Investigating sensory characteristics and flavor profiles of ten cucumber cultivars using descriptive and sensory instrumental analysis

This study aimed to assess selected cucumber sensory characteristics using quantitative descriptive analysis (QDA) and link with instrumental analysis of volatile aroma and non-volatile taste compounds. QDA, using a trained panel (n=10), identified and quantified 14 flavor descriptors for 10 cucumber cultivars. SPME-GC-MS was used to identify 145 volatiles in both the flesh and peel. Sugars (glucose, fructose, sucrose) and acids (citric acid, fumaric acid, malic acid) in the flesh and peel were quantified using HPLC. Amino acids were quantified with GC-MS for 26 amino acids and HPLC for citrulline and arginine. Key sensory attributes for cucumber included fresh, green, cucumber-like, crispy, sweetness, and juiciness, with significant differences (p≤0.05) in fresh, bitter, and crispy between 10 cultivars. UW05 and UW06 possessed high cucumber-like, fresh, and sweet notes, while UW02 and UW08 had high melon, waxy, umami, and juicy notes. UW10 and UW07 were most crispy, while UW01 was bitter, sour, and salty. Major identified volatiles were C6 and C9 compounds. Flesh possessed the highest amount of total volatiles, compared to peel. UW10 had the highest total volatiles and C6 compounds, while UW08 had the highest C9 compounds. For acid and sugar contents, flesh and peel were similar, while each cultivar varied significantly from one another. UW01 was the highest in citric and malic acid, while UW03 had the highest concentration for all sugars. Major amino acids found in both flesh and peel included glutamine (sweet), arginine (bitter), serine (sweet), and citrulline. UW08 contained a high level of umami and sweet amino acids -- glutamate, aspartate, proline, leucine, and serine. UW01 contained a high amount of sweet and bitter taste-related amino acids -- glycine, alanine, threonine, and valine. Overall, UW01, UW03, UW06, UW08, and UW10 had significantly high values for a combination of sensory and flavor chemical composition. This study identified the underlying flavor chemicals that impact cucumber sensory characteristics, which could assist the development of cucumber varieties with a high market value.