Morphology of the surface of cooked sausages made with the collagen-containing protein additive “bilkozyne”

<p>The purpose of this study was to investigate the effect of the collagen-based additive <em>Bilkozyne</em> on the texture of cooked sausages. This additive is a food ingredient obtained by partial hydrolysis of a beef skin split. We suggested that <em>Bilkozyne</em> usage in the formulae of meat products will allow reducing production costs and improving the texture of the final product. We used scanning electron microscopy (SEM) regarded as a unique tool in the comprehensive research of the texture of food products. Prior to that, we had developed a protein stabiliser (PS), based on <em>Bilkozyne</em> and other hydrocolloids, in order to distribute fats uniformly in the protein matrix of mincemeat. The influence of PS on the surface morphology of dried samples of cooked chicken sausages made from the mincemeat has been investigated. The main component (60 %) of the PS was collagen containing the protein <em>Bilkozyne</em>. The PS levels in the cooked sausages were 10 % and 15 %. Qualitative changes of the texture of cooked sausages have been examined by means of high resolution SEM. The following morphological parameters of the samples have been examined: the number of holes per 1000 µm² of the area of the sample; the average area of the holes, µм²; the holes ellipticity; the average area of the surface without the holes per 1000 µм² of the area of the sample. It has been shown that adding 10 % of the PS in the hydrated form results in essential improvement of the morphological features of the sausages as compared to those made with non-hydrated PS. It has been found that an increase of the PS in the formulae from 10 % to 15 % has a negative impact on the texture of the final products, causing a significant decrease in the hydration degree of the myofibrillar proteins of the meat’s muscle tissues. <em>Bilkozyne</em> has a positive effect on the distribution of fats and proteins in the mincemeat. This makes it possible not to change the source of fats in cooked sausages. Thus, the inclusion of <em>Bilkozyne</em> into the formula of cooked sausages results not only in the improvement of their texture, but also in the increase of essential amino acids content.</p>