جستجوی مقالات مرتبط با کلیدواژه « oncorhynchus mykiss » در نشریات گروه « صنایع غذایی »

The effects of storage of rainbow trout processing by-products at 4 ºC on fatty acid composition and nutritional values of hydrolyzed-derived oils were determined. Polyunsaturated fatty acids (PUFA, 39.97-43.70%) were the major fatty acids followed by monounsaturated (MUFA, 31.90-34.05%) and saturated (SFA, 19.27-22.59%) fatty acids. Among fatty acids, linoleic, cis vaccinic, and palmitic were the main fatty acids. N-6 fatty acids represented 34-38% while n-3 fatty acids were 4.5-6.6% of all fatty acids (P<0.05). Hypocholesterolemic/hypercholesterolemic ratio (h/H) index in oils was between 4.23 and 5.15. The highest value was found at day 2 while showed no changes among other storage times (P>0.05). Thrombogenic index (TI) at days 0 and 2 were the lowest among storage times while at days 5 it represented the highest value. However, the change was not significant (P>0.05). N-6/n-3 ratio ranged from 5.01 to 7.6. PUFA/SFA was between 1.77 and 2.29 and showed the highest value at day 2 while after 5 days significantly decreased (P<0.05). The highest fish lipid quality (FLQ) index was for fresh by-products (day 0) (P<0.05) and showed no differences from day 1 to 5 (P>0.05). Also, nutritive value index (NVI) ranged from 2.25 to 2.55 with no significant differences during storage (P>0.05). The sum of EPA and DHA was between 1.73 and 4.05% and decreased with increasing storage days (P<0.05). Polyene index (PI) decreased to the end of storage time up to 4 days compared with the fresh by-products and significantly decreased thereafter after 5 days (P<0.05). Results of the present study showed that fatty acid composition and nutritional quality of oils from hydrolysis-derived oils were influenced by the storage days to some degree.

The fishing industry is one of the most important factors affecting the economy of many countries in the world. By-products of aquaculture processing constitute a large part of fish (He et al., 2013). The use of waste from aquatic processing will not only increase the economic value of aquatic harvesting, but also by reducing the amount of aquatic processing waste, it will reduce pollution and economic costs related to the treatment of produced waste (Fang et al., 2017). The main of by-products of aquatic processing industries including skin, intestines and viscera and blood, which contain a good amount of protein that can be used as a source for bioactive peptides (Chalamaiah et al., 2012). Hydrolyzed protein usually contains small fragments of bioactive peptides that contain 2-20 amino acids (Ryan et al., 2011). The most important functions of these bioactive compounds, can mention the anti-oxidation, anti-microbial, anti-cancer and immune system boosting activities (Vioque et al., 2001). Fiches viscera are one of their most important wastes and are rich in unsaturated fatty acids and protein (Bhaskar et al., 2008). Since the production of bioactive peptides from fish waste and their bioactive properties including antioxidant properties have been done in other studies, in this research we are looking for the effect of the molecular weight of peptides on their antioxidant properties using ultrafiltration membranes.

The viscera of rainbow trout (Oncorhynchus mykiss) were prepared from fresh rainbow trout from the salmon breeding farm in Mashhad and were transported to the laboratory with sufficient amounts of ice in the shortest time and it was kept at -20°C until use. Approximate analysis of the samples was determined according to the standard method of AOAC (2005). Production of hydrolyzed protein from viscera was done by the method of Ovissipour et al (2012). The amount of protein in the solution phase was measured by the method of Lowry et al (1951) and the degree of hydrolysis was estimated by the equation of Kristinsson and Rasco (2000). The antioxidant property of the hydrolyzed protein of treatments 1 and 2 was measured by examining of DPPH free radical inhibition and ABTS+ radical scavenging power indices. and according to the results, it was determined that treatment 2 (2% concentration of alkalase) has a higher antioxidant effect, therefore this treatment were divided by ultrafiltration membranes with molecular weights (<30KDa, <10KDa and <3KDa) and treatment 1 was removed at this stage. After this step, the antioxidant property of peptide fractions in molecular weights (<30KDa, <10KDa and <3KDa) in the treatment of 2% alkalase was measured again by examining the DPPH and ABTS+ indices. Then, the antioxidant properties of peptide fractions in different molecular weights from treatment of 2% alkalase were again measured by the DPPH and ABTS+ indices.

The results of approximate compositions showed that the highest compositions of viscera were moisture (60.817%), and fat (21.91%) and protein content (13.57%), followed by was the low amount of ash content (1.12%) and carbohydrates ( 2.17%). The chemical compounds of food play an important role in the body's health by providing essential nutrients. The ratio between waste compounds is varied according to the age and sex of fish. The amount of moisture from this evaluation was similar to the waste of rainbow trout 64.52% (Mirsadeghi 2015) and the amount of protein is similar to the waste of Zalon fish 13.00 (Nemati e al., 2019). The ash similar to common Kilka 1.46% (Soleymani et al., 2016) and the fat was 22.83% similar to Anchoy Kilka (Mehdabi et al., 2021). The degree of hydrolysis estimates the change of peptide content in a hydrolytic reaction. The degree of hydrolysis increased by increase of enzyme concentration in hydrolysis, so treatment 2 showed a significant increase (68.15±0.02%) compared to treatment 1 (53.60±0.22%) (p<0.05). The results of antioxidant property using DPPH and ABTS+ indicators on research treatments showed that treatment 2 (2% concentration of alkalase) had a higher antioxidant property than treatment 1. The results of the antioxidant property of the peptide components again using DPPH and ABTS+ indicators on the treatment of 2% alkalase enzyme concentration showed that the hydrolyzed protein and all peptide components (<30KDa, <10KDa and <3KDa) have the ability to DPPH and ABTS+ free radicals inhibition but in the comparison of peptide components with the same concentration (1.25 mg/ml), the peptide component <3KDa had a higher inhibitory property than other fractions, that the value in DPPH free radical inhibition was 76.55±0.01 and ABTS+ free radical inhibition was 88.25±0.05 and the difference between the peptide components was significant (p<0.05). It should be noted that free radical scavenging of DPPH and ABTS+ had icreased by use of the ultrafiltration process. Also, short-chain peptides have higher antioxidant properties than long-chain peptides (Bordbar et al., 2018), the reason of this case is the number of hydrophobic amino acids in peptide components that affect the intensity of antioxidant activity (Guillén et al., 2010). The results of this study about the DPPH radical inhibition were similar to the results of Wang et al (2013), Jang et al. (2017) and Xi et al (2008). Also, the results of the antioxidant properties of ABTS+ were consistent of the results of Ma et al (2010) and Martysiak-Zurowska and Venta (2012).

The results of this study showed that, firstly, the used of concentration of the enzyme and the degree of hydrolysis has an effect on antioxidant property of the hydrolyzed protein and secondly, the ultrafiltracin process had a different effect on the antioxidant properties of peptides, so that all peptide components had antioxidant properties but also the molecular weight has an effect on the bioactivity, so that peptides with low molecular weight has an stronger bioactivity properties.

Nowadays, consumers are applicant to usage of natural replacements causing to side effects of synthetic preservatives such as carcinogenicity and teratogenicity. The tendency to use natural preservatives and replacing them with chemical preservatives has led to various studies of natural compounds with antioxidant properties such as essential oils. Considering the environmental problems raised from current plastic packaging, edible and biodegradable coating could be developed and also be effective in controlling the chemical and microbial properties of food; especially if their effect be strengthened by adding natural antioxidant and antimicrobial agents like herbal essential oils. Various herbal compounds such as black pepper essential oils with antioxidant properties can be effective in combining with natural biodegradable coatings such as chitosan in oxidation control and enhance the effects or prevent or delay the chemical spoil. Safety and shelf-life of foods can be improved by using this technologies such as using natural preservatives. Adding essential oil, as a suitable source of antioxidant, for improvement the quality of the fish is the main purpose. Many fruits, especially orange, are rich in polyphenols. These materials are the most commonly existing phytochemicals in most fruits. Orange juice concentrate can be a good source of antioxidant and can be employed as a preservative in food products. Omega-3 fatty acid is used in daily healthy diet and plays an important role in prevention of disease. Being a considerably main source of Omega-3 fatty acid groups, fish preservation against oil oxidation and any other similar causatives seems quite necessary. In the present study, the effects of orange juice concentrate and chitosan coating enriched with black pepper essential oil on the chemical degradation of rainbow trout fillet stored in a refrigerator investigated. The chemical composition of black pepper essential oils were determined using a gas chromatography equipped with mass spectroscopy (GC/MS). GC-MS analysis of the essential oil was performed using Agilent-Technologies 6890N Network gas chromatographic (GC) system, equipped with Agilent Technologies 5975 inert XL Mass selective detector and Agilent-Technologies 7683 B series auto injector (Agilent-Technologies, Little Falls, CA, USA). Samples were stored at 4 ± 1 C° up to 12 days and evaluated periodically ( on days 0, 4, 8 and 12) for chemical and sensory characteristics. The samples were divided into 8 groups and assessed for PH-values, total volatile nitrogen (TVN), thiobarbituric acid (TBA), peroxide value (PV), free fatty acids (FFA) and sensory evaluation .The samples were also evaluated for antioxidant activity by measuring their scavenging abilities to DPPH radical (2,2 diphenyl-1-picril hydrazyl) and RP (Reducing power). Statistical analysis was performed using SPSS 20 software.Results & Results showed that More than 21 compounds were identified in oil, representing 97.75% of the total oil. The major constituents of essential oils obtained from the black pepper were β-caryophyllene (25.56%), Limonene (15.19%), Sabinene(12.2) , α-copaene(8.5) and beta –bisabolene (7.81) respectively. Results revealed that in comparison to the other treatments the control showed a significant increase in the trend of oxidative and sensory indexes and In the coated samples, the sample of fish coated with orange juice concentrate ,chitosan, and black pepper essential oil was the least amount of indexes than the rest (p<0/05) and showed lower indexes during the storage time .The radical scavenging DPPH, orange juice concentrate with a Brix 1/39 (66/9 %)and pepper essential oil 2% (64/1%) have more ability and had a greater antioxidant activity. In investigating corruption oxidation and sensory evaluation in all samples,chitosan coating with pepper essential oil and orange juice concentrate was higher(score:7/2) than other treatments and there were significant differences between treatment and control (p<0/05). Final peroxide value (meq O2/Kg oil) and tiobarbituric acid (m gr/kg oil MD) number using chitosan coating with pepper essential oil and orange juice concentrate in sample was 0.14 and 0.015, respectively. This significant deference was also observed when comparing to control sample (p<0.05)Minimum oxidative changes were observed in samples treated with orange juice concentrate,chitosan, and black pepper essential oil and had the best conditions in reduction of oxidative rancidity. The results obtained in this study showed that the chitosan coating enriched with black pepper essential oil with orange juice concentrate has a good potential to being employed as an active packaging to preserve food products. Overall, this study demonstrated that using concentrated juice incorporated with chitosan coating with pepper essential oil has a good effect on the quality of rainbow trout fillets and can keep on the sensorial attributes acceptably during 12 days storage time and present a good potential for their application in the food industry.

This study investigated the antimicrobial and antioxidant properties of Citrus aurantium L. essential oil on increasing the shelf life of rainbow trout fillet (Oncorhynchus mykiss) at 0 ° C. Sampling of trout fillets with 0, 0.4, 0.8 and 1.2% of orange essential oil on days 0, 3, 6, 9, 12 and 15, and antioxidant properties, chemical tests (TVN, TBA), PV, FFA, pH) and microbial were investigated. In evaluating the antioxidant property, the concentration of orange (mg/ ml) was 67.6 and 32.71 mg/ml for BHT. The results showed that the pH in the fillet increased from zero to fifteenth day. The volatile nitrogen volumes (except for treatment 2 and 3 on days 6 and 9), free fatty acids and thiobarbituric acid, were significantly different between treatments at different days (P <0.05). The highest and lowest levels of peroxide value were observed in the control treatment at 12.16 ± 0.014 (mg/ kg body weight) on day 12 and treatment at day zero was 0. 862 ± 0.006 (mg/ kg) Fat) was obtained. The total bacterial count in the fillet in the control treatment was higher than the standard level from the 9th to the 15th day and exceeded the limit in treatment 1on the fifteenth day but in other treatments it did not exceed the permitted limit until the fifteenth day (7 log cfu/ g). According to the results, the best shelf-life of rainbow trout fillets was influenced by 1.2% of essential oil of orange leaves on day 9.

The aquatic zoonotic bacterial Streptococcus iniae represents a threat to the worldwide aquaculture industry. This study was carried out to evaluate the antibacterial activity Cuminum cyminum essential oil and nisin for control of S.iniae in fillets of Rainbow trout (Oncorhynchus mykiss) in 4 Cº on basis hurdle technology between 2012 and 2013.The effect of different concentrations of nisin (0, 0.25 and 0.75 µg/ml) and Cuminum cyminum (0, 0.005, 0.135 and 0.405 %) were conducted on growth of S.iniae GQ850377 for 15 days. The results showed that growth of bacterial delayed in samples treated with nisin and essential oil singly to 9 days and together to 3 days. Samples treated with essential oil showed a significant decrease on the growth of the bacteria compared with nisin and control sample (P<0.05). No significant different was observed on the growth of S.iniae in samples treated with higher concentrations of C.cyminum (0.135 and 0.405 %) (p>0.05), but different concentrations of nisin was statistically significant (p<0.05). Synergistic effects were observed at concentration of 0.405% C.cyminum and 0.75 µg/mL nisin.