Lecture 6 Food Biotechnology PDF

Biotechnological Applications In Food Industry Dr. Eman Owis Lecturer Of Microbial Biotechnology – Mansoura Uni P h. D. G ö t t i n g e n U n i - G e r m a n y [email protected]  Food biote...

Biotechnological Applications In Food Industry Dr. Eman Owis Lecturer Of Microbial Biotechnology – Mansoura Uni P h. D. G ö t t i n g e n U n i - G e r m a n y [email protected]  Food biotechnology Nanotechnology in Microorganisms Fermentation Genetically Modified Enzymes in food Introduction agriculture and food associated with food Biotechnology Food industry industry & Bioethics Bacteria, yeast and Applications of Definition Introduction Genetic Engineering Introduction molds nanotechnology Production of food Ethical aspects of food Branches of Factors influencing Fermenter DNA, RNA, Protein enzymes from and agricultural biotechnology microbial activity microorganisms biotechnology Benefits of Importance of Molecular Biology Different enzymes in Types of bacteria in the food biotechnology industry fermentation techniques food industry Food biotechnology Importance of yeasts safety and regulations in foods Different techniques associated with food biotechnology - What are enzymes? - Historical notes………. - Chemical nature & structure of enzyme - Enzyme catalysis - Applications Enzymology: The branch of science that deals with the biochemical nature and activity of enzymes Enzymologist: a person who is trained in or engaged in enzymology What is the difference between protein and enzyme?? Protein: is a biochemical macromolecule consisting of one or more polypeptide typically folded into a globular or fibrous form. Proteins could be structural or functional ones. - Structural proteins: Structural proteins are fibrous proteins. The most familiar of the fibrous proteins are probably the keratins, which form the protective covering of all land vertebrates: skin, fur, hair, wool, claws, nails, hooves, horns, scales, beaks and feathers. collagens of tendons and hides, which form connective ligaments within the body and give extra support to the skin where needed. - - Functional proteins: are the enzymes In the cell, there are transport proteins and signaling proteins  Is it correct to say: all proteins are enzymes?? Enzymes Proteins Proteins Enzymes x √ No, It is correct to say: all enzymes are proteins What is an enzyme? Enzyme: is the functional protein that catalyzes (increase the rate of) biochemical reactions. In another word we can term them enzymes as biological catalysts. All the chemical reactions run in the cell need enzymes. E: enzyme S: substrate P: product  Enzymes =Life Almost all chemical reactions in a living cell need enzyme in order to proceed at rates sufficient for life. Formula for a simple enzyme catalyzed reaction  Chemical nature of enzyme Enzymes (and proteins) are a linear chain of amino acids connected with peptide bonds (polypeptide chain). Substituted to give different amino acids Amino acid Structure of enzymes Often, the reactions catalyzed by enzymes require the incorporation of additional chemical groups to facilitate rapid reaction. Thus to fulfill reactivity needs that cannot be achieved with the amino acids alone, many enzymes incorporate non-protein chemical groups into the structures of their active sites. These non-protein chemical groups are collectively referred to as enzyme cofactors or coenzymes. The co-factor may be inorganic or organic. The inorganic co-factor may comprise metal ions, e.g., copper for cytochrome C oxidase, and their binding to the enzyme is essential for enzyme activity. The organic co-factor may associate with enzyme through non- covalent interactions, such as those described previously (e.g., H- bonding, hydrophobic interactions). They are generally regarded as co-enzymes since they usually bind to the enzyme before the other substrate bound, participate in many reactions and may be recovered to their original form by many other enzymes. In enzymes requiring a cofactor for activity, the protein portion of the active species is referred to as the apoenzyme, and the active complex between the protein and cofactor is called the holoenzyme. Enzymes could be Extra-cellular enzymes (exo-enzymes): That are produced and secreted outside the cell. It is usually used for breaking up large molecules that would not be able to enter the cell otherwise (amylase). Entra-cellular enzymes (endo-enzymes): That are produced and work inside the cell. 29 How could the enzyme work efficiently? The essential role of enzymes in almost all physiological processes stems from two key features of enzymatic catalysis: (1) enzymes greatly accelerate the rates of chemical reactions; and (2) enzymes act on specific molecules, referred to as substrates, to produce specific reaction products. Together these properties of rate acceleration and substrate specificity afford enzymes the ability to perform the chemical conversions of metabolism with the efficiency and fidelity required for life. 31 1- Enzyme substrate interaction In an enzyme-catalyzed reaction, the formation of a n enzyme- substrate complex is the first step; substrate (S) binds to the enzyme (E) to form a complex (ES). The formation of the ES complex leads to the formation of transition state species, which then form the product. The substrate binds to the enzyme at the active site usually by non- covalent interactions (hydrogen bonding, electrostatic, hydrophobic interactions, and van-der Waal forces). 33 2- What happen after binding? For any chemical transformation to be carried out, the reactant`s (A) energy should increase to overcome the activation energy barrier to give products (B) 34  Without enzyme, the activation energy is high With enzyme, the activation energy is lowered Whether with or without enzyme (catalyst), the ΔG (free energy change) is not changed Applications Of Enzymes In the Food Industry  Enzymes used in food industries Dairy Brewing Baking Wine and production fruit juice Rennet β-Glucanase Maltogenic Pectinase amylase Lactase α-Amylase Glucose oxidase β-Glucanase Protease Protease Pentosenase Catalases Amylogluco - sidase  Dairy industry Rennet Lactase Protease Catalase  RENNET  Extracted from the fourth stomach of young calves  Contains enzymes that cause milk to become cheese  It separates solid curd and liquid whey  Different animal rennet is used for different cheese  The most common vegetable rennet is “thistle”  LACTASE  Present in the brush border of the small intestine  Artificially extracted from yeast  Required for the digestion of whole milk  Used in the production of lactose-free milk  Also used in the production of ice cream and sweetened flavored and condensed milk  CATALASE  Produced from bovine livers or microbial sources  Breaks down hydrogen peroxide to water and molecular oxygen  Along with glucose oxidase it is used in treating food  wrappers to prevent oxidation  Also used to remove traces of hydrogen peroxide in the process of cold sterilization  Protease  Widely distributed in the biological world  Hydrolyses the specific peptide bond to generate para-k-casein and macro peptides in production of cheese  Results in bitter flavor to the cheese and also in desired texture  BREWING INDUSTRY Protease β – Glucanase α - Amylase Amyloglucosidase  Protease  Peptidase works to provide the worth with amino acid nutrients that the yeast will use.  Protease breaks up the larger proteins, enhancing the head retention of beer and reducing haze.  In fully modified malts, these enzymes have done their work during the malting process  β – Glucanase  Beta- Glucanase represents a group of carbohydrate enzymes which break down glycosidic bonds within.  beta-glucan Aids in filtration after mashing and brewing  α - Amylase  Converts starch to dextrins in producing corn syrup  Solubilizes carbohydrates found in barley and other cereals used in brewing  Decreases the time required for mashing  THE BREWERY PROCESS 1. MALTING Raw barely is heated and dried with the crushing of the grain. Malting aims to isolate enzymes needed for brewing. The barely grain is then passed through grits mils to form grits 2. MASHING the grits mils is introduced to hot water and left to activate the natural enzyme that helps to break down starch into sugar. 3. LAUTERING the grits are separated from water. The sugar–water saturation is drained off from grains the sticky liquid is called wort 4. BOILING the wort is boiled for at least 60 to 120 min 5. FERMENTATION boiled strained and cooled wort is transferred to the fermentation vessel and yeast is added. Yeast helps to convert sugar into alcohol releasing carbon dioxide during the process. 6. BOTTLING AND AGING After the fermentation beer needs to mature to develop flavor and for the carbonation effect. The beer is kept for aging from a few months to a few years followed by bottling and then ready for commercial use. BAKING INDUSTRY Maltogenic amylase Glucose oxidase Pentosanase  Glucose oxidase  Oxidizes glucose and produces gluconic acid and hydrogen peroxide  H2O2 is a strong oxidizing agent that strengthens the disulfide and non-disulfide cross-links in gluten  Good working conditions help the proper function of the bakery system. WINE AND FRUIT JUICE INDUSTRY ▪ Pectinase ▪ β – Glucanase  Pectinase  Prevents pectin from forming haze and hence to get a clear solution.  Additionally, it is used for the extraction of color and juice from fresh fruit  It breaks down pectin and releases methanol  β – Glucanase  It accelerates all biological mechanisms linked to maturation on lees  Reduces maturation duration  Improves clarification and filtration and improves the action of fining agents.