Development of real time-pH sensitive intelligent indicators for monitoring chicken breast freshness/spoilage using real packaging practices.

Real-real time CO2-sensitive freshness indicators, phenol red (PR) and bromothymol blue (BTB) dyes, in three-layer system using cellulose based binder was developed to determine the freshness/spoilage of chicken breast. The developed indicators were used to monitor chicken meat spoilage packaged in polyamide/polyethylene (PA/PE) pouches under air and 100% nitrogen (N2) at 4 °C for 10 days. Changes in the ΔE and ΔRGB values of the indicators, CO2/O2 gas composition of packs, and chemical (TVBN, pH, trimethylamine), microbial, and sensory quality parameters of chicken breast meat were analyzed. The visual color change in the PR-based indicator was insufficient for the consumer to detect the spoilage with the naked eye in both simulation and food trial. However, three stage color (dark blue-turquoise-green) change was occurred in BTB-based indicators, and the color transition in the spoilage level of CO2 (10-15% (v/v)) is supported by the physicochemical, microbiological and sensorial properties of the chicken breast. The shelf life of chicken breast under air was limited to 4 days, while the shelf life under 100% N2 was 6 days which are supported by the visual color change of BTB indicator. The BTB-based indicators were found promising on a real packaging conditions and could be adapted to industrial scale for monitoring real-time freshness/spoilage of poultry, ensuring food safety.

Formation of heterocyclic aromatic amines in doner kebab cooked with different methods at varying degrees of doneness.

This study was designed to determine the formation of heterocyclic aromatic amines (HCAs) in two different types of doner kebab (yaprak doner-YD or mix doner-MD) cooked with different cooking methods (gas or electric) at varying degrees of doneness (rare, medium, well-done). In doner samples, nine common HCAs (IQ, IQx, MeIQ, MeIQx, PhIP, 4,8-DiMeIQx, 7,8-DiMeIQx, AαC, MeAαC) were detected. Additionally, the changes in the HCA precursors were evaluated. The initial concentration of precursors gradually decreased with the increase in doneness degree due to degradation or possible contribution in the Maillard reaction to form HCA compounds as a result of heat treatment (p < 0.05). Creatine content decreased, while creatinine content increased because of the conversion reaction. The two most abundant HCA in doner samples were 4,8-DiMeIQx and IQ, which measured in the range of 0.020-2.865 ng g-1 and 0.052-0.513 ng g-1, respectively. Other detected HCAs were determined in especially well-done samples. In conclusion, the diversity and the amount of each HCA compound in doner kebab samples showed variation depending on the effect of doneness degree, doner kebab type or cooking methods (p < 0.05).