Advances in Bioprocessing Engineering

The following sections are included:

• FOREWORD

• PREFACE

• CONTRIBUTORS

• CONTENTS

The following sections are included:

• INTRODUCTION

• MECHANISMS OF MICROWAVE HEATING

• FACTORS AFFECTING DIELECTRIC PROPERTIES OF FOODS
  • Effects of Frequency and Temperature
  • Effect of Moisture Content
  • Other Factors
  • Predictive Models

• PENETRATION DEPTH OF MICROWAVES

• ENERGY COUPLING

• MEASUREMENT OF DIELECTRIC PROPERTIES
  • Open-End Coaxial Probe System
  • Transmission Line Method
  • Resonance Cavity Method

• TEMPERATURE AND PRESSURE MEASUREMENTS

• COMMERCIAL APPLICATION OF MICROWAVE HEATING IN FOOD PROCESSING
  • Microwave Drying
  • Tempering
  • Pre-Cooking of Bacon
  • Microwave Pasteurization

• RECENT RESEARCH ACTIVITIES AT WASHINGTON STATE UNIVERSITY
  • Microwave Drying in a Spouted-Bed
  • Microwave Sterilization
  • Microwave Pasteurization

• ACKNOWLEDGEMENTS

• REFERENCES

A pilot plant scale pulsed electric field (PEF) continuous processing system was integrated with an aseptic packaging machine to demonstrate the efficacy of PEF technology as a non-thermal pasteurization method for fresh orange juice. Major system components include a 40000 V/17 MW_p high voltage pulse generator, a set of multiple stage co-field flow PEF treatment chambers, a fluid handling system for flow control and a Benco Aspack/2 aseptic thermal form packaging machine. Orange juice was processed at a 75 ∼ 125 L/h flow rate and packed aseptically into 200 ml plastic cup containers. Microbially-enhanced orange juice (MEOJ) tests validated the microbial inactivation effect of this integrated PEF system. The processed orange juice was aseptically packaged and was stored at different temperatures for quality evaluation. The orange juice pasteurised in a conventional HTST plate heat exchanger (95°C for 15 seconds) packaged and stored under the same conditions was treated as a control.

Experimental results showed that the heat–treated orange juice had higher losses of Vitamin C (7–14.5%) compared to the PEF treatment (4.6%). Similarly, during storage at 4°C and 22°C, the Vitamin C losses were higher in the heat-pasteurised orange juice (44% and 56%) compared to PEF-processed orange juice (28% and 35%), respectively after 90 days of storage. Whereas, at 37°C PEF-treated juice had 20% loss in Vitamin C compared to 50% loss in heat-treated orange juice after 15 days of storage, however, the difference was not significant during subsequent storage. The kinetics of Vitamin C degradation followed a psuedo-first order reaction. The color parameters (L, a and b) measured using a Hunter lab colorimeter showed no significant difference in color between PEF- and heat-treated orange juice stored at 4°C. Whereas at 22°C, the PEF-treated juice indicated better color retention compared to heat-treated samples, however, the difference was not significant after 15 days at 37°C. The PEF-treated and aseptically packaged orange juice demonstrated the feasibility of PEF technology to extend the product shelf life with little loss of flavor, Vitamin C and color.

This chapter presents an overview of machine vision techniques for inspection of fruits and vegetables by colors and other qualities. Literature reviews of researches conducted by both academia and industrial R&D are provided. Some general design considerations and configurations involving on-line vision inspection systems are discussed. An example of advanced on-line machine vision sorting system is illustrated. A method on large-scale precision color sorting system development is also presented in this chapter.

This chapter addresses major difficulties and solutions associated with on-line high-speed machine vision inspection of defects on fruit. An adaptive spherical image transform method is presented for extracting fruit's defective segments in real time. This method solves the problems caused by the gradient light reflectance of spherical fruit objects and the fruit's natural variations in size and brightness. A dual camera near-infrared/mid-infrared (NIR/MIR) imaging technique proves to be very effective for distinguishing the stem-ends/calyxes from the real fruit defects. This chapter also discusses the construction of a knowledge base and the testing of this knowledge base for on-line defect sorting decision-making.

The following sections are included:

• INTRODUCTION

• PROCESSES FOR MAKING AQUEOUS HRC

• CHEMICAL AND PHYSICAL PROPERTIES OF HRC
  • Chemical Characterization
  • Degree of Polymerization
  • Physical Properties
    • Specific surface area, particle size and crystalline index
    • Rheological properties
    • Water-holding capacity
    • Microstructure

• INNOVATIVE USE OF HRC
  • Medical Applications
  • Pharmaceutical and Cosmetics
  • Food Applications
  • Edible Coating and Films
    • Water vapor permeability
    • Tensile strength
  • Molded HRC Articles
  • Filtration

• REFERENCES

Environmental pollution from petroleum-based disposable plastic wastes has become a severe global problem. Starch and protein polymers have recently been considered as alternatives to petroleum polymers for disposable items, such as fast food utensils, shopping/trash bags and biodegradable composites. The objective of this paper is to give an overview of current and related research works and application potentials of starch and protein polymers.

The following sections are included:

• Index