Comparative study of natural and synthetic preservatives on quality of fruit jam during storage

Abstract:

Synthetic preservatives such as sodium benzoate and potassium sorbate remain the default choice in commercial jam production, yet growing consumer demand for clean-label products has pushed food processors to seek plant-derived alternatives. This research compared the effectiveness of two synthetic preservatives (sodium benzoate at 0.1% and potassium sorbate at 0.1%) and two natural preservatives (tulsi extract at 2% and ginger extract at 3%) alongside a citric acid reference (0.3%) and an unpreserved control on the physicochemical, microbiological, and sensory quality of mixed-fruit jam stored at ambient temperature (28 ± 2 °C) for 90 days. The trial was conducted at the Cerrado Agricultural Institute, Goiânia, Goiás during January-April 2023. Sodium benzoate-treated jam retained the highest ascorbic acid (22.7 mg 100 g⁻¹), lowest browning index (0.18), and best sensory scores (overall acceptability 7.9 on a 9-point scale) at 90 days. Among natural options, tulsi extract performed closest to the synthetic treatments, preserving 19.8 mg 100 g⁻¹ ascorbic acid with an acceptability score of 7.4. Ginger extract imparted a detectable flavour that lowered its sensory rating. The unpreserved control showed visible mould by day 75. These findings indicate that tulsi extract offers a viable clean-label alternative for jam preservation, though it does not fully match the shelf-life extension of synthetic additives.