This study focused on the phytochemical, antioxidant, and antimicrobial activities of the ethanol extracts of golden berry calyx and fruits. The phytochemical analysis of calyx and fruit extracts revealed high total phenols and flavonoids. High antioxidant capacity was recorded for fruit extracts. Fruit extracts also gave the highest antibacterial activity against Pseudomonas fluorescens, Escherichia coli, and Salmonella typhimurium. Furthermore, tomato paste was prepared using sodium benzoate and golden berry extract as food preservatives. The incorporation of golden berry extract and chemical preservatives maintained the paste quality indicators over the control samples. A rapid decline in total antioxidant capacity was also observed in control samples (21.6%) as compared with the treated samples (15.21% and 15.41% for sodium benzoate and golden berry extract, respectively) after 30 days of storage. This study demonstrated that dried fruit extract with high phytochemical and antimicrobial properties could be used as a natural food preservative.