Italian National Agency for New Technologies, Energy and Sustainable Economic Development
Health: Tomato by-products as a source of antioxidant molecules
A study by ENEA and University of Tuscia (coordinator) has shown that tomato industrial by-products exhibit a considerable amount of beneficial molecules. The results of the study have been published in the journal “Food Chemistry” and compare, for the first time, the different nutritional and functional properties of tomato pomace, i.e. skin and seeds (equivalent to 20 percent by weight), obtained from the varieties San Marzano and Sun Black - the latter with its characteristic purple pigmentation - and the Colorless fruit epidermis type with transparent skin.
“We have shown that from these waste products it is possible to obtain a tomato pomace nutritionally comparable to commercial tomato powder but with a significant content of bioactive antioxidant molecules like flavonoids and anthocyanins, known to be effective in preventing the onset of serious diseases and delaying aging,” explained Maria Sulli at the ENEA Green Biotechnologies Laboratory and coauthor of the study with Gianfranco Diretto and Barbara Farinon, Martina Felli, Daniele V. Savatin, Andrea Mazzucato, Nicolò Merendino and Lara Costantini from the University of Tuscia (Viterbo).
Among the different pomaces analyzed, the Sun Black tomato one contained an abundance of beneficial compounds (anthocyanins and flavonoids with percentages ranging from 16.5 % to 36.5 % compared to the other varieties studied) that make it particularly promising as a functional ingredient in pasta, bread and cookies as it can provide them with antioxidant molecules, dietary fiber and minerals. “The tomato powders we have obtained from pomace show important characteristics that could improve the nutritional and antioxidant profile of many foods on the market. We are currently working to analyze their incorporation in different foods and their functionality in vivo through a clinical trial,” explained Lara Costantini at the Laboratory of Cellular and Molecular Nutrition of the University of Tuscia and coordinator of the project.
The study also investigated the possible efficacy of extracts produced from the waste against the bacterium P. syringae and the fungus F. graminearum, which are known to cause damage to tomato crops. “Considering the need for agriculture to find alternative ways of protecting harvests from pests and diseases caused by phytopathogens, and that phenols may also have antimicrobial and antifungal activity, we will evaluate in further studies a potential application as biopesticides of tomato by-products” Sulli pointed out. “It has already been shown that the accumulation of anthocyanins in tomato skin reduces susceptibility to the fungus Botrytis cinerea, one of the most important post-harvest pathogens, ensuring extended shelf-life,” Sulli concluded.
Tomato (Solanum lycopersicum L.) is one of the world’s most cultivated vegetable crop, with a production of over than 189 million tons in 2021, of which about 18 million tons were produced in the European Union[1]. Italy is the largest EU producer of tomatoes with 6.64 million tons in 2021 (36.7 percent of total EU production)[2].
The tomato is a main component of the Mediterranean diet, which can be consumed raw or processed. It is estimated that more than half of total tomato production is processed (into passata, sauces, purees, ketchup or canned tomatoes), generating millions of tons of by-products globally. These byproducts still contain several healthy molecules and could be reused as functional ingredients in a circular economy perspective. The alternative use of tomato processing waste fits into the European Commission's Farm to Fork (F2F) strategy, which aims at a 50% reduction of all food waste by 2030.
