Introduction to food analysis

1. Introduction to food analysis

2. Food analysis objectives • Developing a theoretical and practical understanding of the methods used to analyse foods • chemical analysis • physical analysis • to ensure high and consistent quality of foods in the food industry

3. Proximate analysis of foods • Definition • “estimation of the main components of a food using procedures that allow a reasonably rapid and acceptable measurement of various food fractions without the need for sophisticated equipment or chemicals”

4. Proximate analysis • Therefore crude estimation; crude fat, crude protein • not true value but adequate

5. Proximate analysis of foods

6. Further development in food analysis due adulteration • Prior to the 18th century food adulteration not a serious problem • Food adulteration and deceptionخداع rampant in 18th century • high value foods substituted for cheap often hazardous materials

7. Food adulteration • adding stone grinds (40%) to flour • milk samples contained lead chromate (red lead) • Black pepper: gravelحصى , leaves, twigs اغصان • Vinegar & lemon juice : sulphuric acid • Coffee: roasted cereals, pulses or vegetables, • Tea: spent, re-dried tea leaves • Sugar: sand, dust,

8. Milk: water, starch, gums and soda • Beer: poison berry extract gave flavour, colour and intoxicating effect • Butter: excessive salt & water, potato flour • Chocolate: starch and ferric oxide

9. Quality • “the sum of features, characteristics and properties of a product which bear on its ability to satisfy stated or implied needs”

10. Quality control (QC) • “operational techniques and activities which sustain quality of goods and services” • QC staff 100% inspect carcasses at abattoir • in cannery, check seems, fill weights, pH etc • laboratory staff carry out analytical tests; • dairy plant fat test & freezing point • phosphate test • direct microscopic counts • lab staff may conduct sensory analysis

11. Quality values of foods analysis • Legal • hygiene, additives, residues, contaminants and composition • Nutritive • national nutritional guide lines, undesirable (additives & residues) • Health • over laps with legal and nutritive values • Food Standards • alert of health hazards during pregnancy • qualifying the value of food categories

12. Technological • convenience foods “heat and eat” • less processing / perceived fresh • Sensory • “like or dislike” measurement of quality via senses • Socio-ecological • food packaging verses pollution • conversion of rain forest to cow pastures • effluent into water ways

13. Quality that may be evaluate? • Attribute : which measure qualitative character of food products • Variables: which measure quantative characters of food products

14. Food chemsitry • Food chemistry is the study of chemical processes and interactions of all biological and non-biological components of foods. The biological substances include such items as meat, poultry, lettuce, beer, and milk as examples. It is similar to biochemistry in its main components such as carbohydrates, lipids, and protein, but it also includes areas such as water, vitamins, minerals, enzymes, food additives, flavors, and colors.

15. discipline also encompasses how products change under certain food processing techniques and ways either to enhance or to prevent them from happening

16. And so to study the chemical processes and interactions of all biological and non-biological components of foods we need to food analysis

17. Food components • Water • Carbohydrates • Lipids • Proteins • Vitamins • Minerals • Enzymes • additives

18. During this course: exploring the different types of reactions and changes that may occur during food processing and to control it by food analysis