[Change in food proteins during technological processing].

Area of Science:

• Food Science and Technology
• Biochemistry
• Protein Chemistry

Context:

• Production of milk-protein concentrates like caseinate and casein hydrolysate involves enzymatic treatments.
• Understanding protein fraction changes is crucial for product quality and sensory attributes.
• Casein, a major milk protein, is susceptible to proteolytic modification during processing.

Purpose:

• To investigate the alterations in casein protein fractions during the production of milk-protein concentrates.
• To analyze the impact of pancreatin treatment on specific casein fractions, particularly beta-casein.
• To correlate observed protein changes with sensory characteristics, such as bitter flavor.

Summary:

• Double disk-electrophoresis in polyacrylamide gel revealed significant changes in casein fractions during pancreatin treatment at pH 6.6-7.0.
• Beta-casein exhibited the highest proteolytic decomposition, yielding new fractions and increasing positively charged gamma-casein fractions.
• A decrease in beta-casein (3.5-11.7%) and an increase in positively charged fractions correlated with heightened bitterness.

Impact:

• The study demonstrates the utility of double disk-electrophoresis for monitoring casein hydrolysis.
• This technique can be applied to regulate and optimize enzymatic processes in food production.
• Findings contribute to controlling the sensory properties of milk-protein concentrates.