不同基质条件下食品防腐剂对冷藏河鲀鱼片腐败菌的抑菌差异

The Difference of Antimicrobial Activity of Food Preservatives on Spoilage Bacteria of Chilled Puffer Fish

为筛选冷藏红鳍东方鲀鱼片的复配保鲜剂,本文通过稀释平板法分离筛选冷藏河鲀鱼片感官腐败末期的腐败菌,利用16srDNA序列进行菌株鉴定,测定接种腐败菌后冷藏河鲀鱼片TVBN和TMA值衡量各腐败菌致腐能力;采用酶标比浊法测定山梨酸钾、尼泊金乙酯和乳酸链球菌素(Nisin)在培养基和河鲀鱼肉汁2种基质条件下对腐败菌的抑菌效果。结果表明:在冷藏红鳍东方鲀鱼片腐败末期分离获得4株腐败菌,分别为荧光假单胞菌、莓实假单胞菌、热杀索丝菌和乡间布丘氏菌,均有显著的致腐能力;随山梨酸钾溶液浓度的降低对腐败菌的抑菌活性显著下降,在鱼肉汁中的抑菌效果显著优于液体培养基条件;尼泊金乙酯溶液在不同基质下均能高效抑制4株腐败菌的生长繁殖;Nisin溶液仅对热杀索丝菌具有显著的抑菌效果,且抑菌活性易受基质的影响。不同防腐剂对冷藏河鲀鱼片腐败菌的抑菌活性排序为尼泊金乙酯>山梨酸钾>Nisin,尼泊金乙酯和山梨酸钾可成为冷藏河鲀鱼片的复配保鲜剂。

To select the food preservatives for puffer fish Tackifugu Rubripes during chilled storage, spoilage bacteria in chilled puffer fish were isolated and identified according 16S rDNA sequences. And the spoilage capabilities of spoilage bacteria were measured by TVBN and TMA value in the puffer fish inoculated by spoilage bacteria during chilled storage. Meantime, three kinds selected food preservatives such as potassium sorbate, ethyl hydroxybenzoate, and nisin were acted on the special spoilage organism under nutrition broth and fish juice. The results showed that the four kinds of spoilage organism isolated from the slice of puffer fish were Pseudomonas fluorescens, Pseudomonas fragi, Brochothrix thermosphacta, and Buttiauxella gaviniae. With the decreasing concentration, the antibacterial effects of potassium sorbate were significantly dropped, and had better antibacterial effect under fish juice. The ethyl hydroxybenzoate had inhibitory effect on all tested bacteria at different matrix. Nisin just had antibacterial effect to Brochothrix thermosphacta. And the antimicrobial activity of nisin was significantly affected by the different matrix. Therefore, the antibacterial effect of three kinds of preservatives could be ranked in decreasing order of antibacterial activity as follows: ethyl hydroxybenzoate > potassium sorbate > nisin. The ethyl hydroxybenzoate and potassium sorbate could be utilized as potential preservatives for chilled puffer fish.