Monitoring and identification of spoilage-related microorganisms in braised chicken with modified atmosphere packaging during refrigerated storage

This study mainly monitored the dominant bacterial populations and identified the spoilage-related microorganisms of braised chicken meat stored under different CO_(2)-modified atmosphere packaging(MAP)during refrigerated storage using a culture-dependent method and 16S rDNA identification.The quality changes and shelf life of the meat were also measured.The growth rate of total viable count(TVC)in braised chicken was slower with an increase of CO_(2) content in MAP,which also occurred in the remaining bacterial species monitored(lactic acid bacteria,Pseudomonas spp.,Brochothrix thermosphacta).The MAP exerted beneficial effects on the quality of braised chicken,as demonstrated by retarding the production of total volatile basic nitrogen(TVB-N)and delaying lipid oxidation(TBARS test).A total of 14 isolates were identified from braised chickens with different packaging at the end of storage,these included P.fragi(6 isolates),P.psychrophila(2 isolates),Enterococcus faecalis(3 isolates),B.thermosphacta(2 isolates),Staphylococcus equorum(1 isolate).

In-package cold plasma treatment of braised chicken: voltage effect

This study investigated the effect of different dielectric barrier discharge cold plasma(DBD-CP) treatment voltages on the microbiological growth and quality characteristics of braised chicken during storage at(4 ± 1) ℃. Argon-packed samples were subjected to DBD-CP treatment for 3 min at voltages of 50, 60 and 70 k V. As a result, there was no significant(P > 0.05) difference in L*, a*, b* and p H of braised chicken between control and treatment groups at the same storage time. However, the development of lipid oxidation in DBD-CP treatment samples was slower than that in air-packed samples. Compared to air-packed samples, the reduction of total viable count, yeasts and molds, lactic acid bacteria and Pseudomonads spp. in 70 k V treated samples on day 15 were 3.21, 2.41, 2.44 and 1.96 lg(CFU/g), respectively. The results indicate that DBD-CP treatment could extend the shelf life of braised chicken without negative impacts on quality characteristics.

Oxidation combined with Maillard reaction induced free and protein-bound N^ε-carboxymethyllysine and Nε-carboxyethyllysine formation during braised chicken processing

The objective of this work was to investigate the effects of oxidation and Maillard reaction on free and protein-bound N^ε-carboxymethyllysine(CML)and Nε-carboxyethyllysine(CEL)formation during braised chicken processing.It was found that a positive correlation was observed between carbonyl,fat oxidation,Maillard reaction,CML and CEL(P<0.05).The sulfhydryl groups could be used as potential indicators to evaluate the compounds’interaction levels between Maillard reaction and protein oxidation.Frying promoted the formation of lysine(Lys),glyoxal(GO)and methylglyoxal(MGO)(P<0.05);boiling enhanced the formation of GO and MGO(P<0.05)while inhibited the levels of Lys(P<0.05);sterilizing blocked the formation of MGO and Lys(P<0.01)but improved GO levels(P<0.05).Finally,a perspective was concluded that the Maillard reaction combined with oxidation is one of the main reasons for the formation of free and protein-bound CML and CEL during braised chicken processing.