## 3 Results and Discussion
### Effect of CSS on the Shelf Life of Cooked Chicken Burger Samples
#### 3.2.2 Volatile Compounds (VOCs) and Warmed Off-Flavours (WOF) in Chicken Burgers
This is a fundamental step in explaining, for example, the absence of sulphur containing volatiles. In line with findings of other researchers [53], these compounds come from the interaction among Maillard reaction compounds and lipid oxidation products. Thus, quick cooking processes, medium/low heating, or their combination seem not to favour this interaction. These settings did not allow the development of traceable Maillard reaction products (desired and undesired). T\({}_{72}\) (CTRL) samples showed an increase in concentration of hexanal, the emergence of heptanal, some alcohols such as 2-Nonen-1-ol, (E)-, ketones as 2,3-Octanedione and 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-2,8-dione, and just one Sulphur containing compound: N-Methyl-taurine. These are all markers of lipid oxidation and muscle damage. The addition of by-products provoked a mitigation of some WOF species, but also gave to patties specific odorants not conducible to meat oxidation and potentially undesirable. CSS addition reduced the occurrence of aldehydes such as hexanal that reduced from 55.1% (CTRL T\({}_{0}\)) to 11.7% (CSS T\({}_{0}\) 1.5%) to 0 (CSS T\({}_{0}\) 3%). At T\({}_{72}\) CTRL contained 72% and reduced to 0 in both concentrations. Heptanal was found only in CTRL T\({}_{72}\); octanal too, was just found in CTRL samples and not found in samples 1.5 and 3% at both times. Some alcohols such as 2-Nonen-1-ol, (E)- were limited in T\({}_{72}\) samples, but were present in T\({}_{0}\) CSS 3% with other alcohols, probably from the degradation of lignocellulosic precursors. This same pathway is followed by hydrocarbons which are totally absent in CTRL samples while being present in added patties [54]. According to data here shown, Nitrogen containing compounds present in CSS formulations probably came from the degradation of CSS proteins and from the Maillard complex of reactions which takes place during the roasting process. As for CSS, the significant role of phenols' interaction with Maillard reaction products to produce specific compounds can be assumed. Unfortunately, CSS developed p-xylene and o-xylene, involved in the rise of WOF and referred to as \"cardboard-like\" [55; 56]. No references are available to compare results obtained, especially for CSS properties. Chromatograms, in all cases, showed a great reduction of WOF or general active odorants. As a demonstration of this, CTRL T\({}_{0}\) and T\({}_{72}\) images had a resolution with an order of magnitude of 10\({}^{10}\), while CSS had values of 10\({}^{8}\). From pictures, the peak of hexanal that eluted at around 6.48 min is always visible and it is clear how much it decreases in respect of additions of by-products. In all samples at around minutes 13.44 and 16.49, long chain aldehydes were eluted (i.e., octanal, decenal). At around minutes 19.35-37 2-Nonen-1-ol, (E)- was eluted in almost all samples. After minute 19.40, the main compounds traced were siloxanes and low matched compounds. Of course, a better characterization of the aromatic profile of these molecules is fundamental to understand if and how volatiles from these substrates can have a negative impact on the final flavour of meat products.