Pressure Drop Process as a Pretreatment for Enhancing Rehydration of Adzuki Beans (Vigna angularis)

Area of Science:

• Food Science and Technology
• Materials Science
• Chemical Engineering

Background:

• Traditional pressure drop processes in food rely on heat, limiting their application.
• Developing nonthermal methods is crucial for preserving food quality and minimizing thermal degradation.

Purpose of the Study:

• To develop and evaluate a nonthermal pressure drop processor for food applications.
• To analyze the effects of novel pressure drop treatments on adzuki bean structure and soaking efficiency.

Main Methods:

• Development of a nonthermal pressure drop processor.
• Application of two improved pressure drop processes: PDA (1 kgf/cm² pressure release) and PDB (gradual pressure decrease).
• Analysis of adzuki bean structure using scanning electron microscopy (SEM) and evaluation of soaking efficiency.

Main Results:

• Both PDA and PDB pretreatments significantly enhanced adzuki bean soaking compared to heat treatments (60°C, 100°C).
• Minimal heat requirement was observed for moisture and gas release, with no significant effect at 25°C.
• Repeated PDB application (over 40 times) further improved moisture absorption without thermal influence.
• SEM revealed structural modifications including hilum cracking, surface wrinkling, and mesh deformation in treated beans.

Conclusions:

• Nonthermal pressure drop treatment is a viable method for enhancing food soaking efficiency.
• Structural modifications induced by pressure drop treatments contribute to improved moisture absorption.
• This technology offers a promising alternative to heat-based pretreatments in the food industry.