Clean Label Preservatives for Foods: An Evidence-Based Systematic Review of Their Antioxidant and Antimicrobial Performance

Global food supply, necessary for human health and survival, is prone to spoilage issues due to several factors, including microbial contamination, chemical reactions and physical changes. According to FAO, one-third of the food produced for human use is spoilt or wasted. Many preservation methods including canning, refrigeration, freezing and synthetic chemical-based preservatives are used to control spoilage or extend shelf life. While synthetic preservatives are generally considered safe but their concentration exceeding the permissible limits have long-term negative or life-threatening health effects. Conversely, clean-label preservatives are defined by the perception and familiarity of the ingredients as well as the exclusion of preservatives with artificial or chemical origin to meet the market-driven expectations of the consumers. They can elongate the shelf life of food products without causing any negative health effects. This systematic review-based thesis provides a comprehensive analysis of clean-label focused research studies conducted on meat, seafood, dairy and bakery products since 2016. These studies were identified by running appropriate search queries on Scopus and PubMed databases. A PRISMA-guided approach was followed for screening using predefined inclusion and exclusion criteria. Descriptive and quantitative data were collected against several variables including specific food items, preservative type and source, shelf-life impact, antimicrobial and antioxidant efficacy and sensorial effects. Out of 195 studies, the largest proportion (n=111) was found to be on meat followed by dairy (n=37), seafood (n=29) and bakery (n=16). These findings indicate that clean-label preservatives, particularly of plant origin, have been widely studied across a variety of food products. While prolongation of shelf life was reported in most of the studies (n= 85), additional benefits due to high phenolic concentrations and antioxidant properties were also reported. Overall, this review highlights the potential of clean-label preservatives by identifying their proven suitability in lab-scale studies. It was also established that further research on pilot- or commercial-scales to improve standardization and scalability of the clean-label preservatives is required prior to application in the mainstream food industry.