Integrated Teaching of Thermal Processing Using Interactive Multi-Media
F. Sherkat, A. L. Halmos
Department of Food Science
Flexible Learning Environment Unit, RMIT University, Melbourne,
An interactive multi-media learning program is being developed in CD-ROM format to assist learner understanding of the concept of thermal processing and its calculations. The program consists of tutorial/experiment building section, explaining with animation, relevant concepts of thermal processing, and a simulation (ëcrucibleí) of thermal processing in a realistic food production context. Small teams of students (2-3) will be working on typical processing situations through the simulation interface, and by changing the processing parameters, will evaluate the impact of the new conditions on equipment performance and product safety. This will help students experience a variety of ìnon-scheduled processingî which in a pilot plant situation are time consuming and too risky or too costly to attempt. Students will have to make critical but accurate decisions, based on calculations, about re-adjusting process parameters, and salvaging the product with minimal loss of quality and manufacturing capacity.
Student assessment will be based on solving an ìIndustrial Problemî using the CD-ROM, and the results will be submitted on a disk containing the calculation steps, the ëscheduled processí and/or justification of the product safety and ëlegalityí. Students will be given feedback on their submissions in tutorial debriefing sessions and the ìApprovedî (and possibly amended) ëscheduleí of each team will be used to actually produce the canned product in the pilot plant. Final assessment will be based on the safety and shelf-life (Commercial Sterility) of the cans produced by the team.
This innovative approach is the first of its kind in the Food Science and Technology education and gives learners access to quality learning opportunities to help them produce safe, legal and acceptable products, and to meet the industry standards of competency and proficiency. This makes the CD-ROM a suitable learning aid for classroom/laboratory, workplace/distance education, problem-based learning exercise and as preparatory learning aid for plant/laboratory activities.
Why has This Package Been Developed?
Millions of tonnes of heat preserved foods (pasteurised, canned or aseptically processed foods) are produced and consumed every year throughout the world. Canned foods occupy a significant position, because of their relatively long shelf-life, low cost, transportability and availability in every part of the world, and wholesomeness, as they do not rely on the use of chemical preservatives. Canned foods have become an inseparable part of healthy eating in the last few decades, and will continue to do so in the next century.
The production of canned foods require a meticulous attention to the details of product formulation, packaging adequacy, required heat intensity and duration, as well as cooling regime, and, processed cans handling and storage. Any failure in controlling these factors will result in product spoilage due to under-processing and/or post-process contamination due to leakage, resulting in financial loss to the company, and in particular cases, to the development of a deadly toxin with fatal results to the consumer.
It is therefore, very important that students in Food Science and Technology courses and production personnel in canning lines gain skill in the principles of thermal processing and the required calculations to produce ësafeí, shelf stable and acceptable products. The proposed CD-ROM is a flexible learning/training tool for not only TAFE and tertiary education levels, but also for workplace training of the production personnel including Retort Operators, Approved Cannery Persons and Production Supervisors.
Thermal Processing is a branch of Food Science and Technology, involved with the processing and preservation of food by the application of heat. The aims of thermal processing are:
Studentsí Learning Difficulty
Thermal Processing is a pivotal subject taught in the last three years of the Food Science and Technology course. It involves a range of disciplines (eg. heat transfer, microbiology, chemistry, packaging) and requires skills to operate retorts, packaging equipment and packaging assessment, and relies on complicated mathematical calculations to design process schedules. Its basic principles and preliminary calculations are introduced in the second year, more complex cases and their relevant calculations are covered in the third year, and the whole concept is employed in the fourth year subjects named Product Development and Quality Assurance, which exposes the students to hands on product and process design and real world manufacturing experiences.
Students experience difficulty understanding the principal concepts of thermal processing in the earlier years, and find it difficult to remember in the final year when the applications of these principles are implemented. In particular students have difficulty mastering the implications of processing decisions (often made in the context of a single discipline) on food quality and safety which is only evident over time and in the context of the whole process of food production. The limited class contact hours also exacerbates the problem.
The Interactive Learning Package
The teaching and learning initiative is developed based on Laurillardís3,4 postulation that Computer-Assisted-Learning (CAL) provides the learner with direct access to a range of learning domains, encourage the manipulation of processing parameters, gives intrinsic feedback and, provides explicitly defined goals. Laurillardís ëtemplate for learningí encourages lecturers to develop applications that will be intellectually challenging, encourage appropriate approaches to learning, and provide guidance and feedback, as students address realistic and complex scenario-based problems. Applications can readily include text, audio and video, and links to University database and Internet.
Based on these postulations, the project team aimed to develop an interactive multi-media Thermal Processing Learning Package (TPLP) to assist Food Science students and other learners to explore and experience the concepts of thermal processing and its associated calculations. The criteria selected for the program were that it should be visually appealing, stimulating and innovative, highly interactive in both illustrations and exercises, self -paced and self-directed to enhance student access and learning efficacy. The program was also required to keep a log of the learnersí navigation and decisions, and provide updates of progress towards the learning goal. Issues such as learner control and navigation, along with the graphical design and interactivity were addressed in the selection of the right educational environment.
The CD-ROM was selected as the environment for teaching and learning because it offers deductive and inductive learning opportunities for individuals as well as collaborative teams both on-campus and off-campus. The Web environment was considered, but due to claims regarding its lacking many of the facilities incorporated into authoring tools for computer-based learning, it was not opted for at this stage. Nevertheless, it is envisaged to convert and adapt the program for on-line delivery using the Web, after preliminary trials of the program for its effectiveness with students learning in 1998.
The computer based learning program consists of two main sections, tutorial and building the Experiment, and a simulation (ëcrucibleí) of thermal processing in a realistic food production context to prepare the process schedule (Fig. 1). Both on-line documentation and audio-visual materials explain and model the relevant concepts of thermal processing. The simulation approach is selected as it provides a bridge between the lecture/tutorials and pilot plant productions and puts students in a micro-world situation, where they have to make decisions which not only have product safety as the main goal, but which also have organisational and strategic implications.
The program is problem-based and is structured to encourage the development of problem solving skills in learners. As the emphasis is on collaborative learning, small teams of students (2-3) will be working on typical processing situations through the simulation interface, and will make decisions in relation to product type (ie. acidity, microbial load and heat transfer mode), container size and shape, equipment type and processing conditions, and by changing the processing parameters will evaluate the impact of the new conditions on equipment performance and product safety and acceptability. This will help students experience a variety of ìnon-scheduled processingî conditions in a micro-world setting, that in a pilot plant situation are time consuming, too risky or too costly to attempt. Students will have to make critical but accurate decisions, based on calculations, about re-adjusting process parameters, and salvaging the product with minimal loss of quality and manufacturing capacity. The program enables students to gain on-line feedback on their performance, thus monitoring their own progress at any time, and be able to print out the results of their experiments and/or supporting materials from the multi-media database.
The assessment will take place in several stages: firstly, student teams will submit a disk containing the calculation steps involved in solving ìIndustrial Problemsî, a product file including product formulation and preparation stages, a ëscheduled processí, and justification of the product safety and ëlegalityí. After interim assessment of the submissions, teams will then be given feedback in tutorial debriefing sessions, and the amended ëscheduleí will be used by the team to produce the canned low-acid product in pilot plant. Final assessment will be based on the safety (assessment of process calculation and achieved lethality), acceptability (sensory panel evaluation) and shelf-life (commercial sterility evaluation in microbiology laboratory) of the canned product produced by the team.
Key Learning Outcomes
Expected Educational Outcomes
The Stated Benefits
Studentsí ability to visualise the different heat transfer mechanisms and its effect on the sterilisation process will enhance their competencies in other similar physical-biological processes interactions. Their ability to predict process parameter ramifications on the basis of process condition and foodstuff properties will add an extra knowledge base that has been difficult to achieve with straight lectures. This skill enhancement is based on the ability to visualise the cumulative effects of heat penetration with time, its progressive result on total bacterial load and hence final outcome of the process time.
The integration of the CD-ROM with the existing educational resources eg. lectures, tutorials and practical sessions, will form a comprehensive program that will increase studentsí access to quality learning opportunity by making their learning self-paced and complementary to classroom and practical sessions. Students assume a more responsible and active role in their learning process, will be able to relate the conceptual learning to practical applications in a more interactive way that allows them a considerable control over their learning strategy, and will come to classes with far greater preparation and appreciation of the concepts and their relationships, thus lectures will become less descriptive and more interactive by addressing the industry related problems.
In tutorial debriefing sessions studentsí decisions in terms of food processing outcomes (the history of student decisions and outcomes will be available through a submitted file) will be revisited. Students will be assessed progressively as they gain a sound conceptual base and learn simple calculations, then move to more complex food processing problems and use the multi-media package to integrate the scientific and mathematical concepts with their application in Product and Process Development and Quality Assurance.
The CD-ROM offers a comprehensive teaching resource that will be accessible in the library, or could be borrowed and used in studentís home computer, or in a work-place training situation. Due to its interactive nature and intrinsic feedback capability, it has the capacity to improve student learning of this significant component of the Food Technology curriculum.
This innovative approach is the first of its kind in the Food Science and Technology education and gives students access to quality learning opportunity. Students will learn to produce safe, legal and acceptable products, and to meet the industry standards of competency and proficiency.
What the Team has Learnt from the Project?
The development process for this project was very long. The main reason was that the project had funding and time restraint. No time was bought for the project leader or other team members, which was somewhat frustrating in best of times.
Nevertheless, the team has produced the first prototype of this CD-ROM (Please see the demonstration) with the shell and one out of six units fully developed. Other units will be developed in the months ahead. Working on this project has helped us to gain a better understanding of student learning of basic and complicated concepts, and has already changed the way we consider our role as educators/facilitators in the academia.
We are planning to put the experience gained in this project at work with other subjects in Food Science and Technology course, by encouraging other colleagues across the department to introduce educational Technology, CAL and on-line delivery mode in their subject matters. We are conscious of the pitfall of radical changes from traditional teaching/learning methodologies to a more learner active role (, as stated by Gay, Trumbull & Mazur (1991), as it could disadvantage some students. Therefore, our approach to this change would be gradual and supported by studentsí improved learning outcomes.
Preliminary Student Evaluation
Food Technology students have been evaluating the program at each stage of development. This approach was selected as it has the advantage of identifying the weaknesses or defects early and rectifying them before the product is completed, thus optimising the achievement of the educational goals. A prototype of the program was trialed with a small group of students who varied in ethnic composition, gender, prior experience level with the topic area, and computer literacy. Student reactions and feedback on attitudes, difficulties and preferences was collected and analysed.
Responses indicated a high level of acceptance by the students at all levels of the course as well as the postgraduate students in terms of intellectual stimulation, challenging, interactivity, and purposefulness. All students surveyed commended the graphic design of the interface as ìvisually easy on the eyesî, ìwhich keeps users interestedí, found the program ìeasy to followî, ìcovering all aspects of thermal processingî, and ìtotally interactiveî. Some students however, would prefer more indepth approach and/or several levels of complexity depending on usersí prior experience. Only two students mentioned their less than desirable computer literacy as a limiting factor.
Some students felt that a CD-ROM offers them ìrepeatability and portabilityî, ie. more flexibility in time and location of learning experience, and that by contrast, Web-based model may not be easily accessible by all students at home.
Implications on Teaching and Learning Food Science and Technology
It is yet premature to comment on the effects of this program on student success rate, and on what has or hasnít worked, and why, as the program is not fully developed, nor yet implemented. The full evaluation of the program in 1998 will incorporate issues such as ease of access, style of use, level of motivation, personal attitudes such as resistance to use or fear and annoyance, and adaptability of the program to suit a range of learning modes.
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(c) F. Sherkat, A. L. Halmos, R. Lord
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