Variation of Quality Parameters of Cured Meat Sausages Revelled by Histological Analysis

Abstract

The objective of this study was to evaluate the quality of cured meat sausages by quantification of skeletal muscles, adipose tissue, connective tissues and blood vessels and spices by histological analysis and automated image analysis. Sample collection. Sausages of two local producers (A and B) were collected within a one-month period at retail shops in Kaunas, Lithuania. Sampling included 28 sausages samples of first and extra quality categories as indicated by the producer on the label. Histological analysis. Samples of each cured sausage were fixed in 10% neutral buffered formalin and routinely processed for paraffin embedding (1). Three histological sections (5 μm thickness) of each cured sausage sample were stained with Calleja method (2). The histological sections were examined with a BX43 light microscope with digital camera DP73 (Olympus, Tokyo, Japan). Image analysis. One of three prepared sections was used for image analysis to quantify the amount of individual animal tissue content. Different tissues were detected and scored with automated and manual colour threshold image analysis by use of an Olympus BX43 light microscope and image analysis program “Olympus Stream Essentials” version 1.9.1 (Olympus, Tokyo, Japan). Statistical analysis. Statistical analysis was performed using SPSS Inc., SPSS 24, Chicago, IL, USA and mean values, standard deviation and statistical significance at P< 0,05 were calculated. The histological evaluation of the cured sausage samples revealed different types of tissues (skeletal muscles, adipose, connective, blood vessels, nerves, glandular) found together with spices. Also, the study showed differences of the tissue composition of cured sausages of two producers and differences between sausages assigned to the first and extra quality categories. The highest mean values of skeletal muscles were found in cured sausages of extra quality of producer A (42,8%), first quality of producer A (41,37%), extra quality of producer B (43.49%), and first quality of producer B (45.49%), respectively. The content of adipose tissue varied from 48.37% (extra quality) to 46.42% (first quality) in sausages of producer A and from 35.23% (extra quality) to 27.22% (first quality) of producer B, respectively. Whereas the content of connective tissue varied between 10.02% (first quality, producer A) and 12.63% (first quality, producer B). Most of the blood vessels and spices found in the sausages of first quality produced by producer B (98.75%). […].