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Introduction to food analysisIntroduction to food analysis
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Food analysis objectivesFood analysis objectives
y Developing a theoretical and practicalunderstanding of the methods used toanalyse foods
chemical analysis physical analysis
y to ensure high and consistent quality offoods in the food industry
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Proximate analysis of foodsProximate analysis of foods
y Definition
estimation of the main components of a food
using procedures that allow a reasonably rapid and
acceptable measurement of various food fractionswithout the need for sophisticated equipment or
chemicals
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Proximate analysisProximate analysis
y Therefore crude estimation; crude fat, crude
protein
not true value but adequate
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Proximate analysis of foodsProximate analysis of foods
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Further development in foodFurther development in food analysis dueanalysis due
adulterationadulterationy Prior to the 18th century food adulteration
not a serious problem
y
Food adulteration and deception rampant in 18th century
high value foods substituted for cheap often
hazardous materials
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FoodFood adulterationadulteration
y adding stone grinds (40%) to flour
y milk samples contained lead chromate (red lead)
y Black pepper: gravel , leaves, twigs
y Vinegar & lemon juice : sulphuric acidy Coffee: roasted cereals, pulses or vegetables,
y Tea: spent, re-dried tea leaves
y Sugar: sand, dust,
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y Milk: water, starch, gums and soda
y Beer: poison berry extract gave flavour, colour
and intoxicating effecty Butter: excessive salt & water, potato flour
y Chocolate: starch and ferric oxide
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y Quality
the sum of features, characteristics and
properties of a product which bear on its ability
to satisfy stated or implied needs
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y Quality control (QC)
operational techniques and activities which
sustain quality of goods and services
x QC staff 100% inspect carcasses at abattoir
x in cannery, check seems, fill weights, pH etc
x laboratory staff carry out analytical tests;
x dairy plant fat test & freezing point
x phosphate test
x direct microscopic counts
x lab staff may conduct sensory analysis
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Quality values ofQuality values of foods analysisfoods analysisy Legal
hygiene, additives, residues, contaminants andcomposition
y Nutritive national nutritional guide lines, undesirable
(additives & residues)
y Health over laps with legal and nutritive values
Food Standardsx alert of health hazards during pregnancy
x qualifying the value of food categories
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y Technological
convenience foods heat and eat
less processing / perceived fresh
y Sensory like or dislike measurement of quality via
senses
y Socio-ecological
food packaging verses pollution
conversion of rain forest to cow pastures
effluent into water ways
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Quality that may be evaluate?Quality that may be evaluate?
y Attribute : which measure qualitative
character of food products
y Variables: which measure quantative
characters of food products
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FoodFood chemsitrychemsitry
y Food chemistry is the study ofchemical
processes and interactions of all biological and
non-biological components of foods. The
biological substances include such items asmeat, poultry, lettuce, beer, and milkas
examples. It is similar to biochemistry in its
main components such as carbohydrates, lipids,
and protein, but it also includes areas such aswater, vitamins, minerals, enzymes, food
additives, flavors, and colors.
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y discipline also encompasses how products
change under certain food processing
techniques and ways either to enhance or
to prevent them from happening
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y And so to study the chemical processes
and interactions of all biological and non-
biological components of foods we need
to food analysis
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Food componentsFood components
y Water
y Carbohydrates
y Lipids
y Proteins
y Vitamins
y Minerals
y Enzymes
y additives
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y During this course: exploring the different
types of reactions and changes that may
occur during food processing and to
control it by food analysis
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