Assessment of extraction variables on agar gelling properties from cultural alga (Gracilariopsis persica) by RSM

In this present, response surface methodology was used to investigate the procedure of agar gelling properties from Gracilariopsis persica agarophyte and optimization them formulation. Base on result, three independent variables - alkalinity concentration (2-8%), extraction temperature (90-120°C) and extraction time (45-240 minutes) - in five levels on viscosity and hysteresis temperature were determined that effects of extraction time and temperature on viscosity and hysteresis temperature were significant (p0.05)

Optimum conditions for protein extraction from tuna processing by-products using isoelectric solubilization and precipitation processes

The by-product from tuna processing is a potential source of edible protein. Therefore, it is very important to extract protein from such raw materials for human food. In this study the optimum pH for protein extraction from tuna by-products was optimized by using isoelectric solubilization and precipitation processes. The Response Surface Methodology (RSM) and the single factor model were used for optimization of the protein extraction process. From ANOVA (one-factor design) tests, significant effects were detected for process variables, functional properties and stability between tuna protein isolate prototypes extracted at acidic and alkaline pH, the latter having the least Total Volatile Basic Nitrogen (TVB-N) and Thiobarbituric Acid Reactive Substances (TBARS), but the highest Water Holding Capacity (WHC), hardness, cohesiveness, springiness and viscosity values. The highest yield percentage was found for the alkaline aided process, too. The alkali-aided process recovered proteins of higher whiteness than the acid-aided process. Accordingly the optimum pH of protein extraction was obtained. The model was then validated and maximized based on the functional properties, stability and recovery yield data. Under the optimized pH, the experimental values were in good agreement with those predicted by the software. Then the properties of the optimum prototypes were compared to the fish protein isolated from different by-products. The results suggest that the proteins recovered from tuna processing by-products could be a valuable source of protein ingredient for fortification/ developing formulated ready-to-eat products

Production of fish cheeses from silver carp by acid coagulation

Fish and fishery products have high nutrition value particularly omega-3 fatty acids. It is expected that the estimated production in 2030 will be 150 to 160 million tones but estimated demand will be 183 million tons. Processing of fish especially (culture fish) is one of the way attentions of people to fish and fishery products. Fish Finger, Fish Berger, Cracker, Fish Ball are the most important of fishery products. In this research was studied production of fish cheese from Silver carp (Hypophthalmichthys molitrix) from sarcoplasmic proteins. After primary preparation of fish (beheading, cutting, filleting and deboning) minced fish was washed with salt solution (0.01, and 0.04 mol) and were isolated sarcoplasmic proteins. Acetic acid (%5) and centrifuge were used for sedimentation and extraction of these proteins. Fifteen formulas were worked for preparing of fish cheese. Minced fish, sedimented protein and fish cheese were examinated for proximal parameters (protein, ash. moisture, carbohydrate and lipid) and microbial and chemical spoilage factors (Total Viable Count, Mold and Yeast, Total Volatile Nitrogen, and Peroxide Value). The shelf life and organoleptic characterization of fish cheese were also surveyed. The results indicated that mean of protein, lipid, ash, moisture and carbohydrate in fish cheese were %14/86, %28/01, %3/46, %48/27, %4/78 respectively. The best formula was treatment of 13 with %18/26 of protein. TVN and PV, in fish cheese, were at standard level but after 30 days stored in 4o C, PV value ere slowly increased. Microbial parameters, in product, (in zero time) were log 3 and 4 but after 30 days were log 4 and 5. Organoleptic factors such as odor, frangibility, taste in fish cheese in zero and 30 days were good and medium respectively. Cost of fish cheese was varied between 2000 to 27000 Rails. As fish cheese is prepared from sarcoplasmic proteins and was not any use from fish tissue, therefore it can be produced as secondary products in processing plants and can be introduced to people as new fish product

Peptone production from marine and culture wastes by commercial enzymes for bacterial culture media

Thirty to 40% of total fish catch is converted to waste. Using different methods of hydrolysis of the protein can be recovered of fish waste and increase the amount of protein efficiency. In this study, the four enzymes Alcalase, protamex, pepsin and trypsin were used for hydrolysis of four fish species including common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and the Big head (Hypophthalmichthys nobilis). The effects of pH, temperature and hydrolysis time on the rate of hydrolysis were studied on soluble proteins and degree of hydrolysis (phase I). In the second step, proximate factors of peptone been evaluated and eventually replace commercial peptone media MRS (Lactobacillus plantarum, Lactobacillus delberuki, Lactobacillus casei, Streptococcus thermophilus) and TSB (Listeria monocytogenes, two species of Bacillus and Pseudomonas, Streptococcus faecium) and the optical density of bacteria at different times were compared with control samples. Results showed that the highest degree of hydrolysis and soluble proteins were referred to alcalase and protamex, pepsin and trypsin respectively. The highest value of hydrolysis, in all treatments, was attributed to grass carp and silver carp, common carp and big head respectively. The best pH and temperature for alcalase, protamex, pepsin and trypsin 8.5and 55, 7.5 and 55, 3.5, 37, 7 and 37 respectively. Best time to achieve the highest degree of hydrolysis and soluble protein was 90 minutes. Qualitative analysis showed that the highest and lowest amounts of protein and fat in the treatment of alcalase (about 70 % protein and less than 0.5 % fat) and protamex, pepsin and trypsin was then. The results of bacteria culture showed that the highest percentage growth of lactic acid bacteria was referred to Streptococcus thermophilus and Lactobacillus casei had the lowest rate of growth. In other bacteria, Pseudomonas and Bacillus species were the highest percentage of growth and Listeria monocytogenes and Streptococcus faecium respectively. In all treatments, alcalase had the best results and the peptone prepared from fish waste grass carp had the best condition for growth of used bacteria. It seems that the initial substrate , the parameters used such as temperature, pH, and enzyme hydrolysis time , have a significant effect on the quality of peptone and protein content in the final product is determined value of protein for culture of bacteria

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Effect of intensity and time ultrasound on yield and functional properties of extracted �-glucan of oat flour

�-glucans are non-starch polysaccharides and water soluble hydrocolloids, Apart from being nutritionally important, �-glucans show an important technological role as thickening, stabilizing, emulsification, gel-forming component and fat substitute in the dairy products, bakeries, meats, pharmacy, cosmetics, and chemical industries, and feed production. The extraction of cereals �-glucans is very difficult. Ultrasonic extraction, represents higher efficiency since this method is a cost- effective which shortens the extraction time,energy and solvent consumption compared to conventional methods..in this study the effect of intensity and time at four different powers (0, 200, 300, 400 w) in three time (0, 3.5 and 7 min) intrevals were investigated on the yield, recovery, color and the functional properties of extracted �-glucan.The results showed that the intensity and time of ultrasound were significant on yield, recovery, color, emulsion stability, water holding capacity, solubility �-glucan (p�0.05). With increasing ultrasonic intensity and time, extracted �-glucan yield, recovery, emulsion stability, water holding capacity increased. The highest extraction yield (3.34), solubility (75.67) were observed at power 400w for 7 minutes, Also the highest recovery (52.04), emulsion stability (69.06), water retention capacity (13.21 g /g), compared to blank sample at power 300w for 7 minutes. L*, a*and b* and were 76.66, 3.2, 3.2 respectively. © 2021 Tarbiat Modares University