Seyed Hassan Jalili; Reza Farhoosh; Arash Koocheki; Abbas Ali Motallebi
Abstract
Introduction: Considerable amounts of essential fatty acids in fish oil makes it possible to use in the production of functional foods to meet nutritional needs and beneficial effects on health. One of the major problems is their high susceptibility to oxidative deterioration and consequent production ...
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Introduction: Considerable amounts of essential fatty acids in fish oil makes it possible to use in the production of functional foods to meet nutritional needs and beneficial effects on health. One of the major problems is their high susceptibility to oxidative deterioration and consequent production of undesirable flavor. At present, some synthetic compounds are used as antioxidants in food and biological systems, but the use of synthetic antioxidants is of concern due to their potential health hazards. Therefore, the use of natural antioxidants in foods is the first choice. Enzymatic protein hydrolysis has been applied to food industry by-products to produce foods with enhanced functional properties. Antioxidant and antiradical activity of protein hydrolysates from meat, skin, bone, viscera and roes of various aquatic species has been reported. Silver carp (Hypophthalmichthys molitrix) skin (SCS), as low price by-product from minced products processing plants is available in I.R. Iran. Amino acids composition and sequencing determines the functional properties of peptides, which depends on the source of protein, the method and conditions of preparation and molecular weight distribution of resulting hydrolysate. The enzyme type and hydrolysis conditions, including enzyme/substrate ratio, temperature, time and pH, can affect the peptides length and functional properties of protein hydrolysates. The effects of hydrolysate from SCS hydrolyzed by alcalase on some quality features and oxidative stability of microencapsulated Kilka (Clupeonella spp.) oil at pH 6.8 and 3.4 were investigated. Materials and methods: SCS was pre-treated with NaOH and acetic acid, washed and freeze dried. Proteolysis with alcalase (1% w/w) at 50 ºC, without pH adjustment, was performed for 4 hours with gentle stirring. Enzyme inactivated by placing the sample in a boiling water bath for 15 minutes. After centrifugation at 13000 g for 20 minutes, supernatant was removed as silver carp skin hydrolysate (SCSH) and freez dried. Emulsions were prepared with 31.25% dry material. 25% of wall materials (equal proportions of maltodextrin and Hi-Cap®100), fish oil 25% and SCSH (for preparing 1, 2, 3, 4 and 5 mg/mL treatments) in two adjusted pH 3.4 and 6.8, was used. Fish oil was refined using multi-layered column chromatography (alumina-silica gel), and fatty acid composition was determined. The emulsion pre-homogenized by the IKA Ultra-turrax at 15,000 rpm for 2 minutes and finally by a HSTO homogenizer at 350 bar for 5 circle, to produce microemulsion. Effects of treatments on the characteristics and oxidative stability of microencapsulated Kilka oil for 28 days in the dark at 45 ºC were compared by determination of surface oil, microencapsulation efficiency, free oil, emulsion stability (%separation), droplet size, optical microscopic observation of morphology and peroxidation stability. Results & discussion: Results showed significant differences between proximate composition of silver carp skin, before and after pre-treatment and revealed that applied method and conditions reduced the amounts of oil and ash to an acceptable level. No aggregation and cluster formation was observed in optical microscopic images of prepared emulsions. The effects of pH on the droplet size and microencapsulation efficiency were insignificant (p> 0.05), but the amount of free oil and emulsion stability were significant at ≥2 mg/mL concentrations of hydrolysate (p<0.05). Peptides effectively retarded the preoxidation of Kilka oil in the model system. Hydrolysate antioxidant power was dose dependent. Peroxidation trends were nonlinear for control and 1-4 mg/mL treatments. These trends continued linearly, with mild slope for 5 mg/mL, and was similar for 2 pH during 28 days. Hydrolysate of SCS may be used as a natural antioxidant for the production of stable microencapsulated fish oil for the enrichment of various kinds of beverages with a wide range of pH.
Atefe Maqsoudlou; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Fidel Toldta
Abstract
Introduction: Bee pollen, commonly referred as the ‘‘life-giving dust’’, results from the agglutination of flower pollens with nectar using salivary substances of the honeybees (Almeida-Muradian et al., 2005). Pollen contains 10 to 40% protein, 1 to 13% lipid, 13 to 55% carbohydrates and 2 to ...
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Introduction: Bee pollen, commonly referred as the ‘‘life-giving dust’’, results from the agglutination of flower pollens with nectar using salivary substances of the honeybees (Almeida-Muradian et al., 2005). Pollen contains 10 to 40% protein, 1 to 13% lipid, 13 to 55% carbohydrates and 2 to 6% minerals. Royal Jelly is produced by enzymatic digesting of bee pollen by proteases and other natural enzymes. Based on dry weight, it contains 27-41% protein, 30% carbohydrates, 8-19% lipids, minerals, trace elements and some vitamins (Sabatini et al., 2009; Wytrychowski et al., 2013). The antioxidant properties of royal jelly and bee pollen, are related to main proteins and phenolic compounds and flavonoids (Nagai and Inue, 2004). The antioxidant activity of peptides can be evaluated using DPPH, radicals scavenging activity, Ferric reducing, Ferrous chelating activity (Khantaphant et al., 2011). Antioxidant and ACE inhibitory activity of pollen, royal jelly and peptides were investigated by different researchers (Bogdanov, 2014; Morais et al., 2011; Salampessy et al., 2015; Marinova and Tchorbanov, 2010; Wiriyaphan et al., 2012). The objective of present research was optimization of enzymatic hydrolysis of bee pollen protein by Alcalase according to its antioxidant and ACE inhibitory activity compared to royal jelly.
Materials and methods: The preparation of the bee pollen extract was performed by mixing the bee pollen with water (1:10) (w/v). The macerates were filtered and centrifuged at 12000 g. The obtained supernatant was lyophilized. The royal jelly extract were prepared using method described by Liu et al., 2008. The total phenolic content of the extracts was recorded using the Folin–Ciocalteu method (Moreira et al., 2008). DPPH radical-scavenging activity was determined as described by Bersuder, Hole, and Smith (1998). The ability of the hydrolysate to reduce iron (III) was determined according to the method of Bougatef et al. (2008). Bee pollen was added and homogenized with 5 volumes of distilled water. pH and temperature of the solution were adjusted to pH=8 and 50◦C. Alcalase in the concentration range of 1 to 2% w/w were added to the pollen protein solution. Enzymatic hydrolysis performed during different times 2 to 5 hours. Hydrolysis was stopped by heating at 80˚C for 10 min. The hydrolysats were centrifuged at 4000x g for 30 min to remove the residue. The supernatants were pooled and then lyophilized (Matsuoka et al., 2012). DPPH radical scavenging ability and reducing power of pollen hydrolysates of pollen hydrolysates were measured. Also ACE-inhibitory activity of pollen hydrolysates was measured was assayed by method reported by Nakamura et al. (1995). Statistical analysis of results before hydrolysis was done by SPSS. Optimization of enzymatic hydrolysis was done by Response Surface Methodology (RSM) in Design Expert software.
Results and discussion: Total phenol value measured for pollen ranged between 48.15 to 174 mg Gallic acid/g for royal jelly ranged from 9.24 to 87.261 mg Gallic acid/g. Considering that royal jelly is obtained by direct digestion of pollen, the amounts of their phenolic compounds were comparable (Bogdanov, 2014). Phenolic compounds increased by increasing concentration royal jelly and pollen extract in dose dependent manner. Increasing concentrations of royal jelly in range of 300 to 1000 mg/l was more effective than pollen (p
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 ...
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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
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 ...
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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.
