Differential Analysis of Nutritional Quality and Flavor Characteristics of Morchella esculenta from Different Regions of Gansu Province

To investigate the differences in nutritional quality and flavor characteristics among Morchella esculenta from four different regions (Qilihe and Gaolan, Lanzhou; Xihe and Chengxian, Longnan) in Gansu province, this study used ultraviolet (UV)-visible spectrophotometry, high performance liquid chromatography (HPLC) and inductively coupled plasma-mass spectrometry (ICP-MS) to quantify polysaccharides, polyphenols, vitamins and minerals. Free amino acids were determined using an amino acid analyzer and other non-volatile flavor substances such as soluble sugars, 5’-nucleotides and organic acids using HPLC. In total, 47 volatile aroma components (including alcohols, aldehydes and ketones) were analyzed qualitatively and quantitatively by gas chromatography-ion mobility spectrometry (GC-IMS), and principal component analysis and cluster analysis were used for differentiation and clustering of M. esculenta. The results showed that there were significant differences in the nutritional quality and flavor characteristics of M. esculenta from different regions of Gansu. The crude polysaccharide (20.48%) and total phenol (20.25 mg/g) contents of M. esculenta from Qilihe were significantly higher than those from the other regions. The soluble sugar (74.48 μg/g) and organic acid (58770.72 μg/g) contents of M. esculenta from Xihe were higher than those from the other regions, while the contents of vitamins (21044.01 μg/g), mineral elements (40392.52 mg/kg), amino acids (30318.78 mg/kg) and nucleotides (13561.98 μg/g) in M. esculenta from Chengxian were significantly higher than those of the other regions. Aldehydes, ketones and alcohols were the major aroma compounds of M. esculenta, 1-octen-3-one, 2-methylbutyraldehyde and ethyl 2-methylpentanoate being identified as the key aroma substances. The four production regions were clustered into three classes by principal component analysis (PCA) and cluster analysis: class Ⅰ, Qilihe and Gaolan, which have similar climates; class Ⅱ, Xihe and Chengxian, which share similar ecological environment; class Ⅲ, Gaolan, Xihe and Chengxian, which share similar soil characteristics. These results of this study provide a theoretical basis for expanding the planting area of M. esculenta.