جستجوی مقالات مرتبط با کلیدواژه « texture » در نشریات گروه « شیلات »

There is an on-growing demand for alternative sources of commercial gelatin. The by-products generated by fish-processing industries are a potential source for the production of halal gelatin in different industries such as food products. In this study, pastille was formulated with different concentrations of fish (Benthosema pterotum) (FG) and bovine (BG) gelatins. Different quality attributes of gelatin including humidity, ash, protein, water activity, sensory, texture and color were investigated. Statistical analysis was done by the ANOVA and LSD test was applied for mean comparison of the samples at p<0.05. Data analysis was carried out by SAS software (Version 9.8). The findings showed that total ash, springiness, elasticity, humidity, water activity and adhesiveness significantly increased with an increase in the Benthosema pterotum gelatin concentration in the pastille samples (p<0.05). However, the best pastille texture was observed in 50% BG 50% FG and for other parameters in samples with 100% BG (p<0.05). According to the results of sensory evaluation and color characteristics of treatments, it can be concluded that 25% Benthosema pterotum gelatin can be added to the bovine gelatin in the pastille formulation. The fish gelatin can be applied as cost-efficient source and also as quality improver in the production of pastilles.

A feeding trial which lasted for eight weeks was conducted to investigate the effects of diludine, a growth promoter, on feed efficiency, muscle structure and proximate composition of juvenile rainbow trout. Diludine was added at 0.0(D0) 0.2(D1), 0.5(D2) and 1(D3) g kg-1 to a casein-based diet, and every diet was given to the triplicated groups of juvenile rainbow trout. At the end of experiment, it was determined that a significant improvability existed for both growth and feed utilization in fish fed diets supplemented with diludine (p

Three different experiments were conducted to study the effect of dietary astaxanthin on the immune response, resistance to white spot syndrome virus (WSSV) and transcription of antioxidant enzyme genes in Pacific white shrimp Litopenaeus vannamei. Each experiment included one triplicate treatment group (fed with 80 mg/kg astaxanthin supplemented diet) and one triplicate control group (fed with basal diet), and the feeding period lasted for 4 weeks. The experiment of immune responses showed that dietary astaxanthin significantly affects the hemolymph immunological index, including total haemocyte counts, phagocytic activity of haemocyte, serum anti-superoxide radical activity, serum phenoloxidase activity, serum anti-bacterial activity and serum bacteriolytic activity. In the experiment of resistance, the shrimp was challenged with WSSV after the feeding stage was finished. The result showed that the mortality of the experimental group 11 days post infection was 76.3%, while that of the control group was 100%. WSSV infection result via polymerase chain reaction (PCR) detection method showed that 95.6% of the dead shrimp in the experimental group were PCR positive, whilst 71.4% of the survived shrimps were WSSV positive. At the end of the experiment, 90% of the shrimps in the experimental group were WSSV positive, while all the the control group were WSSV positive. The result indicated that dietary astaxanthin could increase the resistance to WSSV. In the experiment of transcription of antioxidant enzyme (cyt-MnSOD, CAT and GPX) genes, the effect of astaxanthin on the transcription of these enzyme genes in the hepatopancreas was studied using semi-quantitative RT-PCR analysis. The results suggested that astaxanthin could promote the antioxidant enzyme gene mRNA expression in the hepatopancreas of L. vannamei.

This study describes the effects of different stocking densities on texture/colour characteristics, protein content /amino acid and lipid content/fatty acid composition of rainbow trout fillet. Stocking density was selected 5 (Group A), 15 (Group B), 25 (Group C) kg fish m−3. Tukey’s Multiple Comparison Test showed insignificant differences between measured size/weight measurement and condition factors. No significant differences were found between A and C groups for colour analysis (L* and a* value) and texture profile analysis (hardness, adhesiveness, cohesiveness and gumminess values) of rainbow trout fillets. The proximate composition analysis showed rainbow trout fillets from the A and C groups to exhibit higher values of moisture than the B group. Fish from the A and B groups had a lower of ash and protein in comparison to C group samples. The highest fat values of rainbow trout were measured in B group samples. The content essential amino acid and non-essential amino acid was lower in A and B groups than in C groups. Fish from the C group had higher content of polyunsaturated fatty acids, especially n-3, docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA) in comparison to A and C group. As a result, 25 kg fish m−3 is recommended stock density in terms of product texture/color and composition quality.

The influence of two types of resistant starches (RS2 and RS4) substituted at 10 and 20% in the batter formulation on the water retention capacity of the batter and on the texture, color, fat content and microstructure of the pre-fried and oven cooked breaded black pomfret fillets (Parastromateus niger) were studied. A significant (p<.05) increase of water retention capacity (3-7%) was found in all batters with RS as compared to the control, which was reflected in the moisture content of the breaded fillets. The addition of the resistant starches significantly (p<.05) decreased the fat content of the breaded fillets. Instrumental texture analysis showed that the presence of the RS in the batter also resulted in a significant increase in hardness and fracturability of the products. The L* and b* values of breading materials were increased in the samples containing 20% of RS.

Talang Queenfish (Scomberoides commersonnianuus) is relatively inexpensive fish with low consumption in Fars Province, South of Iran. In this research which was done in 2011, minced fish sausages were produced from mince and surimi of this species and some physicochemical attributes of the products were investigated during 60 days of cold storage at 4 °C. According to the results, free fatty acid (FFA), peroxide and TBARS values of minced fish sausage were significantly higher than those for surimi sausage (p<.05). It was found that minced fish sausage significantly had (P<.05) more breaking and gel strength compared to the surimi sausage at each time of preservation. There were significant differences (P<.05) in L*, a* and whiteness colorimetric parameters of the sausages. Scanning electron microscopy images demonstrated that the surface porosity increased during preservation. This study demonstrated that surimi sausage had better textural and chemical characteristics than minced fish sausage during cold storage.