不同加工方式对羊肚菌水提液鲜味及抗氧化性能的影响

本文研究了热加工（70、90 ℃）和非热加工（室温、超声、均质和超高压）对不同粒径羊肚菌水提液鲜味成分及抗氧化性能的影响，为羊肚菌的精深加工提供参考。采用高效液相色谱和氨基酸分析仪分别检测了提取液中5’-核苷酸（5’-CMP、5’-UMP、5’-XMP、5’-GMP、5’-IMP和5’-AMP）和游离氨基酸（17种）的含量，并计算、对比各加工条件下羊肚菌的等鲜度（EUC）。通过三种抗氧化法（DPPH、FRAP和ABTS）综合评价各提取液的抗氧化性能。结果表明，除室温处理外，其它处理下，超微粉碎（P2或P3，菌粉粒径分别为35.52和6.28 μm）不同程度地提升羊肚菌水提液中5’-核苷酸含量，但降低了提取液中呈鲜味氨基酸和总游离氨基酸（FAA）含量，使得菌粉的EUC值从106.58 g MSG/100 g~493.97 g MSG/100 g降低至74.70 g MSG/100 g~364.35 g MSG/100 g。相比室温处理，其它处理均能提高羊肚菌水提液的EUC值，但热处理降低了提取液的抗氧化性能，非热处理中HHP（超高压处理）能够取得最优的EUC值和理想的抗氧化效果，其中，未经超微粉碎的菌粉经HHP处理后具有最高EUC值和抗氧化能力，适用于羊肚菌水提液的精深加工。

Effects of Different Processing Methods on Umami Taste and Antioxidant Capability of Water Extracts of Morchella esculenta

This study was aimed to compare the effects of thermal treatment (70, 90 ℃) and non-thermal treatment (room temperature, ultrasound treatment, homogenization and high hydrostatic pressure) on the umami taste and antioxidant capability of water extracts of Morchella esculenta. The content of 5’-nucleotide (5’-CMP, 5’-UMP, 5’-XMP, 5’-GMP, 5’-IMP and 5’-AMP) and free amino acid (17 kinds) in these extracts were analyzed by high performance liquid chromatography and amino acid analyzer respectively, and their corresponding value of Equivalent Umami Concentration (EUC) were calculated. Antioxidant properties of each water extract of Morchella esculenta were comprehensively evaluated by DPPH, FRAP and ABTS methods. Except for the treatment of RT (room temperature), other treatment on finely pulverized Morchella esculenta powder (P2 or P3, 35.52 and 6.28 μm, respectively) increased the contents of total 5'-nucleotides while decreased the contents of umami amino acids and total free amino acids (FAA) in their corresponding water extract. Therefore, the EUC values of the Morchella esculenta extracts were changed from 106.58 g MSG/100 g~493.97 g MSG/100 g to 74.70 g MSG/100 g~364.35 g MSG/100 g. Compared with the room temperature treatment, other treatments improved the EUC value of the water extracts. However, thermal treatment decreased the antioxidant capacity of the extract, and non-thermal treatment of HHP displayed the highest EUC value and ideal antioxidant effect. Especially, the original Morchella esculenta powder without superfine grinding had the highest EUC value and the best antioxidant capacity after HHP treatment, which might be suitable for the further processing of Morchella esculenta.