To control Pseudomonas and Shewanella as important psychrotrophic spoilage bacteria in fish meat, we used ethanolic extracts of oregano (Origanum vulgare subsp. vulgare) and nettle (Urtica dioica), with phytochemical characterisation of the extracts and their bioactive compounds. Liquid chromatography coupled with photodiode array detection and electrospray ionisation–mass spectrometry was used for qualitative compositional determination of the extracts. Four main compounds were identified in the oregano extract, with rosmarinic acid the most abundant, followed by three glycosylated phenolics, one of which is reported for the first time in O. vulgare: 4′-O-β-d-glucopyranosyl-3′,4′-dihydroxybenzyl-4-hydroxybenzoate. Six main compounds were identified in the nettle extract, as caffeoylmalic acid and five flavonoid glycosides. These oregano and nettle ethanolic extracts showed in-vitro antimicrobial activities against selected Pseudomonas and Shewanella strains in broth and fish meat homogenate when evaluated at two inoculum concentrations. The antimicrobial activities were more pronounced for the nettle extract at the lower inoculum concentration, and for both the Shewanella strains. Growth inhibition in the fish meat homogenate was evaluated at 3.13 mg/mL and 1.56 mg/mL at 5 °C. Again, the nettle extract showed greater antimicrobial activity, which was seen as the lowest maximum growth rate, followed by the oregano extract, which was inhibitory only at 3.13 mg/mL. Finally, the extracts were applied to fish meat that was then stored at 5 °C for 9 days. Evaluation here was for the counts of the mesophilic, psychrotrophic, Pseudomonas and H₂S producers. These confirmed the better antimicrobial effects of the nettle extract, especially against the H₂S-producing bacteria, which included Shewanella. Both of the extracts were rich in glycosides of flavonoids and phenolic acids. The enzymatic activities of the Pseudomonas and Shewanella spoilage bacteria and their actions on the phenolic glycosides from natural sources will be further investigated.

为了控制假单胞菌和希瓦氏菌，如鱼肉重要的嗜冷腐败菌，我们用牛至的乙醇提取物（牛至亚种大麦），荨麻（荨麻），与提取物及其生物活性化合物的植物化学表征。液相色谱结合光电二极管阵列检测和电喷雾电离质谱用于定性提取物的成分测定。牛至提取物中鉴定出四种主要化合物，其中迷迭香酸含量最高，其次是三种糖基化酚类化合物，其中一种是首次报道于普通大麦中：4′-O-β- d-吡喃葡萄糖基-3'，4'-二羟基苄基-4-羟基苯甲酸酯。在荨麻提取物中鉴定出六个主要化合物，即咖啡酰苹果酸和五个类黄酮苷。这些牛至和荨麻乙醇提取物在两种接种物浓度下评估时，对肉汤和鱼肉匀浆中的选定的假单胞菌和希瓦氏菌菌株显示出体外抗菌活性。在较低接种浓度下，荨麻提取物和希瓦氏菌的抗菌活性均更为显着。株。在5°C下，鱼肉匀浆的生长抑制评估为3.13 mg / mL和1.56 mg / mL。同样，荨麻提取物显示出更高的抗菌活性，这被认为是最低的最大生长速率，其次是牛至提取物，其仅在3.13 mg / mL时具有抑制作用。最后，将提取物应用于鱼肉，然后将其在5°C下保存9天。这里的评估是嗜温，精神营养，假单胞菌和H ₂ S产生者的计数。这些证实了荨麻提取物具有更好的抗微生物作用，尤其是对产生H ₂ S的细菌，包括希瓦氏菌。两种提取物均富含类黄酮和酚酸的糖苷。假单胞菌和希瓦氏菌变质细菌的酶活性及其对天然来源酚类糖苷的作用将得到进一步研究。