Characteristics of Open and Closed Pores, Their Measurement Techniques and Exploitation in Dehydrated Food Products

Food dehydration, the process of reducing moisture in food to improve shelf life, is one of the oldest food preservation methods used by the food processing industry. During dehydration, the porous structure within foods undergoes various alterations, significantly impacting both process efficiency and consumer acceptance. The types of pores, namely, open pores, characterized by connectivity to the external surface of the food, and closed pores, which lack external surface access, distinctly influence the dehydration and rehydration kinetics, stability of the dehydrated product, and textural properties of foods, such as hardness, strength, crispness, and chewiness. This study aims to comprehensively investigate the characteristics of open and closed pores and examine their distinct impacts on food attributes. It seeks to explore the mechanisms underlying pore formation and assess the effects of varied dehydration technologies on pore structure. It finally evaluates the applicable measurement methodologies and identifies the challenges and opportunities of measuring pores within the food industry. Furthermore, this study examined the utility of artificial intelligence in porosity modeling and discussed the potential for encapsulating functional compounds within pores. Overall, this comprehensive review provides valuable insights into the distinct characteristics and implications of open and closed pores on dehydrated food products.