Polarized light microscopy guarantees the use of autochthonous wheat in the production of flour for the Protected Geographical Indication ‘Galician Bread’

‘Galician Bread’ is a traditional baked product and national benchmark that has recently been granted the European mark of Protected Geographical Indication (PGI), which requires at least 25% flour to be produced from autochthonous varieties such as ‘Caaveiro’. The objective this work was find method guarantees presence percentage ‘Caaveiro’ wheat in blended flours by using microscopy techniques. Using optical microscopy, including bright-field polarizing foreign were analysed compared. starch presented different birefringence pattern (associated with higher amount amylose) respect other cultivars used produce flours, feature make computation two granule types mixtures flours. Repetitions mixture percentages allowed us develop mathematical model estimate present mixture. Firstly, most effective for preparing samples determined ensuring homogeneity and, subsequently, validation carried out blind samples. Starch properties detection foreign/Castilian determine applying calibration line (R2 = 0.9577). Deviations due difficulty obtaining precise happened Simple Sequence Repeat (SSR)-based methods same This novel detecting contraventions/infractions simple, inexpensive.