English for food science and technology

Objective The purpose of this course is to provide students with the basic knowledge of food science and technology in English, and to improve speaking, reading, writing, translating sk

English for Food Science and

Objective

The purpose of this course is to provide students with the basic knowledge of food science and technology in English, and to improve speaking, reading, writing, translating skills in this field

Teaching method

This subject include: 3 units (30/15)

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Contents

Section One: Introduction and Background (13)

Chapter 1 Concepts of food science & technology (1)

Chapter 2 Quality factors in foods (3)

Chapter 3 Unit operations in food processing (6)

Chapter 4 Food deterioration (3)

Section Two: Preservation (17)

Chapter 5 Heat (2)

Chapter 6 Cold (2)

Chapter 7 Drying and Dehydration (3)

Chapter 8 Fermentation, Microorganisms, and Biotechnology

 Section Three: Foods and Food products (8) - Seminar

Chapter 11 Milk (2)

Chapter 12 Beverages (3)

Chapter 13 Fruits and Vegetables (3)

 Section Four: Related Issues (7)

Chapter 13 Food safety (4)

Chater 14 Regulation and Labeling (3)

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Contents

Section One Introduction and Background

Chapter 1

Concepts of food science & technology

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What is food science & technology?

 Science  through observation/ experimentation 

understand, or to understand better (knowledge)

 When science becomes knowledge?

 Science becomes knowledge by publication of research

results

 Food science is the study of the physical, biological, and

chemical makeup of food/ to better understand food processes

What is food science & technology?

Technology: the methods for using scientific discoveries

for practical purposes, esp in industry

Food technology is the application of food science to

the selection, preservation, processing, packaging, distribution, and use of safe food

 Food science  Basic science

 Food technology  Apply science

What Is Food Science & Technology?

The Institute of Food Technologists defines food science

as "the discipline in which the engineering, biological, and physical sciences are used to study the nature of foods, the causes of deterioration, the principles underlying food processing, and the improvement of foods for the consuming public"

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What Is Food Science & Technology?

 Food scientists are involved in all aspects of this process, from the point of animal and crop production to the time of food consumption This includes developing new and improved foods, analyzing food for its nutritional value and safety, and researching better ways

to preserve food

Become a food scientist

 Food technologists develop and improve existing food products and set standards for producing, packaging and marketing food They also undertake basic and applied research into aspects of food preservation, food quality and shelf-life

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Become a food technologist

Chapter 2 Quality factors in foods

(3h)

2.1 Concept

Quality of food product involves maintenance or improvement of the key attributes of the product-

including color, flavor, texture, safety, healthful, shelf

life and convenience

To maintain quality, it is importance to control microbiological spoilage, enzymatic degradation, and chemical degradation

 These components of quality depend upon the composition of the food, processing methods, packaging, and storage

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2.2.1 Color

Of these two, color is by far the most important

 Comsumers expect meat to be red, apple juice to be light yellow and clear, orange juice to be orange, and so on

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 Food color meansurements provide an objective index of

food quality

 Color is an indication of ripeness or spoilage

 Changes in expected colors can also indicate problems

with the processing or packaging

 But with the development of biotechnology  everything change!

2.2.1 Color

 Source of color in food:

 Naturally occurring pigments (anthocyanins)

2.2.1 Color - Measuring

In order to maintain quality, the color of food products must be measured and standardized

 Colorimeters or spectrophotometers can be used for

color measurent (juice or colored extract)

 The color of liquid or solid foods can be measured by

comparing their reflected color to defined (standardized) color tiles or chips

2.2.2 Size and Shape

 Depending on the product, comsumer expect food to have certain sizes and shapes

 Size and shape are easyly measured Fruits and vegetables are graded based on their size and shape, and this is done by the openings they will pass through during grading

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2.2.4 Flavor factors

 Food flavor includes taste sensations perceived by the tongue – sweet, salty, sour, and bitter – and smells perceived by the nose

 Often the term flavor and smell

(aroma) are used interchangeably

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Taste areas of the tongue

 Food flavor and aroma are difficult to measure and difficult to get people to agree on

 A part of food science called sensory science is dedicated to finding ways to help humans accurately describle the flavors and other sensory properties of their food

 Food flavor is a combination of taste and smell, and it is very subjective and difficult to measure

 People deffer in their ability to detect tastes and odors

2.2.4 Flavor factors

 For comsumer quality acceptance, the best method of measuring taste is to have people taste the products

 Taste panels may be a group of professionals, or they may be a group of customers

 Typically taste panels are in separate booths so that they cannot influence each other

 Food samples are coded with letters and numbers, and tasters are given an evaluation form to complete as they taste the product and evaluate it

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2.2.4 Flavor factors

Taste panels

Food samples HS-SPME

Data analysis

GC-MS determination

Compounds Identification MSD ChemStation software

2.2.4 Flavor factors

Food aroma compounds: tools and techniques for detection

2.2.5 Additional quality factors

 Additional quality factors include shelf life, safety, healthfulness, and convience

 The extension of storage life of products generally involves heat treatments, irradiation, refrigeration or freezing, or reduction of water activity by either addition

of water – binding agent, like sugars, or drying Inmany cases compromises are made to achieve desired shelf life

or convience

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 Food irradiation (the application of ionizing radiation to food) is a technology that improves the safety and extends the shelf life of foods

by reducing or eliminating microorganisms and insects Like pasteurizing milk and canning fruits and vegetables, irradiation can make food safer for the consumer

2.2.5 Additional quality factors

Your opinions on Food irradiation

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 The factors that influence changes of various ingredients in

foods include the following: proteins, lipids, carbohydrates, vitamins, and microbiological characterizatics

 Protein:

 Heat denaturation  solubility and texture;

 Light oxidation  off flavor

 Enzymatic degradation  changes in body, texture

and also bitter flavors

 Freezing  conformation and solubility in some

2.2.5 Additional quality factors

 Microbiological characterizatics :

 Processes that are aimed at prevention of growth include: Irradiation, Refrigeration, Freezing, Drying, Control of water activity (adding of salt, sugars, and so forth)

 Processes that are aimed at minimizing organisms include: Pasteurization, Sterilization (canning), Cleaning and sanitizing, and so forth

2.2.5 Additional quality factors

2.2.5 Additional quality factors

 Quality standards

Quality standards help ensure food quality Types of standards include:

 Research standards (by company),

 Trade standards (by members of an industry),

 Government standards

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Quality Control: the process of looking at goods when

they are being produced to make certain that they are all

of the intended standard

Quality Assurance: the managing of every stage of a

2.2.5 Additional quality factors

 Quality control

 TQM (Total Quality Management)

 HACCP (Hazard Analysis Critical Control Points)

 GMPs (Good Manufacturing Practices)

 GAP (Good Agriculture Practices)

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2.2.5 Additional quality factors

Review questions

1. What qualities do consumers expect of their food?

2. How to maintain quality of food?

3. Where are the quality of products made?

Chapter 3 Unit operations in food processing

(6h)

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3.1 Objectives of this chapter

 Provide students with the knowledge of:

 Materials handling,

 Methods of reducing the size of food product

 Methods of separating food products

 Common methods of drying

 Reasons for packaging food products

3.2 Materials handling

 Materials handling includes the variety of operations from harvesting on the farm, refrigerated trucking of perishable produce, to conveying a product

 During all of these operations, sanitary conditions must

be maintained, losses minimized, quality maintained, and bacterial growth minimized

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 All transfers and deliveries of materials must be on time and that time kept to a minimum for efficiency and quality

3.2 Materials handling

3.3 Cleaning

 The way foods are growth or produced in open environments on the farm or ranch often requires cleaning before use

Why foods and drinks must be clean?

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3.3 Cleaning

 Cleaning ranges from the removal of dirt to the removal

of bacteria from a liquid food

 Brushes, high-velocity air, steam, water, vacuum, magnets, microfiltration, and mechanical separation are all used to clean foods

 Aside from the food itself, food processing equipment requires frequent, through, and special cleaning to maintain the quality of the product

 Also, the floors and walls of the processing facility must

be cleaned

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3.3 Cleaning

3.5 Size reduction

 Size reduction is a major part of food processing

 Size reduction can be through the use of high-shear forces, graters, cutters, or slicers

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 Mixing food : to combine different substances

 Mixing may be placed in a tank for a number of purposes

 Two major purposes of mixing are either heat transfer or ingredient incorporation

3.6 Mixing

 Concentration can be achieved through evaporation and through reverse osmosis

 Evaporation generally involves heating the fluid in a vessel under a vaccum to cause a change in state of water from liquid to vapor and then recovers water by passing the vapor through a condenser  loss of flavor volatiles

 Reverse osmosis (RO) is a process where the fluid is passed through a semipermeable membrane with very small pores that permit only the transfer of water

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3.7 Concentration

 Three common methods of drying:

 Sun or tray drying (1)

 Spay drying (2)

 Freeze drying (3)

 Least expensive: 1 > 2 > 3

3.8 Drying

 Base on characteristics of the product  choice the drying method:

 Products that are solid  Sun or tray drying

 Products that are very heat sensitive  Freeze dried

 Fluid products  Spray drying

 Often foods need to be formed into specific shapes

 Processes used to form foods can include compacting, pressure extrustion, molds, powers and binding agents, heat and pressure, and extrusion cooking

3.9 Forming

3.10 Packaging

 Material used for wrapping or covering goods to

protect them

 Packaging is used for a variety of purposes including

shipping, dispensing, improving the usefulness of the product, and protection from microbial contamination, dirt, insects, light, moisture, drying, flavor changes, and physical alterations

 Attractive packaging also helps with marketing of the food product

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 Foods are packaging in metal cans, glass and/or plastic bottles, paper, plastic and metallic films

 Now, more products are being packaged in flexible and formable containers

3.10 Packaging

 Machines that automatically package food products operate at high speeds, and the complete process is step-wise and automated from the forming of the container, filling of the container, to the sealing, labeling, and stacking

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3.10 Packaging

 In morden processing plants, the instrumentation and

Review question

1. Why are foods packaged?

2. Why is it important to handle food materials carefully?

3. Explain the three common methods of drying foods

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Chapter 4

Food Deterioration

(3h)

4.1 Concept

 Deterioration includes changes in organoleptic quality, nutritional value, food safety, aesthetic appeal, color, texture, and flavor

 All foods undergo deterioration after harvest  the role

of food science is to minimize negative changes as much

as possible

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4.2 Types of food deterioration

 Three general categories of food deterioration are:

4.3 Shelf life and dating of foods

 Shelf life is the time required for a food product to reach

 Food manufacturers put code dates on their products “Pack

date” is the date of manufacter

 The date of display is called the “display date”, and the

“sell by date” is the last day to sell

 “Best used by date” or the last date of maximum quality

 The “expiration date” indicates when the food is no longer

acceptable

4.3 Shelf life and dating of foods

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4.4 Cause of food deterioration

4.4.1 Caused by microorganisms

 Where are microorganisms from?

 Soil, water, and air; on animal skins, plant surface, and

in digestive tracts  not in healthy tissue!

 Bacteria produce spores  resistant to heat, chemicals, and other adverse conditions

 Some of yeast produce spores,

 All of molds produce spores

4.4 Cause of food deterioration

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4.4.1 Caused by microorganisms

 In foods these microorganims attack basically all the food components – sugars, starches, cellulose, fats, and protein

 Depending on the food and the microorganism, the action on food could be to produce acids, making the food sour, or produce alcohol, some produce gas, and other unwanted pigments or toxin

4.4 Cause of food deterioration

4.4.1 Caused by microorganisms

 Invironmental conditions that affect microbial growth:

oxygen and temperature

 Microbial that prefer cold temperature  pyschrophilic

 Microbial that prefer normal temperature  Mesophilic

 Microbial that prefer hot temperature  Thermophilic

 Microbial require oxygen  aerobic

4.4 Cause of food deterioration

 Food becomes soft and smells bad  moulds and yeasts

 Food does not always look bad, even if it is severely infected (more dangerous)  Bacteria

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4.4 Cause of food deterioration