Effects of different drying conditions on the rehydration ratio and water holding capacity properties in three different species of algae Ulva lactuca, Codium vermilara and Codium tomentosum

Abstract

Over the last years, algae have been increasingly used in Human food due their rich chemical and nutritional composition, particularly the high supply of essential nutrients to the human body such as protein and dietary fiber. Dietary fiber can be divided into two different types: soluble and insoluble. The characteristics of soluble dietary fiber are related to some physical and chemical properties such as rehydration ratio and water holding capacity and are important in assigning the functional and organoleptic properties and in preventing some human pathologies such as cardiovascular disease and obesity. The present study aimed to investigate the influence of different drying conditions on the rehydration ratio and water holding capacity of three green algae, Codium vermilara, Codium tomentosum and Ulva lactuca. The methods used for the determination of water retention capacity and rehydration ratio were similar to those used in previous studies (Susuki, T. et al., 1996). The algae were processed in a tray dryer and the drying conditions were: Temperature: 30ºC and 40ºC; Relative Humidity: 28%47% ; air velocity 1,9 m/s. In this work, it was concluded that higher drying temperature conditions originate lower rehydration ratio and consequent lower water holding capacity possibly due to a higher physical damage in the algae tissues. It was also observed that both Codium species have higher values for these two parameters than Ulva lactuca, under the same rehydration conditions

Effect of Oven-Drying on the Recovery of Valuable Compounds from Ulva rigida, Gracilaria sp. and Fucus vesiculosus

“…To our knowledge, the effect of oven-drying on valuable compounds of Ulva , Gracilaria and Fucus genre has been scarcely studied. Robic et al [20] evaluated the impact of oven-drying at 50 and 70 °C, on the yield of recovery and physicochemical features of ulvans, obtained from wild Ulva rotundata of France origin, while Rodrigues et al [21] focused the rehydration ratio and water holding ability of Ulva lactuca (unspecific origin) oven-dried at 30 and 40 °C. Lastly, recently, Uribe et al [22] studied the impact of different drying methods, including oven-drying at 70 °C, on the surface color and phytochemical content and amino acid and fatty acid profiles of wild Ulva spp.…”

Physicochemical Changes of Air-Dried and Salt-Processed Ulva rigida over Storage Time

“…is widely distributed throughout the world and one of the two Chlorophyta genera allowed for consumption as vegetables and condiments in Europe [11], but still, the scientific knowledge about the impact of preservative processing in this genus is quite limited and only performed at a laboratory scale. In particular, Robic et al [12] evaluated the impact of oven-drying (50 and 70 °C) on the yield of recovery and physicochemical features of ulvans, obtained from wild Ulva rotundata , while Rodrigues et al [13] reported the influence of oven-drying (30 and 40 °C) on the rehydration ratio and water holding ability of Ulva lactuca . In turn, Uribe et al [14] evaluated the effect of distinct drying methods, namely freeze-, vacuum-, solar-, and convective drying (at 70 °C), on the surface color of wild Ulva spp.…”