Effects of frying by different frying oils on fatty acid profile of silver carp (Hypophthalmichthys molitrix)

The study aims to determine the influence of frying (shallow and deep) with olive, canola and sunflower oil on fatty acid composition of silver carp. Frying by olive oil and canola oil increased the monounsaturated fatty acids (MUFA) significantly (p<0.05) that consequently decreased saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA) and ω-3 fatty acids. Frying by sunflower oil increased PUFA significantly (p<0.05), which caused to decrease in SFA and MUFA. The ω-6/ω-3 ratio of control samples (0.224) after shallow fat frying and deep frying, increased to 1.287 and 0.615; to 2.290 and 1.538; and to 9.381 and 5.950 by olive oil, canola oil and sunflower oil, respectively. Results suggest that frying oil can change the fatty acid composition of fish. The changes are depending to the kind of frying oil and method of frying which used

The effects of washing with Tamarind (Tamarindus indica L.) water solution on shelf life of silver carp (Hypophthalmichthys molitrix) fillet during refrigerator storage

This study evaluated the antibacterial and antioxidant effects of tamarind water solution on shelf life of silver carp (Hypophthalmicthys molitrix) fillet during refrigerator storage. Treatments of this study were unwashed samples (control), and samples washed with 1% and 2% tamarind water solution. Microbial, physicochemical and sensory analysis including total viable count (TVC), peroxide value (PV), thiobarbituric acid (TBA), total volatile base (TVB-N) and pH were measured during 15 day storage at refrigerator (with 3 days intervals). Proximate analysis of samples also measured at day 0. TVC content was 0.93, 0.50 and 0.10 log CFU/g for control and treatments 1% and 2%, respectively and reached to 6.24, 5.82 and 5.21 log CFU/g at the end of storage period. At the end of storage period, the PV, TBA and TVB-N content were 8.4, 4.3, and 3.0 meq O2/Kg for control, 2.75, 1.35, and 0.50 mg/100g for 1% treatment, and 33.17, 23.90, and 22.10 mg N/100g for 2% treatment, respectively. This results showed the positive effect of tamarind to inhibit and delay fish fillet spoilage. According to sensory evaluation, the density of 1% tamarind was selected as the best density

Effect of different levels of dietary betaine on growth performance, food efficiency and survival rate of pike perch (Sander lucioperca) fingerlings

A 6-week feeding experiments were carried out to determine the effects of different levels of dietary betaine on growth performance, food efficiency and survival rate of pike perch which has a critical period during transition feeding. Fingerlings of pike perch were fed with live food (treatment A), without betaine added to biomar (treatment B), 1% betaine added to biomar (treatment C) and 2% betaine added to biomar (treatment D) in 1000 l concreted tanks. 200 fingerlings (1.50 g, mean weight) were stocked in each tank and fed up to 7 meals per day. Higher increment in body weight (4.99 ± 0.73 g), specific growth rate (3.90 ± 0.06) and food efficiency (104.42 ± 4.27) were obtained with treatment D (2% betaine added to biomar). This treatment also showed significant (P<0.05) decrease in food conversion ratio (0.93 ± 0.04) in comparison with other treatments. Highest survival rate was observed in treatment B (biomar without betaine) with a 34.5 % rate and greatest cannibalism (1.03 ± 0.01) was found in treatment D, respectively. It was concluded that betaine could increase the palatability and acceptability of food and could be suitable to weaning the pike perch fingerlings to artificial diet

The influence of sodium chloride replacement with potassium chloride on quality changes of hot smoked kilka (Clupeonella cultriventris caspia) during storage at ± 4°C

The aim of this work was to study the effect of sodium chloride replacement with potassium chloride on quality changes of hot smoked Kilka during storage at ± 4°C. To achieve this, after initial preparation, samples were exposed to brining process in two salts. This study was designed in two stages: in the first stage, different levels of salt replacement were used to select the best smoked treatment based on sensory test. In this stage, treatments were as: control (100% of NaCl), treatment 1 (75%NaCl/25%KCl), treatment 2 (50% NaCl/50%KCl), treatment 3 (25%NaCl/75%KCl), treatment 4 (100% of KCl). Samples were processed at slow and fast speed smoking for about 4 h, cooled and then tested by test panel. In the second stage, biochemical changes of selected treatment (treatment 1) were compared with control samples during storage at ± 4°C for 15 days. There were no differences (p>0.05) in content of fat, moisture, ash and TBA indices between control and treatment 1. Protein levels and salt intake were significantly (p<0.05) increased while the TVB-N and PV indices decreased in treatment 1. The results indicated that 25% sodium replacement with potassium is desirable for this product

Fatty acid composition of fresh and smoked Black and Caspian Sea sprat, Clupeonella cultriventris (Nordmann, 1840) treated with different salt composition

The effect of salting by different salt composition on fatty acid profile studied in hot smoked Black and Caspian Sea sprat, Clupeonella cultriventris. After initial prepare activities, samples were exposed to brining process within two salt concentrations including of 100 % NaCl (treatment 1 or T1) and 75 % NaCl- 25 % KCl (treatment 2 or T2) under 15% brine solution for 3 hrs. The smoking process included turning the samples into drying and hot smokes by slow and high rates of smoking machine (Atmoos) set and packaged. Fatty acid profiles of treated samples were compared with fresh fish samples (control). Smoking process decreased the content of SFA and contemporary increased the content of PUFA in comparison to control samples. These changes were slightly higher in T2. N-3/n-6 ratio of control samples (7.30) was increased in T1 samples (7.71) and decreased in T2 samples (6.86) after smoking process. Atherogenic index (AI) value was decreased after smoking process in both treatments with higher decrement for T2. Thrombogenic index (TI) value was also decreased after smoking process in both treatments. Partial sodium replacement did not affect fatty acid composition, PUFAs content, AI and TI values

Remote Assessment of Cultural Heritage Environments with Wireless Sensor Array Networks

The logistics and cost of environmental monitoring can represent challenges for heritage managers, partly because of the sheer number of environmental parameters to consider. There is a need for a system, capable of monitoring the holistic impact of the environment on cultural materials while remaining relatively easy to use and providing remote access. This paper describes a dosimetric system based on piezoelectric quartz crystal technology. The prototype sensing module consists of an array of piezoelectric quartz crystals (PQC) coated with different metals (Fe, Cu, Ni and Sn) and includes a temperature and relative humidity sensor. The communication module involves an 802.15.4 low-power radio and a GPRS gateway which allows real time visualisation of the measurements online. An energy management protocol ensures that the system consumes very low power between measurements. The paper also describes the results and experiences from two heritage field deployments, at Apsley House in London, UK, and at the Royal Palaces of Abomey in Benin. Evaluation of PQC measurements, temperature, relative humidity and the rate of successful transmission over the communication systems are also reported

Effects of genistein on melanosis and microbial quality of Litopenaeus vannamei during ice storage

Utilization of genistein as a natural inhibitor was studied alone and in combination with conventional treatments on melanosis and microbial quality of fresh L. vannamei during 10 days ice storage. Treatments were as followed: A (dipping samples in distilled water), B (dipping in 1.25 % sodium metabisulphite solution), C (dipping in 0.01 % genistein + 2% glycerol solution), D (dipping in 0.1 % genistein + 2% glycerol solution), E (dipping in 1% NaCl + 0.05 % EDTA + 0.5 % ascorbic acid + 0.5 % lactic acid solution), F (dipping in 0.01% genistein + 2 % glycerol + 1 % NaCl + 0.05 % EDTA + 0.5 % ascorbic acid + 0.5 % lactic acid solution) and G (dipping in 0.1 % genistein + 2 % glycerol + 1 % NaCl + 0.05 % EDTA + 0.5 % ascorbic acid + 0.5 % lactic acid solution). Results showed that G treatment was more affective on inhibiting of melanosis in L. vannamei. Mesophilic and psycrophilic bacterial counts in G treatment were lower than other treatments during ice storage

Statistical Optimization of Tannase Production by Penicillium sp. EZ-ZH390 in Submerged Fermentation

Tannase has several important applications in food, feed, chemical and pharmaceutical industries. In the present study, production of tannase by mutant strain, Penicillium sp. EZ-ZH390, was optimized in submerged fermentation utilizing two statistical approaches. At first step, a one factor at a time design was employed to screen the preferable nutriments (carbon and nitrogen sources of the medium) to produce tannase. Screening of the carbon source resulted in the production of 10.74 UmL-1 of tannase in 72 h in the presence of 14% raspberry leaves powder. A 1.99-fold increase in tannase production was achieved upon further screening of the nitrogen source (in the presence of 1.2% ammonium nitrate). Then the culture condition variables were studied by the response surface methodology using a central composite design. The results showed that temperature of 30°C rotation rate of 85 rpm and fermentation time 24 h led to increased tannase production. At these conditions, tannase activity reached to 21.77 UmL-1, and tannase productivity was at least 3.55 times (0.26 UmL-1h-1) in compare to those reported in the literature. The present study showed that, at the optimum conditions, Penicillium sp. EZ-ZH390 is an excellent strain for use in the efficient production of tannase

Effect of different cooking processes on the fatty acid profile of grass carp (Ctenopharyngodon idella) fillets during chill storage

The effects of different cooking methods (deep fat frying, boiling and steaming) on lipid content and fatty acid composition of grass carp (Ctenopharyngodon idella) fillets during chill storage were investigated. Fillet samples were cooked and then stored at + 4°C for 4 days. The control and the cooked fillet samples were analyzed for their chemical characteristics. Twelve fatty acids were identified with 39.11, 15.37 and 45.52 g/ 100 g of saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) respectively. The n-3/n-6 ratios of raw, deep fried, boiled and steamed samples were 1.12, 0.10, 1.45 and 0.72, respectively. The patterns of changes in fatty acid groups was different in fried, boiled and steamed samples after 1 and 4 days of chill storage. The EPA+DHA/C:16 ratio was higher in boiled and boiled- chill stored samples than steamed and fried samples. EPA+DHA/C:16 ratio for cooked, stored for 1 day and then 4 days were as 0.051, 0.003 and 0.017 for fried, 0.492, 0.583 and 0.489 for boiled and 0.247, 0.037 and 0.149 for steamed samples, respectively. These results showed that the boiled process is better than other cooking processes on the FA pattern of grass cap

Sliding mode controller design for stabilization of the three-phase grid-connected inverters in the presence of unbalanced local loads

Considering the presence of different model parameters and controlling variables, as well as the nonlinear nature of DC to AC inverters; stabilizing the closed-loop system for grid current balancing is a challenging task. To cope with these issues, a novel sliding mode controller is proposed for the current balancing of local loads using grid-connected inverters in this paper. The closed-loop system includes two different controlling loops: a current controller which regulates the output current of grid-connected inverter and a voltage controller which is responsible for DC link voltage regulation. The main features of the proposed nonlinear controller are reactive power compensation, harmonic filtering and three-phase balancing of local nonlinear loads. The developed controller is designed based on the state-space averaged modelling its stability and robustness are proved analytically using the Lyapunov stability theorem. The accuracy and effectiveness of proposed controlled approach are investigated through the PC-based simulations in MATLAB/Simulink