Apple Slinky – Lunchbox Idea #1




It’s back to school time and with it comes the packing of school lunches.

I realise that I’m a bit of an oddity in the US… my kids don’t eat the cafeteria lunches that all the other kids eat. I send them to school with a packed lunch. They get made-from-scratch instead of the chemical laden, mass produced mac & cheese. The horror. I am such an embarrassment of a mother.

Anyway, part of every good school lunch is a piece of fruit. I love apples because they are low GI, loaded with fibre, cheap to buy, and withstand the beating that schoolbags often endure. And active kids don’t need to worry about the fructose content. But if your kids are anything like mine, they eat a few bites and then put the remainder back in their lunchbox. Then I have to deal with the brown sticky mess that afternoon (ok, ok, I’m actually madly washing lunch boxes at 7:30am each morning because I forgot to do it the previous day…)

With my youngest starting kindergarten this year, I’m on a mission to find a way to send apple pieces to school, instead of a whole (uncut) apple. I’ve tried spraying the apples with lemon juice, which does work, but then the apple tastes like lemon and doesn’t get eaten. But now I think I’ve found the perfect solution.

Citric Acid.

You can buy it from the grocery store (you’ll often find it with the jam making supplies), but it’s cheaper to buy it in bulk on the internet. Most health stores, home brew or cheesemaking supply places will sell it.


Here’s what you need to do:

1.  Into a ziplock bag put 2 teaspoons of citric acid and 1/8 cup of water. Just guess, it doesn’t have to be exact and heaven knows I’m not going to create more dishes to wash by actually measuring things.

2.  Seal the bag and shake it around until the acid is dissolved. It should only take a minute. Better yet, get the kids to shake it while you enjoy your coffee.

3. When it’s fully dissolved, you can add your pieces of apple, apple slinky or whatever you don’t want to turn brown.

4.  Seal and shake again, making sure that all the exposed edges of fruit get coated in the acid mixture. Again, this is a job the kids can do for you. I’m told that a week’s worth of fruit can be stored this way, but I personally haven’t tried that yet.

5.  Take the day’s fruit out of the bag. Now this is where it gets interesting. If you eat the fruit just like this, it will taste sour. Really sour. Try it! Better yet, give it to your partner or child without telling him/her and watch their face. 🙂

6.  To get rid of the excess citric acid, rinse the fruit under the tap. Then you can put it into a container and into the lunch box. Voila. Perfect, non-brown apple pieces that don’t taste like lemon.


In this photo, you can see the difference that it makes. The apple core on the slinky maker was left for an hour to go brown. The slinky apple was treated with citric acid and doesn’t have a single spot of brown on it.



For the science geeks:

Apples (and other fruit) turn brown because of an enzyme called polyphenol oxidase (sometimes called phenolase). When the apple is cut, this enzyme chemically reacts with the oxygen in the air and produces melanins, which are brown in colour. This is a similar process to rusting of metal. The reaction occurs when the pH level is between 5.0 and 7.0. However, below a pH level of 3.0, the enzyme no longer reacts. Citric acid has a low pH so coating your apple with it with prevent the reaction from occurring. Other methods of stopping the brown involve limiting the fruit’s exposure to oxygen (for example, vacuum sealing the container), or adding a donor chemical like Ascorbic Acid (vitamin C) which will react with the oxygen before the phenolase will. Which method works best? Sounds like the makings of a great science experiment!


2 thoughts on “Apple Slinky – Lunchbox Idea #1

  • November 1, 2015 at 3:56 am

    Gorgeous photos! How did you get your countertop so shiny? : ) I haven’t tried citric acid for apples but have some and might give it a go. We like to chunk up the apples and add lemon and cinnamon. Haven’t had trouble browning (or maybe the cinnamon disguises it!) : ) and our family loves the extra flavor from the cinnamon. Thanks for the tip!

    • November 1, 2015 at 12:41 pm

      Thanks for the comment! Lemon will act the same as the citric acid in preventing the brown. And I love my countertops – they’re granite and so easy to clean. Although I have to admit that the shine is mostly do to with the angle of the light, rather than my cleaning ability. 🙂


Leave a Reply

Your email address will not be published. Required fields are marked *