Changes in proximate composition, lipid class and fatty acid profile in Greenshell™ mussels (Perna canaliculus) over an annual cycle

Abstract

Greenshell TM mussel (GSM, Perna canaliculus) is New Zealand's most important aquaculture species. This study looked at changes in the proximate composition, lipid class and fatty acid profile of male and female market ready mussels over a year from April 2016 through to March 2017. There were differences over the season as well as differences between male and female mussels. Winter GSM had lower lipid, carbohydrate and protein concentrations than other seasons. Female mussels had a higher lipid (on average 1.8 AE 0.5 g/100 g ww) and carbohydrate (on average 5.0 AE 1.1 g/100 g ww) compared with the males (lipid, 1.5 AE 0.4 g/100 g ww and carbohydrate 4.5 AE 1.2 g/100 g ww). The major differences observed between seasons in the omega 3 and fatty acids content of the GSM were driven by the fat content, with the highest fat content found in female mussels in the spring prior to spawning. The majority of lipids found in mussels are polar lipids. Overall, this study provides the most comprehensive data on the composition and the lipid content of GSM to date and provides solid base-line data as the New Zealand GSM industry continues to improve their production procedures. The enhanced nutritional payload of mussels harvested outside of winter (particularly female mussels in spring) could drive a differentiated higher value mussel product.

Application of a Fourier transform—near infrared reflectance spectroscopy method for the rapid proximate analysis of the greenshell mussel ( Perna canaliculus ) and king (Chinook) salmon ( Oncorhynchus tshawytscha )

“…One of the major advantages of FT‐NIRs predictive models is the reduction in cost per sample and the higher throughput of samples. Particularly in GSM, we have seen large individual variability in mussels grown in the same areas and harvested at the same times (Miller, Pearce, & Bettjeman, ; Miller & Tian, ). Brown et al () completed a cost‐benefit analysis of NIRs on oysters and showed a cost reduction in between US$57 and US$6 per sample, depending on the number of samples assessed per calendar year.…”

“…In addition to the work reported in this paper we attempted to determine parameters and develop a calibration for fatty acid (FA) profiles for both GSM and king salmon. In the case of GSM, the content of fat was relatively low (0.8–2.4 g/100 g) and therefore fatty acid composition such as omega‐3 content or docosahexaenoic acid (DHA, 22:6n‐3) and eicosapentaenoic acid (EPA, 20:5n‐3) was even lower (Miller & Tian, ). The models developed for these parameters were not optimal as no defined peaks in the spectrum, outside of the C‐H stretch peak, could be identified to be attributed solely to the polyunsaturated fatty acids (such as a C = C stretch).…”

“…One of the major advantages of FT-NIRs predictive models is the reduction in cost per sample and the higher throughput of samples. Particularly in GSM, we have seen large individual variability in mussels grown in the same areas and harvested at the same times (Miller, Pearce, & Bettjeman, 2014;Miller & Tian, 2018 2018). Therefore, harvesting mussels for this product with a high fat content is vital to gain the greatest yield through the drying and extraction processing.…”

“…The proximate composition, lipid class and fatty acid profile of male and female market ready GSM has previously been reported throughout the year, from April 2016 to March 2017 (Miller & Tian, ). It was shown that there were differences in composition over the season as well as differences between male and female mussels (Miller & Tian, ). The findings of this earlier study form the basis of the FT‐NIRs models developed for the current paper.…”

“…More information on the environmental conditions at the time of sampling (e.g. water temperature) can be found in Miller and Tian (2018).…”