Production of fermented and non-fermented tomato paste, conversion to instant form, and determination of quality characteristics

In this study, tomato pastes were produced from fermented and non-fermented tomatoes, and the resulting pastes were subsequently converted into instant (powder) form to conduct comprehensive quality analyses. Fresh tomato, fermented paste, non-fermented paste, fermented dried paste, and non-fermented dried paste samples were evaluated. A wide range of analyses was performed on the samples, including moisture content, pH, Brix, viscosity, total acidity, salt content, color parameters, black spot occurrence, sensory properties, total phenolic content, flavonoids, carotenoids, lycopene, antioxidant activity, and mineral composition. Among the fermented and non-fermented paste samples, the highest Brix value was recorded in the non-fermented paste sample (30.55). The lowest moisture content was found in the powder forms, ranging from 5.43% to 3.40%. Titrable acidity reached its highest levels in the instant paste samples (4.672–5.344%), while the highest salt content was detected in the fermented powder paste (3.097 g/100ml) and the reconstituted fermented powder paste (3.185 g/100ml). No black spot formation was observed in any of the samples analyzed. In the bioactive compound analyses, the highest carotenoid content and antioxidant activity were measured in the fermented powder paste sample, with values of 128.76 mg/g and 1.454 mmol TE/L, respectively. The non-fermented powder paste samples exhibited the highest flavonoid and total phenolic contents, at 1017.7 mg/L and 806.9 mg GAE/L, respectively. An increase in phenolic compound concentrations was observed in fermented paste samples, with the highest levels detected for catechin, p-coumaric acid, resveratrol, quercetin, and cinnamic acid. Additionally, fermented paste samples demonstrated higher lycopene contents compared to other sample types. The findings also revealed that fermentation enhances the bioavailability of mineral elements by facilitating their release. In conclusion, fermentation and conversion into instant form significantly improved the nutritional, functional, and sensory properties of tomato paste, offering new potential applications for industrial production.