Final answer:
The majority of the mass in dry sweet peas is made up of complex carbohydrates, particularly starches and fibers, after excluding the high water content present in those harvested green.
Step-by-step explanation:
The majority of the mass in sweet peas (Pisum sativa), like most legumes in the pea family (Fabaceae), is made of water, carbohydrates, proteins, and fats, with carbohydrates as the dominant macronutrient in dried seeds. For green vegetable crops like peas that are harvested before they dry, the water content will be significantly higher. However, in the context of dry weight, where peas such as the cowpea [Vigna unguiculata (L.) Walp.] and others are considered, complex carbohydrates such as starches would comprise the majority of the mass.
Like peas, soybeans (Glycine max), when harvested as edamame, are picked while still green and have a higher water content. For dried beans, like selected seeds from pea, corn, and bean, that have been bred over thousands of years for larger size, these carbohydrates, particularly the starches and fibers, constitute the majority of their dry mass.