Food Biotechnology
Soheyl Reyhani Poul; sakineh Yeganeh; Reza Safari
Abstract
Introduction: One of the synthetic and harmful preservatives used in sausage is sodium nitrite. Sodium nitrite in meat products helps to increase the storage period and marketability of the product by preventing the growth of anaerobic bacteria, especially clostridiums, exerting an antioxidant effect, ...
Read More
Introduction: One of the synthetic and harmful preservatives used in sausage is sodium nitrite. Sodium nitrite in meat products helps to increase the storage period and marketability of the product by preventing the growth of anaerobic bacteria, especially clostridiums, exerting an antioxidant effect, stabilizing the red color of the meat and improving the taste. Besides these benefits, sodium nitrite is very dangerous for health and it can cause malignant diseases. For this reason, it is necessary to replace this substance with a natural preservative. Pigments extracted from aquatics such as astaxanthin with antioxidant activity, antimicrobial properties and pink color may be a good substitute for sodium nitrite. But these pigments must be nanoencapsulated first due to their sensitivity to food production conditions, including high temperature. The aim of the current research at the first is to extract astaxanthin from Haematococcus microalgae by acid-acetone method and pigment nanoencapsulation with maltodextrin-caseinate combination coating. Then, the nanocapsules produced with different proportions will replace sodium nitrite in the sausage formulation, and oxidative and microbial spoilage tests, color and sensory evaluation will be performed for different treatments.Materials and Methods: First, astaxanthin pigment was extracted from Haematococcus microalgae (Haematococcus pluvialis) using acid-acetone technique. Then, the extracted pigment was nanoencapsulated with maltodextrin-sodium caseinate combined coating and the resulting nanocapsules in the form of treatments A (120 mg/kg sodium nitrite), B (120 mg/kg nanocapsules carrying astaxanthin), C (90 mg/kg sodium nitrite+30 mg/kg nanocapsules carrying astaxanthin), D (60 mg/kg sodium nitrite+60 mg/kg nanocapsules carrying astaxanthin) and E (30 mg/kg sodium nitrite+90 mg/kg nanocapsules carrying astaxanthin) replaced sodium nitrite in the sausage formulation. These treatments were evaluated in terms of oxidative spoilage, microbial spoilage, color indices and sensory properties during 28 days of storage at refrigerator temperature along with the control (without sodium nitrite and nanocapsules). This research was conducted in a completely randomized design. Data were analyzed by one-way analysis of variance and the difference between the means was evaluated by Duncan's test at 95% confidence level. Results and Discussion: According to the results, the lowest levels of thiobarbituric acid and peroxide value during the storage period were related to B, E and D (p>0.05) treatments (p<0.05). A and C treatments had no significant difference in terms of thiobarbituric acid and peroxide until day 14 (p>0.05), but with the passage of time this difference became significant and treatment A showed higher values (p<0.05). The results of this section showed that the power of astaxanthin in controling with oxidative spoilage is significantly greater than that of sodium nitrite, and if the purpose is only to control this type of spoilage, there is no need to replace or use sodium nitrite. The results showed that in the field of controlling microbial spoilage, sodium nitrite has more power than nanocapsules carrying astaxanthin. So that, the lowest amount of total volatile basic nitrogen (TVB-N) and the most standardized pH were related to treatments A, C and D (p>0.05) during the storage period (p<0.05). B and E Treatments (p>0.05) were ranked next (p<0.05). The results of this section showed that if from 120 mg/kg sodium nitrite to 60 mg/kg is replaced with astaxanthin carrying nanocapsules in the sausage formulation, the resulting product has the same antimicrobial power as product containing 120 mg/kg sodium nitrite. Evaluation of the color and sensory properties of treatments showed that A, C and D treatments are at a higher level than treatments B and E and the control in terms of color indices and general acceptance (p<0.05). Comparison of the color and sensory properties of the treatments on days 0 and 28 of storage at refrigerator temperature showed that the color and sensory indices remained constant in the formulated treatments, unlike the control.Conclusions: Nanocapsules carrying astaxanthin with combined maltodextrin-sodium caseinate coating as a natural product with many properties in health, control and prevention of various diseases, have a high efficiency to replace the harmful sodium nitrite preservative in sausage formulation. So that, if 30 to 60 mg/kg of the permissible limit of 120 mg/kg of sodium nitrite in the sausage formulation is replaced with nanocapsules carrying astaxanthin, the resulting product will be similar to the product containing 120 mg/kg of sodium nitrite in terms of shelf life, resistance to oxidative and microbial spoilage, color indices and sensory evaluation.
Food Technology
Reza Safari; Soheil Reyhani Poul
Abstract
Introduction Phycocyanin is one of the pigments used in the food industry due to its antioxidant and antibacterial as well as coloring properties. This pigment is commercially produced from Spirulina platensis microalgae, in the form of photoautotrophic cultures and in open environments in large ...
Read More
Introduction Phycocyanin is one of the pigments used in the food industry due to its antioxidant and antibacterial as well as coloring properties. This pigment is commercially produced from Spirulina platensis microalgae, in the form of photoautotrophic cultures and in open environments in large ponds or pools in tropical or subtropical areas at the edges of oceans. Different techniques are used in order to extract phycocyanin from spirulina microalgae.. Each technique has its own advantages and disadvantages besides different efficiency. These methods include freezing-defrosting, enzymatic, ultrasound, high hydrostatic pressure, ultracentrifuge, ultra homogenization, extraction using water and various solvents. Of course recently, the production of recombinant phycocyanin has been considered as a suitable option for the production of heterotrophic phycocyanin. The purpose of the current research was to cultivate Spirulina platensis, evaluation of the microalgae growth process, and comparison of the efficiency of different methods in the extraction of phycocyanin pigment. Materials and Methods The pure sample of Spirulina platensis microalgae was prepared from Algaeology Laboratory, Biology Department of Tarbiat Modares University. For the cultivation of spirulina, Zarrouk culture medium with different compositions was used, and after cultivation in smaller scales (100 and 500 ml), the final cultivation was carried out in volumes of 5 and 50 liters. After cultivating the microalgae and exposing them to fluorescent light with appropriate light lux intensity (3500 to 8000) and a period of 12 hours of darkness and 12 hours of light, the samples were placed at 29 °C for 16 days. In order to evaluate the growth process of the algal mass, the absorbance of the solution containing the algal cells was read at a wavelength of 540 nm. After preparing the dry mass of spirulina microalgae, four methods of ultrasound, freezing-defrosting, enzymatic and mineral solvent technique were used to extract phycocyanin. In the next steps, the efficiency of each method was evaluated by measuring the concentration and purity of phycocyanin. In addition, the effect of applying the purification process by ammonium sulfate on the concentration and purity of the extracted pigment was also evaluated. This research was conducted in a completely randomized design and SPSS and EXCEL softwares were used for statistical analysis and drawing of diagram, respectively. Data were analyzed using one-way analysis of variance and the difference between the means was evaluated by Duncan's test at 95% confidence level. Results and Discussion The results showed that microalgae growth from day 0 to 14 had an upward trend and the resulting changes were significant at all times, except days 14 and 16 (p<0.05). Also, after passing the short resting phase (2 days), the microalgae entered the logarithmic growth phase and continued to grow until the 14th day, but between the 14th and 16th days, the growth was almost constant. In the following, it was found that the mass produced after 16 days is 1120 mg/l. The concentration of phycocyanin extracted in enzymatic and ultrasound methods (1.815 and 1.786 mg/ml, respectively) had no significant difference (p>0.05) and was at a higher level than the other two methods (p<0.05); In addition, the pigment concentration was higher in the freezing-defrosting technique (1.535 mg/ml) than in the mineral solvent method (1.121 mg/ml). After purification of the pigment using ammonium sulfate, the pigment concentration and purity increased significantly in each method (p<0.05). The results of this research showed that by choosing the optimal method and applying the purification process using ammonium sulfate, the extraction efficiency of phycocyanin from Spirulina microalgae (Spirulina platensis) could be increased. Conclusion Based on the results of this research, the growth trend of Spirulina platensis in Zarrouk culture medium was ascending first and then constant (during 16 days). Ultrasound technique and enzymatic method (lysozyme enzyme) to extract phycocyanin pigment from Spirulina platensis microalgae have more efficiency than freezing-defrosting and inorganic solvent (hydrochloric acid) methods. Also, purification of the extracted pigment using 40% ammonium sulfate increases the concentration and purity of phycocyanin in each method.
Food Chemistry
Reza Safari; Seyed Vali Hosseini; Sharareh Firouzkandian; Soheyl Reyhani Poul; Mona Zamani
Abstract
[1]Introduction: One way to turn chicken waste into high value-added product is to produce fermented silage (biosilage). This product is superior to fish powder due to its characteristics such as high quality protein, probiotic bacteria and low price and can be considered as a suitable alternative for ...
Read More
[1]Introduction: One way to turn chicken waste into high value-added product is to produce fermented silage (biosilage). This product is superior to fish powder due to its characteristics such as high quality protein, probiotic bacteria and low price and can be considered as a suitable alternative for feed industry. Silage can be produced from protein wastes by both acidic and biological methods. The acidic method of producing silage (acidic silage) uses a variety of organic and inorganic acids such as formic acid and sulfuric acid. In the production of biological silage, two methods of autolysis (using internal enzymes) and fermentation (using microbial starters) are used. Starters used for inoculation are mainly from the group of lactic acid bacteria. To produce silage, protein wastes are used, especially fish wastes. Since poultry waste has not been used for biosilage production in the country so far, the aim of the present study is to produce biological silage from chicken waste and evaluate the profile of amino acids and fatty acids in the biosilage. Materials and methods: Chicken intestine was prepared from meat production complex in Golestan province, Kordkoy city and also Simin Naz poultry industrial slaughterhouse in Sari and was transferred to the processing pilot of Caspian Sea Ecology Research Institute in the shortest time in cold container. During the biosilage production process, protein-degrading bacteria (containing protease enzymes such as gram-positive sporulated bacteria) and acid-producing bacteria (to reduce the pH of the suspension and accelerate the fermentation process, such as lactic acid bacteria) were used as initiator bacteria or microbial starters for intestinal digestion. The product was analyzed for protein, fat, moisture and ash according to standard methods. In this study, high performance liquid chromatography (HPLC) of Cecil model (Seri 200) was used for amino acids analysis. Samples were prepared for assaying amino acids profile in two stages including hydrolysis and derivatization and the results were expressed in grams per 100 grams of substrate. To determine the fatty acids composition of the biosilage sample, the fat was first extracted. In order to evaluate the profile of fatty acids, a Shimadzu model gas chromatography device was used and the results were expressed as a percentage. Results and discussion: The product produced contained about 60% protein and 21% fat. According to the results, the total of essential amino acids in the produced biosilage was 24.416, the total of non-essential amino acids was 30.959 and the total of essential and non-essential amino acids was 55.375 g per 100 g of substrate. Among essentialamino acids, the highest amount belonged to the amino acids leucine (7.334±0.45 g/100g) and valine (4.71±0.27 g/100g) and among non-essential amino acids, the highest amount belonged to glutamic acid (10.6±0.73 g/100g) and alanine (5.864±0.81 g/100g). It was also found that all essential amino acids except tryptophan are present in biosilage. Evaluation of biosilage fatty acids profile revealed that the total amount of saturated fatty acids (SFA) was 33.57%, monounsaturated fatty acids (MUFA) was 41.17% and polyunsaturated fatty acids (PUFA) was 24.36%. It was further found that in biosilage the total omega 3 was 2.07%, the total omega 6 was 22.91% and the sum of EPA and DHA was 2.06%.The profile of amino acids and fatty acids in the biosilage produced from chicken waste is almost the same as that of other products made from protein waste (such as fish meal, fish waste biosilage and hydrolyzed protein powder). This property, along with cheap production and high nutritional value, allows the use of biosilage obtained from chicken waste in the livestock, poultry and aquatics feed industry.
Soheyl Reyhani Poul; Sakineh Yeganeh; Reza Safari
Abstract
[1]Introduction: Nisin is one of the antimicrobial substances that is used today as a preservative in various foodstuffs. It is a bacteriocin comprised of 34 amino acids and a molecular weight of 3.5 Da. With all the benefits of nisin, there are barriers to its use in dairy and protein rich products. ...
Read More
[1]Introduction: Nisin is one of the antimicrobial substances that is used today as a preservative in various foodstuffs. It is a bacteriocin comprised of 34 amino acids and a molecular weight of 3.5 Da. With all the benefits of nisin, there are barriers to its use in dairy and protein rich products. One of these barriers is the combination of nisin with fats, proteins and sugars and the consequent reduction of its antibacterial activity. In the food science and industry, the use of the technique of encapsulation and production of liposome is the best possible solution in such cases. Also, by adding an antimicrobial agent such as chitosan to the coating of nanoliposomes, the antibacterial activity of the product may be increased. The aim of the present research was to produce nanoliposomes carrying nisin with (and without) chitosan coating and to evaluate the physical and antibacterial properties against two gram-positive bacteria, Bacillus cereus and Staphylococcus aureus. Materials and Methods: In this study, four treatments of nanoliposomes carrying nisin (NN), nanoliposomes carrying nisin coated with chitosan 0.05% ((NN-CH (0.05)), nanoliposomes carrying nisin coated with chitosan 0.1% (NN-CH (0.1)) and nanoliposomes carrying nisin coated with chitosan 0.5% (NN-CH (0.5)) were prepared and examined in terms of physical properties (average particle size, particle dispersity index, zeta potential and encapsulation efficiency) and antibacterial activity (against two gram-positive bacteria, Bacillus cereus and Staphylococcus aureus with two diffusion methods in agar medium and microdilution test). This research was conducted in a completely randomized design and SPSS and EXCEL softwares were used for statistical analysis and drawing of diagram, respectively. Data were analyzed by one-way analysis of variance and the difference between the means was evaluated by Duncan's test at 95% confidence level. Results and Discussion: The results showed that the average particle sizein different treatments with each other are significantly different (P<0.05) and vary from about 110 to 327nm; Also as the amount of chitosan in the coating increased, the particle size increased (P<0.05). This indicates the successful binding of chitosan to the surface of the nanoliposome, which results in the formation of a layer around the nanoliposome and an increase in particle size. Particle dispersity index was recorded less than 0.3 in all treatments and was not related to the amount of chitosan in the coating. With increasing the amount of chitosan in the coating of nanoliposomes, zeta potential increased significantly (P<0.05). This index changed from -55.34 in NN treatment to 53.14 mV in NN-CH (0.5) treatment. In fact, chitosan as a cationic polysaccharide changes the potential to positive values. As the amount of chitosan in coating of nanoliposomes increased, the encapsulation efficiency increased significantly in the treatments (P<0.05); this index increased from 32.19% in NN treatment to 75.14% in NN-CH (0.5) treatment. The results of the antibacterial activity of nisin in two methods of diffusion in agar medium and microdilution test showed that its antibacterial activity increased with nanoencapsulation of nisin with (and without) chitosan coating (p<0.05). Also, with the increase in chitosan concentration, the antibacterial activity of carrier nanoliposomes increased and the highest antibacterial activity was recorded in NN-CH (0.5) treatment (p<0.05). The diameter of the non-growth halo of Bacillus cereus against the research treatments (with five concentrations of 2.5 to 25 μg/ml) varied from about 4.5 to 17.5 mm. This amount for Staphylococcus aureus was recorded from 2.1 to 26.5 mm. By increasing the concentration of nisin and carrier nanoliposomes, the diameter of the halo of non-growth of both bacteria increased significantly (p<0.05). But an exception was recorded in this case; The diameter of the non-growth halo for Staphylococcus aureus in two concentrations of 2.5 and 5 μg/ml of treatments was the same and had no significant difference (p>0.05). The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the examined treatments for Bacillus cereus were in the range of 100 to 400 and 200 to 500 μg/ml, respectively. These two concentrations for Staphylococcus aureus were recorded as 50 to 200 and 100 to 400 μg/ml respectively. Based on the values of diameter of non-growth halo, MIC and MBC it can be claimed that Bacillus cereus is more resistant to the examined treatments than Staphylococcus aureus.Nanoencapsulation of nisin in the form of carrier nanoliposomes with chitosan coating is a suitable solution to improve its physical and antibacterial properties. In such a way that by increasing the concentration of chitosan in the coating, both of the aforementioned properties improved significantly. Nanoliposomes carrying nisin with (and without) chitosan coating have the ability to inhibit the growth and killing Bacillus cereus and Staphylococcus aureus bacteria. The antibacterial activity increases with the increase in nisin and carrier nanoliposomes concentrations. The value of non-growth halo, minimum inhibitory concentration and minimum bactericidal concentration confirm that Bacillus cereus is more resistant to nisin and its carrier nanoliposomes than Staphylococcus aureus.
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. ...
Read More
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.
Soheyl Reyhani Poul; Seyed Ali Jafapour; Reza Safari
Abstract
Introduction: With the growing population and following the efforts of food production industries, more waste is produced which can be recovered by adding value and brought them back into the cycle of production and consumption. The reason behind is firstly the reduction of waste and secondly the economic ...
Read More
Introduction: With the growing population and following the efforts of food production industries, more waste is produced which can be recovered by adding value and brought them back into the cycle of production and consumption. The reason behind is firstly the reduction of waste and secondly the economic importance of value added resultant products. Aquaculture sector produces large volume of wastes including the head, tail, fins, spine, and most importantly their viscera. If the waste managed properly, valuable materials such as hydrolyzed protein powder (the resulting waste hydrolysis using proteases enzymes) and fish oil (byproduct of enzymatic hydrolysis) can be produced. In this study rainbow trout waste was chosen, due to its large volume production in the country. The functional properties and antioxidant activity of hydrolysates as well as the oil fatty acid profile are the main factors to be considered. This study was aimed to investigate the hydrolysis of rainbow trout viscera (oncorhynchus mykiss) by protamex and neutrase enzymes individually and compare the functional properties and antioxidants activity of protein hydrolysate as well as analyze the fatty acid profile of fish oil obtained as by-product of enzymatic hydrolysis process.
Materials and methods: Rainbow trout viscera (Oncorhynchus mykiss) were obtained from the fish market in Sari and transported in ice containers to the laboratory. Protamex and neutrase enzymes were purchased from Novozymes Company and protein hydrolysates prepared enzymatically according to the method of Guerard et al. (2002). Proximate analysis was carried out according to the procedures outlined by the AOAC (1995). Degree of hydrolysis determined as described by Hoyle and Merritt (1994). Peptide chain length (PCL) was measured using the method of Adler-Nissen and Olsen (1979). Protein recovery (PR) determined using the method used by Ovissipour et al (2009). Protein solubility for hydrolysates was determined using the method of Robinson and Hodgen (1940). Foam stability index was measured according to the method described by Sathe and Salunkhe (1981). Water holding capacity (WHC) was determined using the method of Rodriguez-Ambriz et al. (2005). DPPH radical-scavenging activity was measured using the method of Yen and Wu (1999). Reducing power was determined by the method of Oyaiza (1986).The chelating activity on Fe2+ was determined, using the method of Decker and Welch (1990).
Results & Discussion: Protamex leads to the production of protein powder with higher degree of hydrolysis (34.76 ± 2.92%) and protein recovery (68/16 ± 1.98%) compared to neutrase (p0.05) despite the difference in L* value. The viscera oil contains 34% monounsaturated, 34.49% polyunsaturated and 31.4% saturated fatty acid. Apart from pH 4 (isoelectric point), the solubility of both protein powders in water was remarkable (more than 90%). The foam activity and stability index of hydrolyzate produced by protamex were more desirable than hydrolyzate produced by neutrase, whereas at pH 6, these indices reached to their maximum values of 200.13± 9.31% and 135.6 ± 5.64 %, respectively. Furthermore, water holding capacity of both hydrolyzates was measured as approximately 4.5 ml/g protein (p>0.05). Protamex leads to the production of protein powder with the higher DPPH radical scavenging activity compared to hydrolyzate produced by neutrase. Conversely, the reducing power of hydrolyzate produced by neutrase was higher than that of protamex (p0.05).
Keivan Ali Asgari; Sakineh Yeganeh; Seyed Ali Jafarpour; Reza Safari
Abstract
Introduction: Nowadays, use of new processing method is important for converting by-products into more marketable and acceptable forms to achieve a better utilization. Sea food processing generate protein rich by-products that their quantity depends on processing method. One of the methods for effective ...
Read More
Introduction: Nowadays, use of new processing method is important for converting by-products into more marketable and acceptable forms to achieve a better utilization. Sea food processing generate protein rich by-products that their quantity depends on processing method. One of the methods for effective protein recovery from this protein rich by-product is preparation of protein hydrolysate through enzymatic, autolytic and chemical hydrolysis. Enzymatic hydrolysis is widely employed to improve the functional and nutritional properties of the fish byproducts. Hydrolysis may be conducted as a method of separating soluble nitrogenous compounds from insoluble particles and fish oil, and offers good predictability of the products. So nitrogen recovery assay can determine enzyme efficiency in separation of soluble protein from insoluble protein. Different factors (Enzyme level, temperature, pH, enzyme to substrate ratio) can effect on the hydrolysis degree, nitrogen recovery and functional properties of protein hydrolysate, so optimization method is used for obtaining the best condition. RSM is a statistical model frequently used for the optimization of complex systems and uses quantitative data from an appropriate experimental design to determine and simultaneously solve multivariate problems. Based on the experimental data, RSM could tell us the optimum conditions to obtain the desired responses, as well as the mathematical model in explaining the relationship between the experimental variables and its responses. Alcalase has great ability to solubilize fish protein and is nonspecific, with an optimum temperature that ranged from 50 to 70°C. It has optimal pH range at the value of 8 to 10 that could reduce the risk of microbial contaminations. Moreover, it has been reported that produced protein hydrolysate by Alcalase had less bitter principles compared to those prepared with papain. Furthermore Alcalase has been documented to be a better candidate for hydrolyzing fish proteins based on enzyme cost per activity.
The Cuttlefish (Sepia offıcinalis) can be found in the south water of Iran including Persian Gulf and Oman Sea and their catch has been recorded about 5102 t according to FAO Statistic. This species has been considered for exporting to other country. During Cuttlefish processing, 30-35 % byproducts including head, arms and viscera are generated that can be invaluable products and environmental pollution while it is protein rich source. The objective of this study was to optimize nitrogen recovery in the enzymatic hydrolysis of head and arms of cuttlefish (Sepia pharaonis) using Alcalase.
Materials and methods: Response surface methodology (RSM) based on Box-Behnken was employed to investigate the effects of different operating conditions including temperature (45, 50 and 55˚C), pH (7.5, 8 and 8.5) and alcalase enzyme to substrate ratio (1, 1.5 and 2) on the nitrogen recovery as a surface response. Referring to the R2 of 0.96 for nitrogen recovery, the mathematical model showed acceptable fitness with the experimental data, which indicated that major part of the variability within the range of values studied could be explained by the model.After obtaining optimum condition for nitrogen recovery, freeze dried protein powder was produced by optimized condition and analyzed for amino acid composition, chemical score of cuttlefish protein hydrolysate and protein efficiency ratio.
Results & Discussion: The obtained results showed the interactive effect of temperature and enzyme to substrate ratio was not significant (P> 0.05) but the interaction effect of enzyme to substrate ratio and pH and the interaction effect of temperature and pH was significant (P
Reza Safari; Zahra Yaghoubzadeh
Abstract
Introduction: Evaluation of fish and seafood markets in Iran show that people have little interest to consume fish, despite the fact that fish consumption in developed countries is the rapid growth. However, despite the significant sources of demand for fish consumption of fish is generally seasonal. ...
Read More
Introduction: Evaluation of fish and seafood markets in Iran show that people have little interest to consume fish, despite the fact that fish consumption in developed countries is the rapid growth. However, despite the significant sources of demand for fish consumption of fish is generally seasonal. One of the problems consumers clean and ready to cook the fish, which need to experience and time, although it is common for all the fish, but the warm water cultured fish is more important, therefore, must be programmed in such a way that the fish are supplied all year. The fish processing provides the possibility that fish that are produced in a limited time and gradually throughout the year are marketed. Due to high production of warm water fish and using of small-scale and traditional methods for processing of fish such as salting and smoking, is necessary to use from modern processing methods for production of high quality of fishery products from fish particularly warm water fish such carp, silver carp, grass carp and big head. In 2004, a joint project with title "improvement of silver carp processing and production of different products from fish" was signed between Iranian Fisheries Science Research Institute and Rivo Institute and Wageningen university of Netherlands. According to the project 7 sub projects were defined that including: quality of fish sausage, fish cheese, fish snake, fish ball, fish ice cream, trimming machines for production of fish fillet and pin bone machines for production of deboned fillet. Two main objectives of the project were production of high quality of fish fillet with low fat and bone and development of various products from silver carp for introduce to market. Fish Cheese is produced from coagulation of soluble proteins (sarcoplasmic proteins) of fish. The aim of this study was to extraction and precipitatation of sarcoplasmic proteins of silver carp (Hypophthalmichthys molitrix) and its use in fish cheese formulations. Materials and methods: After washing, the fish was beheaded, gutted, and again washed and bones were manually separated. Fish fillets were grained and prepared for surimi production. Minced fish were washed three times in 10 ° C water ( 1 to 4 w/v) for 15 minutes, and the third stage was rinsed in the brine (0.3%). For coagulation and concentration of sarcoplasmic proteins were used from acetic acid (5%) and centrifuge in 5000 rpm for 15 minutes respectively. At the end of the process the sugar and sorbitol, (each in the amount of 4%) and tri sodium polyphosphate was used in the amount of 0.3%. Proximate composition (total protein, total fat, moisture and ash) and chemical parameters (peroxide value (PV) and total volatile base nitrogenTVB-N) and microbial analysis (total viable counts) were examined for three forms of fish (minced fillets, concentrated protein and fish cheese). All examinations were done as standard methods for food analysis. Results & Discussion : The results showed that the mean of fat, moisture, ash and protein in silver carp minced was 2.71%, 79.44%, 0.91%, 16.90%, in the concentrated sarcoplasmic protein 1.16%, 81.97%, 0.42% 16.41% and in fish cheese 2.30%, 48.41%, 3.46% and 17.50% respectively. The optimized formula of fish cheese was obtained with 22.26% of protein. The mean of TVB-N and PV in minced fillets were 11.32 mg/100 and 1.51 meqo/kg, in the concentrated sarcoplasmic were 13.63 mg/100 and 3.65 meqo/kg and fish cheese 15.03 mg/100 and 5.38 meqo/kg respectively. The mean total count of bacteria in minced silver carp was 2.7 × 104 cfu/g. The most and least of TVC were 4.5 × 104 and 1.1× 103 cfu/g respectively. Mean of molds and yeasts in minced fish was 3.5 × 103 cfu/g. Highest and lowest of mold and yeast were 7.2× 103 and 1.2× 103 cfu/g respectively. The mean total count of bacteria in concentrated sarcoplasmic protein of silver carp was 1.3 × 104 cfu/g. The most and least of TVC were 2.5 × 104 and 8.1× 103 cfu/g respectively. Mean of molds and yeasts in concentrated sarcoplasmic protein were 3.1 × 103 cfu/g. Highest and lowest of mold and yeast were 5× 103 and 1.5× 103 cfu/g respectively. The mean total count of bacteria in silver carp cheese was 1.8 × 103 cfu/g. The most and least of TVC were 4 × 104 and 8.5× 103 cfu/g respectively. Mean of molds and yeasts in fish cheese was 3.2 × 103 cfu/g. Highest and lowest of mold and yeast were 7.2× 103 and 1.2× 103 cfu/g respectively. Total count of bacteria in different forms of silver carp showed that the number of bacteria in the range of log 4 and the final product was a slight decrease (in some treatments). Changes in the number of bacteria in the processing time depend on two factors, time and temperature. Processing in low temperature and little time are caused that the count of bacteria will be at the standard level. For introduce the new product to market is needed to additional examination such as sensory and organoleptic evaluation.
Marjaneh Alinejhad; Bahareh Shabanpour; Reza Safari; Mozhgan Alinejhad; Hassan Nasrollahzadeh Saravi
Abstract
The objective of this study was to produce fish peptone from tuna (Thunnus tonggol) viscera, by Alcalase. Response Surface Methodology (RSM) was employed for optimizing the temperature and pH. Hydrolysis was done in different tempratures (50-65˚C) , pH (8-8. 5) and selected 13 treatments. Samples with ...
Read More
The objective of this study was to produce fish peptone from tuna (Thunnus tonggol) viscera, by Alcalase. Response Surface Methodology (RSM) was employed for optimizing the temperature and pH. Hydrolysis was done in different tempratures (50-65˚C) , pH (8-8. 5) and selected 13 treatments. Samples with higher value of protein were used instead of the standard peptones which applied in commercial media for Listeria monocytogenes. Based on the three-dimensional graphs, the optimum condition for temperature and pH were determined to be 50˚C and 8. 5 respectively. The results showed that the highest (76. 89 g/l) and the lowest (38. 54 g/l) rates of protein content were related to pH 8 at 57˚C and pH 8 at 50˚C. Maximum bacterial growth rate was related to pH 8 at 65˚C. Results also showed that tuna (Thunnus tonggol) viscera can be used as low cost nitrogen sources for Listeria monocytogenes growth media.
