Rebalancing Nutrients, Reinforcing Antioxidant and Osmoregulatory Capacity, and Improving Yield Quality in Drought-Stressed Phaseolus vulgaris by Foliar Application of a Bee-Honey Solution.

Bee-honey solution (BHS) is considered a plant growth multi-biostimulator because it is rich in osmoprotectants, antioxidants, vitamins, and mineral nutrients that can promote drought stress (DtS) resistance in common bean plants. As a novel strategy, BHS has been used in a few studies, which shows that the application of BHS can overcome the stress effects on plant productivity and can contribute significantly to bridging the gap between agricultural production and the steady increase in population under climate changes. Under sufficient watering (SW (100% of crop evapotranspiration; ETc) and DtS (60% of ETc)), the enhancing impacts of foliar application with BHS (0%, 0.5%, 1.0%, and 1.5%) on growth, productivity, yield quality, physiological-biochemical indices, antioxidative defense ingredients, and nutrient status were examined in common bean plants (cultivar Bronco). DtS considerably decreased growth and yield traits, green pod quality, and water use efficiency (WUE); however, application of BHS at all concentrations significantly increased all of these parameters under normal or DtS conditions. Membrane stability index, relative water content, nutrient contents, SPAD (chlorophyll content), and PSII efficiency (Fv/Fm, photochemical activity, and performance index) were markedly reduced under DtS; however, they increased significantly under normal or DtS conditions by foliar spraying of BHS at all concentrations. The negative impacts of DtS were due to increased oxidants [hydrogen peroxide (H2O2) and superoxide (O2•-)], electrolyte leakage (EL), and malondialdehyde (MDA). As a result, the activity of the antioxidant system (ascorbate peroxidase, glutathione reductase, catalase, superoxide dismutase, α-tocopherol, glutathione, and ascorbate) and levels of osmoprotectants (soluble protein, soluble sugars, glycine betaine, and proline) were increased. However, all BHS concentrations further increased osmoprotectant and antioxidant capacity, along with decreased MDA and EL under DtS. What is interesting in this study was that a BHS concentration of 1.0% gave the best results under SW, while a BHS concentration of 1.5% gave the best results under DtS. Therefore, a BHS concentration of 1.5% could be a viable strategy to mitigate the DtS impairment in common beans to achieve satisfactory growth, productivity, and green pod quality under DtS.

The Effect of Wall Material Type on the Encapsulation Efficiency and Oxidative Stability of Fish Oils.

Fish oil is the primary source of long-chain omega-3 fatty acids, which are important nutrients that assist in the prevention and treatment of heart disease and have many health benefits. It also contains vitamins that are lipid-soluble, such as vitamins A and D. This work aimed to determine how the wall material composition influenced the encapsulation efficiency and oxidative stability of omega fish oils in spray-dried microcapsules. In this study, mackerel, sardine waste oil, and sand smelt fish oil were encapsulated in three different wall materials (whey protein, gum Arabic (AG), and maltodextrin) by conventional spray-drying. The effect of the different wall materials on the encapsulation efficiency (EE), flowability, and oxidative stability of encapsulated oils during storage at 4 °C was investigated. All three encapsulating agents provided a highly protective effect against the oxidative deterioration of the encapsulated oils. Whey protein was found to be the most effective encapsulated agent comparing to gum Arabic and maltodextrin. The results indicated that whey protein recorded the highest encapsulation efficiency compared to the gum Arabic and maltodextrin in all encapsulated samples with EE of 71.71%, 68.61%, and 64.71% for sand smelt, mackerel, and sardine oil, respectively. Unencapsulated fish oil samples (control) recorded peroxide values (PV) of 33.19, 40.64, and 47.76 meq/kg oil for sand smelt, mackerel, and sardine oils after 35 days of storage, while all the encapsulated samples showed PV less than 10 in the same storage period. It could be concluded that all the encapsulating agents provided a protective effect to the encapsulated fish oil and elongated the shelf life of it comparing to the untreated oil sample (control). The results suggest that encapsulation of fish oil is beneficial for its oxidative stability and its uses in the production of functional foods.