1. Packaging Machinery and Line Operations

• Typical Packaging Line: Involves steps such as moving containers, cleaning, filling, sealing, labeling, and palletizing. Two main layouts:
  • Straight-line: simple, flexible, but slower.
  • Rotary: faster, precise, but costly and harder to maintain.
• Unscramblers: Prepare containers (metal, glass, plastic) by depalletizing, cleaning, and sterilizing before filling.
• Filling: Techniques vary by product (solid, powder, liquid). Methods include filling by weight, volume, or count. Special technologies address foaming, viscosity, and container type.
• Sealing and Closures: Includes push-fit, screw-threaded, roll-on pilfer-proof, lug/twist-off, crimped, and can-sealing methods.
• Form-Fill-Seal (FFS): Vertical (VFFS) and horizontal (HFFS) machines form flexible packs, fill them, and seal by heat, pressure, or cold adhesives. Includes sachets, thermoforming, blister packs.
• Labeling: Self-adhesive, unglued, or sleeve application. Requires precision in material handling.
• Coding Systems: Embossing, hot foil, inkjet, laser, and thermal transfer, enabling batch tracking.
• Wrapping and Cartoning: Shrink/stretch wrapping and cartonning for protection and secondary packaging.
• End-of-Line Equipment: Palletizing, stretch-wrapping, and labeling for logistics.
• Efficiency & Quality: Sensors, storage conditions, equipment maintenance, training, and line efficiency calculation are critical. Changeovers and investments in machinery affect productivity.

2. Food Biodeterioration and Preservation

• Agents of Deterioration:
  • Enzymes: Cause browning, softening, spoilage.
  • Microorganisms: Bacteria, yeasts, molds (classified by temperature range and growth). Pathogens like C. botulinum and Listeria require strict controls.
  • Non-enzymic reactions: Browning (Maillard reaction), chemical spoilage.
• Preservation Methods:
  • High temperature: Blanching, canning, sterilization, pasteurization, UHT, aseptic packaging.
  • Low temperature: Chilling and freezing.
  • Drying: Reducing water activity through spray drying, freeze drying, etc.
  • Chemical methods: Preservatives (sorbic, benzoic acid, nitrates, antioxidants), curing, pickling, smoking.
  • Fermentation: Uses microbes for controlled preservation (e.g., yogurt, pickles).
  • Modified Atmosphere Packaging (MAP): Changing oxygen, CO₂, nitrogen levels to extend shelf life.
  • Other methods: Irradiation, high pressure, novel technologies.