Q.Bottled fruit juices are clearer as compared to those made at home, as they are clarified by the use of : (A) Lipases and pectinases (B) Pectinases and proteases (C) Proteases and cellulases (D) Nucleases and lipases

Homemade fruit juices often appear cloudy because they contain suspended particles, primarily plant cell wall components like pectin and various proteins. To achieve the clear appearance characteristic of bottled fruit juices, these suspended materials must be broken down and removed. This clarification process is accomplished by adding specific enzymes. Pectinases are used to degrade pectin, while proteases break down proteins. The action of these …

When you make fruit juice at home, you often notice it's quite pulpy and cloudy. This is because the process of crushing or blending fruit releases not just the liquid, but also tiny fragments of fruit pulp, cell wall material, and other suspended particles. These particles, though small, are numerous enough to scatter light, giving the juice its characteristic opaque or cloudy appearance.

Commercial fruit juice manufacturers, however, aim for a clear, appealing product. To achieve this, they employ specific enzymes that act on the components causing the cloudiness. The two primary enzymes used for this clarification process are pectinases and proteases.

Let's understand their roles:

• Pectinases: Fruits contain a complex polysaccharide called pectin, which is a major component of plant cell walls and the middle lamella that glues plant cells together. When fruit is processed, pectin can be released into the juice, forming a colloidal suspension that makes the juice thick, viscous, and cloudy. Pectinases are enzymes that specifically break down pectin into smaller, soluble molecules. By doing so, they reduce the viscosity of the juice, release more liquid from the pulp, and most importantly, eliminate the suspended pectin particles that contribute significantly to the cloudiness.

• Proteases: While pectin is a major culprit, proteins present in the fruit can also contribute to the turbidity and haze in juice. These proteins can aggregate or denature, forming fine suspended particles that make the juice cloudy, especially over time. Proteases are enzymes that break down proteins into smaller peptides and amino acids, which are much more soluble and do not cause cloudiness.