Vegetable & Fruit Nutrient Scanner


“You are what you eat.” It means our diet determines our health. The food we eat is a basic and fundamental ingredient of our lives. Through the digestive process, food is broken down into smaller pieces and absorbed to support our daily functioning.
With the rising consciousness of a healthy lifestyle, we now know that other than eating to fill ourselves up, we also need to eat well to optimize our body operations and prevent chronic illnesses. However, what does ‘eat well’ means? Here, we refer to obtaining adequate and diverse nutrients our body needs, apart from macronutrients such as carbohydrates, proteins or fats, micronutrients such as minerals, vitamins and antioxidants are equally essential. So, can we get all essential nutrients from the plate?

The Declining Nutrient Content in Food 

Increasing evidence has been showing that the mainstream industrial food system is not serving us well when it comes to the nutritional value of food. (Read more to know why our food nutrient content is decreasing.) A landmark study from the University of Texas (UT) found 5%-40% declines in nutrient contents in 43 types of vegetables and fruits over the past half century, including proteins, calcium, vitamin B2 and vitamin C[1]. These nutrients are essential to our health. Diets lacking in such nutrients will lead to biological dysfunction and diseases, such as heart disease and type II diabetes[2].

Agriculture development over the past decades has been focusing solely on yields while neglecting the equally important factor: Nutritional Value of food. The concept of “Nutrient Density” has been raised in recent years to draw attention to the importance of nutrient contents in our food[3]. It recognises that food with the same type and weight could contain different concentration and variety of nutrients, particularly micronutrients like minerals, vitamins and antioxidants, in addition to macronutrients like carbohydrates, proteins and fats[4].

The two apples in the picture look equally great, but have you ever wondered if they are equally nutritious? Apples are supposed to be rich in iron. If these two apples, of similar sizes and masses, are vastly different in iron content, they are then having very different nutrient density.

Among all the nutrients found in food, antioxidants are the group that has been gaining attention in recent years as they help us prevent the aforementioned chronic diseases and serve cosmetic purposes.

The Importance of Antioxidants 

What are antioxidants? Antioxidants are substances which can prevent or reduce body cells’ damage caused by oxidation. They help us prevent cell aging and improve our immune responses. Plant-based foods are good sources of antioxidants, including fruits, vegetables, whole grains, nuts and seeds.

Among all types of antioxidants, polyphenols have been one of the trending antioxidants in recent years. Polyphenols are naturally synthesized in plants as immune. For us, polyphenols can also act as antioxidants and reduce inflammation, which is thought to be the root cause of many chronic illnesses[5]. Common types of polyphenols include flavonoids in brightly colored vegetables, curcumin in turmeric and lignans in flax seeds, sesame seeds and whole grains.

The amount and type of antioxidants in our foods depend on the food species, its origin, ripeness and how it was farmed, transported, stored and prepared[6]. Thus, the antioxidant content of each vegetable and fruit in the market can be different.

With variance in nutrient content in vegetables and fruits, how do we, as consumers, differentiate our purchases according to their nutritional values?

If I want to buy blueberries which are known to contain beneficial nutrients like anthocyanins (a type of polyphenols), potassium and vitamin C. However, there are thousands of blueberries in the market. How can I choose the blueberries with higher polyphenol content when they all look the same? Is there a convenient and instant method to help us understand better what vegetables and fruits are nutrient-dense or healthy?

This is how our project starts.


[1] Davis, D. R., Epp, M. D., & Riordan, H. D. (2004). Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999. Journal of the American College of Nutrition, 23(6), 669–682.

[2] Chadwick, R. (2004). Nutrigenomics, individualism and public health. Proceedings of the Nutrition Society, 63(1), 161-6.

[3] Rodale Institute. (2021). Nutrient Density.
Retrieved from

[4] Greg, F., & Vita, L. (2021). 3 Major Factors Affecting Access to Nutrient Dense Foods: Where Have All the Nutrients Gone?.
Retrieved from

[5] Hunter, P. (2012). The inflammation theory of disease. The growing realization that chronic inflammation is crucial in many diseases opens new avenues for treatment. EMBO reports, 13(11), 968–970.

[6] Petre, A. (2019, July 8). What Are Polyphenols? Types, Benefits, and Food Sources. Retrieved from