Preparation Of Ferulic Acid-?-cvclodextrin Inclusion Complexes And Preservation For Hairtail (Trichiurus Lepturus)

Ferulic acid,a hydroxycinnamic acid that commonly existed in plant cell wall,has properties of antioxidant,antimicrobial,anti-inflammatory,anti-cancer and vasodilatory.The inclusion system of ferulic acid(FA)into ?-cyclodextrin(?-CD),were prepared by a co-precipitation method at three different host-guest stoichiometry(1:0.5,1:1 and 1:2).The inclusion effects,structures and biological activities of inclusion complexes were determined.Four mathematical models were applied to adjust FA release profile and identify preferential kinetics in distilled water or different pH.The spoilage organism in hairtail(Trichiurus lepturus)during refrigerated period were isolated and identified.And the antibacterial activity of inclusion complexes on main spoilage organism separated from hairtail was evaluated.Moreover,some physicochemical indicators,combined with sensory evaluation were determined to evaluate the preservation effect of FA-?-CD.The main results were as follows:1.The inclusion system of ferulic acid(FA)into ?-cyclodextrin(?-CD)were created successfully by a co-precipitation method.The inclusion effect of host-guest in different proportion was evaluated.And the results showed that the entrapment efficiency and loading rate of IC 1:0.5 were significantly higher than those of other ratios.The inclusion complex was characterized by various analytical techniques,such as thermal analysis(DSC and TGA),X-ray diffraction(XRD),Fourier Transform Infrared Spectroscopy(FTIR)and scanning electron microscopy(SEM).2.The antioxidant activity of inclusion complexes gradually enhanced with higher the proportion of ferulic acid in DPPH radical scavenging and hydrogen peroxide scavenging test.There is no direct connection between antibacterial ability and the content of ferulic acid in minimum inhibitory concentrations(MIC).Compared with pure ferulic acid,the antimicrobial capacity of inclusion complexes was not affected.In addition,4 mathematical models(zero-order,first-order,Higuchi and Ritger-Peppas kinetic models)were applied to adjust FA release profile and identify preferential kinetics in distilled water or different buffer medium(pH=2.2,7.4 and 8.4).IC 1:0.5 and IC 1:1 mostly released in accordance with Higuchi model in different buffer medium;release mechanism of IC 1:2 showed good fit for the linear regressions derived from Ritger-Peppas model.In case of distilled water,those release profiles of complexes mentioned above followed Fickian diffusion model which was a type of Ritger-Peppas model.3.The main spoilage bacteria of hairtail during refrigerated period were isolated and identified as Myroides phaeus,Morganella morganii,Serratia fonticola and Carnobacterium maltaromaticum.The results indicated that Carnobacterium maltaromaticum was extremely sensitive to the inclusion complexes.The inhibitory effect obviously enhanced with the increase of ferulic acid content in the inclusion compound.4.The effect of FA-?-CD inclusion complexes pre-treatment on the quality of hairtail during refrigerated storage at 4? for 15 days was investigated.The results revealed that inclusion complexes had not only decreased the growth of pH values but also a better ability to inhibit formation of volatile bases(TVB-N)and lipid oxidation products(TBARS and POV).Hence,inclusion complexes significantly extended the shelf life and delayed the deterioration of fresh meat of hairtail.