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For brittle food samples like cookies and rice crackers, breaking stress-the force required to break them-and crispness (crunchiness) derived from minor force fluctuations during breaking serve as quality indicators. These foods readily absorb moisture from their surroundings, significantly altering their texture, making it crucial to monitor physical property changes under controlled humidity conditions using a constant-humidity chamber.

For elastic samples like gummies and marshmallows (gels), evaluating elasticity—how well they return to their original shape after biting—is essential, along with stress relaxation tests that examine how stress decreases when a certain deformation is maintained. In gummies, where viscoelasticity is complex, both initial chew resistance and mid-chew softness can be quantitatively assessed.

For semi-fluid condiments like mayonnaise and ketchup (emulsions), analyzing viscoelastic behavior, which includes both viscosity and elasticity, is crucial. Since smoothness and water separation vary depending on emulsification and dispersion states, observing viscosity changes under continuous force (e.g., stirring or scooping with a spoon) helps assess particle dispersion and creaminess.

For semi-solid foods like jelly and yogurt that are contained in a package, the balance between hardness, viscosity, and elasticity directly affects texture. The internal structure is formed based on the degree of gelation and the aggregation state of milk proteins, making it important to understand how manufacturing conditions impact physical properties. Since it is difficult to remove these foods from their containers for independent measurement, compression and pull-up tests are usually conducted with the container intact to replicate texture.

In evaluating cooked rice, compression tests on individual grains or sets of three grains allow for detailed analysis of hardness and elasticity, enabling numerical assessment of cooking conditions and varietal differences. Additionally, performing compression tests while the rice remains sealed in a retort container allows for objective evaluation of its fluffiness after reheating and the degree of quality deterioration over time.

For processed fish products such as kamaboko and chikuwa, texture quality—referred to as ashi (足) in Japanese quality evaluation—is determined by elasticity, derived from the unique heat-induced coagulation of fish paste, as well as by fracture characteristics under applied load. By analyzing the combined results of elasticity and fracture tests, manufacturers can assess mixing uniformity, production process stability, and detailed texture characteristics related to ashi.

For tablets, evaluating fracture strength—the point at which a tablet breaks under compressive or breaking force—is critical to preventing damage during transport and storage. Understanding mechanical durability also supports formulation optimization, influencing both swallowability and disintegration time. If a tablet is too hard, disintegration may be delayed, which can in turn slow the dissolution of active ingredients. Determining the appropriate hardness balance is therefore essential for effective quality control.

For capsules, it is essential to evaluate the pull-out strength of the shell connection to prevent breakage. This involves measuring the force required to separate the capsules, providing an indicator of leakage and disintegration risk. The strength and disintegration properties vary depending on the material and filling type, requiring proper measurements from the design stage to ensure safe and effective ingestion. Excessive pull-out resistance can lead to swallowing difficulties or issues with opening the capsule, making balance a crucial factor.

Granules exhibit different physical properties at the single-particle level and as an aggregate, requiring evaluation from both perspectives. At the single-particle level, particle size, shape, and binding force influence dissolution rate and hygroscopicity, while at the aggregate level, inter-particle friction and cohesion affect powder flowability. Understanding these mechanical properties helps stabilize granulation and tableting processes during manufacturing and improves dissolution and dispersion during ingestion. Proper control of particle size and aggregation is directly linked to ingredient uniformity and smooth absorption.

Lipstick and lip balm are semi-solid cosmetics mainly composed of waxes and oils, where application smoothness and break resistance are critical. Bending tests evaluate fracture characteristics under applied force, while penetration tests assess hardness and viscoelasticity during application. Proper formulation and rheological design enable both smooth application and shape stability. Break resistance is particularly sensitive to temperature, and ingredient ratios and crystallization control affect moisture retention, making physical property evaluation essential from the development stage.

For foundation products, skin adhesion and the consistency of the finish are key factors in overall performance. However, powder-type foundations are prone to cracking and brittleness due to impact or drying. Fracture behavior is evaluated through compression and bending strength tests, while controlling particle binding and binder composition helps optimize the balance between durability and ease of application. Rheologically, the viscoelasticity of the powder influences cohesion and compressibility, which in turn affect spreadability and tactile friction on the skin. Achieving proper mechanical properties helps prevent powder scattering and contributes to a smooth, even finish.

In cream physical property evaluation, viscosity, elasticity, and hardness significantly affect usability. Excessive viscosity makes application difficult, while low viscosity increases the risk of liquefaction and separation, making ingredient ratios and particle dispersion critical. Elasticity represents the ability to return to its original shape after force removal, while hardness affects shape retention in the container and stability during application. Rheological evaluation enables the balance of an easy-to-use texture, application feel, and product longevity.

Rubber and elastomers possess high elasticity, returning to their original shape when external forces are removed. Once the yield point is exceeded, plastic deformation begins, increasing permanent strain. Understanding the elastic modulus and yield point helps optimize impact absorption and durability, enhancing vibration control and sealing material reliability.

Adhesion determines the attachment strength to a substrate and affects the resistance felt when peeling. Evaluating elongation is crucial for understanding the elasticity when the tape is stretched. Since adhesive tapes are sensitive to temperature and humidity, mechanical testing under expected usage conditions is necessary. By selecting the appropriate formulation and base material, optimal adhesion and recovery properties can be achieved. These evaluations help improve ease of application and durability.

Films are thin-layer materials where bending properties and tensile strength significantly affect quality. Bending property evaluation helps assess flexibility and crack resistance, predicting damage risks during processing and use. Tensile tests quantify the load and deformation tolerance, determining the ease of fracture. Utilizing this mechanical data allows optimization of lamination and coating processes, ensuring high reliability in packaging and electronic components.