Processing of astaxanthin-rich Haematococcus cells for dietary inclusion and optimal pigmentation in Rainbow trout, Onchorynchus mykiss L.

A range of physical cell disruption techniques have been evaluated to aid the processing of astaxanthin-rich haematocysts of Haematoccus pluvialis for inclusion in salmonid feeds. Cell disruption by a scaleable pressure treatment system was shown to be effective in breaking open the haematocysts without altering the content or isomeric composition of carotenoids in the algal cells. Storage of disrupted cells was optimal at -20°C in the dark under nitrogen. Disrupted cells were spray-dried, incorporated into commercial diets and fed to Rainbow trout (Onchorynchus mykiss L). A marketable level of pigmentation in fish muscle was achieved after 10 weeks dietary supplementation. The geometric and optimal isomer composition of the astaxanthin deposited in the muscle was nearly identical to that seen in Haematococcus. Changes were observed in the chirality of the astaxanthin deposited in the skin in comparison to that isolated from both the white muscle and the alga

The Impact of Brain Drain on Haiti\u27s Rural Communities: The Case of a Small Town in Central Haiti and Its Surroundings.

This qualitative participatory action research study investigated the causes and impacts of brain drain on Haiti’s rural communities, focusing on a small town in Central Haiti and its surrounding communities. Research shows that the brain drain has affected developing countries for many years. The pull factors from developed countries make the push factors in the home country more evident, leaving the latter depleted of educated human resources. It is particularly true in rural communities in Haiti. The researcher aimed to understand the causes through a community-based series of interviews, focus groups, and narratives. Participants expressed their views on the phenomenon and proposed workable ways to deal with their community’s brain drain issue. The interview questions were open-ended and semiformal, affording participants the liberty to freely express their opinions. During focus group sessions, individuals told their stories while answering guided questions from the researcher. Two narratives illustrated the potential of returnees to help in the transformation of conditions in communities. The study found brain drain to be a phenomenal fact in the targeted community and the country. The causes and their impact, as observed by participants, were evident, and participants shared ideas reported in chapter 5 of this paper on how to address the issue

Genetic variation of flesh colour in canthaxanthin fed rainbow trout

Genetic experiments were conducted using either random independent full-sib families (9 and 11 respectively) or sire-half-sib families (18) of rainbow trout who were fed an experimental diet supplemented with canthaxanthin. The resulting orange-red colour of the flesh from each fish was analyzed through spectrophotometry and expressed in standard terms of luminosity (Y), dominant wavelength (λd) and excitation purity (Pe). The following results were obtained : - There is a substantial genetic variability among families in each colorimetric parameter. Estimated values of heritability from full-sib and from half-sib families do not differ significantly. - Positive correlation between λd . and Pe, and negative correlations between Y and λd and between Y and Pe, are consistent with the pattern of canthaxanthin deposition in the flesh. Genetic correlations do not differ significantly from phenotypic ones. - Pigmentation intensity is correlated to fish weight. This relationship, however, accounts for but a minor part of colour variation among market-size fishes.Des expériences génétiques ont été réalisées chez la Truite arc-en-ciel sur des familles aléatoires et indépendantes de pleins-frères (au nombre de 9 et 11) ou demi-frères de pères (18), alimentées par un régime expérimental supplémenté en canthaxanthine. La couleur de chair orange-rouge obtenue chez chaque poisson a été analysée par spectrophotométrie et exprimée en termes standards de luminosité (Y), longueur d’onde dominante (λd) et pureté d’excitation (Pe). Les résultats obtenus sont les suivants : - Il y a une variabilité génétique notable entre familles pour chaque paramètre colorimétrique. Les valeurs d’héritabilité estimées à partir des familles de plein-frères et de demi-frères ne diffèrent pas significativement. - Les corrélations, positives entre λd et Pe et négatives entre Y et λd et entre Y et Pe, sont conformes au mode d’action de la canthaxanthine se déposant dans la chair. Les corrélations génétiques ne diffèrent pas significativement de leurs homologues phénotypiques. - L’intensité de la pigmentation est corrélée avec le poids des poissons. Cette relation toutefois n’explique qu’une part minime de la variation de couleur chez des animaux de taille marchande

Effect of dietary bile extracts on serum response of astaxanthin in rainbow trout (Oncorhynchus mykiss): a preliminary study

Effects of porcine bile extracts added at three different dietary concentrations 0, 10 and 20 g kg)1 were studied on astaxanthin serum concentration in rainbow trout (mean weight 200 ± 7 g). Astaxanthin from micro-algae Haematococcus pluvialis and synthetic astaxanthin (CAROPHYLL pink) were incorporated in diets of rainbow trout at a rate of 100 mg astaxanthin kg)1 of feed. Fish were hand fed twice a day. After 5 days of feeding there was a significant effect of the pigment source on the ratio (total blood astaxanthin per unit body weight to cumulative astaxanthin intake per unit body weight). Trout receiving synthetic astaxanthin showed a significantly (P < 0.05) higher ratio than trout fed algal astaxanthin. Increasing dietary bile extract did not lead to produce any effect on this ratio. The power of the statistical analysis is discussed. Therefore, the interaction (pigment source · dietary bile concentration) showed no more effect

Effect of carotenoid source and dietary lipid content on blood astaxanthin concentration in rainbow trout (Oncorhynchus mykiss)

Astaxanthin concentration in the blood of rainbow trout was studied in a feeding trial with two different astaxanthin sources: green algae Haematococcus pluvialis and commercial beadlets of 8% astaxanthin content (CAROPHYLL® Pink), and two different dietary lipid levels. The green algae contained 1.4% of carotenoids on a dry matter basis: free astaxanthin (<1%), astaxanthin monoester (24.3%); astaxanthin diester (70.2%) and lutein (4.8%). Algal biomass was mechanically ground to disrupt the cell wall before incorporation in the feed. Hydrolysis of astaxanthin esters from algae occurred during the pelletization even at a low process temperature (43°C). Rainbow trout with an initial mean body weight of 150 g were fed experimental diets supplemented at a rate of 100 mg pigment/kg diet combined with two different lipid levels (9 and 24%) during 5 days. Astaxanthin concentration in the serum ranged from 5.3 μg/ml (8.9 nmol/ml) to 9.0 μg/ml (15.1 nmol/ml). Astaxanthin concentration in the serum was higher for fish fed high lipid level diets, independently of the astaxanthin source. No differences in the astaxanthin serum concentration were found for fish fed diets supplemented with either natural or synthetic astaxanthin, respectively 9.0±1.9 and 8.4±2.4 μg astaxanthin/ml serum, when dietary lipid level was high (24%). On the other hand, there was a higher blood astaxanthin concentration in fish fed diets supplemented with algal biomass (7.0±2.4 μg astaxanthin/ml serum) compared to synthetic astaxanthin (5.3±2.0 μg astaxanthin/ml serum) when dietary lipid level was low (9%