Abstract：
This study aims to detect Clostridium botulinum and its control using natural leaf extracts of Citrus limon, Citrus sinensis, and Citrus unshiu in Egyptian fish products, e.g., canned tuna, canned sardine, canned mackerel, fesikh, moloha, and renga, as well the application of C. limon in tuna. Moreover, the antibacterial activity of the C. limon leaf extract was also estimated. In the water extract, ascorbic acid, total flavonoid content (TFC), and total phenolic content (TPC) were determined by volumetric, aluminum chloride, and Folin-Ciocalteu approaches, respectively. The antioxidant ability of the extract was analyzed in vitro via free radical scavenging (DPPH) and Ferric reducing assays. The results showed variability in the distribution of the total number of positive C. botulinum in fish samples from three different governorates under study, which were (24) Alexandria, (16) Beheira, and (17) Gharbia, out of the 120 tested samples in each governorate. Additionally, the findings revealed that all three Citrus extracts contain an appropriate number of secondary metabolites, with a sustainable presence of saponin and tannins in the C. limon extract. Furthermore, all Citrus extracts inhibited bacterial growth by increasing the inhibition zone, with C. limon being the best extract (25 mm) compared to C. sinensis and C. unshiu. The overall results showed the high antioxidant and anti-Clostridium powers (p < 0.05) of C. limon leaf extract, indicating its preservative activity in fishery products during storage. Finally, C. limon leaf extract can fight off C. botulinum and is considered a promising natural preservation candidate in ensuring safe and fresh fishery products.
摘要：
本研究旨在使用柑橘的天然叶提取物检测肉毒梭菌及其控制，柑橘,和埃及鱼产品中的柑橘，例如，金枪鱼罐头,沙丁鱼罐头,鲭鱼罐头,fesikh,莫洛哈,还有Renga,以及C.limon在金枪鱼中的应用。此外，还估计了C.limon叶提取物的抗菌活性。在水提取物中，抗坏血酸,总黄酮含量（TFC），和总酚含量(TPC)通过体积测定，氯化铝,和Folin-Ciocalteu接近，分别。通过自由基清除（DPPH）和铁还原试验在体外分析提取物的抗氧化能力。结果表明，来自三个不同省份的鱼类样本中阳性肉毒杆菌总数的分布存在差异。这是（24）亚历山大，（16）贝海拉，和（17）Gharbia，在每个省的120个测试样本中。此外,研究结果表明，所有三种柑橘提取物都含有适当数量的次生代谢产物，在C.limon提取物中持续存在皂苷和单宁。此外，所有柑橘提取物都通过增加抑制区抑制细菌生长，与C.sinensis和C.unshiu相比，C.limon是最好的提取物（25毫米）。总体结果显示C.limon叶提取物的高抗氧化和抗梭菌能力（p<0.05），表明其在储存过程中在渔业产品中的防腐活性。最后,C.limon叶提取物可以抵抗肉毒杆菌，被认为是确保安全和新鲜渔业产品的有前途的天然保存候选物。
