菱角壳黄酮提取物抑菌活性评价及对冷鲜鸭肉中假单胞菌生长特性的影响

为探究菱角壳黄酮提取物的抑菌能力及其对冷鲜鸭肉中假单胞菌生长特性的影响,采用抑菌圈法、MIC值测定和液体中生长曲线来评价其对食品中常见微生物生长的抑制作用,建立假单胞菌经浓度为2.5 mg/mL的黄酮纯化物处理后的鸭肉基质中的一级生长预测模型。结果表明:菱角壳黄酮提取物对假单胞菌、金黄色葡萄球菌有明显的抑制作用,其中黄酮纯化物对假单胞菌和金黄色葡萄球菌的抑菌效果更好,抑菌圈直径分别为(47.01±0.43)、(45.06±0.35) mm;菱角壳黄酮提取物对热杀索丝菌有一定的抑制效果,对大肠杆菌、乳酸菌和酵母菌无抑菌效果。菱角壳黄酮粗提物和纯化物对假单胞菌的MIC值均为3.125 mg/mL,对金黄色葡萄球菌的MIC值分别为12.000和3.125 mg/mL。采用对供试菌抑菌效果最好的菱角壳黄酮纯化物浓度(2.5 mg/mL)处理鸭肉,在不同温度下储藏,发现与10、15和20 ℃相比,0和5 ℃可将冷鲜鸭肉的货架期延长至8 d以上,并且通过建立假单胞菌在经浓度为2.5 mg/mL的菱角壳黄酮纯化物处理后的鸭肉基质中的一级模型可知,在0~15 ℃储藏时,菱角壳黄酮提取物作为保鲜剂的抑菌效果较好,能够有效延长食品保质期,但随温度升高,其抑菌能力逐渐减弱,这为菱角壳开发为天然抑菌剂提供了理论基础。

Evaluation of Antibacterial Activity of Flavonoid Extracts from Trapa bispinosa Roxb Shell and Its Effect on Growth Characteristics of Pseudomonas in Duck Meat

The research was designed to investigate the antibacterial ability of the flavonoid extract of Trapa bispinosa Roxb shell and its effect on growth characteristics of Pseudomonas in duck meat. Inhibition of six common microbial growth in foods was evaluated by inhibition zone method,MIC value determination and liquid growth curve. A first-order growth prediction model of Pseudomonas in the duck meat matrix treated with a concentration of 2.5 mg/mL of flavonoids was established. The results showed that the flavonoid extract of Trapa bispinosa Roxb shell had obvious inhibitory effects on Pseudomonas and Staphylococcus aureus. The purified flavonoids had better antibacterial activity against Pseudomonas and Staphylococcus aureus and the inhibition zone diameters were(47.01±0.43)and(45.06±0.35)mm. The flavonoid extract of Trapa bispinosa Roxb shell had a certain inhibitory effect on Brochothrix Thermosphacta,and had no bacteriostatic effect on Escherichia coli,lactic acid bacteria and Saccharomyce. The MIC values of crude extracts and purified extracts of flavonoid were 3.125 mg/mL for Pseudomonas,and the MIC values for S. aureus were 12.000 and 3.125 mg/mL. The duck meat was stored at different temperatures after treatment with the purified porphyrin flavonoids(2.5 mg/mL)which had the best antibacterial effect on the test bacteria. It was found that compared with the high temperature group(10,15 and 20 ℃),the low temperature group(0 and 5 ℃)could extend the shelf life of chilled duck meat to more than 8 days. From the first-level model of the duck meat matrix treated with the purified P. monocytogenes treated with 2.5 mg/mL of flavonoids,the extract of the water chestnut shell as a preservative had better antibacterial effect and could effectively prolong the shelf life of the food when it was stored at 0~15 ℃. However,the antibacterial ability of the purified flavonoids of Trapa bispinosa Roxb shell gradually weakened with the increase of temperature. The experimental results provided a theoretical basis for the development of Trapa bispinosa Roxb shell as a natural bacteriostatic agent.