Sensory Stability of Maize Grains Preserved by a Triple Packing System and Biopesticides (Leaves of Lippia multiflora Moldenke and Hyptis suaveolens Poit)

The aim of this study was to evaluate the sensory stability of maize grains preserved in a triple bagging system with or without plant biopesticides (leaves of Lippia multiflora and Hyptis suaveolens), using a three-factor central composite design (CCD).

The first CCD factor consisted of 6 observation periods, namely: 0; 1; 4.5; 9.5; 14.5 and 18 months. The second factor was the type of treatment, which consisted of 1 control batch with polypropylene bags (WB) and 9 experimental batches, including 1 in a triple bag with no biopesticides (TS0) and eight (8) additional batches containing ratios and/or combinations of biopesticides (TS1 to TS8). Finally, the third factor concerns the combination of two biopesticides, with the percentage (%) of Lippia multiflora as the reference.

The samples were stored at room temperature for 18 months and periodically removed from storage for descriptive sensory analysis. All samples showed significant differences in sensory attributes initially and after storage. Intensity scores for negative sensory attributes such as musty and rancid aromas and acidic and astringent flavors increased during storage. After 18 months of storage, samples stored in a triple bagging system without biopesticides showed the highest intensity scores for rancid, moldy, acidic, and astringent flavors. These scores were 7.33±0.35; 6±1.67; 3.57±1.15; 4.38±1.57 respectively. However, samples preserved in triple bagging systems with biopesticides showed the lowest intensity scores for these negative attributes (4.5±0.8; 3.2±0.6; 2.18±1.73 and 1.96±0.67, respectively). In addition, the intensity scores for color, sweetness, and corn aroma decreased for all samples. Samples stored in triple bagging systems showed the smallest decrease at the end of storage for these positive attributes (5.67±1.21 for color, 5.66±1.5 for sweetness, and 5.25±1.47 for corn aroma).