This study explored the mechanism of melon resistance to Alternaria alternata (A. alternata) infection in Jiashi and 86-1 melons. Melons were inoculated with A.alternata and 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 resist A. alternata infection better than 86-1 melon. After inoculation with A. 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. The C4H, PAL, and 4CL gene 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 to A. 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.

The purpose of this paper is to determine the phytochemical composition and evaluate the nutritional value of qamgur (Brassica rapa L., a characteristic crop in Xinjiang). The fresh qamgur was processed with hot air drying and freeze drying and then sliced into FD qamgur slices and ground into qamgur powders. The results show that qamgur powders and FD qamgur slices are rich in the nutrients essential for human health, such as total sugar (41.4 and 44.8 g/100 g), polysaccharide (16.3 × 10 3 and 20.4 × 10 3 g/100 g), Vitamin C (39.3 and 46.5 g/100 g), flavonoids (45.0 and 33.0 g/100 g) and total saponins (46.0 and 30.0 g/100 g) compared with the fresh qamgur. Moreover, major elements and micro elements analysis were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the results showed that an abundant number of mineral elements (e.g. K, Na, Ca, Mg, Cu, Fe, Zn and Mn) were found in qamgur. The content of Ca was 4.5×10 3 mg/kg, 15.7 mg/kg for Zn, and 81.1 mg/kg for Fe. Similarly, the highest protein value was observed in the qamgur powders (12.4 g/100 g), whereas the fresh samples contained only 2.78 g/100 g. In addition, the proportion of essential amino acids (EAA) and nonessential amino acids (NEAA) of the powders were 59.7% and 40.3%, whereas for the FD slices, they were 61.0% and 39.0%. Overall, the nutritional value of qamgur was significantly improved through processing. So, in this paper, we provide the theoretical basis for the study on the nutritional value of qamgur and the development of medicinal foods and functional foods.