Types of Syrups and Their Uses

Syrups

• Syrups are concentrated aqueous solutions of sugar with optional medicinal or flavoring ingredients.
• They are characterized by their sweet taste and high viscosity.

Types of Syrups

• Non-medicated syrups: Used as a vehicle for other preparations.
• Medicated syrups: Contain active pharmaceutical ingredients (APIs) and have therapeutic effects, examples include antihistamines and cough syrups.
• Sugar-based syrups: Made with concentrated sugar solutions, primarily sucrose or dextrose.
• Sugar-free syrups: Use artificial sweeteners and viscosity builders.
  • Often used for diabetic patients who need to restrict their sugar intake.
  • Require the addition of viscosity builders like glycerin, methylcellulose, or hydroxyethyl cellulose to achieve the desired consistency.

Sucrose-Based Syrups

• Sucrose is the preferred sugar for syrups because it is pure, readily dissolves, has a high sweetness rating, and is inert.
• Stability of sucrose-based syrups:
  • Sucrose is susceptible to fermentation and hydrolysis in aqueous solutions.
  • Fermentation:
    • Microorganisms (moulds and yeast) can grow in dilute solutions of sucrose, leading to turbidity, odor changes, and taste changes.
    • Nearly saturated sucrose solutions (close to maximum solubility) are self-preserving as there is limited free water available for microbial growth.
    • Preservatives (benzoic acid, sodium benzoate) are often added to syrups at a concentration of 0.1-0.2% w/v.
  • Hydrolysis:
    • Sucrose breaks down into glucose (dextrose) and fructose (levulose) with the presence of acids and heat.
    • This process is known as "inversion" because the solution rotates polarized light differently after hydrolysis.
    • Inverted sugar solutions ferment more easily, are sweeter than sucrose alone, and can lead to browning of the syrup (caramelization) due to the formation of fructose.

Dextrose-Based Syrups

• Dextrose can be used to replace sucrose in syrups containing strong acids, preventing the browning associated with sucrose hydrolysis.
• Differences between sucrose and dextrose:
  • Dextrose solutions are less viscous than sucrose solutions, with a saturation point of 70% w/v.
  • Dextrose dissolves slower than sucrose.
  • Dextrose is less sweet than sucrose (74% sweetness).
  • Dextrose solutions are more easily fermented than saturated sucrose solutions (not self-preserving).
  • Preservatives, like glycerin (30-45% v/v), are often required for dextrose-based syrups. Glycerin contributes to viscosity and sweetness.

This quiz covers the various types of syrups, including medicated and non-medicated options as well as sugar-based and sugar-free varieties. It highlights their characteristics, uses, and applications in both culinary and medicinal contexts.