In this work, 10 processing type Hungarian tomato gene bank accessions were investigated in a 3-year open-field experiment together with three commercial varieties for quantifying the genotype × environment interaction for their total soluble solids, total acid, dry matter, lycopene, total polyphenol content and antioxidant activity. Results showed remarkable differences of accessions in phytonutrient content over the 3 years (environments). Genotype main effect plus genotype × environment interaction biplots were created for the visualization of the best performing samples and of their relation to a theoretical best variety. Obovate fruit-shaped accessions (especially RCAT031257 and RCAT060349) reached outstanding nutritional results in every environment. According to extremities in weather conditions, two landraces (RCAT060348 and RCAT060349) with higher drought tolerance, and two (RCAT031257 and RCAT029837) less prone to excessive rainfalls were identified. The results can contribute to the enrichment of tomato nutritional phenotypic data banks, facilitating the utilization of gene bank accessions in genomic studies.