Pungency and fruit quality in Mexican landraces of Piquin pepper (Capsicum annuum var. glabriusculum) as affected by plant growth environment and postharvest handling

Deisy D. Díaz-Sánchez1, Pedro A. López2, Higinio López-Sánchez2, Hilda V. Silva-Rojas1, Alfonso A. Gardea-Béjar3, Nicacio Cruz-Huerta1, Iván Ramírez-Ramírez1, and Víctor A. González-Hernández1*
The variability in fruit pungency, size and quality was analyzed in 31 landraces of piquín pepper (Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill) collected from 10 Mexican states. The response of fruits collected in situ and harvested in greenhouse was compared. Pungency was estimated by measuring capsaicinoids content with HPLC. Additionally, pungency was recorded along fruit maturity stages in greenhouse-grown fruits. On average, greenhouse- produced fruits were markedly more pungent than fruit collected from field locations (29 485 vs. 6114 SHU). Field-collected fruits averaged 5017 μg mL-1 capsaicin content, while dihydrocapsaicin averaged 7618 μg mL-1. In contrast, greenhouse-harvested fruits contained substantially more capsaicin and dihydrocapsaicin (34 762 and 26 174 μg mL-1, respectively), while the capsaicin:dihydrocapsaicin ratio inverted. The three most pungent field-collected landraces averaged 35% of the pungency measured in the three most pungent greenhouse-grown fruits. Pungency increased as maturity stage advanced:green (14813 SHU) < intermediate (24767 SHU) < red (29485 SHU). The fruits collected from 31 field locations had lower titratable acidity, higher content of total soluble solids, and higher maturity index than fruits harvested in greenhouse. Greenhouse harvested fruits were larger and heavier than those collected in the field.
Keywords: Capsaicinoids, fruit quality, fruit size, landraces, maturity stages, piquín pepper, pungency.
1Colegio de Postgraduados, Campus Montecillo, Carr. México-Texcoco km 36.5, Montecillo 56230, Texcoco, Estado de México, México.*Corresponding author (vagh@colpos.mx).2Colegio de Postgraduados, Campus Puebla, Carr. Federal México-Puebla km 125.5, Santiago Momoxpan 72760, Puebla, México.3Centro de Investigación y Desarrollo, A.C. (CIAD), Carr. Gustavo E. Astiazarán Rosas N° 46, CP 83304, Hermosillo, Sonora, México.