Multiphase porous media model for Intermittent Microwave Convective Drying (IMCD) of food

Intermittent microwave convective (IMCD) drying is an advanced drying technology that improves both energy efficiency and food quality during the drying of food materials. Despite numerous experimental studies available for IMCD, there is no complete multiphase porous media model available to describe the process. A multiphase porous media model considering liquid water, gases and the solid matrix inside the food during drying can provide in depth understanding of IMCD. In this article, firstly a multiphase porous media model was developed for IMCD. Then the model is validated against experimental data by comparing moisture content and temperature distributions after each heating and tempering periods. The profile of vapour pressures and evaporation during IMCD are presented and discussed. The relative contribution of water and vapour fluxes due to gas pressure and diffusion demonstrated that the fluxes due are relatively higher in IMCD compared to convection drying and this makes the IMCD faster.

Introduction: Food literacy for contemporary food and eating

This chapter provides an introduction to the term “food literacy”. Its use in the literature, policy and practice, implies that the term is an attempt to encapsulate the knowledge, skills and behaviours needed for everyday eating. This chapter will first review the use of the term in policy and practice, then go on to review what is known about contemporary food and eating and its influence on the emergence of this term and conclude with an overview of the key ideas to be explored in this book.

An overview of the use of the term food literacy

This chapter examines the history and breadth of use of the term “food literacy” in scholarly literature. It reviews and compares various popularly used definitions from diverse paradigms. Other terms such as “cooking”, “food skills” and “food wellbeing” used to describe the everyday knowledge, skills and behaviours used to meet food needs are also examined.

A definition of food literacy and its components

This chapter defines food literacy and its components using the empirical data collected in two studies undertaken in 2010 and 2011 as part of the author’s PhD thesis. The first was a Delphi study of Australian food experts and the second was a study of young adults across a spectrum of disadvantage. Defining food literacy and identifying its components was an iterative process. At different times throughout the research, each study informed the other. This chapter will describe the components of food literacy, the data used to identify them and how they combined to produce a definition of food literacy.

Relating food literacy to nutrition and health

This chapter describes the evolution of a model to propose the relationship between food literacy and nutrition. This model can also be used as a framework for program planning, implementation and evaluation. Practitioners and policy makers invest in food literacy with outcome expectations beyond diet quality. For this reason, a second model was developed to conceptualise the role of food literacy with respect to food security, body weight and chronic disease risk. This second model is useful in positioning food literacy within multi-strategic public health nutrition and chronic disease plans.

The development of food literacy

This is the first of four chapters examining the development of food literacy. It reports the findings of the Young People Study, described in earlier chapters. Participants reflected on the evolution of their food and eating style. They describe this at the individual level but in doing so discuss the interplay between other key institutions of health, education and community organisations. These results are considered alongside learning and development theory to propose how food literacy develops, including the role of individuals, households, communities and nations, and their influence to each other.

Food literacy: Key concepts and the elephants in the room

This chapter summarizes the content of this book. It identifies key issues that require further investigation and development. It re-enforces key concepts.

Food Literacy: Key Concepts for Health and Education

Globally, the food system and the relationship of the individual to that system, continues to change and grow in complexity. Eating is an everyday event that is part of everyone’s lives. There are many commentaries on the nature of these changes to what, where and how we eat and their socio-cultural, environmental, educational, economic and health consequences. Among this discussion, the term "food literacy" has emerged to acknowledge the broad role food and eating play in our lives and the empowerment that comes from meeting food needs well. In this book, contributors from Australia, China, United Kingdom and North America provide a review of international research on food literacy and how this can be applied in schools, health care settings and public education and communication at the individual, group and population level. These varying perspectives will give the reader an introduction to this emerging concept. The book gathers current insights and provides a platform for discussion to further understanding and application in this field. It stimulates the reader to conceptualise what food literacy means to their practice and to critically review its potential contribution to a range of outcomes.

The effect of consumer risk perceptions and information search on willingness to buy GM food products: A cross cultural analysis

This paper seeks to address the widespread call in the literature for the cross-cultural examination ( and validation) of accepted concepts within consumer behaviour, such as consumer risk perceptions and information search. The findings of the study provide support for a number of accepted relationships, whilst identifying distinct cross cultural differences in external information search and willingness to buy genetically modified (GM) food products by consumers.

A quasi stationary approach to drying kinetics of cylindrical food particulates in a heat pump asisted fluid bed dryer

Experiments were undertaken to study drying kinetics of moist cylindrical shaped food particulates during fluidised bed drying. Cylindrical particles were prepared from Green beans with three different length:diameter ratios, 3:1, 2:1 and 1:1. A batch fluidised bed dryer connected to a heat pump system was used for the experimentation. A Heat pump and fluid bed combination was used to increase overall energy efficiency and achieve higher drying rates. Drying kinetics, were evaluated with non-dimensional moisture at three different drying temperatures of 30, 40 and 50o C. Numerous mathematical models can be used to calculate drying kinetics ranging from analytical models with simplified assumptions to empirical models built by regression using experimental data. Empirical models are commonly used for various food materials due to their simpler approach. However problems in accuracy, limits the applications of empirical models. Some limitations of empirical models could be reduced by using semi-empirical models based on heat and mass transfer of the drying operation. One such method is the quasi-stationary approach. In this study, a modified quasi-stationary approach was used to model drying kinetics of the cylindrical food particles at three drying temperatures.

Prediction of fluidization behaviour and a quasi-stationary approach to drying kinetics of irregular particulate food materials

Changes in fluidization behaviour behaviour was characterised for parallelepiped particles with three aspect ratios, 1:1, 2:1 and 3:1 and spherical particles. All drying experiments were conducted at 500C and 15 % RH using a heat pump dehumidifier system. Fluidization experiments were undertaken for the bed heights of 100, 80, 60 and 40 mm and at 10 moisture content levels. Due to irregularities in shape minimum fluidisation velocity of parallelepiped particulates (potato) could not fitted to any empirical model. Also a generalized equation was used to predict minimum fluidization velocity. The modified quasi-stationary method (MQSM) has been proposed to describe drying kinetics of parallelepiped particulates at 30o C, 40o C and 50o C that dry mostly in the falling rate period in a batch type fluid bed dryer.