Nutritional Composition of the Hehu Field Snail Cipangopaludina hehuensis: A Comparison of Open-Air and Greenhouse Paddy Culture Systems

The Hehu field snail (Cipangopaludina hehuensis) is a regional edible gastropod, but its nutritional composition across production systems remains poorly characterized. We evaluated edible muscle from open-air and greenhouse paddies (three independent units per system, each pooling 50 snails) for proximate composition, hydrolyzed amino acids, fatty acids, vitamins, elements, and exploratory volatile profiles. After Welch t tests with Holm correction, greenhouse snails had higher ash (21.77 vs. 19.76 g/100 g dry weight; adjusted p = 0.044), whereas moisture, crude protein, crude fat, and quantified amino acids did not differ significantly. Fourteen of 19 quantified fatty acids differed, with their summed concentration higher in open-air snails (1095.76 vs. 817.63 mg/kg wet weight; adjusted p = 0.004). The atherogenicity (0.397 vs. 0.489) and thrombogenicity (0.670 vs. 0.719) indices were lower in open-air snails. Vitamin C (254.11 vs. 220.44 mg/kg wet weight) and Fe were higher in open-air snails, whereas vitamin A (0.049 vs. 0.235 mg/kg wet weight), Co, Al, and Pb were higher in greenhouse snails. Acetophenone was the only volatile assignment differing after correction (adjusted p = 0.006). These findings establish a nutritional baseline and identify culture-associated differences. Future studies should examine seasonal variation and environmental and dietary contributions.