Comparison of physico chemical and sensory properties of innovative fish spread emulsions manufactured using herring (Clupea harengus) milt, cod (Gadus morhua) roe and plaice (Pleuronectes platessa) roe.

Abstract

Typically, in Ireland, male and female marine fish gonads are either discarded at sea or processed onshore for low-value fishmeal. The aim of this study was to establish the feasibility of developing emulsion-based spreadable food products using locally sourced milt and roe to add value to this currently under-utilized nutritious seafood resource. Two new innovative ready-to-eat spreadable emulsions were developed using underutilized herring milt with, 1) cod roe, SCD and 2) plaice roe, SPL. This study investigated the physico-chemical and sensory acceptance of the products were tested on 86 consumers, using hedonic and just-about-right scales. Chi-square tests on contingency tables were used to analyze open-ended questions relating to consumer likes and dislikes of the products. The main characteristics showed sensory drivers for liking was flavor, color and texture with similar characteristics also used for disliking. Instrumental colour and texture analyses showed significant differences (P<0.05) between the products which were also detected by panelists during sensory evaluation (color, texture, appearance, P<0.05). No significant difference was observed between aroma, flavor, mouthfeel and overall liking (P>0.05) between both emulsions. Of the respondents, 72.0% indicated a positive liking of SPL; while 67.5% indicated liking of SCD. Penalty analysis of JAR showed overall liking was most impacted by level of fishiness (fish flavour). The positive results in sensory acceptance of the products suggests underutilized and under-valued milt and roe could be used successfully in Irish food product development. This use of fish by-products presents an opportunity to add value while contributing to waste reduction.