Eur Food Res Technol (2006) 222: 650–657 DOI 10.1007/s00217-005-0151-6 ORIGINAL PAPER Akkasit Jongjareonrak · Soottawat Benjakul · Wonnop Visessanguan · Munehiko Tanaka Fatty acids and their sucrose esters affect the properties of fish skin gelatin-based film Received: 27 June 2005 / Revised: 28 August 2005 / Accepted: 6 September 2005 / Published online: 16 December 2005 C  Springer-Verlag 2005 Abstract The effects of fatty acids (FA) [palmitic acid (PA) and stearic acid (SA)] and their sucrose esters (FASE) on the mechanical properties, water vapor permeability (WVP), light transmission, and color of films from bigeye snapper and brownstripe red snapper skin gelatins were investigated. Tensile strength (TS) of films generally de- creased with the addition of FA (p<0.05), while gradually increased with increasing FASE amount (p<0.05). WVP of films generally decreased with increasing amount of FA or FASE (p<0.05). However, films containing FASE exhibited the superior WVP barrier property to those added with FA. Marked increase in elongation at break (EAB) was observed when either FA or FASE at a level of 25% substitution was incorporated. Light transmission of films in both UV (200–280 nm) and visible ranges (350–800 nm) decreased with increasing FA amount. Films added with FASE were generally more transparent than those with FA. Chain length of FA or FASE affected the properties of films differently, depending upon gelatin sources. Therefore, the properties of fish skin gelatin-based films, especially water vapor barrier, could be improved by the addition of FA or FASE. Keywords Gelatin . Film . Fatty acid . Sucrose ester . Bigeye snapper . Brownstripe red snapper A. Jongjareonrak · S. Benjakul () Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand e-mail: soottawat.b@psu.ac.th Tel.: +66-74-286334 Fax: +66-74-212889 W. Visessanguan National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Rd., Klong 1, Klong Luang, Pathumthani, 12120 Thailand M. Tanaka Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan 4, Minato, Tokyo 108-8477, Japan Introduction Edible films derived from protein materials have been paid more attention for the use in the food protection and preser- vation owing to their biodegradable and environmental characteristics [1, 2]. The films can extend the shelf-life and improve the quality of almost any food system by serving as a barrier to mass transfer or as a mechanical protection [3]. Although edible films prepared from those renewable sources such as proteins and carbohydrates generally have the good mechanical properties, their water vapor barrier properties are usually indigent because of their hydrophilic character [4]. To retard the water vapor permeability (WVP) of edible films, lipid materials including edible oil, neutral lipids, fatty acids, as well as waxes are incorporated into the film [2]. Bilayer films in which the lipid layer was laminated over a supporting film [5–7] and the emulsion films in which the lipid was uniformly dispersed throughout the film [8–12] have been developed. Although, emulsion films are not the effective barrier as bilayer films, they possess superior mechanical properties [13]. Among all proteins, gelatin has attracted the attention for the development of edible films due to their abundance [14]. Gelatin is generally produced from the land-based animal skin or bone, generated during the animal slaughtering and processing. However, the outbreak of bovine spongiform encephalopathy (BSE) and the foot-and-mouth disease crisis has resulted in the anxiety among users of gelatin products from land-base animal origin [15]. Recently, the protein-based film has been prepared from gelatins of big- eye snapper and brownstripe red snapper skins. However, the films exhibited poor water vapor barrier property [16, 17]. The use of lipid materials incorporated into the gelatin- based film would be an effective means to improve the water vapor barrier property. FA have been reported to dis- tribute uniformly and prevent the water vapor permeability of films [7, 18, 19]. Ayranci and Tunc [11] observed that stearic acid was the most effective fatty acid in decreasing WVP and the CO 2 transmission of cellulose-based films, when compared with palmitic acid and lauric acid. In