Lipolytic activity with the membrane fraction of bovine skim milk

Area of Science:

• Dairy Science
• Biochemistry
• Food Chemistry

Background:

• Skim milk contains various components, including proteins and membrane fractions, which can influence its properties.
• Lipolytic activity in milk can affect its flavor and shelf-life.
• Understanding the localization of lipolytic enzymes is crucial for dairy processing.

Purpose of the Study:

• To investigate the distribution of lipolytic activity in colloidal phosphate-free skim milk.
• To identify the specific fractions of skim milk exhibiting lipolytic activity using gel filtration.

Main Methods:

• Colloidal phosphate-free skim milk was prepared.
• Gel filtration chromatography using Sepharose 4B was performed.
• Lipolytic activity was assayed in eluted fractions.

Main Results:

• Lipolytic activity was detected in the void volume fraction, corresponding to membrane material.
• Significant lipolytic activity was also found in the protein fraction, spanning a wide range of molecular weights.
• This indicates a heterogeneous distribution of lipolytic enzymes within the skim milk.

Conclusions:

• Lipolytic enzymes in skim milk are associated with both membrane components and soluble proteins.
• Gel filtration is an effective method for separating and identifying fractions with lipolytic activity.
• Further research can focus on purifying and characterizing these lipolytic enzymes for targeted applications.