Wykorzystanie komputerowej analizy obrazu do oceny struktury i różnicowania jakości wybranych produktów mięsnych

Abstract

The aim of this study was to determine whether the quality of meat products may be differentiated based on their structural characteristics. It was assumed that the results will (i) confirm the effect of the technological process on the structure, and as a consequence on texture, sensory quality and physico-chemical parameters of meat products; (ii) show which of the analysed additives being animal fat substitutes has a greater effect on quality of finely comminuted sausages; (iii) indicate how technical parameters of the cutter affect fat distribution in the final product, and as a consequence its texture and sensory quality. Material and methods. Material for analyses in the first research task comprised the semimembraneous muscle and the quadriceps muscle of the thigh subjected to brine injection, massaging and pasteurisation. In the next task the experimental material consisted of sterilised pates, in which 100% of animal fat was replaced with vegetable fat: Akoblend BEP, Akoroma OM, Akoroma OMW and Akoroma LS, as well as batters and the resulting finely comminuted wiener sausage, in which animal fat content was varied by substitution with Akoroma OM vegetable fat added at 50, 75 and 100%. In the last research task the experimental material comprised finely comminuted batters and wiener type sausage produced in a bowl chopper and an emulsifier. Finely comminuted batters were analysed in terms of their rheological properties as well as contents of free water and thermal drip, while in final products their basic chemical composition and colour were determined using the instrumental method, along with penetrometric properties and texture. Moreover, after each stage of the technological process in the production of pasteurised hams as well as sterilised pates and finely comminuted products morphometric analyses were performed, while final products were subjected to consumer trait evaluation. Results. Analyses showed that the semimembraneous muscle was characterised with greater dynamics of changes in the level of structural elements in the process of massaging and pasteurisation when compared to the quadriceps muscle of the thigh. Injection of curing brine resulted on shrinkage of muscle fibre cells in both analysed muscles. Brine remaining in the intercellular spaces caused compression of cells, which were absorbed inside the fibre only during the massaging process, while pasteurisation preserved the produced structure. Both the shear force analysis and consumer evaluation showed that hams from both muscles were characterized by high tender. In sterilised pates the 100% animal fat substitution with vegetable fats had a significant effect on the colour and the basic chemical composition of the final product. It was shown that the best comminution and fat dispersion as well as advantageous mechanical and sensory attributes were observed in sterilised pate produced with 100% replacement of animal fat with vegetable fat Akoroma OM. It was observed that animal fat substitution with Akoroma OM in the amount exceeding 50% in wiener sausage results in a deterioration of fat dispersion, texture and sensory attributes. Computer image analysis showed that the use of an emulsifier to produce finely comminuted batters provides a greater degree of comminution of the connective and fatty tissues as well as better sensory attributes of the final product. Conclusions. Histometric analysis provided valuable information on the quality of the product, while performed measurements of structure elements (muscle fibre cells, fat globules, collagen fibres). The applied computer image analysis facilitated evaluation of diversification of microstructure and selection of the raw material for the production of hams, appropriate animal fat substitute as well as most suitable equipment for the production of finely comminuted products.