制曲原料对低盐发酵鱼露性质的影响

Effects of Koji-materials on the Properties of Low-salt Fish Sauce

以大麦、大米、大豆为原料接种酱油曲(koji)对蓝圆鲹进行发酵制备低盐鱼露。结果发现,鱼露酱醅pH在发酵前期迅速下降,发酵20 d后趋于稳定,提高盐分含量可以使发酵酱醅pH更加稳定。当酱醅盐分含量为10%时,经过60 d发酵,大麦或大豆成曲发酵的鱼露其氨基酸态氮(AA-N)含量可以达到1.30 g/100 mL,但在15%的盐分含量下,无论是添加哪种成曲经过90 d发酵制备的鱼露其AA-N含量都低于1.10 g/100 mL。制曲原料对鱼露的可溶性总氮含量的影响与AA-N变化趋势类似。另一方面,酱醅盐分含量高时,鱼露产品挥发性盐基氮含量低,感官评价结果表明鱼腥味和胺味弱,但苦味游离氨基酸含量却出现上升。

The low-salt fish sauce was prepared from mackerel （decapterus maruadsi） using koji prepared from the materials of barley, rice or soybean, respectively. As a result, the pH of fish sauce mash decreased rapidly during the initial fermentation. It was followed by the stability after 20 days of fermentation and become more stable when increasing the salt content. When the salt content of fish sauce mash was 10 %, the amino-acid （AA-N） offish sauce could reach up to 1.30 g/100 mL after 60 days of fermentation using barley koji or soybean koji. When the salt content was increased to 15 %, the AA-N of fish sauce could not reach 1.10 g/100 mL irrespective of koji, although they had been fermented for 90 days. Similar trend was observed in the total soluble nitrogen of fish sauces fermented with koji. On the other hand, total volatile basic nitrogen content, fishy smell and ammonia odor was lower when fish sauce production fermented under higher salt concentration, while the content of bitter amino acids was increased significantly.