Submit Manuscript | http://medcraveonline.com Abbreviations: WPI, whey protein isolate; SCFE, supercritical fuid extract; FFS, flm forming solutions; TVC, total viable counts; CFU, colony forming units; CFC, cetrimide-fucidine-cephalosporine; LAB, lactic acid bacteria; EO, essential oil; S-SCFE, sage SCFE; Or- SCFE, oregano SCFE; Gar-SCFE, garlic SCFE; Rg-SCFE, rosemary SCFE Introduction Fish has been an important part of the human diet in many countries for centuries. Among fsh species, tuna (Thunnus alalunga) is highly appreciated due to its high content of omega-3 fatty acids. It is an essential component of the well-known Mediterranean diet. In Spain, approximately 27.95millionkg of fresh tuna were consumed in 2014 representing 5% of the total fresh fsh consumed. 1 Fish, though, is one of the most highly perishable food products. Its spoilage process begins immediately after catching. The average losses related to fsh spoilage is estimated in 25%. 2 The major cause of food spoilage is microbial growth and can be manifested as changes in the sensory characteristics like production of off-odours and favours, slime formation, production of gas, discolouration and/or large visible pigmented or non-pigmented colonies. 3 Gram-negative bacteria like Pseudomonas, Moraxella, Acinetobacter, Shewanella, Flavobacterium, Vibrionaceae and Aeromonadaceae are normally part of the biota of fresh fsh and seafood. But Gram-positive organisms such as Bacillus, Micrococcus, Clostridium, Lactobacillus and Corynebacterium can also be found in varying proportions. 2 In western societies consumers increasingly demand fresh refrigerated foods with extended shelf life and with restrictions in the use of additives especially chemical ones. This fact has made the food industry search for innovative preservation technologies to extend the shelf-life, while ensuring safety of fresh foods. Therefore, prevention of spoilage has become an important challenge for the food industry. On the other hand, to avoid the use of chemical additives, the use of natural extracts has been studied in the last years. Plants, herbs and their essential oils have been used in the food industry since ancient times. In the past, it was very common to use herbs for improving organoleptic characteristics of foods or to preserve food. Essential oils from plants such clove, rosemary, thyme, 4 sage, 5 oregano and laurel 6 among others, have been described as antimicrobial substances and suggested as an alternative to chemical preservatives. Many authors have related the antibacterial activity of these substances with their high content of phenolic compounds such as carvacrol, thymol, 1-8-cinoleo, 7 eugenol, borneol 8 Oregano, rosemary, sage and garlic are herbs and plants commonly used in Spanish cuisine and characterised by their high content in the aforementioned active compounds, making these essential oils a valid alternative to synthetic preservatives against microorganisms associated with food spoilage. 8,9 The supercritical fuid extracts (SCFEs) used in the present study was selected after a careful bibliographic review where antibacterial activity of such substances against different bacteria strains was reported. 8–10 Besides, those extracts were also selected taking into account the possible application in the preservation of fsh and fsh products since they have organoleptic properties that could be compatible with these food products. MOJ Food Process Technol. 2017;5(2):273‒280. 273 ©2017 Granda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Development of whey protein isolate flms incorporated with rosemary extracts to improve the microbiological quality of fresh tuna Volume 5 Issue 2 - 2017 Ximena Carrión Granda, 1 Idoya Fernández Pan, 2 Bruno Iñarra, 3 Susana Mezquita, 3 Jordi Rovira, 4 Juan I Maté 5 1 Viscofan SA R+D Department, Spain 2 BCC Innovation, Basque Culinary Center, Spain 3 Food Sustainable Area, AZTI Tecnalia, Spain 4 Laboratorios CINFA SA, Spain 5 Department of Biotechnology and Food Science, Universidad de Burgos, Spain 6 Department of Food Technology, Universidad Pública de Navarra, Spain Correspondence: Idoya Fernández Pan, BCC Innovation, Basque Culinary Center, Paseo Juan Avelino Barriola, 101 20009 Donostia-San Sebastián, Spain, Tel 943-574-547, Fax 943-574- 502, Email ifernandez@bculinary.com Received: October 29, 2017 | Published: November 14, 2017 Abstract The antibacterial activity of supercritical fluid extracts (SCFEs) of sage, oregano, garlic and rosemary was tested against 12 bacteria related with the spoilage of fish. Results show that rosemary SCFE was the most effective followed by garlic extract. Bacteria like S. epidermidis was the most sensitive. In addition, rosemary SCFE was included in whey protein isolate (WPI) films at three different concentrations and their antibacterial activity was also tested. WPI-rosemary films showed different activity clearly dependent on the concentration of extract and bacteria strain. S. putrefaciens was the most sensitive strain. When fresh tuna steaks (Thunnus alalunga) stored at refrigeration conditions were coated with WPI incorporated with 2 different concentrations of rosemary SCFE, the growth of microorganisms was inhibited especially aerobic mesophilic and Enterobacteriaceae. Whey protein edible films could be proposed as a preservation technology to improve the microbiological quality and food safety of fish products. Keywords: antimicrobial agents, edible coatings, supercritical fluid extracts, whey protein isolate, fish preservation MOJ Food Processing & Technology Research Article Open Access