Screening, evaluation and identification of promising plant extracts for development of novel natural preservatives

Abstract

Chemical preservatives are widely employed as the primary approach to inhibit food spoilage, yet their acceptance among consumers is progressively diminishing. Consequently, researchers have increasingly made efforts to explore natural preservatives. Phytochemicals with diverse bioactivities offer promising opportunities for development of natural preservatives. In this study, extracts from a total of 90 plant materials were screened and evaluated for their inhibitory effects against the two pathogenic fungi, Aspergillus flavus and Penicillium citrinum. Initially, 20 plant extract samples that exhibited an inhibition rate exceeding 85 % against either or both fungal strains were conducted for further screening. Then, evaluations of their minimum inhibition concentration (MIC), spore germination, and mycelial growth were carried out for the subsequent screenings. Finally, GC-MS analysis was preformed to detect the chemical composition of the selected plant extracts. Thus, the antifungal index of the 90 plants was calculated, forming a repository of raw material for plant-based preservatives. The results revealed significant antifungal activities in the petroleum ether (PE) fractions of Cinnamomum cassia, Syzygium aromaticum, Amomum tsaoko, Nardostachys jatamansi, Angelica sinensis, and chloroform fractions of Cinnamomum cassia, Syzygium aromaticum, Houpoea officinalis and Ruta graveolens. Especially, the MICs of Cinnamomum cassia PE fraction (CMPE) against the Aspergillus flavus and Penicillium citrinum were only 0.125 mg/mL and 0.25 mg/mL, respectively. Moreover, CMPE also exhibited strong inhibiton effects on sprore germination (> 90 %) and mycelial growth (> 50 %, 1 day). These plant extract fractions are considered as potential candidates for novel natural preservatives.