传统毛霉型豆豉中苯甲酸形成机理的研究  

Benzoic Acid Formation Mechanism in Traditional Fermented Douchi

作　　者：沈祥森[1,2] 阚建全[1,2] 冯铄涵[1,2] 李帅[1,2] 谢德芳 曾凡玉 

机构地区：[1]西南大学食品科学学院,重庆400715 [2]重庆市农产品加工及贮藏重点实验室,重庆400715 [3]永川豆豉食品有限公司,重庆402160

出　　处：《食品科学》2013年第1期150-154,共5页Food Science

摘　　要：通过高效液相色谱(HPLC)方法分析测定传统毛霉型豆豉在不同发酵时期的苯甲酸、苯丙氨酸和β-苯丙烯酸(肉桂酸)的含量以及苯丙氨酸解氨酶酶活性的变化趋势,以研究苯甲酸在传统毛霉型豆豉的发酵生产中的形成机理,揭示传统毛霉型豆豉中苯甲酸在非人为添加情况下自然存在的原因。结果表明:在制曲2d(S3)时,苯甲酸含量为2.43mg/kg,随后其含量不断增加,到后发酵215d(S14)时,达到37.23mg/kg;而苯丙氨酸含量也由原料大豆的4.89mg/100g增加到了S14(后发酵第215天)中的272.23mg/100g;中间产物β-苯丙烯酸在制曲阶段含量较高,在后发酵阶段逐渐减少,并且其在制曲阶段含量较大时苯甲酸增加趋势明显,在后发酵阶段含量较小时苯甲酸含量增加趋势不明显;同时催化苯丙氨酸转化为β-苯丙烯酸(肉桂酸)这一反应的苯丙氨酸解氨酶(PAL)酶活性在制曲阶段较强,在后发酵阶段逐渐减弱。在后发酵阶段人为添加β-苯丙烯酸后通过动态检测得出苯甲酸、β-苯丙烯酸含量呈现一升一降的结果。因此可以得出,传统毛霉型豆豉中苯甲酸形成的机理可能为:大豆中的蛋白质首先部分水解为氨基酸,其中的苯丙氨酸在PAL的催化下转变为β-苯丙烯酸,β-苯丙烯酸在一定条件下最终氧化形成苯甲酸。To explore the mechanism of benzoic acid formation during production of traditional fermented douchi and discover the reason for natural existence of benzoic acid without adding it, changes in the contents of benzoic acid, phenylalanine and fl-cinnamic acid and phenylalanine ammonia lyase （PAL） activity were determined by HPLC at different stages of fermentation. After 2 days of incubation, the benzoic acid content of the koji was 2.43 mg/kg and then gradually increased with increasing incubation time, reaching 37.23 mg/kg after 215 days of post-fermentation. Similarly, the phenylalanine content of the starting raw material （soybean） was 4.89 mg/100 g and increased to 272.23 mg/100 g after 215 days of post-fermentation, fl-cinnamic acid showed a high level during the koji making stage, resulting in an obvious increase in benzoic acid level, but gradually declined during the post-fermentation stage, without considerably increasing benzoic acid level. Moreover, the PAL activity, which catalyzes the transformation of phenylalanine into fl-cinnamic acid, was stronger during the koji making stage, but gradually became weaker during the post-fermentation stage. The contents of benzoic acid and fl-cinnamic acid increased and decreased, respectively, due to addition of β-cinnamic acid during the post-fermentation stage. Hence, we conclude that the mechanism of benzoic acid formation during production of traditional fermented douchi may partial hydrolysis of proteins into peptides in the staring raw material, subsequent PAL-catalyzed transformation of phenylalanine into β-cinnamic acid and final oxidization of β-cinnamic acid into benzoic acid under required conditions.

关 键 词：传统毛霉型豆豉 苯甲酸 苯丙氨酸 β-苯丙烯酸 苯丙氨酸解氨酶 形成机理 

分 类 号：TS201.3[轻工技术与工程—食品科学]