Are Processed Tomato Products as Nutritious as Fresh Tomatoes? Scoping Review on the Effects of Industrial Processing on Nutrients and Bioactive Compounds in Tomatoes
A major question among nutrition experts and consumers is whether tomato processing — such as turning tomatoes into paste, purée, sauce, or canned tomato products — reduces the nutritional and health value compared to fresh tomatoes. A 2021/2022 scoping review titled “Are Processed Tomato Products as Nutritious as Fresh Tomatoes?” addresses this concern by summarizing existing research on how industrial processing affects nutrients and bioactive compounds in tomatoes.
Findings from the Review
1. Changes in Moisture and Solids — Concentration Effect:
Fresh tomatoes typically contain 5–10% dry matter; in contrast, processed tomato products (like paste) are concentrated, often removing water and increasing total and soluble solids substantially. This concentration changes the nutritional density per gram of product.
2. Carotenoids — Especially Lycopene — Behavior:
Tomatoes contain various carotenoids and bioactive compounds including β-carotene, phytoene, phytofluene, xanthophylls, and especially lycopene, which typically makes up 60–90% of total carotenoids by weight.
In raw tomatoes, lycopene is mostly in the “all-trans” form, which is relatively poorly absorbed by the human body. Heat processing (as in producing paste, purée, sauce, or canned tomatoes) can alter the cellular matrix, break down cell walls, and convert lycopene into cis-isomer forms. These structural changes substantially increase the bioavailability of lycopene.
3. Variation in Effects — Not Uniform Across Nutrients:
The effect of processing on nutrients is complex and depends on multiple factors: tomato variety, processing conditions (temperature, duration, oxygen exposure), presence of added ingredients (salt, oil, acid), and which specific nutrient or bioactive compound is considered.
For example: while lycopene and some carotenoids may become more bioavailable or even increase in concentration per weight, other nutrients sensitive to heat or oxidation (like vitamin C) may decrease in processed products.
4. Potential Advantages of Processed Tomato Products:
Because of concentration (less water) + enhanced lycopene bioavailability, a typical serving of tomato paste, purée, or sauce may deliver equal or even greater antioxidant potential compared to the same weight of fresh tomatoes.
Processed products can provide stable, year-round access to tomato nutrients, independent of seasonality — which is valuable in diets where fresh tomato is not always available.
5. Limitations and Need for Caution:
The data are still limited — only a small number of studies (about a dozen) have systematically compared fresh vs. processed tomatoes across nutrients and bioactive compounds.
The effects are inconsistent across studies; for some nutrients or compounds processing causes losses, while for others it improves bioavailability.
The “nutritional value” of a tomato product depends not only on the tomato itself but also on the processing method, added ingredients, storage, and how the product is consumed. Hence, one cannot claim a blanket equivalence or superiority.
The review concludes that the question “Are processed tomato products as nutritious as fresh tomatoes?” does not admit a simple yes/no answer. Instead, the nutritional and health value depends on many variables.
That said, for many important bioactive compounds — particularly lycopene — processed tomato products (paste, purée, sauces, canned tomatoes) can be as beneficial or even more effective than fresh tomatoes, because processing often increases the concentration per serving and significantly improves bioavailability.
Therefore, incorporating processed tomato products into the diet — especially in contexts where fresh tomatoes are unavailable or out-of-season — can be a valid and effective nutritional choice.
