Adding value to under-utilised fish roe in Ireland: a comparison of physico-chemical and sensory characteristics of salted air-dried roe from Irish pollock (Pollachius pollachius) with commercial mullet and cod roe products (Mugil cephalus and Gadus morhua).

Abstract

In Ireland, fish roe is generally either discarded at sea or processed as low-value fishmeal. The aim of this study was to establish the feasibility of developing a fish roe product to add value to this currently underutilised nutritious seafood resource. Roe is the gastronomic term for the ovaries of a gravid female fish (OECD 1990). Roe includes products where individual eggs have been carefully detached from the gonads (e.g. caviar), as well as products made from the whole intact ovary. Fish ovaries are generally paired, and either fully or partially fused together (Bond 1996) as shown in Figure 1(i, ii, iv). Roes are high in marine oils and proteins (Slizyte et al 2014), have nutritionally beneficial long chain ω-3 PUFA and antioxidants (Kalogeropoulos et al 2008 and 2012) and therefore have the potential to be developed into value-added seafood products that are both nutritious and tasty, while contributing to the sustainability and profitability of the Irish fisheries industry. While not traditional in Ireland, many countries produce ready-toeat food products using fish roe by salting and air drying. Salted air-dried mullet roe has been produced in the Mediterranean since the Phoenician era (Monfort 2002) and is known as ‘Bottarga’ in Italy and ‘Avgotaracho’ in Greece (OECD 1990). These high value products are sold either in whole or grated form: whole roe retailing up to approx. €250/kg (data not shown). Bledsoe, Bledsoe and Rasco (2003) described mullet bottarga as having a chewy mouthfeel with a rubbery texture and a yellow-ish red colour. Bottarga is generally consumed sliced or grated (Monfort 2002). According to Rosa et al (2016) mullet roe should be considered as a natural bioavailable source of omega-3, while Kalogeropoulos et al (2012) show how mullet roe also has antithrombotic potential. Given its geographical availability and suitability of roe size, pollock (a gadoid which spawns in the first half of the year and is commercially important in Irish fisheries) (Marine Institute 2017) was chosen to evaluate the feasibility of producing a salted air dried roe product.