High Lycopene Tomato Ketchup Slice: Development, Drying Kinetics, and Storage Study

This study presents a novel, shelf-stable tomato ketchup slice (TKS) that offers a concentrated, nutrient-dense, and portable alternative to conventional ketchup, addressing storage, wastage, and convenience challenges in tomato-based products. The formulation was optimized using different hydrocolloids (pectin, xanthan gum, guar gum, acacia gum at 0.5% to 2.5%) and modified starch (1.0% to 2.5%) to achieve desirable texture, lycopene retention, and product stability. Drying temperature (50°C, 60°C, and 70°C) served as the independent variable; while drying time, lycopene retention, texture profile, sensory acceptability, and water activity were the dependent parameters. Pectin (0.75%) was identified as the most effective hydrocolloid based on sensory and texture profile analysis. TKS was dried using hot air drying at 60°C, 70°C, and 80°C, and drying kinetics were modelled using three thin-layer models. Among them, the Wang & Singh model provided the best fit (R² > 0.99). The optimized formulation consisted of 0.75% pectin and 1.0% modified starch, dried at 60°C for 495 min. It produced TKS with 14.11 ± 0.28% moisture (w.b.) and 22.42 ± 0.03 mg 100g^-1 lycopene, higher than conventional ketchup (15.45 ± 0.03 mg 100g^-1). Storage studies conducted for 60 days at 28 ± 2°C and 65 ± 5% RH in LDPE pouches showed minimal degradation in lycopene, increased textural firmness, and no detectable microbial growth (<10 cfu g^-1), with water activity remaining below 0.6. These findings confirm that TKS is a microbiologically stable, nutrient-dense, and convenient ketchup alternative with commercial potential for dry condiment applications.