发酵粘液乳杆菌后生元与亚硝酸钠对肉糜的协同护色作用OA

This study systematically investigated the synergistic effects of postbiotics from Limonsilactobacillus fermentum(PLF)and sodium nitrite on color preservation in minced meat.The experiment comprised six treatment groups.Three groups were treated with sodium nitrite at three different concentrations of 150,75,and 37.5 mg/kg(150N,75N,and 37.5N).The other three groups were treated with combinations of sodium nitrite and 2%PLF(150N+2%PLF,75N+2%PLF,and 37.5N+2%PLF).Meanwhile,a control group with no added was set up for comparison.Changes in the redness value(a*),myoglobin(Mb)and nitrosomyoglobin(NOMb)relative contents,and nitrite residue of minced meat were systematically analyzed during storage.Results indicated that better color preservation was observed in the combined treatment groups compared to the corresponding nitrite-only groups.Specifically,the a* of the 150N+2%PLF group reached 13.14±0.21,which was significantly higher than that of the 150N group.Mechanistic studies revealed that the addition of PLF effectively maintained the reduced state of Fe2+in Mb,mitigated nitrite-induced oxidative damage,and significantly promoted NOMb formation:in the 150N+2%PLF group,NOMb relative content rapidly increased from 12%to 36.1%within 9 h,with a generation rate 2.1 times that of the 150N group.Concurrently,PLF accelerated the degradation of nitrite;the nitrite residue in the 150N+2%PLF group decreased by 32.6%after 63 h of storage,with a degradation rate of 0.37 μg/(h·g).Analyses using ultraviolet-visible(UV-Vis)spectroscopy,Fourier transform infrared(FTIR)spectroscopy,and surface-enhanced Raman spectroscopy(SERS)indicated that PLF stabilized the secondary structure of Mb,enhanced electron delocalization within the porphyrin ring and hydrophobic interactions,and facilitated the formation of a hydrogen bond network and π-π* stacking structures by modulating the microenvironments of tryptophan and tyrosine residues,thereby inhibiting Fe2+oxidation.SERS further confirmed that PLF promoted Fe-NO coordination,favoring NOMb formation.Fluorescence quenching experiments indicated that the interaction between PLF and Mb was primarily driven by hydrophobic forces(enthalpy change(ΔH)>0,entropy change(ΔS)>0).This study confirms that the synergistic use of PLF and nitrite can reduce the nitrite content by approximately 50%while maintaining the excellent color of minced meat,demonstrating that PLF have significant potential for partial replacement of nitrite.