Enriched makiang (Cleistocalyx nervosum var. paniala) seed extract and citric acid to control pathogenic bacteria and color of fresh cut cantaloupe

Consumers demand for good appearance and safe fresh-cut fruits without synthetic preservatives. Phenolic compounds from makiang seeds were extracted and applied as a natural preservative. Makiang seed extract (MKSE) was treated with 5 various amount of Diaiont HP-2MG, a macro porous resin, to enrich the phenolic compound content. The application of 0.375 g Diaion (R) to 1 mL of 12.5 mg mL(-1) MKSE was suitable for adsorbing the phenolic compounds. The eluent of 70% ethanol was able to release phenolic compounds with the highest recovery rate (61.22%). After drying, the phenolic enriched MKSE (PMKSE) contained 97.24% phenolic compounds and 4.99% flavonoids. The antagonistic effect of the MKSE was increased with the enrichment of phenolic content. The fresh cut cantaloupe (FCC) soaked with 1MBC PMKSE reduced the number of bacterial count on FCC, but affected the FCC color. The equal volume of 3.13 mg mL(-1) PMKSE and 6.25% citric acid (MC) could reduce the number of spiked E. coli on FCC to 1.66 log CFU g(-1) and retard the growth of pathogenic bacteria without significantly change in color. The MC had a potential to be applied for maintaining the bacterial quality and color of fresh-cut produce and minimal processed foods.

Automated summary

This study utilized makiang seed extract as a natural preservative and improved the anti-bacterial effect and color performance of fruits through the addition of citric acid. Results showed that makiang seed extract enriched with phenolic compounds exhibited antibacterial properties, reducing bacterial counts while maintaining fruit quality.