complicated. The reason for this is because most of our fresh fruit and veggies are processed in some way. Now before I begin to confuse you too much, I should firstly explain what processing is.
WHAT IS FOOD PROCESSING?
When you think of processed food, what comes to mind first? For me, I instantly think of salami, chips, lollies, cakes and biscuits. These foods are highly processed and often based on refined ingredients. All foods will undergo some form of processing-whether we like it or not. This includes things like picking fruit from a tree, washing, packing and storing. Highly processed foods however, have been processed to the extent that they barely resemble their original form. There are other types of processing that isn’t so bad for our food-these include freezing, canning milling, heating, drying, pickling and smoking.
WHAT ARE THE CONSEQUENCES OF FOOD PROCESSING?
Food processing actually plays a very important role in our food system. It ensures our food is kept safe, by eliminating the growth of any harmful bacteria and that our food can last longer. However, one of the major downfalls of food processing is that it can actually harm the nutrients within your food. This means that the more processed your foods are, the less nutrients they will likely have!
FRESH, FROZEN OR CANNED- WHICH RETAINS THE MOST NUTRIENTS?
o The canning process loses nutrients during the initial treatment, however they remain relatively stable during storage.
o Frozen products lose minimal nutrients to begin with, however they continue to lose nutrients during storage.
o The time and the temperature at which fresh foods are stored will determine if they are superior to frozen or canned.
o Fresh produce is most beneficial when they are garden fresh (ie. just harvested) and when they have been stored appropriately (i.e in the fridge at 50C or lower) for a short period of time. Canned and frozen are still good options if you don’t have the time to regularly pop into the store or markets.
WHAT NUTRIENTS ARE AFFECTED?
The greatest losses occur for B and C vitamins. This is because these vitamins are water soluble, meaning they leach out into water during different stages of processing. B vitamins are essential for helping the body obtain energy from our food and are commonly found in fruit and green leafy vegetables. Vitamin C is an important antioxidant and is essential for growth and repair of body tissues. Good sources of vitamin C include broccoli, tomato, green leafy vegetables and citrus fruits.
HOW TO GET THE MOST NUTRIENTS OUT OF YOUR FOOD
o Shop at your local fruit and veg store or farmers market, as they are likely to re-stock regularly. Even better- Create your own little veggie patch!
o Minimise storage time by shopping regularly (try for 2-3 times p/week)
o Protect them from heat and light by storing suitable fruit and veggies in the fridge at a stable, chilled temperature (50C or below). Those best kept at room temperature should be stored away from direct contact with sunlight.
o Chop-up just prior to meal times. This reduces the time of exposure to oxygen.
o Cook with larger vegetable portions and use minimal water when cooking. This reduces the amount of surface area and water available for nutrients to leach out into.
o Use cooking methods such as steaming, microwaving and stir-frying.
o Reduce keeping foods hot (i.e. at 600C or higher) to less than 90 minutes.
o Ensure your freezer is kept at a stable temperature (-18C is best).
Hi fellow food lovers! My name is Paris Owen and I am currently undertaking a Masters in Nutrition and Dietetics at University of Wollongong. I am also a university-qualified Nutritionist, graduating last year with a Bachelor of Science in Nutrition. I work with Body Bloom, a women’s fitness training group, providing specialised sports nutrition advice and meal plans. Bondi Farmers Markets is where you will find me on Saturdays making nutritious goodies with an incredible team at the Inside Out Nutritious Goods stall.
I like to take an evidence-based approach for nutritional recommendations to ensure the best health outcomes for each unique individual. I also like to approach health in a holistic way incorporating physical, mental and spiritual wellbeing. In the future, I will become an Accredited Practicing Dietitian, working in the public health system and eventually, in private practice. I am particularly interested in food allergies and intolerances and sports nutrition, however there are so many other areas I am yet to discover!
Johns Hopkins Bloomberg School of Public Health 2011, Food Processing Background Reading, viewed 19 October 2014, <http://www.jhsph.edu/research/centers-and-institutes/teaching-the-food-system/curriculum/_pdf/Food_Processing-Background.pdf>.
Rickman, JC, Barrett, DM, Bruhn, CM 2007, ‘Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds’, Journal of the Science of Food and Agriculture, vol. 87, no. 6, pp. 930-944.
Walton, K 2014, ‘Food Service Systems and Nutrient Losses’, lecture notes, DIET956, University of Wollongong, delivered 1 August.
NSW EPA, Fridge and Freezer Tips, viewed 20 October 2014, <http://www.lovefoodhatewaste.nsw.gov.au/save-it/fridge-and-freezer-tips.aspx>.