390 likes | 946 Views
Introduction to Food technology. Canning. Canning. Raw material: Care for variety Tomatoes with higher solid more tomato paste (24%) more efficient Uniformity: In maturity, in size. Canning. Storage Better storage facility higher flexibility
E N D
Introduction to Food technology Canning By: Dr. Ossama Dimassi
Canning • Raw material: • Care for variety • Tomatoes with higher solid more tomato paste (24%) more efficient • Uniformity: • In maturity, in size By: Dr. Ossama Dimassi
Canning • Storage • Better storage facility higher flexibility • Materials bought at optimal price to quality • Depends on our processing capability By: Dr. Ossama Dimassi
Canning • Soaking & washing: (1/3) • Necessary cleaning step • Hot/ cold water • Depending on raw material By: Dr. Ossama Dimassi
Canning • Soaking & washing: (2/3) • Detergents: • Alkaline (Against protein – esp. milk protein) • Acid (Against organic complexes) • Surface active agents (like soaps) • Enzymes (lipases, Carbohydrases.. etc.) By: Dr. Ossama Dimassi
Canning • Soaking & washing: (3/3) • Example: • HCl Lead arsenate (Insecticide) removal • Prohibited • Used in apple orchids By: Dr. Ossama Dimassi
Canning • Sorting and grading: • Remove spoiled food • Bad oranges • Sort • Size • Maturity By: Dr. Ossama Dimassi
Canning • Blanching: • Treatment with boiling water for short time • Inactivate enzymes • Facilitate peeling • Time for blanching can be determined: • Measuring peroxides activity • Peroxidase is a resistant enzyme • Plays a role is bleaching of vegetables By: Dr. Ossama Dimassi
Canning • Peeling, pitting and/or coring • By hand: • Sensitive product and small factory • By heating • By machines • Lye peeling • 1-2% NaOH dip By: Dr. Ossama Dimassi
Canning • Filling into Containers • Glass Jars • Aluminum Can • Tin Can • Plastic Material By: Dr. Ossama Dimassi
Canning • Glass Jars vs. Tin & Aluminum: (1/2) • Advantages: • Attractive • Inert • Reusable • Disposable By: Dr. Ossama Dimassi
Canning • Glass Jars vs. Tin & Aluminum: (2/2) • Disadvantages: • Breakable • Usually transparent • Temperature sensitive • Glass that can withstand T fluctuation expensive By: Dr. Ossama Dimassi
Canning • Aluminum Can: (1/2) • Beverages, cheeses, meat, tuna etc. • Cans consist of 2 pieces • One by molding • Cover is the other piece By: Dr. Ossama Dimassi
Canning • Aluminum Can: (2/2) • Advantages: • Less Reactive than Tin • Soft easy to open cover lid • Disadvantage • More expensive • Soft type • Careful during sterilization using pressure By: Dr. Ossama Dimassi
Canning • Tin Can: (1/2) • Three pieces to form can • Top • Wall • Bottom • Identified by: • Height and Diameter • Concentric circles on top and bottom resist pressure By: Dr. Ossama Dimassi
Canning Technical Information about canning By: Dr. Ossama Dimassi
Topic 1 • Double Seam (Hermetic seal): (1/2) • Formed by interlocking the can body and the can end during two rolling actions. • The first action • Roll curls the edge of the can end up under the flange of the can body • Folds the metal into file thicknesses • Embedding the flange into the compound. • Edge of can end is reduced wrinkle formation By: Dr. Ossama Dimassi
Topic 1 • Double Seam (Hermetic seal): (2/2) • The second action roll • flattens and tightens the seam hermetic seal is formed. • Causes • The wrinkles to be ironed out • The “compound” to be forced into any gaps By: Dr. Ossama Dimassi
Topic 1 1 2 By: Dr. Ossama Dimassi
Topic 1 4 3 By: Dr. Ossama Dimassi
Topic 2 • Can lining: • Depending on product look at: • Need for lining • Sulfur resistance (canning meat for ex.) • Enamel • Acid resistance • Resin • New subject has to be careful for BPA By: Dr. Ossama Dimassi
Topic 3 • Vacuum: • Head space vacuum • Bet. Food and lid • Prevent swelling • Food expands • Reduce O2 less oxidation • Reduce corrosion of can By: Dr. Ossama Dimassi
Topic 3 • Vacuum: • Build up vacuum • Thermal exhausting • Hot food before sealing Vapor put lid T lowers Vapor condense to water Vacuum • Mechanical • Seal in a vacuum chamber • Control and measure vacuum by a gauge By: Dr. Ossama Dimassi
Topic 4 • Thermal exhaustion: • Prevent enzymatic activity • T > 60º • Prevent microbial activity • Anaerobic Spore forming bacteria • Primary challenge By: Dr. Ossama Dimassi
Topic 4 • Thermal Sterilization: • To apply successfully we need: • Information about product • Liquid, solid… etc. • Information about expected m-organisms • Spore forming …etc. • Understand Coldest point concept By: Dr. Ossama Dimassi
Topic 4 • Product information • Provide insight on heat transfer: • Conduction in solids • By contact • Coldest point easy to visualize (middle) • Convection • Nature of fluids • In 211 Can 1 inch from bottom. By: Dr. Ossama Dimassi
Topic 4 • Product information Conduction Convection Coldest point By: Dr. Ossama Dimassi
Topic 4 • Product information • Provide insight on heat transfer rate: • Heat travels faster in liquid foods • Each product have a curve • X axis processing time • Y axis T ºC (Logarithmic Scale) • From rate and target T and time at coldest point KNOW PROCESSING TIME By: Dr. Ossama Dimassi
121º Liquid Solid Temperature ºC Time (min) Topic 4 By: Dr. Ossama Dimassi
Topic 4 • m-organism information • Kind of m-organism to be expected • Low acid food pH> 4.5 • Spore forming • More difficult to sterilize • High acid food pH< 4.5 • Easier to sterilize By: Dr. Ossama Dimassi
Topic 4 By: Dr. Ossama Dimassi
Topic 4 • m-organism information • Thermal destruction of bacteria: • The most notorious is Cl. Botulinum • A survival curve is constructed • @ Constant lethal temperature (usu. T:121.1ºC) • Decimal reduction time is (D) • Time to reduce spore from 10000 to 1000 = Time to reduce spore from 100 to 10 By: Dr. Ossama Dimassi
Topic 4 By: Dr. Ossama Dimassi
Topic 4 a/ D values quoted are those at the reference temperature of 121.1°C, with the exception of that for C. botulinum type E, the spores of which are relatively heat sensitive, being killed at pasteurization temperatures (e.g., 82.2°C) b/ Although the temperature range for optimum growth of C. botulinum type E is 30-35 °C, it has a minimum of 3.3°C which means that it is able to grow at refrigeration temperatures By: Dr. Ossama Dimassi