Drying of tomatoes and tomato processing waste: a critical review of the quality aspects

Tomatoes are a valuable highly perishable agricultural product that are dried on a large scale for extending shelf life. The drying of both tomatoes and tomato processing waste can yield valuable products. The dried forms serve as raw material for different commercial products, as an ingredient for functional foods. It is also used all over the world for direct consumption. However, the production of dried forms with quality attributes equivalent to those of fresh tomatoes such as the nutrient content, appearance, flavor, texture, reconstitution properties etc. are major challenges. This paper provides an overview of the diverse drying techniques employed along with the effects of pretreatment to produce dried tomatoes, powders, and various by-products of tomato processing industries. A comparison is provided with regard to the quality of dried tomato products obtained by different drying techniques for lycopene content, ascorbic acid, beta-carotene, total phenolic content, flavonoids, antioxidant activity, rehydration ratio, color change, texture, and flavor.

Automated summary

Tomatoes, as a valuable agricultural product, can be dried on a large scale for various commercial products, functional foods, and direct consumption. The challenge lies in producing dried forms with quality attributes equivalent to those of fresh tomatoes. Various drying techniques and pretreatments are employed to produce dried tomato products with different qualities.