贮藏温度对鲜切胡萝卜品质及总酚和γ-氨基丁酸含量的影响

Effect of Storage Temperature on Quality and Total Phenolic and γ-Aminobutyric Acid Content in Fresh-Cut Carrot

研究了不同贮藏温度对鲜切胡萝卜品质及总酚、γ-氨基丁酸(γ-aminobutyric acid,GABA)含量的影响。将新鲜胡萝卜切丝后置于4、10℃和20℃下分别贮藏6、4、2 d。结果表明:在贮藏期间鲜切胡萝卜菌落总数、质量损失率、白度升高,而总胡萝卜素和抗坏血酸含量下降;与10、20℃相比,4℃低温贮藏能明显抑制鲜切胡萝卜菌落总数、质量损失率、白度的增加及总胡萝卜素、抗坏血酸含量的下降;鲜切胡萝卜在贮藏期间总酚、GABA含量及1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力增加,而苯丙氨酸解氨酶(L-phenylalanine ammonialyase,PAL)和谷氨酸脱羧酶(glutamate decarboxylase,GAD)活力则先上升后下降;与4℃和10℃相比,20℃条件下鲜切胡萝卜中总酚和GABA积累最多,DPPH自由基清除能力及PAL、GAD活力也最高。这些结果表明,传统的低温贮藏有利于保持鲜切胡萝卜的品质,而较高温度短期贮藏既能保证鲜切胡萝卜的品质和安全性,同时可促进酚类物质和GABA的合成积累,提高抗氧化活性和营养价值。

The effects of different storage temperatures on the quality and total phenolic and γ-aminobutyric acid (GABA) content of fresh-cut carrot were investigated. Fresh-cut carrots were cut into shreds and stored at 4, 10 and 20 ℃ for 6, 4 and 2 days, respectively. The results indicated that total bacterial count, mass loss rate and whiteness of fresh-cut carrot increased while total carotene and ascorbic acid content decreased during storage. Compared with storage at 10 and 20 ℃, low temperature storage at 4 ℃ significantly inhibited the increase of total bacterial count, mass loss rate and whiteness and the decrease of β-carotene and ascorbic acid contents. Moreover, total phenolic and GABA content as well as 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical scavenging activity increased steadily during storage, while L-phenylalanine ammonialyase (PAL) and glutamate decarboxylase (GAD) activity increased first and then decreased. Total phenolic and GABA content, DPPH radical scavenging capacity, and PAL and GAD activity were significantly higher when stored at 20 ℃ than at 4 and 10 ℃. These results indicated that conventional low temperature storage could maintain the quality of fresh-cut carrot, whereas storage at a higher temperature for a shorter period could promote the synthesis and accumulation of phenolic compounds and GABA while ensuring the quality and safety of fresh-cut carrot, thus enhancing the antioxidant activity and improving the nutritional value of fresh-cut carrot.