Food Technology
Dornoush Jafarpour; Parisa Ataei
Abstract
Introduction: Every year during marine fishing, some species that are caught are not suitable for human consumption and they are known as surplus fishing or low consumption, which is an important factor in wasting these rich resources. Therefore, it is necessary to set arrangements to use such species ...
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Introduction: Every year during marine fishing, some species that are caught are not suitable for human consumption and they are known as surplus fishing or low consumption, which is an important factor in wasting these rich resources. Therefore, it is necessary to set arrangements to use such species for human consumption, including the production of surimi. The surimi industry mainly uses Alaska pollock fish as the main source for surimi production. However, due to the increase in the world’s population and partly the depletion of the fish stocks, followed by a reduction in the surimi production of Allaska Pollock fish (due to restrictive fishing laws), the need to use new species is considered urgent. In this regard, additives such as gums can be used to reform and improve the properties of surimi. Therefore, in this study, the possibility of producing surimi paste and gel from Lizardfish and Talang Queenfish was investigated and the effect of Konjac on the physicochemical properties of the product produced from these two types of fish was evaluated. Materials and methods: In this study, Talang Queenfish and Lizardfish with approximate weight of 225.9±33.6 and 275.9±24.4 g and average size of 15.1±2.4 and 17.3± 2.6 cm, respectively, were purchased freshly from the fish market. After preparing surimi paste from both types of fish, Konjac gum in concentrations of 0.25, 0.50 and 0.75 % (w/w) was added directly to the surimi paste. Then to prepare surimi gel, first, the samples were placed in a water bath at 25 ° C for 3 hours for setting and then cooked at 90 ° C for 20 minutes. After that, the prepared gels were cooled in iced water immediately. The produced paste and gel were evaluated in terms of chemical composition, water holding capacity and color factors. Texture and sensory characteristic were assessed on the produced gels of both types of fish and compared with the control sample (without gum). Results and discussion: According to the results, the yield of Lizardfish was 28% and Talang Queenfish was 22%. It seems that the larger size of Lizardfish has been effective in its higher yield than Talang Queenfish. Based on the results, the percentage of ash, protein and fat in the treatments did not change significantly compared to the control sample. Also, there was no significant difference between the two types of fish in the amount of mentioned factors (p>0.05). As the contraction level of Konjac gum increased, the amount of moisture and water holding capacity of the paste samples of both fish increased significantly, which is due to the absorption and binding of water by the Konjac hydrocolloid. The lightness level (L*) of the surimi paste and gel of both types of fish increased significantly with the addition of Konjac, which is related to the increase in water content in the samples. The lightness of the surimi paste and gel of Lizardfish was higher than that of Talang Queenfish, which is due to the presence of more pigments in the Talang Queenfish meat. Control Sample and treatment of 0.25% of Talang Queenfish surimi paste showed more yellowness and redness than Lizardfish, but in the resulting gel, their values were reduced, indicating that the formation of gel structure by Konjac gum and binding to the proteins covered the yellowness and redness of the samples. By increasing the concentration of Konjac in surimi gel of both fish the parameters of texture (firmness, cohesiveness, adhesiveness, springiness, chewiness) breaking force and deformation increased significantly compared to the control sample. Also, the results showed that the surimi gel from Lizardfish has higher firmness, cohesiveness and strength than Talang Queenfish. Sensory evaluations showed that the panelists assigned the highest score for the surimi gel from Lizardfish to the 0.5% treatment and for the Talang Queenfish to the 0.75% treatment of Konjac. Based on the findings of the present study, it was found that surimi gel from Talang Queenfish has a lower quality than Lizardfish, but with the addition of Konjac gum, its properties can be improved.
Narjes Badfar; Seyed Ali Jafarpour; Mehdi Abdollahi
Abstract
Introduction: There is an expanding market for surimi in the world, and much interest in surimi throughout the seafood and food industry by the rapid growth in popularity of surimi-based products. This interest justifies an investigation into the applicability of freshwater fish species such as Silver ...
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Introduction: There is an expanding market for surimi in the world, and much interest in surimi throughout the seafood and food industry by the rapid growth in popularity of surimi-based products. This interest justifies an investigation into the applicability of freshwater fish species such as Silver carp, as an alternative fish resource, for surimi and surimi based products. Rheology concerns the flow and deformation of substances and, in particular, to their behavior in the transient area between solids and fluids. Moreover, rheology attempts to define a relationship between the stress acting on a given material and the resulting deformation and/or flow that takes place. Rheological properties are determined by measuring force and deformation as a function of time. Rheological evaluation is a useful technique for gathering information on the textural characteristics of surimi and kamaboko. It describes the surimi dynamic characteristics in the form of storage modulus (G′), loss modulus (G″), and phase angle (δ). Materials and methods: Whole Silver carp fish were gutted and the head removed, Fillets were minced by a meat mincer with a mesh size of 3 mm, then mince washed one, two and three times at ratio of 1:3 and 1:2 (mince: water) and dewatered. The mince was turned into surimi in a food processor operated for 2 min. salt (2%) was sprinkled over the mince. Ice water was also sprinkled over the mince to adjust the moisture content of the paste to 80 mL/ 100 g.Dynamic tests using a rheometer (MCR-301, Anton Paar- Germany) were carried out on the surimi gel after setting. The region of linear viscoelasticity of the surimi paste was determined by both stress and frequency sweep tests. The thermorheological behavior of Silver carp surimi was evaluated using a temperature sweep test and reported using sol-gel transition thermographs. The stress of 100 Pa was considered as the stress and the frequency of 1 Hz was considered as the frequency in the frequency sweep test, then Temperature sweep test involved heating the surimi samples from 10 to 90°C. Also Crip-recovery test was performed on the surimi in 300 seconds. Results & discussion: Rheological tests: Frequency sweep, Stress sweep and Temperature sweep graphs were relatively similar and in all samples affected by H2O2 and the control sample, the lowest value of G' was recorded between 50 and 52°C. Then, with increasing temperature from 52 to 62°C, the curve G' increased and the curve was stable at temperatures up to 80°C. Changes in the G' graphs can be attributed to the process of forming the gel by heating. Changes in the G" graph showed a similar trend with G’. In the creep-recovery test, the lowest and most strain were belonged to the control and sample 5 (1% H2O2, 1: 2, twice washing). Studying the figure of Creep-recovery test showed the samples affected by H2O2 had more resistance against applied stress in compression with control sample which expressed the effect of H2O2 on creating more and effective covalence cross-linking resulting more stable and constant gel network. During Surimi's heating, there are several reactions that involve various mechanisms, such as protein gelation. About Surimi, the observed macroscopic changes are related to the effect of temperature on proteins. The presence of H2O2 during the washing process did not have a significant negative effect on rheological properties of Surimi.
Reza Farahmandfar; Reza Safari; Fahimeh Ahmadi Vavsari; Tahmineh Bakhshandeh
Abstract
In this study, effect of Thyme (Thymus vulgaris) ultrasonic extract on the quality of Hypophthalmichthys molitrix surimi was evaluated. For this purpose, the leaves of Thymus vulgaris were dried, grinded and soaked in methanol (1:10 w/v) for 30 min at 45˚C and sonicated at 30 kHz for 15 min at 40˚C. ...
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In this study, effect of Thyme (Thymus vulgaris) ultrasonic extract on the quality of Hypophthalmichthys molitrix surimi was evaluated. For this purpose, the leaves of Thymus vulgaris were dried, grinded and soaked in methanol (1:10 w/v) for 30 min at 45˚C and sonicated at 30 kHz for 15 min at 40˚C. The extract was suspended by Dimethyl sulphoxide and mixed with surimi (0.4 and 0.8% w/w). Then, the analysis of chemical (free fatty acid, peroxide value, Thiobarbituric acid and total volatile base nitrogen) and microbial (mesophilic and psychrotrophic viable count) properties of the samples were done at specific intervals after zero, 4, 8, 12 and 16 days of storage at 2 ºC. Results of chemical and microbial analysis showed that 0.8% concentration of T. vulgaris could increase the shelf life of Hypophthalmichthys molitrix surimi and there is significant difference between control and treated samples. Moreover, the results could be claimed that the T. vulgaris due to marvelous antioxidant and antimicrobial component such as thymol (52.17%), ρ-cymene (14.42%), carvacrol (9.11%) and γ- terpinene (4.45%) has significant effect on preventing the Hypophthalmichthys molitrix surimi oxidation and microbial growth. The results also showed ultrasound was the effective way to extract the Thymus vulgaris beneficial compounds.
Bahareh Shabanpour; Mansoureh Neirizi; Zeinab Noori Hashemabad
Abstract
Introduction: Surimi is one of the procedures that nowadays it is suggested to increase the consumption of fish such as silver carp (Shabanpour et al., 2008). Surimi is washed and minced fish meat myofibrillar concentration of proteins, this would wash out most of the soluble material in surimi (Sultanbawa ...
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Introduction: Surimi is one of the procedures that nowadays it is suggested to increase the consumption of fish such as silver carp (Shabanpour et al., 2008). Surimi is washed and minced fish meat myofibrillar concentration of proteins, this would wash out most of the soluble material in surimi (Sultanbawa & Li- chan, 1998). Raw fish freshness and quality of the most important factors affecting the quality surimi (Phatcharat et al., 2006). Low-temperature storage, especially storage in ice, one of the most suitable criteria for refrigeration methods and maintain the quality of fish (Benjakul et al., 2002), although changes in chemical, biological and physical on the ice completely stopped when maintenance is not are (Benjakul et al., 2003; Riebroy et al., 2007). The aim of this study was to evaluate the maximum duration of storage of silver carp in ice for surimi production with high quality and efficacy during storage on the quality of surimi made from these fish when kept in ice. Materials and methods: Silver carp ((Hypophthalmichthys molitrix fish at intervals of 0, 4, 8, 12 and 16 days after initial preparations into surimi process and the assessments of microbial (bacterial load and total bacterial load of cool), chemical and sensory respectively. Chemical experiments: Thiobarbituric acid method Siripatrawa and Noipha (2012), volatile nitrogen bases by Goulas and Kontominas (2005), protein solubility and humidity values of pressure Rawdkuen et al (2009), pH Suvanich method and colleagues (2000). White index by Kristinsson et al (2005) using a colorimeter Lovibond CAMsystem500 model model was calculated and determined. Measuring the properties of gel production: Preparation Gel by (Jafarpour & Gorczyca, 2008) and evaluation gel by (Lanier, 1992) were done. Microbial testing of samples was done according to (Sallam, 2007) Sensory analysis of samples: To assess quality parameters include color, odor, taste and overall acceptance of samples of hedonic scale (slightly modified) was used. In order to test a panel group consisted of 10 people consisted of very good quality Grdydstvh use with a score of 7, well with a score of 5, acceptable with a score of 3, bad and very bad rating with a score of 0 is 1 (Shabanpour and et al., 1386). Data analysis: The results of ANOVA using SPSS 16 software analysis and comparison of data using Duncan's multiple range test was 0/05 Sensory evaluation and analysis of non-parametric Mann-Whitney U test was used to test. Results and Discussion: The research results showed that the solubility of proteins soluble salt (because ice crystals formed during cold storage the concentration of mineral salts in muscle cells increases), protein solubility, chemical indicators, microbial and sensory surimi (Due to raw materials oxidation (hydroperoxides) secondary unstable and prone to decomposition products such as aldehydes), White indicator, the ability to get qualitative rating factors evaluated (taste, odor, color and overall acceptability) negative trend and Percent moisture (Because denaturation of proteins myofibrils), microbial changes, changes in pH (Due to volatile nitrogen bases), changes in the volatile nitrogen bases ( Due to microbial growth) and TBA (Because tissue damages) has increased. Sensory and microbiological analysis results showed that the shelf life of silver carp in ice for surimi production is suitable for 8 days.
