Natural and Synthetic Food Additives and Preservatives; A Systematic Review of Their Implications for Food Quality Assurance, Shelf-Life, Food Safety, and Human Health

Objective The contemporary food industry relies heavily on additives and preservatives to mitigate spoilage, extend shelf-life, and uphold safety standards amid global supply chain pressures. This systematic review aims to synthesize and critically appraise the evidence from primary studies from 2020 to 2026 investigating natural and synthetic food additives and preservatives. Methods This systematic review followed PRISMA guidelines. Focusing on original empirical studies, the analysis contrasts natural additives/preservatives, e.g., plant extracts, bacteriocins, protein hydrolysates, etc., and synthetic additives/preservatives, e.g., benzoates, sorbates, nitrites, etc., followed by a comparative synthesis across four core domains of quality assurance, shelf-life extension, microbial safety, and human health outcomes. Results Drawing on 33 included studies, this systematic review found that natural additives/preservatives frequently match or surpass synthetics in targeted antimicrobial efficacy and oxidative stability while presenting fewer chronic toxicity concerns. However, regulatory revaluations highlight ongoing scrutiny of synthetic additives/preservatives. Original tables summarise key findings under subheadings such as Additive, Source, Food/Pharma Matrix, Shelf-life Extension, Microbial Reduction, Quality Assurance, Food Safety, Health Implications, Study Design, Limitations, etc. Findings demonstrate a shift toward hybrid clean label strategies, although gaps persist in long term human cohort data and scalability of novel bio preservatives. Conclusion Recent findings consistently signal a decisive shift toward hybrid preservation systems that integrate natural antimicrobials with smart delivery technologies while reducing reliance on synthetic additives. Policymakers and industries should priorities evidence based integration of additives/preservatives to balance their efficacy, food safety, and maintain consumer trust.