Effect of coffee by-products on the quality of cooked chicken meat-based burgers

In this study coffee silver skin (CSS) was tested as an active ingredient in new formulations of chicken meat burgers. The by-product was characterized to understand how it can best match the meat industry and consumers' demands for more sustainable products. Increasing CSS to the meat led to differentiate those effects on the final quality of uncooked and cooked meat. CSS was received from a local toasting plant and was reduced to a final granulometry size ~250÷125 µm before the use. Analyses as: aW, moisture, ashes, proteins, lipids, total dietary fibres, macro- and micro-minerals for the by-product were done. Chicken burgers were obtained from fresh breast fillets (provided by an Italian company) following a standard formulation including salt and water. Ingredients were homogenized and the whole mixture was split into 3 batches: control (CTRL) with any addition; +1,5% and +3.0% of CCS (CSS 1.5% and CSS 3%, respectively). From each batch, a representative number of burgers (45 g each) were obtained. Physical, Physico-chemical and sensory analyses of raw and cooked samples were done. Furthermore, the compositive and volatile profile was investigated on cooked samples. Data have shown a great potential role for CSS as an implementation in meat formulations limiting losses connected with the cooking process enhancing the yield of the item. Losses are limited even with little inclusions registering a high capacity. CSS showed a slowdown effect on off-flavours with pretty good activity on the emergence of hexanal, octanal, alcohols and other markers of lipid oxidation. Results also demonstrated that CCS is a good source of minerals (calcium and potassium) and fibres, so they can satisfy dietary requirements. The sensory analysis confirmed that the oxidation process was better controlled, no low score has been attributed for the taste or appearance, even if the bitterness and astringency represented a criticism of CSS containing formulations. Anyway this by-product needs deeper analyses to know possible toxicity traits linked to the obtention process, to answer to this question: can be newly formulated burgers considered as "functional" foods?