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Food Chemistry
Food Chemistry 103 (2007) 287–294 www.elsevier.com/locate/foodchem

Effect of processing steps on the physico-chemical properties of dried-seasoned squid
Xue-Yan Fu a, Chang-Hu Xue a,*, Ben-Chun Miao b, Zhao-Jie Li a, Yong-qin Zhang a,c, Qi Wang a
a

Department of Food Science and Technology, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003,PR China b Department of Pharmacology, Marine Drug and Food Institute, Ocean University of China, Qingdao, Shandong Province 266003, PR China c Department of Biological and Pharmaceutical Engineering, Qingdao University of Science and Technology, 266042, PR China Received 3 March 2006; received in revised form 23 July 2006; accepted 26 July 2006

Abstract The effects of processing steps on thephysico-chemical properties of dried-seasoned squid were studied using two kinds of squids. Browning was observed as indicated by an increase in yellowness (b* value) during the semi-drying and roasting step. The temperature and time of heating and type of roasting, as well as the material itself were the key factors influencing the browning. A high level of trimethylamine oxide (TMAO), and lowcontents of trimethylamine (TMA) and dimethylamine (DMA) were detected in the raw material. TMAO gradually decreased during the processing, while TMA, DMA and formaldehyde (FA) increased significantly especially in boiled meat. The temperature of boiling was the most crucial factor impacting the production of FA. FA could be greatly decreased during the cooling process by washing with water or changingthe roasting techniques. Therefore, to improve the quality of dried-seasoned squid, more attention should be paid to the temperature and roasting techniques during the processing. Ó 2006 Elsevier Ltd. All rights reserved.
Keywords: Dried-seasoned squid; Processing; Browning; FA; TMAO

1. Introduction Dried-seasoned squid is very nutritional and popular in many countries of the world. Neon flyingsquid and jumbo squid are the main species available. Undervalued squid species are utilized in many countries of the world in the manufacture of a popular semi-moist seasoned product. The primary quality attributes of dried-seasoned squid are its colour and appearance. Brown discoloration caused by sugar–amino (Maillard browning) reaction in manufacturing is a critical problem in marine foodindustry, which can cause considerable loss to this industry. The susceptibility to browning formation, however, differs among different species of squid. The dried products of neon flying

*

Corresponding author. Tel./fax: +86 532 82032468. E-mail address: xuech@mail.ouc.edu.cn (C.-H. Xue).

squid and Atlantic short finned squid undergo browning more readily than other squids (Sugiyama, Konosu,Hanabe, & Okuda, 1989; Haard & Arcilla, 1985). A number of studies have indicated that some amino acids such as Gly and Arg in neon flying squid, and Tau and Pro in Atlantic short-finned squid and Argentina squid might greatly contribute to Maillard browning reaction during the processing and storage (Tsai, Pan, & Kong, 1991b; Suyama & Kobayashi, 1980; Haard & Arcilla, 1985). Moreover, the breakdownproducts produced by O2, light, and heat may be another important factor contributing to browning (Hayashi & Takagi, 1979; Morita, Kubota, & Aishima, 2002). In addition, temperature and water activity were also believed to significantly affect browning reaction (Tsai et al., 1991b). The degree of browning in cold air was lower than that in sun and hot air (Kim et al., 2000). In addition, thebreakdown caused by enzymes from the squid can lead to undesirable fishy

0308-8146/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2006.07.047

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odours and flavours. Therefore an investigation into the effects of processing steps in manufacture of dried-seasoned squid is needed. These days, individuals...