Efficacy of different multi-layer hermetic bags on the seed quality of the faba bean (Vicia faba L.) in outdoor storage condition

Faba bean seeds' sustainability correlates with the initial quality of cultivated seeds. The duration of storage is a significant factor that can affect the quality retention of any crop seed. Additionally, the hermetic bags effectively influence the quality of crop seeds during the storage process. This study evaluated two faba bean cultivars, Nubaria 1 and Giza 716, after various storage periods of 6, 12, 18, and 24 months. Seeds stored in 3 and 7-layer hermetic bags have shown significantly improved bulk temperature after 12, 18, and 24 months (neither more than ≈ 30 °C nor less than ≈ 15 °C). However, the relative humidity (RH%) increased significantly in both bags and cultivars throughout the storage periods, reaching 61, 59.77% and 59.53, 57.53% at the end of the storage period for Nubaria 1 and Giza 716 inside the 3 and 7-layer bags, respectively. The seeds' germination % decreased significantly (20%) after 24 months at the 3-layers compared with 13.12% at the 7-layer bags for Nubaria 1 with superior germination% of Giza 716 under the same conditions where the decrease in the percentage of germination reached 15.56% and 8.86% reduction for both 3 and 7 layers, respectively. The seedling vigor index exhibited the same trend of germination % with better results of the 7-layer bags for both cultivars. The moisture content (MC%) was substantially elevated by 1% at the end of the storage for both cultivars and bags. After 12 months, beans considerably increased color deterioration, with a loss of 43.16 and 53.60% for Giza 716 and Nubaria 1 stored in 3-layer bags, respectively; however, 7-layer bags were always better than 3-layer bags (with a loss of 32.56 and 45.56%). Furthermore, storage in 7-layer hermetic bags triggered a significant decrease (14.94%) in the total phenolic (TPC) after 24 months for Giza 716 without a substantial difference with Nubaria 1. Additionally, the simulation showed that after 18 months and 24 months of storage, the Nubaria 1 seeds packed in the 7-layer hermetic bags produced total tannins (TTC) 39.1% and 42.5%, respectively, more than those packed in the 3-layer hermetic bags. That TTC had a negative correlation with the testa's darkness. Taken together, the faba bean seeds could be stored for a long period in the 7-layer hermetic bags, preserving seed quality and expanding marketing prospects.