Characterization of β-cyclodextrin inclusion complexes embedded with lemongrass and basil essential oils and their modified sustained-release pads for large yellow croaker (Larimichthys crocea) fillet preservation

Abstract

To study the characteristics of the inclusion complexes (ICs) of lemongrass essential oil (LEO) and basil essential oil (BEO) using β-cyclodextrin (β-CD) as wall and their application potential in preservation of large yellow croaker (Larimichthys crocea), the ICs with different weight ratios (8:92, 11:89, 14:86, and 17:83 w/w) were prepared. The ICs were successfully prepared according to the results of differential scanning calorimetry and scanning electron microscopy. The DPPH scavenging rates of pure LEO and BEO at 0.1 mg/mL were 43.84% and 77.64%, respectively. Their inclusion complexes (LEO-IC and BEO-IC) had the DPPH scavenging rates of 57.27% and 67.17%, respectively. And both inclusion complexes (LEO-IC and BEO-IC) have good antibacterial potential, with the ratio of 14:86 (w/w) being the optimal. Subsequently, the modified sustained-release pads with LEO/BEO-ICs were applied to preserve large yellow croaker, and the effect was evaluated in comparison with EOs and commercial absorption pad (AP). The total viable counts of fillets without any treatment reached 8.70 log CFU/g on day 6, but those of samples placed on sustained-release pads (LEO-IC/AP and BEO-IC/AP) were only 7.16 log CFU/g and 7.33 log CFU/g, respectively. The modified sustained-release pads also showed effectiveness on inhibiting the increase of pH, maintaining texture properties and the decrease of water-holding capacity of the fillets. It can be a potential method for commercial application, but further study on odor and muscle changes should be conducted.