खाद्य सुरक्षा, गुणवत्ता मानक व पैकेजिंग

Smart packaging and automatic identification systems:

• Barcodes (1D UPC/EAN linear codes and 2D QR codes) are printed directly onto packaging labels using standard ink printing technology at negligible marginal cost ($\lt 0.001$ per label).
• They are ubiquitous across global retail and supply chain management.
• In contrast, RFID tags, chemical TTIs, and biosensors involve microchips, electronic circuitry, or reactive chemical substrates that carry substantially higher unit production costs.

Barrier properties of food packaging substrates:

• Polyethylene (LDPE/HDPE) has good water vapor barrier properties but is permeable to oxygen and aroma compounds.
• Polyvinyl chloride (PVC) is permeable to gases and moisture.
• Polyvinylidene chloride (PVDC / Saran) provides an excellent polymeric barrier, but retains minor finite transmission rates.
• Aluminium foil (at thicknesses $\ge 25.4\ \mu\text{m}$ or $1\text{ mil}$) forms a continuous metallic crystalline barrier that is $100\%$ impermeable to light, water vapor, oxygen, and other gases (zero transmission rate).

Definition and mechanism of active packaging systems:

• Maintaining a static modified gas composition is the characteristic function of passive Modified Atmosphere Packaging (MAP).
• Active packaging is defined as a packaging system that incorporates deliberate active additives (such as oxygen scavengers, ethylene absorbers, carbon dioxide emitters, moisture absorbers, or antimicrobial agents) directly into or onto the packaging film material to actively interact with the packaged food and internal atmosphere to extend shelf life.
• Rapid random gaseous fluctuation is detrimental and uncontrolled.
• Active packaging is designed to prevent spoilage rather than cause contamination.