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Basic foods

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Grexia Fortunato

This document discusses several chemical reactions that occur in foods during processing and cooking. It describes the Maillard reaction which creates brown pigments in meats, as well as enzymatic and non-enzymatic browning reactions in fruits and vegetables. It also explains hydrolysis reactions that break down proteins and polysaccharides, altering textures and properties in foods. Various oxidation reactions are outlined as well, which can produce undesirable odors, flavors or discoloration. References are provided at the end for additional information.

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BASIC FOODS FOOD SELECTION AND PREPARATION Davina Gracia L. Fortunato
FOOD OPhysiological: Any substance which when taken into the body provides energy, build and repairs tissues and regulates body processes. OBiological: Any substance which when eaten sustains life and nourishes the body.
OFoods are derived from plants and animals, both terrestrial and aquatic. OFood materials follow a development process as illustrated by the changes that a fruit undergoes before it can be used as food.
Basic foods
Basic foods
Basic foods
CHEMICAL REACTIONS IN FOOD
MAILLARD REACTION
MAILLARD REACTION OThe Maillard reaction creates brown pigments in cooked meat in a very specific way: by rearranging amino acids and certain simple sugars, which then arrange themselves in rings and collections of rings that reflect light in such a way as to give the meat a brown color.
ENZYMATIC BROWNING
OThe purpose of an enzyme in a cell is to allow the cell to carry out chemical reactions very quickly. These reactions allow the cell to build things or take things apart as needed. This is how a cell grows and reproduces. ENZYMATIC BROWNING
ENZYMATIC BROWNING OEnzymatic browning reaction needs oxygen either from the air or from intercellular spaces within the tissue.
Obananas turn brown because a hormone within them triggers the release of ethylene gas (C2H4). This accelerates the ripening processes until the banana becomes over-ripe. OEthylene has an accomplice called polyphenol oxidase (or PPO for short). It¡¯s found in apples and potatoes, so leaving your banana next to an apple will hasten the ripening process.
OXIDATION REACTIONS
OIs a reaction that takes place when oxygen has access to products containing fat or pigments.
OIf fats oxidize, they produce ¡°off¡± odors and flavors OIf pigments oxidize, they can change color completely
HYDROLYSIS OF PROTEINS AND POLYSACCHARIDES
OProtease is a general term for enzymes that breakdown proteins. When a protease breaks down a protein, the texture of the food is altered because the protein will lose its ability to bind water.
OProteases refers to a group of enzymes whose catalytic function is to hydrolyze (breakdown) proteins
O Proteins are made up of lots of amino acids joined together by peptide bonds. O Hydrolysis of the protein is what happens when the peptide bonds are broken. O lysis = splitting; hydro = water O The result of hydrolysis is smaller amino acid chains (peptides), and free amino acids. O The solution containing the protein pieced (small peptide chains and free amino acids) is called a hydrolysate solution.
Basic foods
OPolysaccharides such as starch, cellulose, and pectins are also prone to hydrolysis with resulting loss in texturing ability. Starch will lose its gelling properties when hydrolyzed.
O http://www.scienceweek.ie/chemistry-of- cooking.html O http://www.britannica.com O DE LEON, S.Y. et al. 1999. Basic Foods for Filipinos 3rd Edition. Merriam and Webster Inc., Metro Manila, Philippines.

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Basic foods

  • 1. BASIC FOODS FOOD SELECTION AND PREPARATION Davina Gracia L. Fortunato
  • 2. FOOD OPhysiological: Any substance which when taken into the body provides energy, build and repairs tissues and regulates body processes. OBiological: Any substance which when eaten sustains life and nourishes the body.
  • 3. OFoods are derived from plants and animals, both terrestrial and aquatic. OFood materials follow a development process as illustrated by the changes that a fruit undergoes before it can be used as food.
  • 9. MAILLARD REACTION OThe Maillard reaction creates brown pigments in cooked meat in a very specific way: by rearranging amino acids and certain simple sugars, which then arrange themselves in rings and collections of rings that reflect light in such a way as to give the meat a brown color.
  • 11. OThe purpose of an enzyme in a cell is to allow the cell to carry out chemical reactions very quickly. These reactions allow the cell to build things or take things apart as needed. This is how a cell grows and reproduces. ENZYMATIC BROWNING
  • 12. ENZYMATIC BROWNING OEnzymatic browning reaction needs oxygen either from the air or from intercellular spaces within the tissue.
  • 13. Obananas turn brown because a hormone within them triggers the release of ethylene gas (C2H4). This accelerates the ripening processes until the banana becomes over-ripe. OEthylene has an accomplice called polyphenol oxidase (or PPO for short). It¡¯s found in apples and potatoes, so leaving your banana next to an apple will hasten the ripening process.
  • 15. OIs a reaction that takes place when oxygen has access to products containing fat or pigments.
  • 16. OIf fats oxidize, they produce ¡°off¡± odors and flavors OIf pigments oxidize, they can change color completely
  • 17. HYDROLYSIS OF PROTEINS AND POLYSACCHARIDES
  • 18. OProtease is a general term for enzymes that breakdown proteins. When a protease breaks down a protein, the texture of the food is altered because the protein will lose its ability to bind water.
  • 19. OProteases refers to a group of enzymes whose catalytic function is to hydrolyze (breakdown) proteins
  • 20. O Proteins are made up of lots of amino acids joined together by peptide bonds. O Hydrolysis of the protein is what happens when the peptide bonds are broken. O lysis = splitting; hydro = water O The result of hydrolysis is smaller amino acid chains (peptides), and free amino acids. O The solution containing the protein pieced (small peptide chains and free amino acids) is called a hydrolysate solution.
  • 22. OPolysaccharides such as starch, cellulose, and pectins are also prone to hydrolysis with resulting loss in texturing ability. Starch will lose its gelling properties when hydrolyzed.
  • 23. O http://www.scienceweek.ie/chemistry-of- cooking.html O http://www.britannica.com O DE LEON, S.Y. et al. 1999. Basic Foods for Filipinos 3rd Edition. Merriam and Webster Inc., Metro Manila, Philippines.