How Well Do You Know Your Produce?

Posted August 20, 2020

In the produce aisle, we do our best to pick fruits and vegetables that look appetizing, undamaged, and ready to ripen when we’ll want to eat them. However, when it comes to nutrition, looks can be deceiving. Nutrition labels use values set by the USDA, that, in some cases, are based on data from small samples recorded over a decade ago! So what’s written on the label often doesn’t match what’s under the peel, and our ways of visually evaluating produce in the store don’t always tell the whole story.

At TeakOrigin, we’re taking on a massive challenge: accurately measuring produce’s true quality and value using analytical chemistry, optical spectroscopy and machine learning. With our data, we’ve created the TeakOrigin Guide, a free resource designed to share the unique, inner qualities of food with consumers.

As a fun way to illustrate our point, we’ve put together this quiz using our own data and samples gathered by our team. Some pairs are practically identical while others are worlds apart. So please go ahead and see how you fare trying to pick the most nutritious piece of produce from the sample pairs below – the answers may surprise you.

Honeycrisp Apple

The honeycrisp apple gets its signature refreshing taste from a combination of sugars (fructose and glucose) and tart malic acid. In addition to fiber, honeycrisp apples are a good source of antioxidants such as vitamin C. However, the amount of vitamin C found in this tasty apple can vary quite a bit.

For your first question, which of these two honeycrisps has the highest level of vitamin C?

CORRECT!

Correct! This apple has around 9mg of vitamin C. That’s nearly twice the USDA average of 4.6mg. For comparison, apple A only had 1.25mg of vitamin C. While the long shelf life of the sugars and acids found in a honeycrisp help it keep its great semi-sweet taste, not all honeycrisp apples are created equal when it comes to vitamin C.

NOT QUITE!

This apple has just 1.25mg of vitamin C. That’s well below the USDA average of 4.6mg, and a fraction of the 9mg found in apple A. While the long shelf life of the sugars and acids found in a honeycrisp help it keep its great semi-sweet taste, not all honeycrisp apples are created equal when it comes to vitamin C.

Banana

It’s easy to see why bananas are so popular: they’re delicious, nutritious, and convenient – a fruit that comes in its own compostable wrapper! Bananas are also rich in potassium, a mineral that keeps your heart healthy and blood pressure low.

Can you identify which of these two bananas contains a higher level of potassium?

CORRECT!

You’re correct, but give a day or two before peeling! At 300mg, sample A has the higher level of potassium, while sample B has 270mg. It might be too green to eat right now, but ripeness has bearing on the potassium level in a banana. Both bananas had less potassium than the 358mg average listed by the USDA. In fact, our analysis regularly found this fruit falling below the USDA average. This is still a potassium-rich product, but low levels of potassium typically indicate poor growing conditions and soil health.

NOT QUITE!

Close, but not quite! Sample B has 270mg of potassium, while sample A had 300mg. Both bananas had less potassium than the 358mg average stated by the USDA. In fact, our analysis regularly found this fruit falling below the USDA average. This is still a potassium-rich product, but low levels of potassium typically indicate poor growing conditions and soil health.

Spinach

You’ve probably heard that spinach has high levels of iron and magnesium, but did you know this leafy green is packed with vitamin C, too? It also contains an “anti-nutrient” known as oxalic acid that can prevent the absorption of certain nutrients, like calcium. Ever noticed your teeth feeling gritty after eating spinach? That’s the result of oxalic acid reacting with the calcium in your saliva!

Now, can you tell which of these two spinach samples has the highest level of vitamin C and oxalic acid?

CORRECT!

That’s right! This spinach had 80mg of vitamin C, equal to a medium-sized orange, and almost three times the amount in sample B, which was closer to the USDA average of 28.10mg. It also had 0.71g of oxalic acid, higher than the 0.57g average reported by peer-review studies (the USDA doesn’t report oxalic acid content for spinach). Typically, larger leaf spinach has more oxalic acid. Too much oxalic acid can have negative side effects as it can bind to minerals in your body, causing kidney stones and other health problems. Luckily, cooking spinach reduces oxalic acid levels.

NOT QUITE!

Not quite! At 29.84mg, this spinach has about a third of the vitamin C of sample A. It also has a lower oxalic acid level, 0.35g, which is less than the 0.57g average found in peer-reviewed studies (the USDA doesn’t report oxalic acid content for spinach). Typically, larger leaf spinach has more oxalic acid. Too much oxalic acid can have negative side effects as it can bind to minerals in your body, causing kidney stones and other health problems. Luckily, cooking spinach reduces oxalic acid levels.

Strawberries

Eye-catching red strawberries are a treat, sweetened by natural sugars like fructose with plenty of antioxidants like vitamin C.

Which of these two strawberries contains the most fructose and vitamin C?

CORRECT!

You’re half right! While this is the sweeter strawberry with 4g of fructose, compared with 3g from sample B, it has far less vitamin C, with just 12.72mg versus the 73.69mg found in B. The USDA average for fructose in strawberries is based on 16 strawberries analyzed in May 2006 and we’ve consistently seen higher fructose levels in the strawberries we’ve tested. Fructose is the sweetest type of sugar and is found naturally in all fruits. More sugar means sweeter strawberries, and sugars are less prone to breaking down due to age compared to other nutrients, giving the sweet taste a long shelf life. Vitamin C, however, is a delicate nutrient that can drop off quickly due to age or improper storage. Freshly harvested strawberries generally have the highest amount of vitamin C.

NOT QUITE!

You’re half right! While this strawberry has less sugar than sample A (4g of fructose compared with 3g), it has far more vitamin C. We recorded 12.72mg of vitamin C, far below the 58.80mg USDA average; sample A contained 73mg. The USDA average for fructose in strawberries is based on 16 strawberries analyzed in May 2006 and we’ve consistently seen higher fructose levels in the strawberries we’ve tested. Fructose is the sweetest type of sugar and is found naturally in all fruits. More sugar means sweeter strawberries, and sugars are less prone to breaking down due to age compared to other nutrients, giving the sweet taste a long shelf life. Vitamin C, however, is a delicate nutrient that can drop off quickly due to age or improper storage. Freshly harvested strawberries generally have the highest amount of vitamin C.

Tomato

Tomatoes are delicious and versatile, and their signature red color comes from lycopene, an antioxidant believed to have wide-reaching health benefits.

Given that, which of these two tomatoes is richest in lycopene?

CORRECT!

That’s right! This tomato registered 2930.87ug, which actually exceeds the USDA average of 2573.00ug. For once, you can believe your eyes: redder tomatoes generally contain more lycopene, while yellow and green tomatoes contain no lycopene at all.

NOT QUITE!

Not quite! This tomato came in much lower than the USDA average of 2573.00ug, registering only 1025.25ug. For once, you can believe your eyes: redder tomatoes generally do contain more lycopene, while yellow and green tomatoes contain no lycopene at all.

Avocado

Botanically speaking, the tree-grown avocado fruit is considered a berry, and it’s a good source of what many consider to be healthy fats.

Which of these two avocados do you think has the highest total oil content?

TRICK QUESTION!

Trick question! Both avocados contain around 23g of total oil content, well above the 14.66g the USDA average. Once picked, the oil content of an avocado doesn’t change, but as the fruit ripens, oil is released from the flesh, making the avocado soft, creamy, and edible. Looks and touch can tell you if an avocado is ready to become guacamole, but the nutrition label doesn’t reflect the maturity and total fat content of the fruit.

TRICK QUESTION!

So, how did you do? Share your results on social media and see if your friends know their fruits and vegetables better than you, and check out the TeakOrigin Guide for more nutrition science about the grocery stores we shop at and the produce we buy.

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