[science] calorie variation in fruit due to climate?

yirara

I've been wondering about this for a while but can't find an answer.

Imagine you have an apple tree in your garden. One year the summer is really not good and your apples are not very sweat. The next summer is hot, sunny, and your apples are very sweat. Will there be a difference in calories, and how big will it likely be for an equal-sized apple?

Same for growing veggies from good and less good soil, or anything else you can imagine.

If there are variations, how does USDA and other organizations determine calories for produce? Is it an average or a highest possible number within.. one standard deviation of the mean or what?

jennifer_417

Most "official" calorie counts are bases on an average. It's almost certainly that calories in various foods vary for lots of different reasons. That's why I sometimes say that calorie counting is as much art as it is science. On the whole, though, it still works.

Jackie9003

Do you think it would make enough of a difference to matter? If an apple is around 80cals and the variance in your example is, say, 10% it would only be 8cals. Also does the cal value include the core, as you wouldn't normally eat that but I wouldn't weigh it and deduct it.
It's an interesting question.

kpsyche

There's a whole bunch of standards for analysis of food: https://www.iso.org/ics/67.050/x/

Mineral content is variable based on the soil things are grown in, or the foods that an animal eats.

As for energy, the Atwater system is a common method for determining metabolisable energy and the results are usually (or should be) averaged.

https://en.wikipedia.org/wiki/Atwater_system
https://www.ncbi.nlm.nih.gov/pubmed/11299073

yirara

Jackie9003 wrote: »

Do you think it would make enough of a difference to matter? If an apple is around 80cals and the variance in your example is, say, 10% it would only be 8cals. Also does the cal value include the core, as you wouldn't normally eat that but I wouldn't weigh it and deduct it.
It's an interesting question.

I doubt think it accounts for much, but I somehow ended up in a discussion on that the whole calorie counting business is *kitten* anyway due to what I wrote above. I know calorie counting works, but this discussion reminded me that I was wondering about this before as well.

yirara

kpsyche wrote: »

There's a whole bunch of standards for analysis of food: https://www.iso.org/ics/67.050/x/

Mineral content is variable based on the soil things are grown in, or the foods that an animal eats.

As for energy, the Atwater system is a common method for determining metabolisable energy and the results are usually (or should be) averaged.

https://en.wikipedia.org/wiki/Atwater_system
https://www.ncbi.nlm.nih.gov/pubmed/11299073

Thanks a lot! This will give me something interesting to read tonight

livingleanlivingclean

Sweeter apples would have more sugar, less sweet apples would have less.... There may also be a difference between juicy vs less juicy. Thicker skin (more fibre) vs thinner skin. Micronutrient content would also differ depending on season, growing conditions, ripeness when picked, storage conditions and length etc.

There would be many variations between varieties and from season to season. The official nutrition info is an average.

kpsyche

yirara wrote: »

kpsyche wrote: »

There's a whole bunch of standards for analysis of food: https://www.iso.org/ics/67.050/x/

Mineral content is variable based on the soil things are grown in, or the foods that an animal eats.

As for energy, the Atwater system is a common method for determining metabolisable energy and the results are usually (or should be) averaged.

https://en.wikipedia.org/wiki/Atwater_system
https://www.ncbi.nlm.nih.gov/pubmed/11299073

Thanks a lot! This will give me something interesting to read tonight

That's ok.

Similar to your apple example varying due to the growing environment, farmers manipulate the food they feed livestock to achieve certain results... a good example might be omega-3 enriched/fortified eggs that are "created" by feeding chickens flax (the omega 3 in the flax ends up in the eggs)

CSARdiver

From a calorie perspective this falls below instrument error (<20% margin of error).

It may impact nutrients, but this has more to do with soil composition.