Food Enzymes: Role in Food Science and Daily Life PDF

BROWNING REACTIONS IN FOOD 2. Role in Daily Lives: Importance of Enzymes A. Digestion: Natural Enzymes: amylase, lipase, & protease, naturally...

BROWNING REACTIONS IN FOOD 2. Role in Daily Lives: Importance of Enzymes A. Digestion: Natural Enzymes: amylase, lipase, & protease, naturally 1. Role in Food Science present in our saliva, stomach, and intestines, are essential for breaking down food into nutrients that the body can A. Food Production: absorb. Without these enzymes, nutrient absorption would be inefficient, leading to malnutrition and digestive Fermentation: amylase and protease are crucial in disorders. fermentation processes used in brewing beer, making bread, and producing dairy products like yogurt and cheese. They Digestive Supplements: supplements are often used by help convert raw ingredients into desired products with individuals with digestive issues to help break down foods specific textures and flavors. more effectively, ensuring that their bodies can access essential nutrients. Food Processing: pectinase and cellulase are used to improve the yield and clarity of fruit juices and wines. They break down complex plant cell walls, releasing more juice and enhancing product quality. B. Household Products: Laundry Detergents: such as proteases and lipases are B. Food Preservation: used in detergents to break down protein-based stains (like blood or sweat) and fat-based stains like grease, making Shelf Life Extension: glucose oxidase reduce oxygen levels laundry more effective at lower temperatures and reducing in food packaging, which helps prevent spoilage and extends energy consumption. the shelf life of products by inhibiting the growth of spoilage microorganisms. Cleaning Products: also used in household cleaners to break down organic matter, making cleaning more efficient & Texture and Consistency: lipase and protease are used reducing the need for harsh chemicals. modify the texture of foods, such as making cheese creamier or meat more tender, enhancing the overall eating experience. C. Health and Medicine: Medical Applications: are used in various medical diagnostics & treatments, such as enzyme-based blood C. Nutritional Enhancement: glucose monitoring in diabetic patients and enzyme replacement therapy for conditions like cystic fibrosis. Lactose-Free Products: Lactase is used to break down lactose in dairy products, making them suitable for lactose- Biotechnology: play a crucial role in biotechnology intolerant individuals. This enhances the accessibility and applications, including DNA replication in genetic testing & nutritional value of dairy for a broader population. the development of pharmaceuticals. Digestive Health: are added to dietary supplements to aid in the digestion of proteins, fats, and carbohydrates, 3. Environmental Impact: improving nutrient absorption and digestive health. Sustainability: enzyme contribute to more sustainable food production & processing methods by reducing the need for chemical additives & lowering energy consumption, which is D. Waste Reduction: beneficial for the environment. Bioconversion: help convert food waste into valuable Biodegradation: Enzymes are used in bioremediation to products, such as using proteases to turn protein-rich waste break down pollutants in the environment, such as oil spills into animal feed or using cellulase to break down plant or waste treatment, contributing to cleaner ecosystems. waste into biofuels. Existence of Enzymes B. CLASSIFICATION Many enzymes contain the suffix “–mase” added to the Early Enzyme Discoveries name of their substrate or to a word or phrase describing their activity. In 1835 by the Swedish chemist, Jon Jakob Berzelius who termed their chemical action catalytic. For example: urease catalyzes hydrolysis of urea and DNA polymerase catalyzes the polymerization of nucleotides to 1926, however, that the first enzyme was obtained in pure form DNA. form, a feat accomplished by James B. Sumner of Cornell University. To isolate & crystallize the enzyme urease from the jack bean. His work was to earn him the 1947 Nobel Prize. John H. Northrop and Wendell M. Stanley of the Rockefeller Institute for Medical Research shared the 1947 Nobel Prize with Summer. They discovered a complex procedure for isolating & purifying pepsin. C. SUBSTRATE BINDING Enzymes in Food Enzyme-catalyzed reactions are characterized by the formation of an enzyme-substrate (ES) complex. Enzymes serve both catalytic & regulatory functions. Acting in organized sequences, they catalyze hundreds of stepwise Substrate binding occurs in a pocket on the enzyme called reactions. the active site. The function of enzymes and other catalysts is to lower the activation energy for a reaction Through the action of regulatory enzymes, metabolic and thereby enhance the reaction rate. pathways are highly coordinated to vield a harmonious interplay among activities necessary to sustain life Enzymes are very specific as to what substrates they bind & the chemical reaction they catalyze. The study of enzymes also plays an important role in the diagnosis & treatment of certain diseases. An early model to account for enzyme specificity was proposed by Emil Fischer in 1894. A. COMPOSITION The Lock and Key model suggest that the substrate Chemical Nature of Enzymes possess specific complementary geometric shapes that fit exactly into one another. Most enzymes are proteins, although a few are catalytic RNA molecules. In 1958, Daniel Koshland introduced the induced fit model where enzymes undergo conformational change during With the exception of a small group of catalytic RNA catalysis. molecules known as RIBOZYMES, all enzymes are proteins. Some enzymes require non-protein molecules called COFACTORS for activity. Cofactors can be inorganic or organic. Organic factors can be COENZYMES, which acts as transient carriers of specific functional groups or prosthetic groups, which are tightly or covalently bound to an enzyme. The protein part of an enzyme is called the APOENZYME, while an enzyme together with the required cofactors for activity is called a HOLOENZYMES sama-sama D. ENZYME IMMOBILIZATION Enzyme immobilization is a widespread empiric technology to achieve more stable, active and reusable enzymes. Enzyme immobilization methods include physical absorption, ionic and covalent bonds, and various techniques such as binding, entrapment, encapsulation, & cross-linking. Enzymes can be immobilized on various organic & inorganic materials or carriers. - physically absorbed Van derWaals Forces - chemically linked to a support Some enzymes are produced by microorganisms like bacteria, yeasts, and fungi. BROWNING IN FOODS - enclosed within a - chemically cross-linked semi-permeable to each other membrane refers to any dark color development during processing, injury or storage. Browning has many important implications on the food industry relating to nutrition, technology, and economic cost. E. ENZYMES IN FOOD INDUSTRY For centuries, we have exploited the impressive catalytic, can be conveniently divided into two types: non-enzymatic efficiency of enzymes for food processing, especially in the and enzymatic preparation of beer, wine, cheese, & bread. ENZYMATIC BROWNING Enzymes are generally extracted from edible plants & animal tissues. discoloration is the result of oxidation of colorless native phenolic compounds by enzymes collectively called polyphenol oxidase (PPO) which is a mixed-function oxidase amount of browning depends on the concentration & nature of phenolic compounds that are present. Enzymatic activity determines the amount of initial browning. Substrates also determine what color the discoloration will be. ENZYMATIC BROWNING IN FRUITS & VEGETABLES Apples, apricots, peaches, & pears will turn brown but never black While bananas and potatoes will first turn pink & then brown & will eventually turn black Another factor in the amount of browning in a fruit or vegetable is maturity. Persimmons, apples, potatoes, and bananas increase in browning as they ripen, but then decrease as the amount of substrate decreases with maturity METHODS TO PREVENT ENZYMATIC BROWNING 2. Caramelization - It is the thermal degradation of sugars leading to the formation of volatiles (caramel aroma) and brown-colored products. - It entails a series of complex reactions which include isomerization, dehydration, degradation, condensation, and polymerization 3. Ascorbic acid browning - It is first oxidized to dehydroascorbic acid & then transformed into diketogulonic acid. - This acid is eventually decomposed to furfural or related HOW CAN WE PREVENT ENZYMATIC BROWNING? compounds which then polymerize or react with nitrogen (as in Maillard reaction) to form brown pigments. This type of browning 1. BLANCHING – Heat treatment; can deactivate enzymes (30 is observed during drying of vegetables. secs dip to the H2O, 70-100°C – mid) 2. REFRIGERATION/FREEZING TREATMENT – Cold 4. Lipid peroxidation treatment can inhibit enzymes – after thawing enzyme will - It occurs by the action of oxygen and reactive oxygen species resume (0 – 10°C – ref; Below 0 or -17°C – freezing). on the fatty acids, especially unsaturated fatty acids. 3. CHANGE IN pH – Acidic environment – will inhibit enzymes - These are oxidized to form aldehydes and ketones which then (above 4.0) react with amino acids to form brown pigments, as in the Maillard reaction. Inhibitory substance – soaking in H2O; blocks the surface - It is possible that peroxidation products induce the browning 4. DEHYDRATION – inhibit not destroy – removal of H2O reaction of the Amadori products. (packing and drying) 5. IRRADIATION – Cold pasteurization – deactivate the PIGMENTS IN FOODS enzyme (use of radioactive materials) No matter how nutritious, flavorful, or well textured a food, it is unlikely to be eaten unless it has the right color. NON-ENZYMATIC BROWNING 1. Maillard Browning Factors which influence the acceptability of color in a certain food: - type of non-enzymatic browning which involves the reaction of Culture simple sugars (C=O) with amino acids, peptides and proteins (-NH2) Geography Sociology -consists of a number of steps to ultimately form brown, nitrogenous polymers and copolymers called melanoidins. COLOR -can occur at room temp. but is optimal at 140 - 165°C. - refers to human perception of colored materials—red, green, blue, etc. -preventing Maillard browning consists of measures intended to slow reaction rates, such as: control of moisture, temp., pH, –’appearance’ are major, & most important attribute of foods. removal of an intermediate, & use of effective inhibitors. – it also influence flavor perception. -give roasted food a savory aroma. However, when you grill or sear food with excessively high heat, it can also produce a – may provide an indication of chemical changes in a food, such possible carcinogen called acrylamide - carcinogenic (toxic that as browning and caramelization. can cause cancer) – Lakes are dyes extended on a substratum and they are oil - Cooking at lower temperatures can prevent this chemical from dispersible appearing.