Impact of previous active dipping in Fucus spiralis extract on the quality enhancement of chilled lean fish Jos  e M. Miranda a ,M  onica Carrera b , Jorge Barros-Vel  azquez a , Santiago P. Aubourg b, * a Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences, University of Santiago de Compostela, Lugo, Spain b Department of Food Science and Technology, Marine Research Institute (CSIC), Vigo, Spain article info Article history: Available online 15 March 2018 Keywords: Fucus spiralis Dipping Chilled megrim Microbial activity Lipid damage Sensory acceptance abstract The first goal of this work was to enhance the quality of chilled fish by applying a preliminary dipping treatment containing a bioactive extract from the alga Fucus spiralis. Megrim (Lepidorhombus whiffia- gonis) specimens were dipped in aqueous solutions containing two different concentrations of the alga extract (0.50% and 0.10% alga/dipping solution, w/v; HAC and LAC batches, respectively). In addition, two control batches were considered (water dipping control and no dipping control). Microbial, chemical and sensory qualities were assessed in fish specimens after 0, 2, 6, 9 and 13 days of chilled storage. An antimicrobial effect at advanced stages of storage (9e13-day period) was observed as determined by the comparative evolution of aerobes, psychrotrophs and Enterobacteriaceae counts in megrim muscle. Likewise, a protective effect against specific lipolytic and proteolytic spoilage bacteria was also achieved at that storage period, as well as a decrease of free fatty acids formation. However, alga extract in the dipping medium had no effect (p > 0.05) on the increase of lipid oxidation in fish muscle throughout chilled storage. Interestingly, average scores revealed improved sensory quality in megrim corresponding to the HAC batch for the 9e13-day chilled period. Consequently, the proposed novel dipping treatment can be considered of interest for both on-board and in-land fish storage, due to the simple methodology employed and the resulting protective effects on fish quality. © 2018 Elsevier Ltd. All rights reserved. 1. Introduction From the very moment wild marine species are caught till they reach the final consumer, they suffer a variety of handling and technological processes that can be decisive for the quality of the final product. To keep the original properties of the fish species, and to offer a high-quality fresh product, ice storage has been recog- nised as the most-employed method (Campos, Gliemmo, Aubourg, & Barros-Vel azquez, 2012). However, because of the high perish- ability of marine species, refrigerated storage has been applied in combination with other preservative strategies such as ozone presence (Pastoriza, Bern ardez, Sampedro, Cabo, & Herrera, 2008), addition of salt (Huidobro, Montero, Tejada, Colmenero, & Borderías, 1990), high-pressure treatment (Tabilo-Munizaga, Aubourg, & P erez-Won, 2016), and the presence of natural com- pounds such as organic acids (Sallam, 2007) or plant extracts (Oral, Gülmez, Vatansever, & Güven, 2008). During on-board and in-land handling, a water dipping step has often been employed prior to chilled storage, to remove blood, digestive juices, slime and faeces, and to partially prevent microbial contamination (L opez-Caballero, Huidobro, Pastor, & Tejada, 2002; Erkan, 2007). To enhance such preservative effects, dips have included preservative compounds such as sodium acetate (Manju, Leema Jose, Srinivasa Gopal, Ravishankar, & Lalitha, 2007) and ellagic acid alone or in combination with ascorbic acid (Zambuchini, Fiorini, Verdenelli, Orpianesi, & Ballini, 2008). Previ- ous research including a dipping step prior to refrigeration (at around 4  C) of fish has also been reported to lead to enhanced quality. Previous studies have involved the employment of tea polyphenols and rosemary extract combined with chitosan (Li et al., 2012), carboxymethyl cellulose combined with Zataria multiflora essential oil and grape seed extract (Raeisi, Tajik, Aliakbarlu, Hamed Mirhosseini, & Mohammad Hashem Hosseini, 2015), alginate- based vitamin C solution combined with tea polyphenols (Song, Liu, Shen, You, & Luo, 2011), lactic acid (Metim, Erkan, Varlik, & Aran, 2001), and rosemary (Rosmarinus officinalis) combined with sage tea (Salvia officinalis)( € Ozogul, Kuley, & Kenar, 2011). * Corresponding author. E-mail address: saubourg@iim.csic.es (S.P. Aubourg). Contents lists available at ScienceDirect Food Control journal homepage: www.elsevier.com/locate/foodcont https://doi.org/10.1016/j.foodcont.2018.03.020 0956-7135/© 2018 Elsevier Ltd. All rights reserved. Food Control 90 (2018) 407e414