Mechanical Disintegration and Particle Size Sieving of Chondrus crispus (Irish Moss) Gametophytes and Their Effect on Carrageenan and Phycoerythrin Extraction

To better understand the migration properties of hybrid carrageenan from the seaweed tissue during carrageenan extraction, the effect of increasing the seaweed surface area by the mechanical disintegration of gametophyte Chondrus crispus chips was studied under various temperature and time extraction conditions. Dried Chondrus crispus seaweed chips were milled by a rotor beater mill and classified into eight different size fractions by sieving with varying mesh sizes from 50 to 2000 μm. During extraction at 22 °C, the red color of the filtrate increased significantly with the decreasing particle size of the fraction, correlating with the increasing phycoerythrin concentration (from 0.26 mg PE/g dry seaweed in the >2000 μm size fraction to 2.30 mg PE/g dry seaweed in the <50 μm size fraction). On the other hand, under the same extraction conditions, only a small increase in carrageenan precipitate was obtained with the decreasing size fractions (from no recovery in the >2000 μm size fraction to 2.1 ± 0.1 g/kg filtrate in the <50 μm size fraction). This yield was significantly lower than the ones from extractions at 45 °C (5.4 ± 0.1 g/kg) or at 90 °C (9.9 ± 2.1 g/kg) for the same particle size and time conditions. It could be concluded that hybrid carrageenan extraction is not surface area dependent, while phycoerythrin is. Therefore, it seems that phycoerythrin and carrageenan extraction follow different mechanisms. This creates potential for the selective extraction of each of those two compounds.

Antioxidant effect of Chondrus crispus and Lentinula edodes on different margarines

Lipid oxidation is the reaction responsible for food degradation, to solve this problem the agri-food industry uses antioxidants, preservatives and chemical stabilizers. Currently there is an increasingly strong demand for healthier eating, because of this, the industry is increasingly interested in replacing chemical compounds with natural products of equal or greater effectiveness. This project studies oxidative stability in margarines of different composition, both qualitative and quantitative, when independently adding dehydrated material from a fungus (Lentinula edodes) and a seaweed (Chondrus crispus), which are characterized for having antioxidant activity. To achieve this, Rancimat equipment was used at different temperatures: 110 ºC, 120 ºC, 130 ºC and 140 ºC ± 1.6 ºC. comparing treated margarine samples with their respective controls. Results varied depending on the temperatures used, the composition of margarines and the natural antioxidants added. The results show that the margarine with a lower proportion in unsaturated fatty acids, and especially in polyunsaturated fatty acids, have greater oxidative stability and it increases to a greater degree when the fungus is added with respect to the addition of seaweed.

Effect of caffeine on the growth and photosynthetic efficiency of marine macroalgae

Caffeine is present in coastal environments worldwide and there is a need to assess its impact on marine organisms. Here, we exposed two species of ecologically important marine macroalgae (Chondrus crispus and Codium fragile subsp. fragile) to a suite of caffeine concentrations and measured their response. Caffeine concentrations of 10–100 ng L−1 had no significant effect on the growth rate or photosynthetic efficiency of either algae. Extremely high concentrations (100–200 mg L−1), which may occur acutely, produced sublethal effects for both species and mortality in C. fragile subsp. fragile. Our results highlight the need to understand how caffeine impacts marine species.