Food tech

• Food refers to a broad range of edible materials containing essential body nutrients like proteins, carbohydrates, fats, vitamins, or minerals
• Chemical composition of food can be determined in a laboratory
• Chemical substances found in the largest amounts in food are carbohydrates, fats, protein, water, vitamins, and minerals
• Carbohydrates are organic compounds of carbon, hydrogen, and oxygen, with major types being sugar and starch
• Proteins are the basic material of life, making up ¾ of our body tissue and can be complete or incomplete
• Fats are essential for the body's proper functioning and serve as storage for excess calories, composed of carbon, hydrogen, and oxygen
• Water is essential to human life, with two forms found in food: free water and bound water
• Minerals act as nutrients essential to many processes in the body
• Vitamins are needed by the body to help regulate functions
• Chemical reactions in food include the Maillard reaction, caramelization, fermentation, gluten formation, pyrolysis, acid-base reactions, protein denaturation, and emulsification
• Food spoilage or deterioration can be caused by yeasts, molds, and bacteria
• Food technology applies food science to the selection, preservation, processing, packaging, distribution, and use of safe food
• Food processing involves changing food properties to preserve it, improve quality, or make it more useful
• Food preservation is the process of treating food to stop or slow spoilage, prevent illness, and maintain nutritional value, texture, and flavor
• Methods of food preservation include sun drying, jam making, curing, refrigeration, canning, pasteurization, dehydration, vacuum packaging, irradiation, and chemical preservatives
• Food packaging is designed to prevent the spoilage of food products throughout the supply chain
• Diversity in food composition and product structure in fresh and processed food products demands unique packaging solutions for each product category
• Functions of packaging:

  • Protection: includes prevention of biological contamination, oxidation, moisture change, aroma loss or gain, and physical damage
  • Convenience: providing convenience to consumers has become a more important function of packaging
  • Containment: involves the ability of the packaging to maintain its integrity during handling involved in filling, sealing, processing, transportation, marketing, and dispensing of the food
  • Communication: the information provided by packaging involves meeting legal requirements and marketing objectives
• Types of packaging materials:

  Flexible Packaging Materials:

  • Papers
  • Composite films (laminate and coextruded)
  • Plastic and flexible films

  Rigid Packaging Materials:

  • Glass containers
  • Metal containers
  • Polypropylene and polyethylene drums, crates, and boxes
  • Wooden containers
• Flexible packaging materials:

  • Papers: materials with a grammage less than 225 grams per square meter (g/m2)
  • Composite films (laminate and coextruded)
  • Plastic and flexible films made from non-fibrous plastic polymers
• Examples of paper uses:

  • Kraft: multi-wall sacks, liners for corrugated boards
  • Sulphite: small bags, pouches, waxed papers, labels, foil laminates
  • Greaseproof: paper for bakery products, fatty foods
  • Glassine: odour-resistant and greaseproof bags, wrappers or liners for boxes, suitable for wax coating to make them water-resistant
  • Vegetable parchment: high wet strength and grease-resistant bags, wrappers or liners for boxes used for meat, fish, fats, etc.
  • Waxed paper: soft wrapping paper for bread, fruits, etc
• Types of plastic films and their uses:

  • Polyethylene: high-density polyethylene for containers, milk and detergent bottles, bags, and industrial wrapping; low-density polyethylene for pallet and agricultural film, bags, coatings, and containers
  • Polypropylenes: bottles, jars, crisp packets, and biscuit wrappers
  • Polyester: processed meats, cheese, candy, and coffee
  • Polyvinyl chloride: coating for films and bottles
  • Nylon: industrial applications
• Rigid packaging materials:

  • Glass containers: commonly used for a wide variety of food products
  • Metal containers: tin plate containers made of steel body coated with tin electrolytically
  • Polypropylene and polyethylene drums, crates, and boxes: have largely replaced wood in many applications
  • Wooden containers: traditionally used for a range of solid and liquid food products
• Methods of food packaging:

  1. Vacuum packaging: removal of external gases in a container
  2. Gas packaging: alteration of the proportional volumes of gases in a normal atmosphere
  3. Aseptic packaging: sterilization of food and packages separately and filling in an aseptic atmosphere
  4. Thermal processing: processing food products of high moisture content in situ in rigid or flexible containers
  5. Minimally processed food packaging: extends storage life of foods intended for easy preparation
  6. Bag-in-box packaging: inclusion of a flexible pouch/bag inside a rigid container
  7. Active packaging: employs a packaging material that interacts with the internal gas environment to extend the shelf-life of food
• Food labeling:

  • Tool to promote and protect public health by providing accurate nutritional information
  • Instrument of marketing and product promotion
  • Reduces the information problem between producers and consumers, and search costs for consumers
• Mandatory labeling of foods includes:

  • Name of the food
  • List of ingredients (in descending order)
  • Net contents and drained weight
  • Name and address of the manufacturer
  • Country of origin
  • Lot identification
  • Date marking and storage instructions
  • Instructions of use
• Food preservation is the science that deals with preventing spoilage of food, allowing it to be stored in a fit condition for future use
• Principles of food preservation include keeping out microorganisms, hindering their growth, and killing them
• Methods of food preservation include low temperatures, drying, high temperatures, high concentrations of sugar and salts, canning, chemical preservation, and radiation
• High Temperature Method:

  • Pasteurization involves the destruction of microorganisms by heat
  • Pasteurization methods include HTST (High Temp Short Time) and LTLT (Low Temp Long Time) methods
• Low Temperature Method:

  • Includes cellar storage, refrigerator or chilling, and freezing
  • Freezing methods include slow freezing, quick freezing, and dehydro freezing
• Canning Methods:

  • Steps include cleaning, blanching, exhausting, sealing the container, sterilizing the sealed container, and cooling the container
• Drying Method / Dehydration:

  • Methods include sun drying, mechanical drying, spray drying, foam mat drying, drying by osmosis, and freeze drying
• High Concentration of Sugar and Salt:

  • Methods like salting, pickling, using sugar, and vinegar aid in food preservation
• Chemical preservation:

  • Only a few chemicals are permitted in prescribed levels for preserving food
  • Examples include sodium benzoate, sorbic acid, and sulphur dioxide
• Preservation by Radiation:

  • Microorganisms are inactivated by different kinds of radiation
  • Foods like spices, vegetables, fruits, pork, and poultry can be preserved by radiation
• Boiler:

  • A double boiler has a detachable upper compartment heated by boiling water in the lower compartment
  • It is placed over a stove to begin heating
• Steam Jacketed Kettle:

  • Uses steam to heat liquid
  • Enclosed by a "jacket" to ensure even heating and has a spout for collecting volumes of liquid
• Pressure Canner:

  • A sealed pot with a dial indicating pressure inside and a weighed gauge for steam control
  • Works by trapping steam and building up pressure inside the pot
• Pressure Dial Gauge:

  • Acts as a safety device to prevent pressure over 15 pounds in the canner