Зміни структурно-механічних властивостей склеєних кишкових оболонок смажених ковбас

Abstract

Визначено закономірності змін товщини, міцності на розрив, міцності зв’язку між шарами та відносного подовження склеєних кишкових оболонок у технології та під час зберігання смажених ковбас. Доведено, що смаження приводить до формування стійкого зчеплення завдяки тепловій коагуляції та денатурації склеєних кишкових оболонок і дозволяє зменшити кількісні втрати під час виробництва і зберігання готової продукції.

Frying of stuffed intestinal casings as a determining process factor in the technology of fried sausages leads to significant quantitative and qualitative changes in the contents of casings, which, along with the formation of finished products identification signs, results in significant losses of moisture. Therefore, the output of finished products for these sausages is one of the lowest. In the conditions of the current shortage of domestic proposals of natural casings, the need for rational use of intestinal raw materials by the closest technological purpose in recent years, the use of glued intestinal membranes in the technology of fried sausages is promising. Their perspective of attraction is also reinforced by the presence of several (two or three) layers, resulting in the creation of the possibility to reduce weight loss. In this regard, the requirements to structuralmechanical characteristics of sausage casings, the main of which are durability and elasticity, are essential. The regularities of changes in structural-mechanical properties (thickness, tensile strength, bond strength between layers and elongation) of glued intestinal membranes in technology and during storage of fried sausages are determined. It is shown that the most noticeable changes of these properties are observed during the stages of casings preparation and frying of sausage. It is found that at the stage of casings preparation, hydrophilic properties of proteins of intestinal films in the state close to native, result in the increase of thickness by 1,44–1,60 times (from 75 mcm to 120 mcm in two-layer, and from 107 mcm to 154 mcm in three-layer), reduction of the tensile strength by 2,7–2,9 times (from 2,81–7,88 MPa to 1,06–2,72 MPa) and strength of bonds between the layers by 3,14 times (from 358 N/m to 114 N/m). It is shown that frying and, as a consequence, denaturation of proteins, compaction of molecules, transition of most globules into fibrils, loss of a significant amount of moisture and hydrophobicity, bring the value of the tensile strength of dry glued casings to the level of 62–65% of the original, and enforce the strength layers of glued intestinal casings, compared to the wet state at the preparation stage, 1,7 times (up to 197–198 N/m), which provides about 55% of the strength values in the dry state of casings. This fact enables effective use of glued intestinal membranes in the technology of fried sausages, taking into account strengthening of the protective properties due to their two and three layers, as well as the formation of stable adhesion due to thermal coagulation and denaturation, which will reduce quantitative losses in the production of finished products. The obtained regularities of changes in the relative elongation are mostly inverse.