Study of the influence of the region, the depth and the drying process on the chemical composition of Gelidium corneum from Moroccan coast

The Gelidium corneum is an algae exploited industrially for its richness in agar. In addition, it is known for its anti-inflammatory, antioxidant and anti-microbial activities. In this study, we established a general overview of the macronutrient composition of G. corneum and compared this composition according to harvest site, harvest depth and drying process. Proteins, lipids and carbohydrates of samples are measured by different methods. The analysis of results show that the protein concentrations of the El Jadida and Mohammadia samples are significantly higher than Casablanca samples (0.026 ± 0.0007 μg/μg DM, 0.024 ± 0.001 μg/μg DM, 0.006 ± 0.0007 μg/μg DM, p < 0.05 respectively). However, Casablanca samples are significantly richer in total carbohydrates (0.023 ± 0.002 μg/μg DM, p < 0.05) and less rich in reducing carbohydrates (0.0001 ± 0.00001 μg /μg DM, p < 0.05) compared to other samples. The lipid concentrations of the samples from all harvest sites do not show any significant difference. According to depth, total protein and sugar concentrations were significantly higher in the coast versus depth samples (0.035 ± 0.004 μg/μg DM vs 0.025 ± 0.0007 μg/μg DM, 0.035 ± 0.006 μg/μg DM vs 0.012 ± 0.005 μg/μg DM, p < 0.05 respectively). For the drying process, protein, total sugars and lipid concentrations were significantly higher in open air samples compared to oven samples (0.025 ± 0.0007 μg/μg DM vs 0.013 ± 0.0003 μg/μg DM, 0.012 ± 0.002 μg/μg DM vs 0.006 ± 0.002 μg/μg DM, 6% vs 3%, p < 0.05 respectively). Our results demonstrate that the chemical composition of G. corneum varies according to the harvest region. In addition, samples harvested on the coast and dried in the open air are the most rich in macronutrients.