Structural and Functional Effects of Traditional Chuño Processing on Potato Starch (Solanum spp.)

Area of Science:

• Food Science
• Biochemistry
• Materials Science

Background:

• Traditional Andean chuño production modifies potato starch structure and function.
• Limited understanding of integrated effects of processing, cultivar, and environment on starch properties.

Purpose of the Study:

• Investigate chuño processing effects on potato starch composition, pasting, morphology, molecular, and crystalline properties.
• Characterize starches from three potato cultivars (Condor Imilla, Luk'i Turno, Dutch Désirée) before and after chuño processing.

Main Methods:

• Amylose quantification
• Viscoamylography
• Scanning Electron Microscopy (SEM)
• Fourier-transform Infrared Spectroscopy (FT-IR)
• X-ray Diffraction (XRD)
• Thermal treatment

Main Results:

• Chuño processing reduced amylose content (6.9-23.4%) and increased gelatinisation onset temperature (~65°C to ~79°C).
• Peak viscosity decreased substantially, while breakdown values neared zero, indicating enhanced thermal stability.
• SEM showed altered granule morphology; FT-IR indicated molecular reorganisation without chemical changes; XRD confirmed retention of B-type crystalline polymorph with reduced order.

Conclusions:

• Chuño processing results in reduced swelling, lower viscosity, enhanced thermal stability, and structural reorganisation, preserving the B-type polymorph.
• Observed differences reflect integrated responses to processing history and material characteristics, not solely genotype.
• Chuño represents a naturally modified starch with unique technological properties.