Most dyes used in the food industry are synthetic and can be a health hazard. Red tomato may serve as a natural alternative dye to replace synthetic colorants. This study aimed to review the literature on the addition of red tomato products (powder tomato, paste, freeze-dried, tomato peel powder, tomato pomace) to reduce the usage of synthetic dyes in the food industry. Red tomato products have been used as coloring in pasta, bologna, sausages, cookies, crackers, macaroons, hamburgers, breads, muffins, cheeses, and nuggets. The trans-cis isomerization of lycopene by oxidative processes directly affects the color of the pigment. The lycopene contained in tomato has antioxidant activity and could reduce or eliminate other oxidants and/or synthetic preservatives in food. Moreover, tomatoes in foods have high sensory scores, nutritional appeal, and marketing potential. However, its use as a food colorant has been not extensively explored. Therefore, further studies are still required, especially on the stability of carotenoids in tomatoes used in processed foods.

Background: Foods that promote health benefits are being increasingly used. Innovative techniques, such as nanotechnology, have been used to improve functional properties, sensory characteristics, or the conservation of foods. Objective: The objective of this study was to identify the technological domain of patents for tomato products with or without nanotechnology and elucidate the technological advances associated with the recent use of tomatoes as a natural food dye in the food industry by exploring patent documents. Methods and Results: The search was conducted using the Espacenet and INPI databases. There was an increase in patent document applications employing nanotechnology in 2013, with a peak between 2017 and 2018. China is the lead country in the number of patent applications. In Brazil, the patent applications are variable, and the food industry is most involved in studies on tomatoes as a natural food dye. Most patent deposits using nanotechnology were from companies, and the main sources of the patent application were the food and pharmaceutical industries. Conclusion: There is an increasing trend for the use of tomatoes as natural food dyes, produced with or without nanotechnology, and number of patents filed yearly. New technologies are being developed in several application areas.