Manufacture of dry-cured ham: A review. Part 2. Drying kinetics, modeling and equipment

Abstract

is a technique which uses natural conditions-the sun and air-for product dehydration. Due to the great influence of weather conditions and not less due to safety reasons, nowadays a drying process takes place in ventilated climate chambers in which the product is held at constant temperature in a controlled atmosphere.The process of dry-cured ham manufacture is long and consists generally of salting followed by a long drying period. During the salting stage, the product is affected by the action of salt (NaCl) which penetrates and distributes uniformly during the resting step. Consequently, the part of moisture is removed from the product by the action of osmotic dehydration. It helps to prepare the product for the further drying step by reducing the energy costs by partial water removal.Drying is the main process of dry-cured ham production and consists of water removal from the product by evaporation which is driven by a concentration gradient between the drying air and the being dried product. Drying is the most energy-and time-consuming process and that is why optimization of this step is of special interest [1]. Latent heat of vaporization for water is 2257 kJ kg −1 water at temperature 100 °C and pressure in 1 atm [2]. It means that for the vaporization of one kilogram water, the energy input which should be applied to the product is 0.63 kWh kg −1 . It is an ideal case, and real energy costs can approach 3500-6000 kWh kg −1 . Thus, maintenance of the atmosphere at certain parameters requires sufficient energy expenses; therefore, it is crucial to achieve the maximally efficient drying process with a certain drying rate. At the same time, the quality of the product needs to be kept at a high level in order to be accepted by consumers. Along with environmental parameters, such product properties as salt content of being dried ham and pH value of the raw material are the Abstract Dehydration in foodstuff manufacture is a process when a product loses the weight by reduction in water content. Regarding the production of dry-cured ham, dehydration mainly takes place during the drying stage. However, during the salting and the resting steps, water content of the hams also reduces by 3-4 %, which should be taken into account in order to adjust the necessary rate of the further drying. In addition, such parameters as pH of the raw material and salt content of being dried hams also influence the drying rate and the quality of the final product. The present paper is devoted to highlighting processes and parameters influencing the dehydration of dry-cured ham during the manufacture. Industrial drying systems used for the manufacture of dry-cured ham are described for the comparison of construction and energy consumption. Mathematical models mostly used to predict the drying behavior of dry-cured ham are described.

Processing of South African biltong – A review

“…Therefore, lower speeds reduce the drying rate while higher speeds increase it. Some studies have been conducted on the drying kinetics of meat (Trujillo et al, 2007;Clemente et al, 2009;Chabbouh et al, 2011;Hii et al, 2014;Ahmat et al, 2015;Kucerova et al, 2015;Petrova et al, 2015). These covered the effects of drying parameters, namely temperature, relative humidity, and air velocity, and meat thicknesses and also modelled these kinetics.…”

Drying dynamics of meat highlighting areas of relevance to dry‐aging of beef

“…As with dry-aging, there is limited information on the drying dynamics of these products. Petrova et al (2015) reviewed some mathematical modeling approaches that could be used to provide information about moisture loss throughout the manufacturing of dry-cured ham. Among the most promising approaches, Fick's second law of diffusion could be solved for different geometries (sphere, cylinder, and infinite slab) and making certain assumptions (e.g., uniform initial moisture content, one-dimensional moisture migration, internal resistance to moisture migration, and no shrinkage).…”

“…On the other hand, empirical models can be derived solely from the experimental data, without having to consider the fundamentals and physical mechanisms underlying the mass and heat transfer (Ashoor et al, 2019). In general, semi-empirical models are mostly used because of their simplicity (fewer assumptions are needed) and quite high accuracy (Petrova et al, 2015). However, semiempirical models are only valid within the drying conditions for which they have been developed (Babalis et al, 2006).…”

Proteolytic resistance of actin but not of myosin heavy chain during processing of Italian PDO (protected designation of origin) dry-cured hams

“…The production of dry-cured ham requires quite long processing times and is associated with proteolytic activity on myofibrillar and sarcoplasmic proteins, resulting in their progressive degradation [1]. Characterisation of the main myofibrillar proteins is essential for predicting the final quality of dry-cured hams in terms of structure and texture [1,2].…”

“…Characterisation of the main myofibrillar proteins is essential for predicting the final quality of dry-cured hams in terms of structure and texture [1,2].…”