Вестник МГТУ, 2024, Т. 27, № 3.

Вестник МГТУ. 2024. Т. 27, № 3. С. 458-470. DOI: https://doi.org/10.21443/1560-9278-2024-27-3-458-470 a critical point in the process of dehydration of cephalopods will occur when the critical moisture of 180 % is reached. The same goes with fish - at 315 % (Fig. 6). The different nature of dehydration is explained by the difference in the internal structure and thermolabile properties of cephalopods and fish as capillary-porous colloidal materials (Fuet al., 2007; Valencia-Perez et al., 2008; Kucherenko et al., 2010; Uribe et al., 2011; Chen et al., 2013; Deng et al., 2014; Wang et al., 2014; Zhao et al., 2017; Mouritsen et al., 2018; Blagonravova et al., 2021; Lekrati et al., 2021). The tissues of cephalopods have greater elasticity than those of fish and retain it much longer during the heat treatment process. On the contrary, in the tissues of fish raw materials, capillaries undergo significant shrinkage with the formation of a crust as they dehydrate which slows down the process of removing moisture. The product quickly loses elasticity and eventually fish tissues can be easily freed from bones and divided into septa (Ginzburg et al., 1982; Ortiz et al., 2013; Wang et al., 2014; Voronenko et al., 2009; Glazunov et al., 2013). 500 400 .I?'3 5 300 200 100 100 200 300 400 500 600 co0 (dry weight), % Fig. 6. Critical moisture dependencies on the initial moisture of hydrobionts ( source: compiled by the authors ) Рис. 6. Зависимости критических влажностей от начальной влажности гидробионтов (источник: составлено авторами) Therefore, in engineering calculations, when designing optimal modes of fish and cephalopods dehydration, it is necessary to use different equations for calculating critical moisture. Cephalopod’s dehydration treatment includes the period of constant drying rate proceeds more intensively than fish. The period is characterized by higher moisture losses over an equal period under identical conditions and comparable initial moisture of raw materials. The scientific novelty of the work includes obtaining general patterns of dehydration processes during heat treatment of squid and octopuses. The assumption about the possibility of generalizing the partial curves of the cephalopods dehydration kinetics under different modes of thermal processes was confirmed. Many curves of cephalopods dehydration are summarized in one generalized relationship and its mathematical description is proposed. Based on the analysis of the research results, it is highly necessary to use different equations in the calculation of critical moisture. The data presented in the work confirm that the period of constant drying rate which cephalopods have is more intensive than fish do. The period is characterized by higher moisture losses for an equal period under identical conditions and comparable initial moisture content of raw materials. This should be considered in engineering calculations when designing optimal resource and energy saving processes for cephalopods and fish dehydration. Dependencies (1-3) indicate that the critical moisture is a function of the initial moisture. At the same time, the durations of reaching critical moistures in conjunction with the latter are the coordinates of critical points on the drying kinetics curves. The critical points show the dependence of the dehydration rate on the rigidity of heat treatment, the size and mass parameters of the dehydrated material, its chemical composition and т . т . Т. Ю . Ш . Ю. properties. Therefore, the use of simplex criteria like — , —— - , —- , —'■ ---- - for computational and analytical T 7w Т И Т Ю ® 7,1 465