Pumpkin (Cucurbita spp.) seeds; wild versus domesticated triglycerides chromatographic profiling analysis

Abstract

Introduction: Triglycerides (TG) represent 98 % of the vegetable oils composition. The evaluation of TG in pumpkin seed extracts is valuable to perceive effects caused by domestication. Objective: To compare the triglyceride profile of wild versus domesticated pumpkins by reversed-phase HPTLC. Materials and methods: Wild pumpkins (Cucurbita foetidissima Kunth and C. radicans Naudin) seeds were collected at mature stage at three sites of the Mexican Plateau and seeds of domesticated pumpkins (C. pepo L., C. moschata Duchesne, C. argyrosperma K. Koch) and sunflower (Helianthus annuus L.) were acquired. Ground seeds were Soxhlet extracted with hexane to obtain the lipids. From the neutral lipid extract, TG were separated on 20 x 10 HPTLC Silica Gel 60 glass plates. Unsaturated TG were used as reference. The bands, in different tracks, were analyzed with the free-to-use GelAnalyzer software. Results and discussion: The TG profile of both wild and domesticated pumpkin seed extract shows similarity among their most abundant bands. In both samples, TG 18:2/18:2/18:2 predominates. In wild pumpkins, TG 18:3/18:3/18:3 bands stand out. Domesticated pumpkins have lower TG with higher unsaturation chain, than wild species, which gives them a greater nutritional value. Conclusions: Wild pumpkin seeds show a characteristic profile of unsaturated TG. Chromatographic profiling and image analysis with GelAnalyzer led to the sample’s differentiation based on the bands found.