Changes in the activities of antimicrobial, antitumor, and antioxidant properties of postbiotics (YCG) are related to changes in the composition of phenolic compounds. Antimicrobial activity was found to be highest in postbiotic (YCG-7) against P. aeruginosa, S. aureus, and E. faecalis with an MIC of 3.1 µg/mL. YCG-7 revealed the most cytotoxicity against LS-174T and PC-3 cell lines with an IC₅₀ of 5.78 and 6.56 µg/mL, respectively. YCG-7 was far more effective for scavenging free radicals in the NO^• and DPPH assays with a scavenging activity of 70.73% and 85.6%, respectively. YCG-7’s total phenolic acid content is up to eightfold higher compared with control. Escherichia coli Nissle 1917 retained high viable counts during refrigerated storage, particularly in YCG (>10⁸ cells g⁻¹) revealing a potential prebiotic activity of Cape gooseberry juice. EcN affected the phenolic profile of the YCG. Pyrogallol, p-coumaric acid, ellagic acid, 4-hydroxybenzoic acid, salicylic acid, gallic acid, vanillic acid, o-coumaric acid, caffeic acid, catechol, syringic acid, and rutin were the predominant phenolic compounds in YCG-7 or YCG-15. Chlorogenic, rosmarinic, cinnamic acid, naringin, and kaempferol were degraded by EcN in YCG-7 and YCG-15. The YCG had significantly higher sensory scores for appearance, smoothness, sourness, mouthfeel, and overall acceptance. These results provide the basis to target the functional benefits of YCG for further human health applications.

Aims The present study evaluated, for the first time, the inhibitory effects of the filtrate of Purpureocillium lilacinum against Penicillium digitatum. Methods and Results No direct contact between P. lilacinum and P. digitatum was observed during the dual culture test and the inhibition zone was 6·1 mm. The filtrate of P. lilacinum completely inhibited P. digitatum growth and spore germination at the concentration of 64%. The filtrate increased the permeability of the cell membrane and the content of MDA in P. digitatum. The ergosterol content in P. digitatum was strongly inhibited at 32% by 81·1%. The green mould incidence and severity in filtrate‐treated fruit at 64% were 71·7 and 80·7% lower than in the control, respectively. The filtrate enhanced the activity of PAL, PPO and POD enzymes in orange fruit. The POD and PAL gene expression levels were significantly upregulated in the fruit treated with the filtrate. Conclusions This study indicated that the antifungal mechanism of P. lilacinum filtrate against P. digitatum is mainly by the damage of the fungal cell membrane and its components. Significance and Impact of the Study This work provides the pioneer evidence on the application of P. lilacinum filtrate as a novel biocontrol agent for orange green mould.

Peaches are grown in many Egyptian orchards for local and global fresh market sales. The interior fruit tissue breakdown (IFTB), often resulting in decayed peaches, is a severe problem during marketing. Therefore, to minimize FTB of peaches, in this study, gum arabic (GA) and polyvinylpyrrolidone (PVP) were mixed with different concentrations of salicylic acid (SA) (0, 1, and 2 mM) and were applied as edible coating to extend the shelf life of peach fruits. Mature peaches were selected and harvested when peaches reached total soluble solid content (SSC: 8.5%) and fruit firmness of about 47 N. Fruits were coated and stored at room temperature (26 ± 1 °C and air humidity 51 ± 1%) for 10 days during two seasons: 2020 and 2021. Fruit coated with GA/PVP-SA 2 mM showed a significant (p < 0.05) inhibition in degrading enzyme activities (CWDEs), such as lipoxygenase (LOX), cellulase (CEL), and pectinase (PT), compared to uncoated and coated fruits during the shelf-life period. Hence, cell wall compartments were maintained. Consequently, there was a reduction in browning symptoms in fruits by inhibiting polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) activities. Thus, the fruit skin browning index showed almost no symptoms. The lipid peroxidation process and ionic permeability declined as well. The result suggests that, by applying GA/PVP-SA 2 mM as an edible coating, fruit tissue breakdown can be minimized, and the shelf life of peach can be extended up to 10 days without symptoms of tissue breakdown.