Taste-Related Sugars, Organic Acids, and 5′-Nucleotides in 18 Pecan Varieties over Two Harvest Years

High Resolution Image Download MS PowerPoint Slide Pecan [ Carya illinoinensis (Wangenh.) K. Koch] is one of the most important nut crops owing to its rich nutritional composition and distinctive sensory attributes. Despite this, taste-related chemical components, such as soluble sugars, organic acids, and 5′-nucleotides, remain poorly characterized. Their variation among varieties and harvest seasons also remains largely unexplored. This study quantified three soluble sugars, four organic acids, and four previously reported 5′-nucleotides in 26 samples representing 18 cultivars, including seven common varieties, across two harvest years. Total sugars ranged from 1.57 to 5.60 g/100 g whole kernel, with sucrose (trace to 5.60 g/100 g) as the primary sugar and only a few varieties containing measurable amounts of fructose and glucose. Total organic acids ranged from 247.94 to 473.13 mg/100 g whole kernel, with citric acid (37.86–245.83 mg/100 g) identified as the major organic acid. The total 5′-nucleotides ranged from 16.49 to 49.68 mg/100 g whole kernel, with inosine monophosphate, an umami enhancer (5.00–20.66 mg/100 g), as the most abundant nucleotide. Significant variety effects were observed for all measured compounds, while harvest-year effects were significant for some but not all components, indicating that variety was the primary contributor of variability. These results provide the chemical basis needed to breed pecan varieties with improved taste attributes, benefiting both consumers and producers.