Transcript Introduction to Food Engineering

ERT 426 Food Engineering
Semester 2 Academic Session 2010/11
BB Lee @ UniMap
1
Subtopics
1. Background
2. Food Industry in Malaysia
3. Typical Food Manufacturing Processes
4. Recent Developments in Food Engineering
Research
5. Present Trends and the Future of Food
Engineering
6. Sociocultural Aspects of Some Critical
Points Limiting Progress
ERT 426 Food Engineering
BBLee@UniMAP
2
1. Background
 Food engineering is a multidisciplinary
field of applied physical sciences which
combines science, microbiology, and
engineering knowledge for food and related
industries.
 Food engineering includes, but is not
limited to, the application of agricultural,
chemical, mechanical, civil and electrical
engineering principles in addition to food
sciences to food materials.
ERT 426 Food Engineering
BBLee@UniMAP
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Background
 Food Engineers:
 provide the technological knowledge transfer essential
to the cost-effective production and commercialization
of food products and services.
• When foods are used as raw materials they offer unique
challenges.
 Perhaps the most important concern in food processing
is the variability in the raw material.
 To achieve consistency in the final quality of a
processed food, the processes must be carefully
designed to minimize variations caused by processing.
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Background
 Food engineering is a very wide field of activities.
Prospective major employers for food engineers
include companies involved in food processing,
food machinery, packaging, ingredient
manufacturing, instrumentation, and control.
Firms that design and build food processing plants,
consulting firms, government agencies,
pharmaceutical companies, and health-care firms
also hire food engineers.
ERT 426 Food Engineering
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2. Food industry in Malaysia
 Malaysia's food industry is as diverse as the multi-
cultures of Malaysia, with a wide range of processed
food with Asian tastes.
 In 2008, the food processing industry contributed
about 10% of Malaysia's manufacturing output.
 Companies in this industry are predominantly
Malaysian-owned.
 In Malaysia, the food industry is dominated by small
and medium scale companies.
 The major sub-sectors are fish and fish products,
livestock and livestock products, fruits, vegetables
and cocoa.
Information is taken from Malaysian Industrial Development Authority (MIDA)
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Food industry in Malaysia
 It is estimated that the present global retail sales in food
products are worth around US$3.5 trillion, and are
expected to grow at an annual rate of 4.8 per cent to
US$6.4 trillion by 2020.
 Malaysia's food exports amounted to RM17.9 billion
in 2008, while imports totalled RM28 billion.
 Malaysia remains as a net importer of food.
 Malaysia exported food products to more than 200
countries.
 The main products exported were:
1. cocoa (RM3 billion),
2. fisheries products (RM 2.5 billion),
3. margarine and shortening (RM 2.4 billion)
4. animal feed (RM1.2 billion).
Information is taken from Malaysian Industrial Development Authority (MIDA)
ERT 426 Food Engineering
BBLee@UniMAP
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Food industry in Malaysia
 Major food imports in 2008 were cereal and cereal
preparations, cocoa, vegetables and fruits, dairy
products and animal feed.
 Raw materials such as cereals and dairy products
will continue to be imported for further processing
for human consumption as well as for the production
of animal feed.
Information is taken from Malaysian Industrial Development Authority (MIDA)
ERT 426 Food Engineering
BBLee@UniMAP
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Food industry in Malaysia
 Currently, Malaysia is the largest cocoa processor in
Asia and ranks fifth in the world.
 However, most of the cocoa beans are imported.
 Malaysia is one of the world major producers of
spices.
 In 2008, Malaysia's was ranked as the fifth largest
exporter of pepper and pepper-related products
(specialty pepper, processed pepper and pepper
sauces).
Information is taken from Malaysian Industrial Development Authority (MIDA)
ERT 426 Food Engineering
BBLee@UniMAP
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Food industry in Malaysia
 The halal industry in Malaysia provides immense
opportunities for Malaysian manufacturers.
 With a global Muslim population of about 2 billion, the
market for halal food is estimated at US$547 billion a
year.
 The concept of halal is associated with food products
which are of high quality in terms of cleanliness,
sanitation and compliance with religious
requirements.
 Local halal food products can gain easy
access into world wide halal markets as
Malaysia‘s halal certification is
globally recognised.
ERT 426 Food Engineering
BBLee@UniMAP
Information is taken from MIDA
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3. Typical food
manufacturing processes
 During the last 30
years, the food
engineering
discipline has
evolved to
encompass several
aspects of food
processing.
 The diversity of
processes typically
employed in a food
processing plant is
illustrated in Figure 1.
ERT 426 Food Engineering
BBLee@UniMAP
(Heldman & Singh, 1981)
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Typical food manufacturing processes
 Typical food processes may include:
i.
ii.
iii.
iv.
v.
vi.
sorting and size reduction,
transport of liquid foods in pipes,
heat transfer processes carried out using heat
exchangers,
separation processes using membranes,
simultaneous heat and mass transfer processes
important in drying, and
processes that may involve a phase change such as
freezing.
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4. Recent Developments in Food
Engineering Research
 Research in food engineering was initially focused on:
 the analysis of food manufacturing,
 the processing and packaging operations,
 the utilization of agricultural materials and energy,
 the environmental issues.
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Recent Developments in
Food Engineering Research
 During the past two decades, however, chemical
engineering and food engineering have shown a
dramatic change in their research emphases because of
revolutionary developments in three fields:
1. Biotechnology
 particularly genetic engineering)
2. Computer science and technology
 applied mathematics and modeling (e.g., kinetics,
neural networks, and fuzzy logic)
3. Material science
 especially understanding the relations between the
molecular structure and functional properties of
materials)
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5. Present Trends and the Future of Food Engineering
 Paradigm for Product/Process
Development in the 21st Century:
1. Development of key scientific "knowledge-based"
components (e.g., food properties)
2. Development of quantitative relationships
between food properties and quality attributes
which should be:
• Quantifiable • Reproducible • Relevant
3. Relationships (models) organized in computerbased information systems similar to those
available in the chemical industry for
thermodynamic properties (e.g., Aspen).
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Present Trends and the Future of Food Engineering
4. Application of models in specific developmental
tasks
5. Development and utilization of on-line sensing
systems for key food properties (eventually
similar sensing systems may be feasible for
quality attributes as well).
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Present Trends and the Future of Food Engineering
 Emulsification technology is important in the
creation of mayonnaise, peanut butter, various full-fat
and low-fat spreads, as well as many beverages and
flavor preparations.
 The rheological and diffusional properties of an
emulsification process are of fundamental importance
as new analytical and instrumental methods are
available and mathematical relations relating them to
process parameters can be established.
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Present Trends and the Future of Food Engineering
 Emulsion Technology-Based Foods:
1. Objectives of material science research:
 Control of texture and mouthfeel
 Control of storage stability and thermal stability
 Ability to use alternative components to modify
nutritional and organoleptic properties
2. Knowledge-based surface properties are :
 Free surface energy, surface viscosity, dynamic tension,
surface elasticity, surface charge
 Rheological properties
 Diffusivity of components
3. Quantitative relational models have:
 Sensory response versus physical properties
 Physical properties versus temperature, pressure and other
variables
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Present Trends and the Future of Food
Engineering
4. Applications:
 Low-fat spreads using fat mimetics
 Design of emulsification systems
 Incorporation of controlled release formulations
5. Relevant new tools:
 Image analysis (visible, IR, NMR, ESM)
 Computer-aided simulation of structure
 New mathematical tools (e.g., fractal analysis)
6. Current status:
 The physical aspects have undergone advanced
research in key corporate and academic institutions
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Present Trends and the Future of Food Engineering
 A useful way of presenting a material's physical
properties is with "State Diagrams," which can relate
them (especially those related to molecular mobility)
to temperature and aqueous system concentration.
 One of their key features is a glass transition line that
relates glass transition temperature (Tg) to the given
solute's concentration.
 Recent work at several research centers has developed
information allowing construction of these diagrams
for multisolute systems and food materials as well.
 The knowledge of glass transition lines allows the
prediction of conditions under which given desirable
or undesirable changes are retarded or accelerated.
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State
Diagram
for food
materials
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Present Trends and the Future of Food Engineering
 Developing Quantitative Relationships Between Physical
and Sensory Properties of Syrups:
1. Mouth feel:
 Sensory thickness is proportional to the shear stress on the surface of
the tongue.
 Sensory smoothness is inversely proportional to the friction force on
the tongue.
2. Perception of properties during pouring:
 Subjective viscosity is related to the bottle-neck area filled by the
syrup.
 Subjective drippiness is related to the normalized instability growth
rate (which can be calculated from known physical parameters).
3. Perception of properties during spreading:
 Sensory viscosity shows a good correlation with the radial growth of a
syrup puddle.
 Sensory smoothness was well correlated with the aspect ratio of the
syrup mass.
[Aspect ratio = Dmin IDmax , Dmin & Dmax - the minimum & maximum
diameters of a spreading puddle]
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BBLee@UniMAP
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Present Trends and the Future of Food
Engineering
 The use of enzymes that act specifically on selected
substrates or intermediates to eliminate undesirable
products or the localization of reactants, catalysts,
or antioxidants in portions of food in which a
particular reaction may be desirable (e.g., surface
browning).
 The requirement for the successful application of
these principles lies in developing sound knowledge
of the mechanism and kinetics of food reactions.
ERT 426 Food Engineering
BBLee@UniMAP
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Present Trends and the Future of Food Engineering
 Potential Approaches for Controlling Complex
Reactions in Foods:
1. Enzymes:
 Using substrate specificity of selected enzymes reactions
may be directed to produce desired products (e.g.,
lipoxidases to control oxidation derived compounds
according to Vliegenthart of Utrecht and Pratt of Purdue).
 Enzymes may also be added to remove undesirable
products or intermediates.
2. Other catalysts or inhibitors:
 Reactions may be directed by catalyzing or inhibiting
specific reaction steps (e.g., pH control in browning
reactions).
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BBLee@UniMAP
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Present Trends and the Future of Food Engineering
3. Addition of substrates or intermediates:
 Reactions may be modified by adding specific
precursors of desired end products.
4. Localization of reactants or catalysts:
 As in liposomes containing proteases in cheese
ripening (Kirby)
5. Controlling environmental factors:
 Different steps may have different activation energies
or reactants of differing solubility; regulating
temperature, pressure, or water activity will control
reactions.
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6. Sociocultural Aspects of Some Critical
Points Limiting Progress
1. Reluctance of consumers to accept the following:
 Compositions perceived as unnatural (even those
that are natureidentical).
 Ingredients created or modified by genetic
engineering.
 Foods processed by nontraditional energy input
such as ionizing radiations.
2. Inadequate public understanding of the interface
between diet and health resulting in temporary
interests that often divert food product development
from more sound long-term objectives.
ERT 426 Food Engineering
BBLee@UniMAP
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