# Modeling of the Drying Process of Apple Pomace
###### Abstract  
Understanding biological materials is quite complicated. The material apple pomace is biologically unstable has been dried under certain conditions. Modeling the pomace drying is necessary to understand the heat and mass transport mechanism and is a prerequisite for the mathematical description of the entire process. Such a model plays an important role in the optimization or control of working conditions. Modeling of the pomace drying process is difficult as apple pomace is highly heterogeneous, as it consists of flesh, seeds, seed covers, and petioles of various sizes, shapes and proportions. A simple mathematical model (Page) was used, which describes well the entire course of the drying process. This is used to control the process. In turn, complex mathematical models describe the phenomena and scientifically explain the essence of drying. Mathematical modeling of the dewatering process is an indispensable part of the design, development and optimization of drying equipment. drying; modeling; apple pomace +
Footnote †: journal: Applied Sciences  
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Footnote 1: _Applied Sciences_  
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_Applied Sciences_  
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Footnote 1: also has a positive effect on human health [1]. Healthy values of apples are indicated by numerous epidemiological studies related to the decrease in LDL cholesterol levels [5], in diabetes prophylaxis, and cancer [6]. The processing of apples in the fruit-vegetable industry is connected with the generation of production waste. The amount of waste produced reaches between 10-35% of the processed apples [7]. Pomace, obtained as a result of the mechanical pressing of apples in juice production has the highest share in production waste. Fresh apple pomace is a biologically and chemically unstable material. It contains juiced flesh, pip integuments, pips and pedicels. It is a material suitable for composing, being an ingredient of feeds, a food product and a material for use in the production of fruit fiber, bio-oils, natural dyes, food colorings or polyphenol extracts [8]. Pomace may be used to cut the cost of a wholesome animal diet. Pomace should be treated as a half-finished product, which may be further processed, as it is rich in nutrients: protein, saccharides, mineral compounds, fiber, pectin, lipids, vitamins and organic acids. Pomace obtained from apples may be a source of pectin. The value of vitamins and provitamins in the waste product, i.e., pomace, after juicing fruits, depends on the conditions during the process of pressing. Moreover, apple pomace may be a source of energy. Energy in the form of biogas may be produced in the process of anaerobic conversion of pomace. Biofuel is produced by extracting energy from biomass, and is possible by means of fermentation of sugars into alcohol. The results of research [9] show that pomace from apples is an excellent raw material for the production of ethanol, which may be used as a biofuel or as a drink--e.g., older. The problem of how to efficiently use apple waste is not an easy one and existing methods are complex. The further processing necessary in the processing plant depends on technical and organizational possibilities. Extending pomace usefulness for consumption and processing requires drying [10]. It is also necessary to dry pomace in order to use it to produce solid biofuels for direct combustion [11]. Drying is one of the most important thermal processes, in which food is preserved. The aim of drying is to reduce water content to a level that prevents enzymatic reactions and the development of microorganisms, which have a negative effect on the quality of the material being dried [12; 13]. High temperatures and long drying times, required to remove water from fruit material during convective drying by air, may result in considerable deterioration of taste, color, nutritional value and may decrease bulk (volumetric) density and rehydration capacity of the product being dried [14; 15].