Synergic Effects of Light Salting,Vacuum Packaging,and Onion Extract on the Quality Retention of Refrigerated Rainbow Trout (Oncorhynchus mykiss) Fillets

This experiment investigated the synergistic effects of vacuum packaging, light salting, and onion extract on the shelf life of rainbow trout (Oncorhynchus mykiss) fillets stored under refrigeration. The chemical, microbial, and organoleptic changes were monitored for up to 18 days in fillets. Total volatile basic nitrogen (TVB-N) and free fatty acid (FFA) values were evident in the order: control (without salting, vacuum packaging, and extract) > air packaged, salted (APS) > vacuum packaged, salted (VPS) > and vacuum packaged, salted, containing 2% and 4% (v/w) onion extract (2% and 4% VPSOE) throughout the storage period. Thiobarbituric acid values in APS groups were higher than control groups. Data from microbial assay showed that treatment with 2% and 4% VPSOE decreased total viable microbial count (TVC) compared with other treatments. APS, VPS, and VPSOE samples remained acceptable for up to 8, 12, and 15 days, respectively. The most suitable indices for determining shelf life of rainbow trout fillets are TVC.     

Oxidative Stability of Spray-Dried Microencapsulated Fish Oils with Different Wall Materials

Multilayer microencapsulation of fish oil was evaluated by using fish gelatin (treated with or without microbial transglutaminase [MTGase]), chitosan, and maltodextrin for its ability to control lipid oxidation. This study showed that a mixture containing gelatin and maltodextrin obtained the highest percentage of core release. The oxidative stability of the formulated mixtures and the bulk oils was investigated during a period of 60 days. The peroxide value (PV) was assessed as a parameter for primary oxidation products, and p-anisidine (p-AV) and thiobarbituric acid reactive sub-stances (TBARS) was used to analyze secondary oxidation compounds. Observation of oxidation products showed that combinations of gelatin and maltodextrin made by adding MTGase and a mixture of gelatin and chitosan were able to increase the oxidative stability, and increases in PV and p-AV and TBARS were found for all oils.     

Investigation of soil compaction on yield and agronomic traits of wheat under saline and non-saline soils

Inappropriate crop management and long-term use of heavy agricultural equipment can lead to soil compaction. On the other hand, soil and water salinity causes reduction in the plant yield in addition to adverse effects on plants tolerance to the various stresses. The aim of this study was to investigate the interaction between soil compaction and salinity on the macronutrients uptake and wheat yield as well as its agronomic traits. The pot experiment was carried out on the loamy soil in a completely randomized block design with three replications. The treatments consisted of two salinity types (saline, EC = 6 dS/m and non-saline soil) and five levels of compaction; control, 5%, 10%, 15% and 20%. The results showed that soil compaction had significant effect on the amount of N, P and K in wheat grain, so that the uptake of N, P and K by grain has been decreased by increasing the compaction level of soil. Soil salinity had significant effect on N, P and K content in grain that the content of N, P and K has been diminished in the saline treatments compared to non-saline treatments. Results on the agronomic traits and yield of wheat also revealed that soil compaction and salinity had significant effect (p < 0.01) on straw weight, number of ears, number of grain, and thousand grain weight which caused reduction in these parameters. The interaction between compaction and salinity had only significant correlation (p < 0.01) with thousand grain weight leading to the decrement of thousand grain weight with increasing compaction levels, particularly in the saline treatment.     

Evaluation of spatial variability of the integral energy of plant available water and its influential properties in paddy soil

Paddy and Water Environment - Plant Available Water is the main concept for describing the existing water content in a soil profile. Along with this concept, Integral Energy shows the energy...     

Quality preservation of salted,vacuum packaged and refrigerated mahi sefid (Rutilus frisii kutum) fillets using an onion (Allium cepa) extract

The combined effect of light salting, vacuum packaging and onion extract on the shelf life of mahi sefid (Rutilus frisii kutum) fillets under refrigeration was assessed using chemical, microbiological and sensory methods. The shelf life of control, air‐packaged, salted (APS), vacuum‐packaged, salted (VPS) and vacuum‐packaged, salted with onion extract (VPSOE) samples was determined to be up to 6, 9, 15 and 18 days respectively. The values of total volatile basic nitrogen, free fatty acid and thiobarbituric acid increased progressively during the storage period for all the treatments. However, the preservative methods applied led to an extended shelf life of fillets based on chemical indices and sensory attributes in the following order: VPSOE>VPS>APS>control group. The assay of the total viable count (TVC) revealed that 2% and 4%VPSOE produced a decrease in TVC throughout the storage period. According to the results obtained, the best method to preserve the mahi sefid fillet was by 4%VPSOE treatment.     

The Influence of Different Dietary Carbohydrate to Lipid Ratios on Some Qualitative Characteristics of Fillets of Beluga (Huso huso) During Refrigeration

In this study, juvenile beluga (Huso huso) were fed diets containing different carbohydrate to lipid ratios for 5 months. At the end of the culture period, proximate compositions of the fish carcasses (moisture, protein, fat, and ash) were measured. Then, qualitative changes in the fishes were evaluated during 24-days refrigeration (4°C), along with changes in their total volatile bases nitrogen (TVN), thiobarbituric acid (TBA), free fatty acids (FFA), pH, and muscle texture profile analysis. The results of proximate analysis of the carcasses showed that moisture, protein, and ash of the carcasses increased significantly (p < 0.05) with higher carbohydrate to lipid ratio, but fat content of the carcasses decreased significantly (p < 0.05). Further, during refrigeration, TVN, TBA, and FFA increased significantly in all the samples (p < 0.05), but these changes did not follow the same pattern in all the treatments. Tissue hardness decreased during preservation. Although pH changes in the fillets were low, they were significant and without a clear-cut pattern. The results showed that use of different carbohydrate to lipid ratios in diet does not lead to clear-cut changes in qualitative characteristics of beluga fillets during refrigeration.     

Growth,survival, and fatty acid composition of Indian white shrimp <Emphasis Type="Italic">Fenneropenaeus indicus</Emphasis> (Milne Edwards) fed diets containing different levels of vitamin E and lipid

The objective of this experiment was to determine the effects of two levels of vitamin E (100 and 300 mg/kg diet) along with two levels of lipid (9 and 14%) and their interaction on growth performance of Indian white shrimp and consequently to evaluate the fatty acid composition and lipid stability of its muscle tissue during frozen storage. Growth of juvenile Indian white shrimp was not significantly affected by dietary vitamin E and lipid levels. Muscle lipid content of shrimp fed diets with 14% lipid was significantly higher than that of with 9% lipid. Obvious effects of the increase in dietary lipid level on muscle fatty acid composition were significant decrease in proportion of 16:0 and increase in proportion of 20:5n-3. The content of vitamin E concentration in shrimp muscle reflected dietary vitamin E concentration and ranged from 6.68 to 14.8 mg/kg muscle corresponding to two (100 and 300 mg/kg) levels of vitamin E in fish diet, respectively. Subsequently, results showed that by increasing the concentration of vitamin E from 100 to 300 mg/kg in diet, the rate of lipid oxidation in the muscle tissue during frozen storage was reduced and, as a result, caused higher HUFA retention in muscle of shrimp fed diet with high lipid level.     

Effect of Thermal Microbial Inactivation and Washing on Quality Properties of Fish Sausage During Cold Storage (4°C)

The effect of microbial inactivation and washing process on physicochemical and sensory quality of pasteurized fish sausage during cold storage (4°C) was evaluated. Mince was obtained after the grinding; washed mince (WM) was obtained by single washing of mince; and surimi was obtained after three washing and dewatering cycles. Texture profile analysis results demonstrated that textural characteristics of pasteurized fish sausages remain stable during storage period (p > 0.05). Color analysis showed that Hunter L* had an increasing trend, and a* and b* had a decreasing trend over time (p < 0.05). Thus, it is possible to inactivate all microorganisms in pasteurized fish sausage without any undesirable effect on physicochemical and sensory quality.