Uses of Food Preservatives PDF

# Uses of Food Preservatives ## Republic of the Philippines ## Department of Education ## Region III ## Schools Division of Cabanatuan City ## Honorato C. Perez, Sr. Memorial Science High School ## Mabini Extension, Cabanatuan City ## Quarter 2/Week 5: Consumer Chemistry ### Uses of Food Preserva...

# Uses of Food Preservatives ## Republic of the Philippines ## Department of Education ## Region III ## Schools Division of Cabanatuan City ## Honorato C. Perez, Sr. Memorial Science High School ## Mabini Extension, Cabanatuan City ## Quarter 2/Week 5: Consumer Chemistry ### Uses of Food Preservatives Food preservatives play a crucial role in food safety and quality by preventing spoilage, extending shelf life, and maintaining appearance and taste. This module covers the major uses of food preservatives, providing in-depth explanations and examples for each. ### 1. Preventing Microbial Growth (Antimicrobial Action) Microorganisms such as bacteria, yeasts, and molds can quickly spoil food, making it unsafe to eat. Antimicrobial preservatives are added to food to prevent the growth of these microorganisms, ensuring the product remains safe and extends its shelf life. #### Examples: * **Sodium Benzoate** * Used In: Soft drinks, salad dressings, and jams * Mechanism of Action: Lowers pH, creating an acidic environment that inhibits microbial growth. * Implication: Effective for acidic foods, but can affect taste if used in high quantities. * **Potassium Sorbate** * Used In: Cheeses, baked goods, and fruit products. * Mechanism of Action: Prevents the growth of molds, yeasts, and some bacteria without affecting taste. * Implication: Helps extend shelf life, particularly for dairy products and baked goods. * **Nitrates and Nitrites** * Used In: Cured meats like ham, bacon, and hotdogs. * Mechanism of Action: Prevents botulism-causing bacteria and preserves the red color of meats. * Implication: Essential in meat preservation, though excessive consumption has potential health risks. * **Sulfites** * Used In: Dried fruits, wine, and certain canned vegetables. * Mechanism of Action: Acts as an antimicrobial and antioxidant, preventing browning and microbial growth. * Implication: Helps in prolonging shelf life, though may cause reactions in people sensitive to sulfites. * **Sorbic Acid** * Used In: Salad dressings, sauces, and cheeses. * Mechanism of Action: Inhibits mold and yeast growth without affecting pH. * Implication: Maintains product quality, especially in dressings and sauces that contain oils. ### 2. Inhibiting Oxidation (Antioxidant Action) Oxidation in food leads to browning and rancidity, particularly in foods containing fats and oils. Antioxidants slow this process, helping preserve freshness, flavor, and nutritional quality. #### Examples: * **Butylated Hydroxytoluene (BHT)** * Used in: Cereals, snack foods, and chewing gum. * Mechanism of Action: Slows oxidation in oils and fats, extending shelf life. * Implication: Effective in products with high-fat content, though it has * **Ascorbic Acid (Vitamin C):** * Used In: Fruit juices, canned fruits, and sauces. * Mechanism of Action: Reduces oxidation by acting as an electron donor, thus preventing browning. * Implication: Maintains visual and nutritional quality, especially in fruits and juices. * controversial health concerns in high doses. * **Butylated Hydroxyanisole (BHA)** * Used In: Potato chips, snack foods, and baked goods. * Mechanism of Action: Protects fats from becoming rancid by interrupting the oxidation chain. * Implication: Maintains flavor and texture but has potential health concerns if over-consumed. * **Tocopherols (Vitamin E)** * Used In: Oils, margarine, and nut butters. * Mechanism of Action: Natural antioxidant that protects unsaturated fats from oxidation. * Implication: Preferred as a “clean label” antioxidant option, especially in health-focused foods. * **Citric Acid** * Used in: Beverages, sauces, and candies. * Mechanism of Action: Acts as a chelating agent, binding metals that accelerate oxidation. * Implication: Common in acidic foods to maintain flavor, aroma, and color. ### 3. Maintaining Freshness and Color (Color Retention) Color retention additives help maintain the appearance of foods by preventing discoloration and degradation, which can occur due to exposure to light, air, and heat. #### Examples: * **Sulfur Dioxide** * Used in: Dried fruits, such as apricots and raisins. * Mechanism of Action: Prevents oxidation, retaining bright color in fruits. * Implication: Extends shelf life and visual appeal but can cause allergic reactions in sensitive individuals. * **Sodium Erythorbate** * Used in: Processed meats, like sausages and hotdogs. * Mechanism of Action: Acts as an antioxidant, maintaining color stability in cured meats. * Implication: Enhances appearance of processed meats without affecting flavor. * **Ascorbic Acid (Vitamin C)** * Used in: Canned vegetables and fruit juices. * Mechanism of Action: Prevents oxidative browning, maintaining the natural green color of vegetables. * Implication: Maintains both the nutritional value and appearance of vegetables. * **Calcium Propionate** * Used in: Bread and bakery products. * Mechanism of Action: Prevents discoloration caused by mold growth. * Implication: Extends freshness in baked goods, especially in humid climates. * **Phosphates** * Used in: Seafood, such as shrimp and fish fillets. * Mechanism of Action: Binds water to retain moisture and prevents discoloration. * Implication: Improves appearance and texture in seafood products. ### 4. Extending Shelf Life (Preservation for Long-Term Storage) Preservatives used for long-term storage prevent spoilage by reducing microbial growth, particularly in foods that are stored for extended periods. #### Examples: * **Sodium Benzoate** * Used In: Jams, jellies, and condiments. * Mechanism of Action: Works in acidic conditions to inhibit the growth of bacteria, molds, and yeasts. * Implication: Extends shelf life in acidic foods but may impart a slight taste if used excessively. * **Propionic Acid** * Used In: Baked goods, especially bread. * Mechanism of Action: Prevents mold growth by creating an inhospitable environment for mold spores. * Implication: Extends shelf life without affecting taste or texture. * **Sodium Chloride (Salt)** * Used In: Pickles, cured meats, and salted fish. * Mechanism of Action: Reduces water activity, making it difficult for bacteria to grow. * Implication: Essential for traditional food preservation, adding flavor as well as shelf stability. * **Vinegar (Acetic Acid)** * Used In: Pickled vegetables, sauces, and condiments. * Mechanism of Action: Lowers pH, inhibiting microbial growth. * Implication: Naturally preserves food while enhancing flavor. * **Sugar** * Used In: Candied fruits, jams, and syrups. * Mechanism of Action: Binds water molecules, reducing water availability for microbial growth. * Implication: Provides dual function as a sweetener and preservative. ### 5. Preventing Rancidity (Preservation of Fats and Oils) Rancidity occurs when fats and oils are oxidized, leading to unpleasant odors and flavors. Certain preservatives are specifically used to prevent this in foods containing fats and oils. #### Examples: * **BHT (Butylated Hydroxytoluene)** * Used In: Butter, oils, and snack foods. * Mechanism of Action: Acts as an antioxidant, preventing oxidative deterioration of fats. * Implication: Extends shelf life of fatty foods, though it may have health considerations if consumed in large quantities. * **Tocopherols (Vitamin E)** * Used In: Oils, nut butters, and salad dressings. * Mechanism of Action: Natural antioxidant that delays the oxidation of fats. * Implication: Preferred in health-conscious products, often labeled as “natural” preservation. * **BHA (Butylated Hydroxyanisole)** * Used In: Potato chips, nuts, and other snack foods. * Mechanism of Action: Protects fats from oxidation by disrupting the oxidation chain reaction. * Implication: Widely used for shelf-stable snack foods, though health concerns have led to regulated usage. * **Propyl Gallate** * Used In: Meat products, especially those with high-fat content. * Mechanism of Action: Acts as an antioxidant that stabilizes fats and oils. * Implication: Useful in preserving flavor and texture in high-fat meat products. ## Introduction to Food Additives Food additives are substances added to food products to enhance their safety, quality, appearance, flavor, and nutritional value. This module explores various food additives, their purposes, and their implications for food processing and consumer health. ### List of Food Additives | Name | Added To Food | Purpose | |---|---|---| | Agar | Ice cream | **Thickener** - Provides body and improves texture in food. | | Ascorbic Acid (Vitamin C) | Yogurt, candies, beverages, frozen fruits | **Antioxidant** - Prevents off-flavors and maintains nutritional quality by inhibiting oxidation. | | Carrageenan | Milk drinks | **Thickener** – Enhances viscosity and stability, preventing separation. | | Dextrose | Bread, soft drinks | **Sweetener** - Adds sweetness and enhances flavor profile. | | EDTA (Ethylene Diamine Tetra-acetic Acid) | Salad dressing, canned vegetables | **Sequestrant** – Prevents browning in vegetables and cloudiness in soft drinks by binding metal ions that catalyze oxidation. | | Glycerine | Cake mixes | **Emulsifier** - Helps mix ingredients that typically separate, improving texture. | | Lecithin | Milk products | **Vitamin/Emulsifier** – Serves as a source of choline and improves texture by stabilizing emulsions. | | MSG (Monosodium Glutamate) | Soup mixes | **Flavor enhancer** – Intensifies umami flavor, making food more savory. | | Potassium Citrate | Instant fruit juice | **Buffer** - Neutralizes acidity, improving taste and stability. | | Sodium Benzoate | Fruit juices, salad dressings | **Preservative** – Prevents microbial growth, extending shelf life. | | Sodium Nitrate | Ham | **Preservative** – Inhibits bacterial growth and gives red color to meat. | | Sodium Sulfate | Fruit juices | **Prevent discoloration** - Helps maintain color and quality of juices. | ### Mechanisms of Action and Implications #### 1. Thickening Agents * **Agar** * Mechanism of Action: Agar is a polysaccharide derived from red algae (specifically, the cell walls of certain algae). When heated in water, agar dissolves and, upon cooling, forms a gel-like matrix. This gel traps water and other components, contributing to the structure and body of the food. * Implications for Food: The gel formation enhances the mouthfeel, stability, and overall texture of ice cream, providing a creamy consistency. It also helps to prevent ice crystallization, thereby improving the quality of frozen desserts. * **Carrageenan** * Mechanism of Action: Carrageenan consists of linear polysaccharides that can form various gel structures depending on their molecular weight and the ionic conditions of the solution. When mixed with water, carrageenan hydrates and forms a viscous gel that can stabilize emulsions and prevent sedimentation. * Implications for Food: Carrageenan enhances the viscosity of milk drinks, preventing separation of cream and stabilizing emulsions. This contributes to a smoother texture and improved palatability in dairy products. #### 2. Antioxidants * **Ascorbic Acid (Vitamin C):** * Mechanism of Action: Ascorbic acid acts as a reducing agent, donating electrons to free radicals and reactive oxygen species. This reduces oxidative stress on food components, particularly lipids, and helps to stabilize flavor and color. * Implications for Food: By preventing oxidation, ascorbic acid maintains the freshness of yogurt and frozen fruits, inhibiting the development of off-flavors and preserving nutritional value. #### 3. Sweeteners * **Dextrose** * Mechanism of Action: Dextrose, a simple sugar, enhances sweetness by binding to taste receptors on the tongue. It can also participate in Maillard reactions during cooking, which develop complex flavors and browning in baked goods. * Implications for Food: Dextrose contributes to the flavor profile of bread and soft drinks, enhancing sweetness and depth of flavor. It also improves fermentation processes, leading to better texture in baked goods. #### 4. Sequestrants * **EDTA (Ethylene Diamine Tetra-acetic Acid)** * Mechanism of Action: EDTA is a chelating agent that binds metal ions (e.g., Fe2+, Cu2+) that can catalyze oxidative reactions, thereby inhibiting enzyme activity that leads to spoilage. * Implications for Food: By preventing oxidation, EDTA helps maintain the color and quality of salad dressings and canned vegetables, ensuring a more appealing product and extending shelf life. #### 5. Emulsifiers * **Glycerine** * Mechanism of Action: Glycerine is a triol that can reduce surface tension between oil and water, allowing for a stable mixture (emulsion). It also adds moisture to dry ingredients. * Implications for Food: In cake mixes, glycerine improves texture and moisture retention, leading to softer baked goods and enhancing the overall eating experience. * **Lecithin** * Mechanism of Action: Lecithin is a phospholipid that stabilizes emulsions by reducing interfacial tension between lipids and water, preventing separation. * Implications for Food: In milk products, lecithin contributes to a creamy texture, enhances mouthfeel, and improves the product’s stability over time. #### 6. Flavor Enhancers * **MSG (Monosodium Glutamate)** * Mechanism of Action: MSG is a salt of glutamic acid that intensifies umami flavor by binding to specific taste receptors on the tongue (T1R1 and T1R3), enhancing savory notes in foods. * Implications for Food: By intensifying umami flavor, MSG makes soups and other dishes more savory and satisfying, improving the overall flavor profile of the product. #### 7. Buffers * **Potassium Citrate:** * Mechanism of Action: Potassium citrate acts as a buffer, helping to maintain a stable pH in food products by neutralizing excess acids. This can inhibit microbial growth and preserve flavor. * Implications for Food: By stabilizing acidity, potassium citrate improves the taste and stability of instant fruit juices, making them more palatable and enhancing shelf life. ## Consumer Chemistry Written Activity: Uses of Food Preservatives ### General Instructions: * Read Carefully: Begin by thoroughly reading the entire activity sheet, including all sections and questions. This will help you understand what is required for each part of the worksheet. * Use Your Notes: Refer back to the module on food preservatives and additives as needed. Your notes will provide valuable information to help you answer the questions accurately. ### Activity 1: Imagine you are a food scientist tasked with developing various food products. You need to select preservatives that will help maintain the quality, taste, color, and shelf life of each product. Use your understanding of preservatives, including natural and artificial options, mechanisms of action, and implications, to complete the tasks below. #### Scenario 1: Fresh Fruit Juice * Product: Fresh fruit juice with no artificial colors. * Requirements: The juice needs to stay fresh for two weeks without losing its color or flavor. * Questions: What preservative(s) would you choose? Explain your choices and how each one contributes to the freshness and color of the juice. #### Scenario 2: Cured Meats (e.g., ham, bacon) * Product: Ready-to-eat cured meats for a deli. * Requirements: Prevent microbial growth and maintain the red color of the meat. * Questions: Which preservative(s) are ideal for this product? Explain the preservative action and why it is suitable for meat preservation. #### Scenario 3: Snack Chips * Product: Potato chips that stay crisp and fresh for a long shelf life. * Requirements: Preserve the texture, prevent rancidity of oils, and avoid flavor loss. * Questions: What preservative(s) would you use for this product? Explain the preservative mechanism and how it prevents rancidity and spoilage. #### Scenario 4: Dried Fruits * Product: Packaged dried fruits that retain a bright color. * Requirements: Prevent microbial growth, avoid browning, and maintain taste. * Questions: * Which preservative(s) would work best? Explain how they help retain color and prevent spoilage. * What is the consumer impact of using these preservatives? Consider taste, texture, and health implications. #### Scenario 5: Bakery Bread * Product: Soft bread for retail sale. * Requirements: Extend shelf life, prevent mold growth, and retain texture. * Question: Which preservative(s) would you select? Describe how each choice helps in extending shelf life, maintaining texture, and preventing spoilage. ### Part 2: Instructions: Match each food additive with its mechanism of action by writing the corresponding letter in the space provided. **Mechanisms:** * **A.** Reduces surface tension between oil and water. * **B.** Acts as a reducing agent, preventing oxidative reactions. * **C.** Binds metal ions to prevent oxidative spoilage. * **D.** Stabilizes emulsions and improves mouthfeel. * **E.** Disrupts cell membrane potential of microorganisms. * **F.** Forms a gel matrix upon cooling. | Food Additive | Mechanism of Action | |---|---| | 1. Agar | | | 2. Ascorbic Acid | | | 3. EDTA | | | 4. Glycerine | | | 5. Sodium Benzoate | | ### Part 3: Instructions: Answer the following questions based on the module content. 1. Describe the implications of using carrageenan in milk drinks. 2. How does ascorbic acid help maintain the quality of frozen fruits? 3. What are the benefits of using sodium nitrate in cured meats? 4. Discuss the importance of emulsifiers like lecithin in food products.