Contrasting effects of two storage temperatures on the microbial, physicochemical, and sensory properties of two fresh red seaweeds, Palmaria palmata and Gracilaria tikvahiae

Abstract

The effects of two storage temperatures, 2 and 7 °C, were investigated on the quality changes of fresh red seaweeds, Palmaria palmata and Gracilaria tikvahiae. Microbial, sensory, and physiochemical properties of the seaweeds were evaluated during 2 weeks of refrigerated storage. The results indicated that the causes and rates of quality loss were species specific, with P. palmata deteriorating faster at 7 °C compared to at 2 °C. In contrast, G. tikvahiae quality was better maintained at the higher storage temperature. As cellular damage increased in the seaweeds during storage, increased drip loss and the subsequent deterioration in texture and color contributed to quality loss in both seaweed species. Microbial counts in P. palmata ranged from 3 to 5 log CFU g−1 throughout storage, whereas G. tikvahiae microbial counts reached over 7 log CFU g−1 by the end of storage. Drip loss, sensory evaluation, and instrumental color results proved to be reliable whereas instrumental texture and soluble protein did not yield consistent, valuable data. Growing interest in minimally processed foods provides an opportunity to promote seaweeds as fresh vegetables. The results of this study provide groundwork to monitor seaweed quality during refrigerated storage and to facilitate marketing and distribution of freshly harvested P. palmata and G. tikvahiae.