Crystallization and demineralization phenomena in washed-rind cheese

Area of Science:

• Food Science
• Microbiology
• Materials Science

Background:

• Washed-rind cheeses are known for their distinct aromas and textures.
• Understanding the biochemical and physical changes during aging is crucial for quality control.

Purpose of the Study:

• To investigate the crystallization and mineral element dynamics in high-moisture washed-rind cheese during aging.
• To characterize the crystal phases present in the cheese smear and their evolution.

Main Methods:

• Observational study of three cheese batches over 10 weeks.
• Analysis of pH, moisture, and mineral elements (calcium, phosphorus, magnesium) in rind, under-rind, and center samples.
• Powder X-ray diffractometry and petrographic microscopy for crystal phase identification and imaging.

Main Results:

• Rind pH increased significantly, while center pH decreased initially. Four crystal phases (brushite, calcite, ikaite, struvite) were identified in the smear.
• Crystals grew up to 250 μm, with calcite and ikaite appearing early. Mineral diffusion led to increased calcium, phosphorus, and magnesium in the rind and decreased levels in the center.
• This is the first documented observation of crystallization and demineralization in washed-rind cheese.

Conclusions:

• Washed-rind cheese aging involves complex crystallization and demineralization processes.
• Mineral redistribution significantly impacts the cheese's composition from center to rind.
• These findings provide novel insights into the aging mechanisms of washed-rind cheeses.