eng Enviro Research Publishers Current Agriculture Research Journal 2347-4688 2321-9971 2026-05-11 14 1 102 118 26861 article Sadvatha Ramanna Haromuchadi 1 Karuppiah Alagusundaram 1 (Agriculture Structures and Process Engineering), Regional Station, ICAR-Central Institute of Agricultural Engineering, Coimbatore, Tamil Nadu. Agricultural Engineering Division, ICAR, New Delhi and MD and CEO, Tamil Nadu Food Processing and Agri Export Promotion Corporation (TN APEX), Govt. of Tamil Nadu. The study evaluated the physicochemical properties and respiration behaviour of two commercial tomato cultivars (CV-613 and Naveen), selected due to their commercial significance and widespread cultivation, at different maturity stages to generate engineering data for the design of harvesting, grading, packaging, and storage systems. Physical properties such as size, surface area, unit weight, density, firmness, and color were measured at mature green, semi-ripe, and fully ripe stages, the geometric mean diameter of cv. Naveen ranged from 48.1 to 56.3 mm, while that of cv. 613 ranged from 47.7 to 52.1 mm. Surface area varied from 7285.9 to 9966.0 mm² for cv. Naveen and 7144 to 8540 mm² for cv. 613. Fruit firmness decreased significantly during ripening, with higher firmness observed in cv. Naveen (5.4–1.45 N mm⁻¹) compared with cv. 613 (3.26–1.28 N mm⁻¹). Color parameters showed decreasing L* values and increasing a*/b* ratios as ripening progressed. Chemical properties, including pH, ascorbic acid and total soluble solids (TSS), increased with maturity stage, whereas titratable acidity decreased. Respiration studies conducted under closed conditions at different temperatures showed that respiration rate increased with temperature and maturity stage, while lower temperatures significantly reduced metabolic activity. The results provide useful engineering data for the design of grading equipment, handling systems, and modified atmosphere storage for tomatoes. http://www.agriculturejournal.org/volume14number1/physicochemical-properties-and-respiration-rates-of-tomato-cultivars-cv-613-and-naveen-at-different-maturity-stages-implications-for-postharvest-handling-and-storage/ Machine; Maturity; Physical properties; Respiration; Tomato fruits; Varieties