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.

Monitoring Stimulated Darkening from UV-C Light on Different Bean Genotypes by NMR Spectroscopy

The use of UV-C cool white light on bean (Phaseolus vulgaris L.) seeds significantly increases the biochemical seed coat post-harvest darkening process, whilst preserving seed germination. The aim of this work consists in monitoring the effect caused by the incidence of UV-C light on different bean genotypes using NMR spectroscopy. The genotype samples named IAC Alvorada; TAA Dama; BRS Estilo and BRS Pérola from the Agronomic Institute (IAC; Campinas; SP; Brazil) were evaluated. The following two methodologies were used: a prolonged darkening, in which the grain is placed in a room at a controlled temperature (298 K) and humidity for 90 days, simulating the supermarket shelf; an accelerated darkening, where the grains are exposed to UV-C light (254 nm) for 96 h. The experiments were performed using the following innovative time-domain (TD) NMR approaches: the RK-ROSE pulse sequence; one- and two-dimensional high resolution (HR) NMR experiments (¹H; ¹H-¹H COSY and ¹H-¹³C HSQC); chemometrics tools, such as PLS-DA and heat plots. The results suggest that the observed darkening occurs on the tegument after prolonged (90 days) and accelerated (96 h) conditions. In addition, the results indicate that phenylalanine is the relevant metabolite within this context, being able to participate in the chemical reactions accounted for by the darkening processes. Additionally, it is possible to confirm that a UV-C lamp accelerates oxidative enzymatic reactions and that the NMR methods used were a trustworthy approach to monitor and understand the darkening in bean seeds at metabolite level.

Six months under uncontrolled relative humidity and room temperature changes technological characteristics and maintains the physicochemical and functional properties of carioca beans (Phaseolus vulgaris L.)

Carioca beans contribute to health maintenance around the world, and the evaluation of commercial postharvest storage (CPS) ensures their quality. This study aimed to evaluate the effect of CPS on technological, physicochemical and functional properties of carioca beans. Two genotypes (Pontal-PO and Madreperola-MP beans) were stored under CPS or controlled conditions and were evaluated after harvest and after three- and six-months storage. PO and MP hardened with time, but the cooking time did not differ. PO is darker than MP and both darkened over time. Storage time affected pH and acidity of the beans and MP presented better physicochemical properties than PO, with lower activity of peroxidase (p = 0.004) and polyphenoloxidase (p = 0.001) enzymes. Glycosylated kaempferol was suggested as a possible chemical marker to differentiate the aging of PO and MP beans. In conclusion, besides the technological differences, the storage was able to prevent physicochemical and functional alterations of beans.