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HNSC 1200 Unit 1

Terms in this set (97)

Definition of Food
Any solid or liquid material consumed by a living organism that maintains life and growth.
Supplies energy, carrier of nutrients.
Can be processed or raw.
Nutrients
substances the body uses for the growth, maintenance and repair of its tissues. There are 6 classes of nutrients that can be divided into 2 groups:
Nutrients Group A
Energy providing (meaning that the body can use the energy they contained)
1. carbohydrate
2. fat
3. protein
Nutrients Group B
Other nutrients (or non-energy containing)
1. water
2. vitamins
3. minerals
Essential Nutrients
nutrients that the body cannot make for itself from other raw materials. Examples of essential nutrients are the minerals, and the essential fatty acids, linoleic and linolenic acid.
Conditionally Essential Nutrients
body cannot make enough to meet the requirements for health (e.g., the amino acid histidine during periods of growth).
Non-Essential Nutrients
nutrients that the body can make for itself, so does not have to rely on our food intake (e.g., some amino acids, some fatty acids).
calorie
Energy is expressed in 1,000-calorie metric units known as kilocalories (shortened to kcalories), but commonly called "calories". When you read "100 Calories" in popular books or magazines, it actually means 100 kcalories (kcal). amount of heat energy required to raise the temperature of one litre of water by one degree Celsius.
Carbohydrate provide us with 4 Cal/g (=kcal/g)
Fat (lipid) provide us with 9 Cal/g
Protein provide us with 4 Cal/g
Alcohol provide us with 7 Cal/g, but is not a nutrient
How to calculate the energy available from foods
Multiply the number of grams of carbohydrate by 4, protein by 4 and fat by 9. Add the results together.
How to calculate percentage of kcal for each nutrient (in relation to total kcal from the nutrients)
Divide kcal of nutrient by total kcal. x100
phytochemicals.
Non-nutrient compounds derived from plants
Have biological activity in the body
May support health beyond roles of traditional nutrients
At one time thought to only play a role in the sensory qualities of a food (taste, colour, texture, etc.).since recognized that some have profound physiological effects on our body:
may act as antioxidants
may mimic hormones
may alter blood constituents to protect against some disease processes, e.g., cancer, heart disease
Supplementing phytochemicals
Added phytochemicals may produce effects that are vastly different from those seen in whole foods.
These chemicals can exert different effects on different people or when taking differing doses, or at different life stages. have the potential to alter body functions,only partly understood
food, not supplements, is currently the most effective and safest source. Currently, insufficient evidence to say for certain whether any is effective at fighting disease, or if it is safe to consume in concentrated doses.
Functional Foods
products that may look like or be a conventional food and are consumed as part of a usual diet, but have physiological benefits or can reduce the risk of chronic disease beyond basic nutritional functions, e.g., soy-based foods. yogurt. cranberry juice
Nutraceuticals
products isolated or purified from food, generally sold in a medicinal form not usually associated with food and have physiological benefits or provide protection against chronic disease, e.g., isoflavones (phytochemical) from soybeans can be extracted and sold in pill form.
Food science
interdisciplinary field of science which overlaps with many other areas, such as nutrition, biology, chemistry, physics, even engineering.
is the scientific study of:
Raw food materials.
and Behaviour of raw food materials when created, processed, stored, packaged, and evaluated as consumer food products.
Food Technology
Applying food science to the:
selection
preservation
processing
packaging
distribution
use
of safe, nutritious, wholesome food.
technology allows for the wide availability and variety of foods. Technology also affects our processed foods through the use of food additives, which can be anything from emulsifiers that help the fat to bind to watery food components to the colour stabilizers in the food or the preservatives that help to keep the food fresh
Safety and Quality of Food
Food processing and manufacturing
Food preservation and packaging
Food safety and wholesomeness
Food quality evaluation
Food distribution
Consumer food use and preparation
Food Scientist
Applies scientific knowledge and technological principles to the study of foods and food components.
Can work in research or manufacturing.
Nutrition Research
Research begins with a question. In search of an answer, scientists make an educated guess called a "hypothesis". The scientists then systematically conduct research studies to test each hypothesis.
The scientific method is the steps that scientist take when trying to solve a problem or doing an experiment.
It is important to find, read and assess previous research that has been done on the topic in question. When interpreting research, it is important to take an evidence based approach, with the gold standard for scientific information being peer-reviewed literature
scientific method
Define the problem
Formulate the hypothesis
Collect Data
Interpret Data
Generalize the findings
Descriptive Studies
can generate a hypothesis, can focus on an individual or a population. Examples include:
Population or correlational study, Case report, Case series, Cross-sectional survey
Population or correlational study
researchers compare data from entire populations to identify factors that might influence the incidence of a disease in various populations. It is impossible to establish causality though since the whole population is being examined. Also referred to as epidemiological studies.
Case report
detailed report on a single patient
Case series
a compilation of multiple case reports
Cross-sectional survey
examines both exposure and disease in individuals.
Analytical Studies
can test specific hypotheses, can include observational and intervention studies. Examples include:
Case-control study, Cohort study, Intervention study
Case-control study
researchers compare people who have a given condition such as a disease with other people who do not have the disease. They closely match them in age, gender and other key variables so that differences in other factors will stand out.
Cohort study
classifies participants based on exposure and follows them for a period of time to assess disease development.
Intervention study
researchers ask people to adopt a new behaviour (e.g., take a vitamin C supplement) and compare their results to a control group taking a placebo. These trials help determine the effectiveness of such interventions in the development or prevention of disease. Intervention studies are usually randomized (participants are randomly assigned to either the treatment or placebo group). With a double-blind design, neither the researchers nor the study participants know who is receiving the treatment and who is receiving the placebo and are considered to provide the most compelling outcomes.
factors play a role in the food choices that we make:
Availability: rural areas may have less accessibility to some foods
Cost: is the food affordable?
Convenience: if you need to eat your meal at school or on the run
Emotional factors: ice cream after a break-up
Social factors: wing night with friends
Media advertising: a commercial makes you hungry, marketing unhealthy food to kids through the use of cartoon characters
Habit: choosing familiar foods
Positive or negative association: foods that have happy associations, dislike foods with negative associations
Personal values: may avoid eating certain foods because of personal beliefs
Weight, health, nutritional value: choosing foods that we perceive to be "good for us"
Personal preference: choosing food because of taste
Occupation: can influence the pattern of eating that we follow.
Cultural / ethnic factors: every culture has typical foods and ways of preparing them.
Ethnocentrism
The belief that one's own pattern of behaviour is preferred over those of other cultures
Cultural Relativism
an approach of understanding and accepting other cultures. Recognizing that values and beliefs can differ, based on culture, but that all are equal.
Aging Canadians
It is projected that there will more seniors and fewer children in the Canadian population in 2020. This will influence the types of food that there is demand for in the population.
An Evolving Society
It is predicted that brand names will become less of a status symbol, and will be used by consumers to express individuality. Other changes also expected to affect food choices, decreased family size, environmental awareness, globalization, and participation in the workforce.
Changing Meal Patterns
Food preparation is predicted to decline, with a shift towards small, frequent meals or snacks instead of three meals a day. result in a greater demand for more portable food options.
Shifting Expenditures
It is forecast that the decline in amount of disposal income spent on food will continue to 2020. This is expected to impact the frequency that Canadians visit restaurants.
Food for Health
The most significant health conditions expected to drive food choices are obesity, heart disease and diabetes.
The Educated Consumer
Consumers will be more conscious of what is in their foods through label reading, with a focus on:
Zero trans-fats
Low sodium
High fibre/healthy carbohydrates
Reduced sugar
Allergen identification
Fortification
Health claims
The New Face of Canada
As immigration into Canada continues to increase so will the influence on our food supply. diversification, fusion and blending of cuisines, as well as easier access to unfamiliar food ingredients, cooking methods and presentation styles.
No Trade-off for Convenience
Consumers will want it all. They will not be willing to make any sacrifices for convenience, so the pressure will be on food producers to create convenient forms of foods that are nutritious, great tasting, fresh and varied (ethnic foods as well).
Veggies Anyone?
The consumption of non-meat meals is expected to increase among non-vegetarians. This is due to consumer focus on health, quick preparation and ethnic food options.
Organic Foods
Organic food consumption is expected to continue to increase.
Small Indulgences
predicted increased demand for gourmet foods and boutique brands of food. see a shift from demand for big portions of cheap food to a demand for smaller portions of high quality, nutritious foods.
Food Safety and Production Issues
Consumer confidence in foods will continue to influence their decision to purchase. Food borne illness, food additives, food processing techniques (like biotechnology and irradiation), ethics, country of origin and contaminants will all continue to be important to consumers.
Food insecurity
Limited or uncertain access to foods of sufficient quality or quantity to sustain a healthy and active life. person may have access to enough calories but not necessarily enough nutrients.
Risk factors include anything that limits resources available for food acquisition, such as an increase in non-food expenditures, under-employment and poverty. leads to hunger, and hunger is a major health issue.
Food security
Access by all people at all times to nutritionally adequate, safe, personally acceptable foods from normal food channels.
The four pillars of food security are: Availability,
Accessibility, Adequacy, Acceptability
Availability
sufficient amount at all times, and variety at a reasonable cost. This is affected by time of year/season, civil conflict/war, food preservation and supply.
Accessibility
determined by entitlements (the bundle of resources needed to acquire food). Accessibility is affected by:
market prices
employment/funds ($)
production and marketing systems
gender and power relations within the household
education
transportation
water
sanitation
Adequacy
provide nourishment. affected by: control over resources, nutrient content of the food/quality, information about food/nutrition.
Acceptability
refers to food that is:
personally palatable
acquired by a socially-acceptable means of obtaining food
culturally appropriate
Famine
widespread and extreme scarcity of food in an area that causes starvation and death in a large portion of the population
Food poverty
hunger occurring when enough food exists in an area but some of the people cannot obtain it because they lack money, are being deprived for political reasons, live in a country at war, or suffer from other problems such as lack of transportation
Food shortage
hunger occurring when an area of the world lacks enough total food to feed its people
hunger
lack or shortage of basic foods needed to provide the energy and nutrients that support health
world food supply
the quantity of food, including stores from previous harvests, available to the world's people at a given time
food banks
facilities that collect and distribute food donations to authorized organizations feeding the hungry
food pantries
community food collection programs that provide groceries to be prepared and eaten at home
emergency kitchens
programs that provide prepared meals to be eaten on-site; often called soup kitchens
Hunger in Developed Countries
The main cause of hunger in developed countrie is food poverty. Although enough food exists in the area, it cannot be obtained because of:
Lack of Money: To buy nutritious foods and pay for other necessities
Political reasons: Up to 80% of hungry children live in countries that produce surplus food, policy makers in those areas, largely determines who in the population has access to the food.
Countries of War: Food transportation may be limited.
Lack of transportation: Can they get to a store to access food?
Cannot Afford: may be on welfare or may be part of working poor.
To stretch meager food supplies, adults often
skip meals or cut their portions
may be forced to break social rules: beg from strangers, steal from markets, scavenge through garbage cans, may even harvest dead animals from roadside. Can lead to dangerous food borne illnesses.
may rely on foods with low nutrient density, but high calorie density, so calorie needs are met, but not nutritional needs. Inexpensive foods like white bread, mac and cheese, pastas. Diet tends to be low in fruit and vegetables, milk product and meats/protein.
According to Agriculture and Agri-Food Canada
"About one-third of the global food supply is lost or wasted every year. Food is lost or wasted at all stages of the agri-food system
"Analysis of food loss and waste in Canada, the United States (U.S.), and other developed countries shows that most of the food loss and waste occurs in households and in the food retail and service sectors."
"In Canada, 6 billion kilograms of food was lost or wasted at the household and retail levels, representing 29.4% of the food supply in 2010, with household food loss and waste accounting for 20.3% of this total and retail accounting for the other 9.1%."
Four common methods of food recovery are:
Field gleaning: collecting crops from fields that either have already been harvested or are not profitable to harvest.
Perishable food rescue or salvage: collecting perishable produce from wholesalers and markets.
Prepared food rescue: collecting prepared foods from commercial kitchens.
Non-perishable food collection: collecting processed foods from wholesalers and markets.
Local efforts
Food recovery programs depend on volunteers. work through local agencies and churches to feed the hungry. For example, soup kitchens serve prepared meals. Other community programs include:
Food Banks: provide groceries and food.
Community kitchens are programs were individuals come together to prepare meals that they can take home to their families. Typically ingredients for set recipes are provided.
Community gardens are typically grown on donated plots of land, and typically the supplies and seeds are donated to a community group as well. The participants are responsible to care for the garden and benefit from the yield of produce.
School feeding programs provide meals, such as breakfast and/or lunch, to children at school.
Food Share programs
Causes and Outcomes of hunger
-Quantity, quality and availability of food - e.g. drought causing famine
-Discrimination factors that affect distribution - e.g. war, government corruption
-Individual household's access to available food - e.g. transportation to get food
-Access to clean water and health services
-Individual childcare practices (e.g. child fed while others in the family go hungry, knowledge of how to mix baby formula)
-Inadequate food or nutrient intakes - causing malnutrition, weakness, disease
-Ultimately disease conditions and malnutrition can worsen one another. This affects the life --expectancy rates - in some African countries, the life expectancy averages 50 years of age.
Two major challenges exist to banishing world food insecurity:
Provide enough for the worlds expanding population, without destroying natural resources need for continued food production.
Make sure everyone has access to this food.
Increased demand for food is influenced by:
-population growth - at the present rate of growth, the world's population is expected to soon surpass the current rate of food production
-urbanization - new developments, destroys farmland
-food losses, wastage and spoilage
-demand for high animal-protein diets - plant based foods take the least amount of energy to produce, while animal foods take the most energy to produce
Increased food production is influenced by:
-productive land
-irrigation
-fuel
-animal health
-animal wastes
-increased productivity
-agricultural chemicals
-aquaculture
-biotechnology - genetic engineering
-decreased food losses
Environmental changes that may have negative effects on food production:
-climate changes - can cause droughts and flooding, destroying crops and peoples homes
-ozone layer depletion - growing thinner, allowing harmful radiation from the sun to penetrate the earth. May potentially damage crops and ecosystems.
-pest resistance to pesticides
-resistance of pathogens to antibiotics and chemicals
-ocean pollution - pollution is killing fish in large dead zones along the coasts
-over-fishing is depleting the fish stock
-fresh water shortages—supplies are dwindling and becoming polluted
-loss of genetic resources
-loss of food producing land - erosion, loss of top soil, land being paved. We are trying to feed more people, with less land to produce food
-deforestation
-accelerated fossil fuel use - causing pollution of --air, soil and water
-inappropriate agricultural systems and/or technology
-extinction of species - more than 140 species of animals and plants become extinct each day. Another 20 percent of species are expected to die out over the next 10 years.
Why plants disappear
-Inability to adapt to climate changes.
-Loss of forests or harvesting of forest resources.
-Severe soil erosion by wind or heavy rains or soil pollution by repetitive use of chemical fertilizers.
-Market pressure on farmers to switch to commercial production of single varieties.
Why should we care about disappearing plants
-Plants provide the essentials of life: food, clothing and medicine.
-Different plants have different characteristics which are determined by their genes. When a plant species vanishes, so do its genes.
-As the plant gene pool shrinks, so do our options for food and medicine.
Biodiversity
Refers to the variety and variability of living organisms and their ecosystems.
includes diversity within species (genetic diversity),
Decrease began with the 'Green Revolution' - the dramatic increase in food production in the 1960s due to new seeds developed from crossbreeding.
The new seeds were resistant to insects and disease and yielded millions of tons of extra grain.
Insects and viruses were able to mutate, overcoming the protection of these plants.
Scientists were forced to search for new genetic codes, resulting in crops that are genetically uniform.
Net result is the extinction of many plant species and decrease in biodiversity.
What can you do to save the environment?
-Leave your car at home - walk / ride bike
-Choose foods lower on the food chain: Choose plant foods, choose smaller fish more often.
-Limit use of canned beef products.
-Grain products require the least amount of energy to produce, followed by plant foods like vegetables and fruits, and pulses/legumes.
-Choose locally grown foods - require less transportation, packaging and refrigeration.
-Avoid overly packaged foods - choose bulk
-Use reusable products, not "throw aways"
-Use fast cooking methods - e.g., stir fry, microwave, and pressure cooking use less energy than stove top or oven cooking.
-Practice wise resource use: reduce, reuse, and recycle.
-Promote sustainability - using resources at a rate at which the earth can keep replacing them
Examples of sustainable agricultural practices are:
-Integrated pest management - the use of two or more techniques such as crop rotation and natural predators (rather than pesticides) to control pests.
-Use of manure to decrease need for chemical fertilizers.
-Plowing of compost back into the soil to increase its water holding capacity.
-Open range grazing.
Why use sensory evaluation?
To determine consumer acceptability
To determine if product reformation results in a perceived difference
To identify taint contamination and determine source of contamination
Necessary to determine end-product quality
Necessary to establish product specifications for quality assurance programs
Necessary to establish shelf-life of products
Sensory Evaluation
the assessment by the human senses of all of the qualities of a food product that are perceived. a multidisciplinary science that uses humans to measure the acceptability and sensory properties of food and other materials. often determine the acceptance or rejection of foods. All five senses are used: sight, smell, touch, taste and sound.
Sight
eyes perceive a foods colour, shape, size, texture, opacity and consistency, gives an impression of the foods initial quality. Colour plays an important role in consumer perception of quality and acceptability. It is a cosmetic attribute that can affect consumer perception of freshness and taste. The colour of foods is based on wavelengths of absorbed and reflected light.
Smell
receptors in the nose are attached to nerves that enter the brain and report on the aromas and odours of food. Hot foods are easier to smell than cold foods. Odors can be sniffed directly through the nostrils or can be sensed through a passage at the back of the throat. gradual decline in the ability distinguish odors.
taste buds
biggest impact on whether we choose a food. A substance should be dissolved in water, oil or saliva in order to be tasted. are tiny receptor organs buried in the surface of the tongue (specifically in the papillae), mucosa of the palate and areas of the throat. The number we have decreases throughout our lifespan; so older adults tend to have less taste sensitivity. Taste perception can vary from person to person and this may be due to genetic variations, and how perceptible sweet, fatty and bitter components are in a food. Taste buds recognize 5 sensations: sweet, salty, sour, bitter, and umami (savoury).
Flavour
combination of the sensations of taste, odour, and mouthfeel, with odor or aroma being the most powerful, providing about 75% of the impression of flavour. Mouthfeel is the perception of tactile sensations and thermal response by the epithelial lining in the mouth. Thermal mouthfeel sensations include heat (e.g., cayenne pepper), coolness (menthol), metallic (if there is contamination with a metal like iron or copper) and astringent (e.g., tea).
sound
affected by the water content of the food and can indicate the foods freshness and ripeness.
touch
Texture perception is complex: first is visual, next is touch either through touch or utensils, third is mouthfeel. Texture is a measure of the physical characteristics of a food, measured as mechanical (e.g. hardness, cohesiveness, viscosity, adhesiveness, gumminess, springiness), geometrical (e.g. flaky, gritty, grainy, crystalline), and moisture properties (e.g. dryness, moistness, oiliness, wetness).
Variables Controlled During Sensory Evaluation
All require carefully controlled conditions in order to obtain valid, reproducible results. important that environment is carefully planned to minimize any distractions that may divert panellist attention away from the samples. individual, partitioned sensory booths are used, along with neutral colour, comfortable seating, and adequate lighting. important that the room is a comfortable temperature to ensure panellist comfort and that there is adequate ventilation to prevent competing odours from influencing the panellists. Samples must be standardized, and panellists are instructed to avoid communication with one another to avoid bias towards samples. Palate cleansers, such as plain bread or room temperature water can be used to prevent carry over taste between samples.
There are two general types of panels a descriptive panel and a consumer panel.
Descriptive panel
determines differences between food samples. Typically participants receive in-depth training and are selected through a series of tests.
Consumer panel
not trained and are selected from the public based on specific demographics / criteria.
four levels of measurement commonly used in sensory evaluation:
nominal, ordinal, interval and ratio. Interval and ratio are higher levels of measurement (more desirable), while nominal and ordinal are lower level.
Three common scales used in sensory evaluation
-Category scales are simple and easy to tabulate.
-Line sales can give participants the feeling that their responses are less limited.
-magnitude estimation scales, participants assign numbers to samples based on the strength of a sensation that they feel compared to other samples.
Overall Difference / Discriminative Tests
-Used to determine if there are differences between two products.
-Typically a control and a test sample are used.
-The simplest of the sensory tests
-Examples of difference / discrimination tests include triangle test and duo-trio test.
Triangle test
Participants are given three number coded samples and told to choose the sample that is most different. Two of the samples are usually the same (only the researcher knows this). Typically used when the difference between the products is qualitative.
Duo-trio test
One reference sample is presented, followed by two test samples (one of which is the same as the reference). Participants are asked to choose the test sample that matches the reference sample or is different from the reference sample.
Attribute Difference / Discriminative Tests
Focus on testing for one specific sensory attribute.
Often used to evaluate qualitative differences in texture, taste or colour.
Paired comparison
Participants are given two samples and have to choose one that has more of a specific characteristic, e.g., which of the two samples is sweeter?
Ranking test
participants are given samples and asked to rank them from lowest to highest for a specific characteristic.
Rating difference test
Participants are asked to rate samples using a rating scale based on a specific characteristic. See Figure 3.9: Example of a rating difference score sheet.
Descriptive Tests
-Attempt to describe the specific attributes of food product (texture, flavour, taste, mouthfeel, etc.) by quantifying how intense the panellists perceive specific characteristics.
-Frequently used for flavour and texture profiling.
-Panellists need to be well-trained.
-Provide the most comprehensive information of all test methods.
-Examples include Quantitative Descriptive Analysis (QDA) and Flavour Profile Analysis (FPA) and Sensory Spectrum (SS).
Affective Test Methods
There are two types: acceptance and preference. quantify the degree of like or dislike (hedonic basis) of one product or another.
Acceptance Tests
Panellists rate two or more samples on a scale to determine the difference in acceptance. Example of a 5-point acceptance score sheet
Preference Tests
-Paired Preference: panellist makes a choice between two products based on a hedonic basis.
-Preference Ranking: panellists put samples in order based on how much they like the samples, or in order of the intensity of a specific attribute (e.g., put in order from most sour to least sour).
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