Sensory and fatty acid analyses of two Atlantic species of Porphyra (Rhodophyta)

Abstract

Sensory analyses were conducted to determine levels of consumer acceptability of Porphyra yezoensis, P. umbilicalis, and P. amplissima to select appropriate species for aquaculture development in Maine (USA). The subjects included children (n = 67) and adults (n = 84); the children participated in study design by helping to select the 9 point hedonic scale used in the affective sensory tests. Two substrates were used; Porphyra was baked in crackers and also used as a coating for popcorn. No significant differences ( p > 0.5) in acceptability of one species over another were observed in either trial, which suggests that native Atlantic species of Porphyra such as P. amplissima and P. umbilicalis have developmental potential in foods for North American consumers. Fatty acids were analyzed in the taste test material and in freshly collected P. umbilicalis; eicosapentaenoic acid [EPA; 20:5 (n-3)] and palmitic acid were the most common fatty acids. Quantitative analysis of EPA determined that freshly collected (January 2005) P. umbilicalis contained 3.2 mg EPA g dry wt −1 (74 mg EPA 100 g fresh wt −1 ). This concentration is not high enough to make P. umbilicalis a primary source of daily omega-3 fatty acids, but the favorable n-3/n-6 ratio (2-3:1) in these species contributes to their nutritional value.

Fatty acid composition of selected macrophytes

“…Only minor levels of myristic (C14:0), heneicosanoic (C21:0), lauric (C12:0) and behenic acids (C22:0) were recorded in the studied species (Table S2). The higher content of lignoceric acid (C24:0) recorded in this study for Porphyra is not in agreement with previous studies (Blouin et al, 2006;Dawczynski et al, 2007) that report a dominance of the PAM. For the remaining species, the results obtained are in agreement to other studies concerning the same genera, e.g.…”

“…Eicosanoic (C20:1) acid was recorded in all species but as a minor percentage of the total FAME (Table S2). These results are in agreement with other studies for the studied genera (Blouin et al, 2006;Dawczynski et al, 2007;Khotimchenko et al, 2002;Xu et al, 1998).…”

“…With the exception of P. capillacea, the present results are in agreement with previous works for the genera Chaetomorpha (Khotimchenko, Vaskovsky, & Titlyanova, 2002) and Porphyra (Blouin, Calder, Perkins, & Brawley, 2006, Dawczynski et al, 2007. Similar findings were also reported for other genera, namely Codium (Xu, Tran, Kraft, & Beardall, 1998), Cystoseira (Khotimchenko et al, 2002), Fucus (Khotimchenko et al, 2002;Marsham, Scott, & Tobin, 2007) and Osmundea (Marsham et al, 2007).…”

“…These results are in general in agreement with the ones published by other authors (e.g. Cystoseira, Fucus, Khotimchenko et al, 2002;Chaetomorpha, Khotimchenko et al, 2002;Codium, Xu et al, 1998;Porphyra;Blouin et al, 2006;Dawczynski et al, 2007). ALA was only recorded in Porphyra sp.…”

Nitrogen uptake by gametophytes ofPorphyra dioica(Bangiales, Rhodophyta) under controlled-culture conditions

“…Essentially, those studies showed that several north-eastern American species of Porphyra can perform as well as or better than the Asian species presently used in aquaculture. An interesting complement to this is the work of Blouin et al (2006), who compared the taste and textural qualities of P. amplissima and P. umbilicalis (two native Atlantic species of Porphyra) with those of P. yezoensis (Asian species). They reported no significant differences between the species in their taste acceptability for human consumption.…”