The by-product of sesame seed coats from the tahini industry was used for the extraction of bioactive compounds as novel antioxidants. This study was designed to evaluate the effect of a natural antioxidant on the quality of refined olive oil (ROO) stored at 60 ± 1 °C for up to 48 days. The lyophilized sesame seed coats extract (LSSCE) was placed into fresh ROO at three levels, i.e., 200, 400, and 600 mg kg⁻¹, and compared with 200 mg kg⁻¹ BHT (reference) and without antioxidant (control). LSSCE exhibited high phenolic (105.9 mg GAE g⁻¹) and lignin (6.3 mg g⁻¹) contents as well as antioxidant activity based on HPLC/DAD. In ROO samples, Including LSSCE, the values of peroxide, p-anisidine, K₂₃₂, and K₂₇₀ were remarkably lower than control during storage. The kinetic rate constant (k) of oxidation indicators was the lowest in ROO samples containing BHT and LSSCE 600 mg kg⁻¹compared with other treatments. LSSCE improved the organoleptic acceptability of ROO samples up to 48 days of storage. Moreover, the shelf life (assuming a Q₁₀ value of 2.0 for lipid oxidation) of ROO treated with LSSCE was increased. The findings revealed that LSSCE is a promising natural antioxidant in delaying oxidation, enhancing oil stability, and prolonging the shelf life (~475 days at ambient temperature).

The purpose of this research was to assess and utilize the bioactive compounds of garlic nanoparticles (Ga-NPs) as a natural antioxidant in sunflower oil (SFO) stored at 65 ± 1 °C for 24 days. The garlic nanoparticles (Ga-NPs) from the Balady cultivar were prepared, characterized, and added to SFO at three concentrations: 200, 600, and 1000 ppm (w/v), and they were compared with 600 ppm garlic lyophilized powder extract (Ga-LPE), 200 ppm BHT, 200 ppm α-tocopherol, and SFO without Ga-NPs (control). The QTRAP LC/MS/MS profile of Ga-NPs revealed the presence of four organosulfur compounds. Ga-NPs exhibited the highest capacity for phenolic, flavonoid, and antioxidant compounds. In Ga-NP SFO samples, the values of peroxide, p-anisidine, totox, conjugated dienes, and conjugated trienes were significantly lower than the control. The antioxidant indices of SFO samples containing Ga-NPs were higher than the control. The Ga-NPs enhanced the sensory acceptability of SFO treatments up to day 24 of storage. The shelf life of SFO treated with Ga-NPs was substantially increased (presuming a Q₁₀ amount). The results show that Ga-NPs are a powerful antioxidant that improves SFO stability and extends the shelf life (~384 days at 25 °C).

Our investigation aimed to evaluate the efficacy of applying Boric, Ascorbic and Oxalic acids as foliar treatments on two strawberry cultivars, i.e., Fortuna and Sensation, during field growth, on controlling gray mold in post-harvest stage. In vitro experiment revealed that all the tested acids were found to have direct fungicidal effect on B. cinerea growth. Oxalic acid was the most effective causing total inhibition to the fungal growth. The disease severity on strawberry fruits stored at 0±1°C for 21 days was significantly reduced in all treatments of acids on both tested cultivars. However, Boric acid (40 mM) was, in general, the most effective treatment in reducing disease severity followed by Ascorbic acid (40 mM), especially for artificially inoculated strawberry fruits, while Oxalic acid and Ascorbic acid were the least efficient in reducing disease severity at the lower concentration. The effect of different acid treatments on the activity of oxidative enzymes revealed a correlation between the reduction in disease severity and increase in enzymes activity of polyphenoloxidase (PPO) and peroxidase (POX). However, there was no consistency in the activity of catalase (CAT) in correlation with disease severity. The total phenols concentrations in fruits were significantly increased with all treatments. The free radical scavenging activity analysis in fruits showed a high correlation between the total phenols concentrations and antioxidants scavenging activities in both tested cultivars. The overall conclusion is that the acids under investigation induced a resistance against B. cinerea in fruits during storage and significantly suppressed gray mold severity.