NUT 1104 Food Sciences I 2024 Fall Term Lecture Notes PDF

NUT 1104 Food Sciences I 2024 Fall Term Ezgi Pulatsu, Ph.D. School of Nutrition Sciences University of Ottawa/ Université d'Ottawa  Course Content 2 Module 1 Module 2...

NUT 1104 Food Sciences I 2024 Fall Term Ezgi Pulatsu, Ph.D. School of Nutrition Sciences University of Ottawa/ Université d'Ottawa  Course Content 2 Module 1 Module 2 Module 3 Module 4 INTRODUCTION FOOD COMPONENTS and CHEMISTRY FOOD and FOOD MATERIALS FOOD ADDITIVES and FOOD SAFETY 3.1 Meat, Poultry and 4.1 Food Additives 1.1 Course Introduction 2.1 Water Fish 4.2 Food Safety Syllabus 2.2 Carbohydrates 3.2 Eggs and Dairy Course content 2.3 Proteins 3.3 Legumes, Pulses and Course calendar 2.4 Lipids Cereals Rules 2.4 Vitamins and 3.4 Flour and Pasta Regulations Minerals 3.5 Bread and Baked Goods 3.6 Chocolate Course Calendar 3  Recommended readings 4 Book 1) Essentials of Food Science, 5th Edition 2021 Vaclavik, Vickie, author.; Christian, Elizabeth W.;Campbell, Tad. Book 2) Fennema's Food Chemistry, 4th Edition, Kirk L. Parkin, Owen R. Fennema (Editors), ISBN: 9780429195273.3) Book 3) Understanding food: principles and preparation, Brown, A. C., Walter, J. M., & Beathard, K. (2015). Boston, MA, USA: Cengage learning. Learning outcomes 5 Become familiar with the chemistry and structure of water Understand the properties of water and relationships with the structure Get to know the definition and applications of water activity Fundamentals of carbohydrates Outline 6 Introduction Water Structure Chemistry Properties Water activity Introduction to CHO Food Science 7 the physical, chemical, and biological properties of foods as they relate to stability, cost, quality, processing, safety, nutritive value, wholesomeness, and convenience. branch of biological science and an interdisciplinary subject involving primarily microbiology, chemistry, biology, and engineering knowledge of the innate properties of biological substances and manipulating them are of common interest with biological scientists (Damodaran et al. 2017) Food Components 8 Water and ice Carbohydrates Proteins Lipids Micronutrients Water 9 Most abundant liquid on earth, prerequisite for life Important subject of current research in chemical physics and physical chemistry Rich phase diagram where different types of ices, amorphous phases, and anomalies Unique thermodynamics of its supercooled liquid state (Gallo et al. 2016) Water 10 Composed of two hydrogen and one oxygen atoms The human body (and that of most animals) consists of up to 75% water 90% of the blood in our bodies and about the same amount of our brain à water Barham, P. (2013). Physics in the kitchen. Flavour, 2, 1-4. What makes water molecule interesting? 11 Can be found as an extracellular or intracellular component in vegetables and animal tissues, etc. Dispersing medium (like in butter and margarine) Universal solvent - dissolves almost everything Can also be the minor component in other foods Unusual Properties of Water 12 Fennema’s Food Chemistry, pp 19-22 Unusual Properties of Water 13 Fennema’s Food Chemistry, pp 19-22 Unusual Properties of Water 14 Fennema’s Food Chemistry, pp 19-22  15 Fennema’s Food Chemistry, pp 19-22  Water and ice 16 Below 0°C at atmospheric pressure, water molecules arrange themselves in space in a hexagonal pattern resulting in the so-called hexagonal ice. Hexagonal ice has an open structure and lower density than liquid water à ice floats on water Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  Water and ice 17 Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  Water and ice 18 Foods freeze faster than they thaw. primarily due to the differences in the thermal properties of water and ice. i.e., heat capacity, thermal conductivity, thermal diffusivity, and heats of fusion and vaporization the thermal conductivity of ice at 0°C is fourfold greater than that of water at 0°C the thermal diffusivity of ice is ninefold greater than that of water and the heat capacity of ice is about one-half that of liquid water Overallà the higher thermal conductivity and diffusivity and lower heat capacity result in the rate of temperature change in ice >> in water when water and ice are exposed to a given temperature gradient Fennema’s Food Chemistry, pp 19-22  Chemistry of Water Molecule 19 Water can exist in three phases Liquid, solid, and vapor under normal temperature and pressure range on earth The anomalous properties are due to its structure Two hydrogen atoms covalently bonded to an oxygen atom for a single water molecule Fennema’s Food Chemistry, pp 19-22  Chemistry of Water Molecule 20 the H–O–H angle is about 104.5°, slightly lower than the tetrahedral structure (109.5°) Fennema’s Food Chemistry, pp 26  Chemistry of Water Molecule 21 But in liquid and solid state, this angle is higher (presumably) due to water-water interactions Fennema’s Food Chemistry, pp 26  Chemistry of Water Molecule 22 The O–H bond length is around 0.96 Å and The van der Waals radius of the oxygen atom is about 1.4 Å The shape of water molecule is not perfectly spherical Fennema’s Food Chemistry, pp 26  Chemistry of Water Molecule 23 Water is a polar molecule the highly electronegative oxygen atom attracts and dislocates the electrons of the O–H bonds more toward it, the hydrogen atoms acquire a partial (+) charge, and the oxygen atom assumes a partial (-) charge. Fennema’s Food Chemistry, pp 26  Chemistry of Water Molecule 24 Water is a polar molecule asymmetrical charge distribu;on with an H–O–H angle of 104.5° à permanent dipole character to the water molecule This permanent dipole moment enables water molecules to form hydrogen bonding via dipole–dipole interac;ons. Fennema’s Food Chemistry, pp 26  25 Image source: link  26 Image source: link Because of its polar nature 27 High specific heat Much energy is needed to break the hydrogen bonds Helps maintain a constant body temperature Cohesion Adhesion Because of its polar nature 28 High specific heat Cohesion The aFracGon between the water-water molecules Hydrogen bond Adhesion Because of its polar nature 29 High specific heat Cohesion Adhesion The interaction of water molecules with other things such as a glass, leaves, on surfaces, etc. Meniscus Image source: link meniscus  Chemistry of Water Molecule 30 One water molecule with two protons and two lone pairs of electrons can form four hydrogen bonds with four other water molecules Therefore, water can form an extended three-dimensional hydrogen-bonded network structure The hydrogen bond is noncovalent, its strength is typically in the range of 2–6 kcal/mol compared to about 80–120 kcal/mol for a covalent bond but its strength is much greater than the van der Waals interac@ons Fennema’s Food Chemistry, pp 26  31 Image source: link Image source: link  Chemistry of Water Molecule 32 Substances are either dissolved, dispersed, or suspended in water where their particle size and solubility differ. Water is a solvent Few H+ dissolves almost everything More OH- 0 7 14 pH scale More H+ Few OH- pH of blood is 7.4à crucial to survival Fennema’s Food Chemistry, pp 26  33 Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  Interactions of Water with Food 34 Constituents Water interacts with other compounds primarily through dipole-ion, dipole-dipole, and hydrophobic interactions. The strength and extent of these interactions are the results of the chemical nature of non- aqueous components e.g., salt concentration, pH, or temperature Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  35 Ionic interactions of water small ions with strong electric fields are structure-forming (e.g., Li+, Na+ or Ca2+) large ions with weak electric fields are structure-breaking with the opposite effect (e.g., K+, Cl− or I−) Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  36 Dipole-dipole interactions of water between water and non-ionic hydrophilic solutes found in food molecules that carry hydroxyl (e.g., monosaccharides), amino (e.g., proteins), or carbonyl (e.g., flavors) groups may form hydrogen bonds with water Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  37 Hydrophobic interactions are the interactions between hydrophobic molecules in aqueous environments the tendency of the hydrophobic molecules is to exclude water and interact each other Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  38 Colligative Properties the proper2es of solu2ons depending on the number of molecules in a given volume of water and not on their chemical nature 1. lowering of vapor pressure, 2. eleva2on of boiling point, 3. depression of freezing point, and 4. osmo2c pressure caused by the presence of small molecules that dissolve in water Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  39 Colligative Properties E,g., sugars (e.g., glucose or sucrose) and salts (e.g., NaCl or CaCl2) Think of a fabrication of a concentrated fruit juice; The boiling point of the fruit juice increases upon evaporation of water Think of a fabrication of a candy making; The boiling point of the sugar syrup increases upon evaporation of water Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  40 Colligative Properties osmosis à the diffusion of water through a semi-permeable membrane, from a solu\on of low solute concentra;on (hypotonic) to a solu\on of high solute concentra;on (hypertonic) Forward osmosis à water moves without energy input across a semi- permeable membrane (permeable to the water, but not to the solute), separa\ng the two solu\ons of different concentra\ons Reverse osmosis à water moves with input energy from the high concentra\on solu\on to the low concentra\on solu\on Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature.  41 low solute concentration à hypotonic high solute concentration à hypertonic Kontogiorgos, V. (2021). Introduction to food chemistry. Springer Nature. Bound water vs Free water 42 Water activity (aw) 43 High water content (g H2O in 100 g) is necessary for living cells, but from microbiological perspec\ve it is not desirable for preserving foods against microbial spoilage and other nonmicrobiological degradaGons during storage Foods with the same water content may differ significantly in their perishability, à it might not be the water content but the “state” or the thermodynamic “ac\vity” of water in foods Fennema’s Food Chemistry Water activity (aw) 44 Water activity (aw) and sorption properties of foods are critical in food formulations and processes Water activity controls most of the biochemical and microbiological reactions The rate of moisture transfer in drying process through the packaging film through edible coating material Sahin & Sumnu (2006) Water activity (aw) 45 Moisture sorp\on isotherm describes the rela\onship between aw and the equilibrium moisture content of a food product at constant T. To prepare sorp\on isotherms of foods à store a weighed sample in an enclosed container maintained at a certain rela\ve humidity at constant T à then reweigh it a`er equilibrium is reached. The desired rela\ve humidity environments can be achieved by using saturated salt solu\ons, sulfuric acid, and glycerol. Sahin & Sumnu (2006)  46 * aw is a dimensionless number, ranges from 0 to 1 Fennema’s Food Chemistry  47 Fennema’s Food Chemistry Water acFvity (aw)- definiFon 48 The ratio of the vapor pressure of water in the system to the vapor pressure of pure water at the same temperature Refers to the intensity with which water associates with non-aqueous constituents Sahin & Sumnu (2006)  Water activity (aw) and sorption isotherms 49 Sahin & Sumnu (2006)  50 Sahin & Sumnu (2006)  51 Sahin & Sumnu (2006) Introduction to Carbohydrates 52 > 90% of the dry maber of plants Essen\ally consist of sugar- usually glucose or various deriva\ves Abundant, available, inexpensive Vilgis, T. A. (2023). Nutrition Biophysics: An Introduction for Students, Professionals and Career Changers. Springer Nature. Introduction to Carbohydrates 53 Main human energy source Starch, lactose, sucrose, D-glucose, D-fructose Supply 70-80% of the calories in human diet worldwide Vilgis, T. A. (2023). Nutrition Biophysics: An Introduction for Students, Professionals and Career Changers. Springer Nature. Introduction to Carbohydrates 54 Composed of C, H, O Table sugar- a disaccharide consists of glucose and fructose Amylases break down the complex carbohydrates into individual glucose molecules – energy supply Vilgis, T. A. (2023). Nutrition Biophysics: An Introduction for Students, Professionals and Career Changers. Springer Nature. Introduction to Carbohydrates 55 For example, starch Found in legumes, seeds of cereals, pseudocereals, root vegetables, etc. Biological purpose is to supply energy for germination and growth If pure glucose to be stored in the seed, immediate death of the seed! Why? Osmotic pressure would burst the seed upon contact with moisture Then, NO germination So, they polymerize and branch to form amylose and amylopectin which mean less osmotic effects Vilgis, T. A. (2023). Nutrition Biophysics: An Introduction for Students, Professionals and Career Changers. Springer Nature.  56 Vilgis, T. A. (2023). Nutri