Effect of multiple freezing/thawing cycles on the physicochemical properties and structural characteristics of starch from wheat flours with different gluten strength.

The physicochemical properties and structural characteristics of starches from three wheat flours with different gluten strength (S-YM20, S-ZM27, and S-ZM366) during freezing/thawing (F/T) cycles were studied. After F/T treatment, the damaged starch content of these three starches all increased, and the lowest increment of damaged starch content after 8 F/T cycles was S-ZM366; the most serious distribution of particle surface concave hole and fracture was S-YM20, followed by S-ZM27 and S-ZM366; additionally, the results of solubility, swelling power, thermal stability and pasting properties indicated S-ZM366 exhibited the strongest resistance to F/T cycles. The differences of freezing resistance among the three starches were possibly ascribed to the differences in compositions, crystallinity and microstructure among these three starches. This study provides theoretical contribution to the development of frozen dough industry from the perspective of wheat variety.