This study explored the mechanism of melon resistance toAlternaria alternata(A.alternata) infection in Jiashi and 86-1 melons. Melons were inoculated withA.alternataand the change in lesion diameter was measured. The changes in cinnamic acid-4-hydroxylase (C4H), phenylalanine ammonia lyase (PAL), and 4-coumaric acid coenzyme A ligase (4CL) activity and gene expression were studied in the pericarp tissues of Jiashi and 86-1 melons. The lesion diameter was smaller in Jiashi melon than in 86-1 melon, and the pericarp lesions were smaller than pulp lesions, indicating that Jiashi melon can resistA.alternatainfection better than 86-1 melon. After inoculation withA.alternata, the C4H, PAL, and 4CL activities of Jiashi and 86-1 melons peaked in the middle and late storage period, and the peak was higher in Jiashi melons. The gene expression changes were consistent with the enzyme activity. TheC4H,PAL, and4CLgene expression was significantly higher in Jiashi melon pericarp than in 86-1 melon, and the C4H, PAL, and 4CL activities in Jiashi melon were positively correlated with their gene expression, confirming the role of phenylpropanoid metabolism enzymes in resistance toA.alternata.

As a non-traditional sample matrix, feather samples can be used to effectively monitor antibiotic addition and organismal residue levels in poultry feeding. Therefore, an ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously determine the residue levels of 26 quinolones in poultry feathers. The feather samples were extracted by sonication with a 1% formic acid and acetonitrile mixture in a water bath at 50 °C for 30 min, purified by the adsorption of multiple matrix impurities, dried with nitrogen, redissolved, and analyzed by UPLC-MS/MS. The linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision were calculated. The 26 antibiotics demonstrated good linearity in the linear range. The recoveries and coefficients of variation were 78.9–110% and <13.7% at standard spiked levels of 10, 100 and 200 μg/kg, respectively. The LOD and LOQ were 0.12–1.31 and 0.96–2.60 μg/kg, respectively. The method also successfully identified quinolone residues in 50 poultry feather samples. The results showed that quinolones can accumulate and stabilize for a certain period of time after transferring from the body to the feathers of poultry.

Qamgur is a widely consumed vegetable and is also used in traditional medicine because of its extensive health benefits. White and yellow are the two main varieties. However, the mechanisms underlying quality development in these varieties, particularly in yellow Qamgur, remain unclear. This study compared nutritional and functional components throughout development. Total phenols and total isothiocyanates showed similar trends and levels in both varieties, whereas total free amino acids showed related but distinct patterns. Yellow Qamgur accumulated significantly higher levels of carotenoids. The integrated use of widely targeted and targeted metabolomics revealed stage-specific metabolites. White Qamgur showed stronger enrichment in secondary metabolite pathways, such as anthocyanin, flavonoid, steroid, terpenoid, and phenylpropanoid biosynthesis. In contrast, yellow Qamgur showed stronger enrichment in primary metabolic pathways, including amino acid biosynthesis. In addition, carotenoid biosynthesis may be the primary pathway responsible for the yellow coloration. Carotenoid profiling revealed that lycopene (28.94 mg/kg) was the predominant carotenoid in yellow Qamgur, followed by violaxanthin, γ-carotene, phytoene, β-cryptoxanthin laurate, and β-carotene.