Food Bioscience 38 (2020) 100770 Available online 14 September 2020 2212-4292© 2020 Elsevier Ltd. All rights reserved. Microbial ecology of different sardine parts stored at different temperatures and the development of prediction models Fevziye Nihan Bulat a, * , Berna Kılınç a , Sevcan Demir Atalay b a Faculty of Fisheries, Fish Processing Technology Department, Ege University, 35100, Bornova-Izmir, Turkey b Faculty of Science, Department of Statistics, Ege University, 35100, Bornova-Izmir, Turkey A R T I C L E INFO Keywords: Sardine pilchardus Bacterial identifcation Prediction models Fish quality Shelf-life ABSTRACT The microbial ecology of sardines stored at 4 and 10 ◦ C was determined using the Application Programming Interface (API) test with a stated statistical accuracy (%) at the species level for lactic acid bacteria, Entero- bacteriaceae and Staphylococcus species. The microbial ecology of the gill (a), skin (b), meat (c) and intestine (d) of sardines stored at 4 ◦ C was as follows; (a) Leuconostoc mesenteroides spp. 99.9%, Candida ciferrii 99.9%, Serratia odorifera 97.9%; (b) Enterobacter cloacae 95.6%, Pantoea spp. 62.8%, Pseudomonas luteola 99.7%, Rahnella aquatilis 78.3%; (c) Acinetobacter baumannii/calcoaceticus 98.5%, Pantoea spp. 62.8%, L. mesenteroides spp. 99.9% and (d) L. mesenteroides spp. 99.9%, Aeromonas hydrophila 65.4%. The microbial ecology of gill (e), skin (f), meat (g) and intestine (h) of sardines stored at 10 ◦ C was as follows: (e) Cryptococcus humicola 79.9%, Cryptococcus laurentii 99.4%, Candida guilliermondii 99.8%, Staphylococcus lentus 99.4%; (f) L. mesenteroides spp. 99.9%, Candida ciferri 53.8–87.9%; (g) Pantoea spp. 25.4–70.5%, Morganella morganii 96.6% and (h) C. ciferrii 53.8–87.9%, A. hydrophila/caviae 97.8%, Cronobacter spp. 96.5%. All bacteria counts were mainly observed in the order: intestine > gill > skin > meat, at both storage temperatures. Statistical prediction models were developed to estimate the quality and shelf-life of sardines during storage. The quality of sardines was measured using regression models. The Pearson correlation r between storage times for the quality and shelf-life of gill, meat and intestine was 0.86 for sardines stored at 4 ◦ C (model 1), and was r = 1 for storage times for the quality of gill and meat at 4 and 10 ◦ C (model 2). 1. Introduction The sardines are classifed in the Clupeidae family. Sardines have a green-blue dorsal color while their sides and abdominal parts are silver- grey colored and also have black spots on the sides. The shape of the sardines is fusiform and the maximum length is ~20 cm. The sardine tail fn is forked and they have only one dorsal fn (Kaya, 2017). Sardines are traditionally caught in large quantities from the Aegean Sea around Turkey. For example, >23,000 tonnes of sardines were landed in 2017, and 5.5 kg of aquacultured sardines per capita was consumed in 2018 (TU ˙ IK, 2018). Sardines are usually consumed as fresh and frozen, but are also available canned and marinated (Kılınç, 2003). The spoilage of seafood can be the result of microbial activity, chemical oxidation and/or autolysis (Odeyomi et al., 2018). Microorganisms lead to an increase in the pH values of seafood, in which they can develop during storage, resulting in a spoilage of fresh and processed seafood (Dousset et al., 2016). Organoleptic changes, occurring as a result of metabolite production by bacteria can lead to lower quality and cause deterioration (Boziaris & Parlapani, 2017). The substances produced by microorgan- isms in the meat and seafood lead to the development of bad smells and taste, which decreases the organoleptic quality. The speed of bacterial spoilage of fsh and seafood can increase if they are contaminated during catching, transporting, processing and selling. Storage is also important to prevent the loss of quality of seafood (Lunestad & Rosnes, 2008). To prevent deterioration and prolong the shelf-life, the storage temperature and processing techniques are important to reduce the bacterial activity of foods (Comi, 2017). Precautions should be taken to protect the sea- food from the period between capture and consumption. For example, Shewanella putrefaciens and Pseudomonas species are mostly observed in seafood stored on ice (Gram & Huss, 1996). Although a large number of studies (Altın, 2006; Chatzikyriakidou & Katsanidis, 2011; G¨ oko˘ glu et al., 2004; Kenar, 2009; Kılınç, 2003; Lyhs et al., 2001; ¨ Ozo˘ gul et al., 2004) have been done on the quality and shelf-life of sardines, little is known about which bacteria are observed at which storage * Corresponding author. E-mail address: nihanbulat@gmail.com (F.N. Bulat). Contents lists available at ScienceDirect Food Bioscience journal homepage: www.elsevier.com/locate/fbio https://doi.org/10.1016/j.fbio.2020.100770 Received 28 May 2019; Received in revised form 9 September 2020; Accepted 10 September 2020