Storage of biofortified maize in Purdue Improved Crop Storage (PICS) bags reduces disulfide linkage-driven decrease in porridge viscosity

摘要

Assessing rheological properties of biofortified maize through post-harvest storage is critical for its successful translation to consumer foods. Changes in flour rheology were assessed following post-harvest storage in Purdue Improved Crop Storage (PICS) of a white and two biofortified orange maize genotypes (OPVI and OPVII). Whole grains were stored in PICS bags with (PICS-oxy) or without (PICS-noxy) oxygen scavenger and compared to storage in traditional polypropylene woven bags. Flour pasting profiles were assessed over 8 months of storage. Initial porridge viscosities from biofortified maize were lower than from white maize. After 8 months, higher viscosities (p < 0.05) were observed in grain stored in PICS relative to woven bags. Sequestration of oxygen had a modest but significant effect (p < 0.05) on peak and final viscosities supporting the notion that oxidative processes mediate these effects. DTT treatment partially restored porridge viscosity suggesting disulfide linkages are involved in rheological changes during storage. Raman spectral analysis suggested storage-induced structural changes to the starch matrix. Overall, storage of biofortified maize in PICS alleviated disulfide linkage-driven decreases in viscosity of cooked porridge. With the potential to improve cooking quality of biofortified maize flours, application of PICS may be useful in translation of these grains to consumers.