Influence of iota carrageenan addition on the properties of soya protein meat analogues Megala Palanisamy a, b, * , Stefan T € opfl a , Kemal Aganovic a , Ralf G. Berger b a German Institute of Food Technologies (DIL e.V.), Prof.-von-Klitzing-Str. 7, 49610 Quakenbrueck, Germany b Leibniz Universitaet Hannover, Institute of Food Chemistry, Callinstrasse 5, 30167 Hannover, Germany article info Article history: Received 15 June 2017 Received in revised form 27 August 2017 Accepted 18 September 2017 Available online 21 September 2017 Keywords: High moisture extrusion Soya protein Meat analogues Iota carrageenan Texture improvement abstract The aim of the study was to investigate the effect of addition of iota (i) carrageenan (ICGN) on physical properties (cooking yield, expressible moisture, and colour), texture, sensory parameters and micro- structure of soya meat analogues produced by high moisture extrusion processing. The high moisture extrusion trials were carried out using soya protein concentrate with the addition of 0.75%, 1.5%, 2.25% and 3% ICGN (by dry mass). The colour of the extrudates was not affected drastically by the addition of ICGN. Expressible moisture and cooking yield were decreased and textural properties, such as cutting force and elasticity, were increased significantly upon the addition of ICGN. Scanning electron micro- scopic observations showed that increasing ICGN levels led to a more compact network in the meat analogues supporting the changes obtained in texture, cooking yield, and expressible moisture. Sensory evaluation results confirmed that the increase in ICGN concentration led to harder, more fibrous and less juicy products resulting in a significantly improved overall acceptance. The extrudate with 1.5% ICGN was preferred by the panellists. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction Plant protein texturization is used to develop meat analogues from plant based proteins to replace animal proteins in the human diet. One of the ways to texturize the plant proteins is through extrusion cooking. The plant-based meat analogues are produced in a way to mimic some of the qualities of meat such as texture, flavour and appearance. Since 1960, low moisture extrusion tech- nology (<35% moisture) has been used to produce traditional meat analogues which have a sponge like texture, and these products are supposed to be rehydrated before consumption (Guy, 2001). However, these products are not well comparable in terms of appearance and texture to the meat. In recent years, high moisture extrusion technology was used to produce meat analogues and considered as a promising technology to obtain fibrous meat-like structures from plant proteins. Texturization with high moisture extrusion is entirely different from other protein texturization processes (e.g., manufacturing of sausages, cheese curds, tofu, fibre formation by spinning or by extrusion cooking, etc.) (Cheftel, Kitagawa, & Qu eguiner, 1992). During extrusion, proteins are plasticized in the heating chamber of an extruder and texturized in a long cooling die at the end of the extruder by varying the mois- ture, temperature, pressure and shear, respectively (Noguchi, 1990). These products are semiefinished and have to be post-processed before being served (e.g., further cooking, marinating as in the meat product preparations). Traditionally, a twin screw extruder is used for texturization. In this study, a planetary roller extruder (PRE) was used which produced less shear during extrusion compared to a twin screw extruder. The most common protein source used for the meat analogues production until to date is soya beans. Soya bean based ingredients, such as soya flour, protein concentrate and protein isolate, have been successfully used in the food industry for many years to develop meat analogues. Other plant protein sources considered for meat analogue production are wheat, cotton seed, legumes, lupine, pea etc. (Asgar, Fazilah, Huda, Bhat, & Karim, 2010). One of the main problems considering the consumer acceptance of meat analogue products is texture. The texture may be modified or improved by adjusting the process conditions or by incorpo- rating food additives. Polysaccharides are one of the main additives generally used in food industries for texture optimization. The ef- fect of hydrocolloids on low moisture texturized soya protein was * Corresponding author. German Institute of Food Technologies (DIL e.V.), Prof.- von-Klitzing-Str. 7, 49610 Quakenbrueck, Germany. E-mail address: m.palanisamy@dil-ev.de (M. Palanisamy). Contents lists available at ScienceDirect LWT - Food Science and Technology journal homepage: www.elsevier.com/locate/lwt https://doi.org/10.1016/j.lwt.2017.09.029 0023-6438/© 2017 Elsevier Ltd. All rights reserved. LWT - Food Science and Technology 87 (2018) 546e552