🍕Principles of Food Science Unit 2 – Food Chemistry: Macro & Micronutrients
Food chemistry explores the intricate world of macro and micronutrients. Carbohydrates, proteins, and fats provide energy and building blocks, while vitamins and minerals support essential bodily functions. Understanding these nutrients' structures, functions, and interactions is crucial for maintaining optimal health.
Chemical reactions in food, like the Maillard reaction and caramelization, affect flavor and appearance. Nutrient bioavailability, influenced by food processing and interactions, impacts our bodies' ability to absorb and use essential nutrients. This knowledge is vital for developing nutritious food products and making informed dietary choices.
Macronutrients provide energy and essential building blocks for growth and maintenance of the body
Carbohydrates, proteins, and fats are the three main macronutrients
Micronutrients are essential nutrients required in small amounts for proper functioning of the body
Vitamins and minerals are the two main categories of micronutrients
Bioavailability refers to the proportion of a nutrient that is absorbed and utilized by the body
Chemical reactions in food involve changes in the structure and properties of food components
Maillard reaction, caramelization, and oxidation are examples of chemical reactions in food
Nutrient density is the amount of nutrients per calorie of food
Foods with high nutrient density provide substantial amounts of vitamins, minerals, and other nutrients relative to their calorie content (leafy greens, berries)
Recommended Dietary Allowances (RDAs) are the average daily intake levels sufficient to meet the nutrient requirements of nearly all healthy individuals
Dietary Reference Intakes (DRIs) are a set of reference values for nutrient intake, including RDAs, Adequate Intakes (AIs), and Tolerable Upper Intake Levels (ULs)
Macronutrients: Structure and Function
Carbohydrates are the primary source of energy for the body and are composed of carbon, hydrogen, and oxygen
Simple carbohydrates include monosaccharides (glucose, fructose) and disaccharides (sucrose, lactose)
Complex carbohydrates are polysaccharides, such as starch and dietary fiber
Proteins are essential for growth, repair, and maintenance of body tissues and are composed of amino acids
Essential amino acids cannot be synthesized by the body and must be obtained through diet (leucine, lysine)
Non-essential amino acids can be synthesized by the body
Fats, also known as lipids, provide energy, insulation, and protection for organs
Saturated fats are solid at room temperature and are mainly found in animal products (butter, lard)
Unsaturated fats are liquid at room temperature and are found in plant-based sources (olive oil, avocados)
Monounsaturated fats have one double bond in their chemical structure
Polyunsaturated fats have two or more double bonds in their chemical structure
Water is essential for many bodily functions, including nutrient transport, temperature regulation, and waste removal
Micronutrients: Types and Importance
Vitamins are organic compounds required in small amounts for various metabolic processes
Fat-soluble vitamins (A, D, E, K) are stored in the body's fatty tissues and can accumulate to toxic levels if consumed in excess
Water-soluble vitamins (B-complex, C) are not stored in the body and need to be consumed regularly
Minerals are inorganic elements that play crucial roles in many bodily functions
Macrominerals (calcium, phosphorus, magnesium) are required in larger amounts
Microminerals or trace elements (iron, zinc, iodine) are needed in smaller quantities
Antioxidants are compounds that protect cells from damage caused by free radicals
Vitamins C and E, beta-carotene, and polyphenols are examples of antioxidants
Phytochemicals are bioactive compounds found in plants that have potential health benefits (flavonoids, carotenoids)
Deficiencies in micronutrients can lead to various health problems
Iron deficiency can cause anemia, characterized by fatigue and weakness
Vitamin D deficiency can lead to rickets in children and osteomalacia in adults
Chemical Reactions in Food
Maillard reaction occurs between amino acids and reducing sugars, resulting in browning and flavor development (seared steak, toasted bread)
The reaction produces melanoidins, which contribute to the color and flavor of foods
Caramelization is the browning of sugars when exposed to heat, resulting in the formation of complex flavors and aromas (caramel, dulce de leche)
Oxidation of lipids leads to rancidity and off-flavors in foods
Antioxidants can help prevent or delay lipid oxidation (vitamin E, rosemary extract)
Enzymatic reactions can cause both desirable and undesirable changes in food
Ripening of fruits involves enzymatic reactions that break down cell walls and change texture
Enzymatic browning occurs when cut fruits and vegetables are exposed to air (sliced apples, potatoes)
Fermentation is a process in which microorganisms convert sugars into alcohol or acids, resulting in unique flavors and textures (yogurt, sauerkraut, beer)
Nutrient Interactions and Bioavailability
Nutrient interactions can affect the absorption and utilization of nutrients in the body
Vitamin C enhances the absorption of non-heme iron from plant-based sources
Calcium can interfere with the absorption of iron and zinc when consumed in large amounts
Bioavailability of nutrients is influenced by various factors, including the food matrix, processing, and individual differences
Heme iron from animal sources has higher bioavailability compared to non-heme iron from plant sources
Fat-soluble vitamins require the presence of dietary fat for optimal absorption
Antinutrients are compounds that can interfere with the absorption and utilization of nutrients
Phytates in whole grains and legumes can reduce the absorption of minerals like iron and zinc
Oxalates in spinach and other leafy greens can bind to calcium and reduce its absorption
Nutrient synergy occurs when the combined effect of nutrients is greater than the sum of their individual effects
Vitamin D and calcium work together to promote bone health
Vitamin C and vitamin E have a synergistic effect in protecting cells from oxidative damage
Food Processing and Nutrient Changes
Thermal processing, such as cooking and pasteurization, can affect the nutrient content of foods
Heat can destroy heat-sensitive vitamins like vitamin C and thiamin
Cooking can improve the digestibility and bioavailability of some nutrients (lycopene in tomatoes, beta-carotene in carrots)
Mechanical processing, such as milling and refining, can remove nutrient-rich parts of foods
Refining whole grains into white flour removes the bran and germ, which contain fiber, vitamins, and minerals
Fortification is the addition of nutrients to foods to prevent deficiencies or restore nutrients lost during processing
Iodized salt helps prevent iodine deficiency disorders
Vitamin D is often added to milk to promote calcium absorption and bone health
Fermentation can enhance the nutritional value of foods by increasing the bioavailability of nutrients and producing beneficial compounds
Fermented dairy products, such as yogurt and kefir, contain probiotics that support digestive health
Fermentation of soybeans into tempeh and miso increases the bioavailability of isoflavones and other beneficial compounds
Health Implications and Dietary Recommendations
Balanced nutrition is essential for maintaining optimal health and preventing chronic diseases
Consuming a variety of nutrient-dense foods from all food groups helps ensure adequate intake of essential nutrients
Dietary Guidelines for Americans provide evidence-based recommendations for healthy eating patterns
Emphasize the consumption of fruits, vegetables, whole grains, lean proteins, and healthy fats
Limit the intake of added sugars, saturated fats, and sodium
Chronic diseases, such as obesity, type 2 diabetes, and cardiovascular disease, are often associated with poor dietary habits
High intake of added sugars and saturated fats can contribute to the development of these diseases
Adequate intake of fiber, vitamins, and minerals can help reduce the risk of chronic diseases
Nutrient deficiencies can lead to specific health problems
Vitamin A deficiency can cause night blindness and impaired immune function
Folate deficiency during pregnancy can increase the risk of neural tube defects in the developing fetus
Practical Applications in Food Science
Food product development involves the creation of new food products with desired nutritional profiles
Formulating products with reduced sugar, fat, or sodium content while maintaining taste and texture
Incorporating functional ingredients, such as prebiotics and probiotics, to promote health benefits
Nutrient analysis is the process of determining the nutrient content of foods
Analytical techniques, such as chromatography and spectroscopy, are used to quantify nutrients
Nutrient databases, such as the USDA FoodData Central, provide information on the nutrient composition of various foods
Food labeling regulations require the disclosure of nutrient information to consumers
Nutrition Facts panels on packaged foods display the amount of calories, macronutrients, and selected micronutrients per serving
Health claims on food labels must be supported by scientific evidence and approved by regulatory agencies
Sensory evaluation is used to assess the acceptability and quality of food products
Trained panelists evaluate the appearance, aroma, taste, and texture of foods
Consumer testing helps determine the preferences and attitudes of target populations towards food products
Food safety practices aim to prevent foodborne illnesses and ensure the quality of food products
Implementing Hazard Analysis and Critical Control Points (HACCP) systems to identify and control potential hazards
Monitoring and controlling factors such as temperature, pH, and water activity to prevent microbial growth and spoilage