Solar drying of duckweed (Lemna minor) under the climatic conditions of the Vale do Ribeira

• Grant number: 24/23294-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Fisheries Engineering
• Principal Investigator: Érico Tadao Teramoto
• Grantee: Angela Hisamitsu Carolino
• Host Institution: Faculdade de Ciências Agrárias. Universidade Estadual Paulista (UNESP). Campus do Vale do Ribeira. Registro , SP, Brazil

Abstract

Duckweed (Lemna minor) is a floating aquatic plant widely used in the phytoremediation of effluents. Due to its rapid growth and nutritional composition, it has attracted the interest of the food and feed industries as a promising alternative to meet the growing global demand for sustainable plant-based protein sources. However, its high water content makes storage and transportation difficult, and there is a lack of information in the literature on drying methods in rural areas. This study, conducted in the Vale do Ribeira, a region rich in biodiversity and with a strong presence of traditional communities, aims to develop a drying technology adapted to rural settings. The choice of Vale do Ribeira is justified by the increasing use of duckweed in aquaculture effluent treatment and the need to promote local economic development sustainably. Two drying methods will be compared: traditional solar drying (sun drying) and the use of a photovoltaic-thermal solar dryer (PVT). The study will evaluate the time required for drying, as well as the physicochemical and microbiological characteristics of the final product. The physicochemical analyses will include color, water activity, pH, and the contents of ash, protein, and lipids. The microbiological assessment will include thermotolerant coliforms, Salmonella spp., enterobacteria, molds, and yeasts. The development of renewable energy-based technologies, adapted to local socioeconomic and environmental conditions, can strengthen the bioeconomy and promote efficient resource use. Furthermore, it seeks to foster an inclusive and sustainable development model, aligned with the principles of biodiversity conservation and traditional rural practices.