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Selected Physical Properties of Processed Food Products and Biological Materials

Poornima Pandey*, Riya Maheswari and Pooja Kumari

Department of Bioscience and Biotechnology, Banasthali Vidyapith, Tonk, Rajasthan, India

Abstract

Food products are made up of numerous diverse micro and macro components, and they have unique physical, thermal, mechanical, electrical, and optical characteristics. The first and most fundamental characteristics of food products are their physical properties. The physical properties of processed food products are defined as those properties that can be measured by physical means rather than chemical means. It provide relationship between product quality and their effect on the behavior of processed food. Here, a variety of physical properties of processed food materials and their measurement techniques are taken into account. Because customers nowadays seek sustainable and nutritious processed foods in their busy schedules, it is essential to look at their physical properties such as size, shape, texture, color, flavor, and many more, with that many measuring techniques to analyze these properties.

Keywords: Crystal, porosity, texture, rheology, crispness, thermal, frequency, velocity

1.1 Introduction

Food has a diverse hierarchical structure, making it one of the most complicated types of soft matter. Foods are typically formed mostly of some basic macromolecules like proteins, polysaccharides, and lipids, each of which is built of even smaller repeating units. The other component of food is water [1]. Additionally, air and minerals are present in food material, which all help food to acquire sophisticated structural complexity [2]. In terms of processed food's structure, stability, and nutritional content, the original food components are crucial. The majority of foods are capable of being seen as complicated colloidal multiphase systems made up of several aggregation phases, including liquid, solid, crystalline, glassy, and even liquid crystalline. However, due to its multiple advantages, food processing is frequently used. Four broad categories may be used to classify these advantages:

• An increase in food safety by elimination or inactivation of microorganisms, pathogens, toxins, constituents, etc.
• Intensifying food product quality by releasing flavorable compounds and constructing enhancements of texture, palatability, and taste.
• Enhancing nutritional value via intensifying bioavailability and digestibility and intensifying food product quality by releasing flavorable compounds and constructing enhancements of texture, palatability, and taste.
• The release or synthesis of molecules having bioactive qualities, such as those that are antibacterial or antioxidant, among others.

Processing technology and food formulation are crucial for food preservation and provide millions of people access to healthy, inexpensive, enticing, and sustainable food worldwide.

Consumer demand for foods that are both fresh and little processed, have their nutritional and organoleptic qualities intact and can be kept in the refrigerator for a long time (without compromising safety), and then heated up fast before eating is expanding. Numerous procedures may or cannot entail heating, as they are used to prepare foods to increase their quality and safety.

Because enzymes and bacteria become inactive beyond a certain temperature, thermal procedures have been widely employed in food technology. Additionally, certain heat treatments, such as baking and roasting, may enhance the sensory and textural qualities of food while denaturalizing enzymes or managing microbiological food safety. Through the destruction of cell walls, dissociation of chemical bonds between food components, and disintegration of intricate molecular structures, this process results in the release of natural bioactive substances. For instance, secondary plant metabolites including glucosinolates, carotenoids, polyphenols, and glucosinolates are among the components that are released.

Thermal procedures can generate fresh bioactive molecules through various chemical processes. Among these, the Maillard reaction, the carbonyl-amine reaction caused by reactive carbonyls produced from carbohydrates, is a crucial chemical process occurring during heat food preparation. Another significant source of reactive carbonyls, which are used in carbonyl-amine processes similar to those involving reactive carbonyls produced from carbohydrates, is lipid oxidation. As an alternative to conventional heating methods, microwave heating has been created and has been used, for instance, to deactivate enzymes in fruits and vegetable products. This procedure may also increase the overall antioxidant capacity of meals due to the probable release of natural antioxidants and the chemical reactions.

Nowadays, microwave cooking is often used as a thermal treatment in both household and commercial systems. Smart valves were first introduced as a component of sealing plastic trays or films, which provide a distinctive chance for rapid vapor cooking technologies modify to fresh or barely, ready-to-eat food, catering, which are now more often employed in conjunction with microwave cooking.

Therefore, it has been shown in several studies that the use of microwave radiation may promote carbonyl-amine reactions that include reactive carbonyls generated from either lipids or carbohydrates. In addition to these thermal processes, various nonthermal methods are used to preserve food and may also contribute to the production of antioxidants.

Because of the selectivity of their reactions under pH and temperature, enzymes are often utilized in the food industries. Enzymes have been used to aid in the creation of antioxidant peptides, for example, in the manufacture of antioxidants. Additionally, fermentation is used as a nonthermal process to increase food nutritional content, remove antinutrients, and enhance the sensory qualities of the meal. The structural breakdown of plant cell walls during this process results in the release of several chemicals, including an increase in the quantity of phenolic and flavonoid molecules. Other products are also created, some of which could have antioxidant characteristics.

By eradicating or harming bacteria, irradiation also enhances the sanitary quality of food materials.

Additionally, it affects the antioxidant content of meals as a result of improved enzyme activities and improved ability of natural antioxidants to be extracted from tissues in which they are present. Both ionizing radiation and nonionizing radiation fall under this category. Increases in reactive carbonyls produced from lipids and carbohydrates in carbonyl-amine reactions may potentially contribute to reported increases in antioxidant activity. In food preparation, high pressures are also used as a reverse to nonthermal inactivation of bacteria and pathogens.

Irradiation, high pressure, and microwave procedures are unique in that they allow for the direct treatment of food within the packaging materials, so it is called in-package food technologies, which has the benefit of shielding processed food items from unfavorable posttreatment encounters like oxygen and microorganisms. Since the packaging materials are treated and then sterilized during the food processing techniques without extra handling and sources of contamination. Irradiation treatment or industrial microwave for prepacked food products has low cost with this, the requirement to predisinfect or sterilize containers when food and packaging cannot be prepared simultaneously so producers has time and quality benefits.

Methods that are becoming more popular in food processing include irradiation or hydrogen peroxide, ozone, cold plasma therapy, or UV light.

The packing material is engaged in all of these processes and is subjected to various processing conditions that might change its mechanical, structural, and mass transfer (barrier and migration) capabilities. Three different mass transfer types must be taken into account:

1. The transfer of vapors or gases (such as water vapor, fragrance compounds, oxygen, etc.) from the external environment into the food products or the headspace via the packing materials.
2. Migration of low-molecular weight chemicals (such as monomers, plasticizers, and solvents) from the packaging into the food, which requires regulatory and toxicological studies.
3. The removal of low-molecular weight hydrophobic components from the food, such as aromatic compounds, which may have a significant impact on both the mass transfer characteristics of packing materials and the quality of the food.

1.2 Physical Properties

The characteristics of food products that can only be assessed physically rather than chemically have been described by their physical properties as seen in Figure 1.1.

Figure 1.1 Physical properties of processed food.

1.2.1 Shape

As the turgor pressure forms, it retains the cells under an elastic tension and preserves the tissue's shape, hardness, and crispness. The fruit's structure will collapse if the turgor pressure is eliminated. Once the natural turgidity has vanished, it cannot be replaced.

1.2.2 Texture

One of the most crucial factors in determining a food product's quality is its texture. We accept the food products based on their texture and how creamy and spreadable a culinary product is. This has an impact on flavor perception [3]. The...