Efficacy of plant-based natural preservatives in extending shelf life of sugarcane juice: Formulation optimization by MOGA and correlation study by principal component analysis

Abstract

Sugarcane juice spoils quickly as a result of microbial contamination and enzymatic reactions. To maintain its quality during storage, synthetic preservatives are generally employed. However, their use has been linked to potential health hazards. In this regard, some plant based natural preservatives can be utilized as safe alternatives. Lemon juice (LJ), basil leaf extract (BE), mint leaf extract (ME), and lemongrass essential oil (LGEO) were used in this study. LJ, BE and ME were varied from 2 to 8% (v/v) and LGEO was ranged between 1 and 3% (v/v). The concentrations of these natural preservatives were optimized by multi-objective genetic algorithm (MOGA) based on contrasting goals of maximizing soluble solids, phenolic content (PhC) and sensory acceptability score while minimizing pH, polyphenoloxidase (PPO) activity and bacterial count. The LGEO followed by LJ inhibited the microorganisms and oxidative enzymes at an appreciable level and ME was the least effective among all. At the same time, LJ offered more preferable sensory scores than others. The optimized concentration suggested by MOGA was 6.84% LJ and 1.05% LGEO which resulted in 10.3% rise in PhC, 49.3% PPO inactivation, 2 log cycle bacterial reduction and 3.5% sensory improvement in the raw juice. The changes in quality parameters during storage and correlations among them were effectively illustrated by principal component analysis. It was revealed from microbial safety analysis that sugarcane juice with storage stability of 26 days at 4 ºC could be prepared by addition of natural preservatives.