Applications of Biotechnology in Food Sciences PDF

Applications of Biotechnology in Food Sciences DR. Heba Sayed Mostafa Associate Professor Food Science Department Lecture 1 biotechnology is technology that utilizes biological systems, living organisms or parts of them to develop or create different products. biotechn...

Applications of Biotechnology in Food Sciences DR. Heba Sayed Mostafa Associate Professor Food Science Department Lecture 1 biotechnology is technology that utilizes biological systems, living organisms or parts of them to develop or create different products. biotechnology= bio (life) + techno (tools) + logy (study of) Lecture 1 (Dr. Heba Mostafa)  Applications of Biotechnology in Food Packaging Lecture 1 (Dr. Heba Mostafa)  Introduction 01 Biopolymers 02 Raw materials 03 Contents Synthesis of PLA There are two methods of production: 04 1- Poly condensation of lactic acid. 2- Ring opening condensation. PLA forms 05 Lecture 1 (Dr. Heba Mostafa)  Introduction Lecture 1 (Dr. Heba Mostafa)  Plastic Lecture 1 (Dr. Heba Mostafa)  How dispose of and manage all the plastic wastes? Lecture 1 (Dr. Heba Mostafa) Did you see this symbol on any packaging material? Lecture 1 (Dr. Heba Mostafa)  Introduction Today, polymers and materials used for food packaging consist of a variety of petrochemical-based polymers, metals, glass, paper, and board, or combinations hereof. They have several disadvantages include: (a) declining oil and gas resources; (b) increasing oil and gas prices during recent decades; (c) environmental concerns for their degradation or incineration and global warming; (d) uneconomical costs and cross-contaminations in their recycling; and (e) consumer toxicity risks about their monomers or oligomers migrating to edible materials. Bio-plastics have gained tremendous attention, due to the increasing environmental pressure on global warming and plastic pollution. Lecture 1 (Dr. Heba Mostafa)  Biopolymers Lecture 1 (Dr. Heba Mostafa)  Biopolymers Definition They are polymers that easily degraded in nature. Biodegradation It is the degradation of a polymer in natural environments, changing into other compounds like water, carbon dioxide, minerals, and intermediate products like biomass and humic materials, when dumped into landfills. The natural environments contain chemical, biological, and physical forces with impinging factors like temperature, humidity, pH, O2 presence which determine the rate and products of the biodegradation process Lecture 1 (Dr. Heba Mostafa)  PLA The worldwide interest in bio-based polymers has accelerated in recent years. One of these biopolymers that produced from natural resources is poly- lactic acid (PLA). It is both bio-based and biodegradable, which has been widely used in many disposable packaging applications. The basic unit of this polymer is Lactic acid. Lactic acid is also known as milk acid that used as acidulant/flavouring/pH buffering agent or inhibitor of bacterial spoilage in a wide variety of processed foods. In contrast to other food acids it has a mild acidic taste. It is non-volatile odorless and is classified as GRAS (generally regarded as safe) by FDA in the US. Lecture 1 (Dr. Heba Mostafa)  Lactic acid Lactic acid (2-hydroxy propionic acid) is the most widely occurring carboxylic acid in nature. Existing in two enantiomeric forms, L- and D-LA. It has been receiving a great attention as a precursor for the synthesis of PLA, a biodegradable. L Chemical synthesis route usually produces D DL-LA, whereas an optically pure L(+)- or D(-)-LA can be obtained by microbial fermentation depending on the strain selected. Lecture 1 (Dr. Heba Mostafa) Lecture 1 (Dr. Heba Mostafa) Microbial sources Comparison between the two methods Chemical method Microbial method This method produces It is chemically and racemic mixture of both economically more feasible D (-) and L (+) lactic because it is based on acid. microbial carbohydrate Furthermore, the metal fermentation (renewable catalyst employed in this sources). process is difficult to Optically pure L(+)- or D(-)- remove which makes it LA can be obtained by unfit in many microbial fermentation applications. depending on the strain selected. Lecture 1 (Dr. Heba Mostafa)  Raw materials The use of a specific carbohydrate feedstock depends on its price, availability, and purity. Some corn cobs, Cassava, Molasses corn stalks barley, and agricultural byproducts are spent wheat bran potato starch wash potential substrates for lactic acid production includes: carrot processing wastes Lignocellulose /hemicellulose hydrolysates Lecture 1 (Dr. Heba Mostafa)  Synthesis of PLA Lecture 1 (Dr. Heba Mostafa)  1) Poly condensation of Lactic Acid: Direct poly condensation of lactic acid is mostly carried out in bulk by distillation of condensation water with or without the presence of a catalyst, while vacuum and temperature are gradually Get a modern PowerPoint increased. Presentation that is beautifully designed. Lecture 1 (Dr. Heba Mostafa)  2) Ring opening condensation (ROP) It consists of three main steps : Finally ROP of lactide is performed to make high-molecular-weight PLAs 3 (Mw > 100 000). Second 2 The low-molecular weight prepolymer is depolymerized to make lactide. 1 First Lactic acid is condensed to give a low-molecular-weight PLA prepolymer (Mw = 1000~5000). Lecture 1 (Dr. Heba Mostafa) Lecture 1 (Dr. Heba Mostafa)  Processing Technologies to produce different packaging materials’ shapes with PLA Extrusion: it is the major step in the conversion of plastic resin into films, sheets, containers. Injection molding: Used to produce bottle caps, food trays. Blow molding: Used for bottles for different foods like fresh dairy liquids, fruit juices, sport drinks and edible oils. Cast film extrusion: used in packaging, food wrap, substrate for coating, protective film. Lecture 1 (Dr. Heba Mostafa) Lecture 1 (Dr. Heba Mostafa) Lecture 1 (Dr. Heba Mostafa)