Improvements in the Shelf Life of Commercial Corn Dry Masa Flour (CMF) by Reducing Lipid Oxidation

Abstract

To improve the shelf life of commercial nixtamalized corn dry masa flour (CMF), the modified atmosphere packaging (MAP) was used. Pouches (20 × 20 cm) of ethyl vinyl alcohol (EVOH) with 180 g of CMF were stored at 55 °C, and a(w) of 0.45; under Light and Dark conditions, antioxidants (0.02% TBHQ), Vacuum, and N(2) and CO(2), and used as treatments. Thereafter, changes in their linoleic acid (LA) concentration by GC, peroxide (PV), and anisidine values (p-A), which were monitored for 180 d. EVOH showed a significantly lower consumption of LA by autoxidation (11.7% ± 0.2% in 117 d) than polyethylene film (70.5% ± 0.3% in 113 d) under the same storage temperature. The elimination of oxygen by vacuum in each pouch allowed a low consumption (16.4% ± 0.1%) of LA. PV (14.5 ± 0.09 mEq/kg of fat), and p-A (63 ± 0.16 mmol/kg) were low, and generated over 121 d of storage. CMF stored under MAP had 100% protection against oxidation of LA. A combination of Vacuum and EVOH packaging extended the shelf life of CMF to 108 d with only 10% of LA loss. For retail stores, the EVOH packaging will reduce lipid oxidation of CMF and safety related to off odors and flavors from the oxidation of tortillas will increase dramatically.