Fish proteins isolation

A pepsin hydrolysate of flounder fish protein isolate has been used as the substrate (40% w/v) for plastein synthesis, using either pepsin at pH 5 or alpha chymotrypsin at pH 7, with an enzyme—substrate ratio of 1 100 w/v at 37°C for 24 h (151). The plastein yields for pepsin and alpha chymotrypsin after precipitation with ethanol were 46 and 40.5%, respectively. 

Metabolic Transit of Lysinoalanine. Urinary and Fecal Excretion of Protein-Bound Lysinoalanine (113). Three different alkali-treated proteins (lactalbumin, fish protein isolate, and soya protein isolate) containing, respectively, 1.79, 0.38, and 0.14 g of lysinoalanine/16 g nitrogen were given to rats and the urines and feces were collected. Lysinoalanine was measured before and after acid hydrolysis. The fecal excretion varied from 33 to 51% of the total ingested lysinoalanine and the urinary excretion varied from 10 to 25%. The higher level of lysinoalanine found after acid hydrolysis indicates that a certain quantity is excreted in the urines as combined lysinoalanine (see Table VII). The total recovery was inferior to the ingested quantity (50 to 71%) indicating that the molecule is transformed or retained in the body of the rat. 

Fish protein isolate Magnesium lactate Psyllium Vitamin Ki Yeast supplement, infant formulas Arachidonic acid Docosahexaenoic acid supplement, mineral Cobalt diacetate supplement, vitamin (+)-y-Tocopherol supporter, storage batteries 2-Chloronaphthalene suppressant, appetite Guar (Cyanopsis tetragonoloba) gum suppressant, smoke paints Zinc hydroxystannate suppressant, smoke plastics Zinc hydroxystannate Zinc stannate suppressant, smoke rubber Zinc hydroxystannate suppressant, sulfide Ferrous sulfate anhydrous suractant mfg. 

Other Lethal Agents. There are a number of substances, many found in nature, which are known to be more toxic than nerve agents (6). None has been weaponized. Examples of these toxic natural products include shellfish poison, isolated from toxic clams puffer fish poison, isolated from the viscera of the puffer fish the active principle of curare "heart poisons" of the digitaUs type the active principle of the sea cucumber active principles of snake venom and the protein ricin, obtained from castor beans (See Castor oil). 

Fouchereau-Peron, M., Duvail, L., Michel, C., Gildberg, A., Batista, I., and Gal, Y. I. (1999). Isolation of an acid fraction from a fish protein hydrolysate with a calcitonin-gene-related-peptide-like biological activity. Biotechnol. Appl. Biochem. 29, 87-92. 

Gildberg, A., Bogwald, J., Johansen, A., and Stenberg, E. (1996). Isolation of acid peptide fractions from a fish protein hydrolysate with strong stimulatory effect on Atlantic salmon (Salmo solar) head kidney leucocytes. Comp. Biochem. Physiol. 11, 97-101. 

Peptides isolated from various fish protein hydrolysates have shown a different biological activities such as antihypertensive, antioxidative, antithrombotic, and immunomodulatory activities. 

All these microcapsules were found to be roughly spherical in shape and of similar size (14-18 pm) (Drusch, 2007). A mixture of chitosan, maltodextrin and whey protein isolate was also found to be also a good wall material for encapsulation of fish oil using an ultrasonic atomizer followed by freeze-drying of the microcapsules (Klaypradit and Huang,... 

Similarly, lysine has been incorporated into gluten hydrolyzate and lysine, threonine and tryptophan have been individually incorporated into zein hydrolyzates. Lysine, methionine, and tryptophan were incorporated simultaneously into hydrolyzates of protein from photosynthetic origin. A very interesting application of this procedure involved the preparation of low-phenylalanine plasteins from a combination of fish protein concentrate and soy protein isolate by a partial hydrolysis with pepsin then pronase to liberate mainly phenylalamine, tyrosine, and tryptophan, which were then removed on sephadex G-15. Desired amounts of tyrosine and tryptophan were added back in the form of ethyl esters and a plastein suitable for feeding to infants afflicted with phenylketonuria was produced. 

It seems that the negative charges can also be on a peptide chain. Fujimaki describes the bitter masking action of peptides rich in glutamyl residues (29 ) and the isolation and identification of acidic oligopeptides from a flavour-intensifying fraction from fish protein hydrolysate (30). 

Noguchi, M., Arai, S., Yamashita, M., Kato, H., and Fujimaki, M. 1975. Isolation and identification of acidic oligopeptides occurring in a flavor potentiating fraction from a fish protein hydrolysate. J. Agric. Food Chem. 23, 49-53. 

The bitter peptide BPI a 114, isolated by Okai et al.239 > from casein hydrolysates, and delicious tasting peptides from fish proteins, will undoubtedly achieve practical importance in the food industry. 

Spinelli, J., Koury, B., and Miller, R. 1972. Approaches to the utilization of fish for the preparation of protein isolates enzymic modifications of myofibrillar fish proteins. J. Food Sci., 37, 604-608. 

Table 6. Umami Peptides Isolated from Fish Protein Hydrolysates by Pronase ...

The study of fish proteins were initiated by the Swiss physiologist Miescher (1897), who first isolated the protamines from the sperm cells of various fishes as early as 1868. The relatively simple amino acid composition of these proteins and their pharmacological action have since promoted extensive researches, first of aU by Kossel and co-workers, whose important... 

Various protein ingredients are utilized to satisfy nutritional requirements for protein quantity and quality in pet foods. Typical sources of protein ingredients are soybean oil meal, soybean flour, soy protein concentrate, soy protein isolate, meat meal, meat and bone meal, meat by-products, fish meal, blood meal, dried blood plasma, yeast, and milk protein (Balaz et al., 1977). In addition, vitamins, minerals, colorants, and other supplements such as choline chloride MgO vitamins A, Bj2,... 

It is now evident that acylation with anhydrides (such as acetic and succinic anhydrides) and with lactones (such as -propiolactone) is being proposed (< ) for improving the solubility of soy protein isolates at acidic pH, particularly for the preparation of coffee whiteners. Moreover, this chemical modification has been evaluated for altering the food-use properties of several milk proteins (40), egg protein (41), wheat protein (42), fish protein (43), and single-cell protein (44). 

Deodorization. Volatile flavor components of soybean have been investigated in detail (79, 80, 81, 82). Arai et al. (83) have studied the interaction of denatured soybean protein with 1-hexanol and 1-hexanal which are the typical beany flavor compounds of raw and processed soybeans. These protein-bound compounds are liberated by treating the denatured soybean protein with pepsin (83). Noguchi et al. (84) observed that not only 1-hexanol and 1-hexanal but also other flavor compounds are effectively liberated and removed from a soybean protein isolate during treatment with an acid protease (Molsin). A subsequent study has ascribed this effect to the activity of aspergillopeptidase A, an endopeptidase, which has been identified as a main constituent of Molsin (85). Fujimaki et al. (88, 87) examined several protease preparations for their usefulness in deodorization and reported that a pepsin treatment followed by ether extraction is most effective for deodorizing some protein preparations of soybean and fish. 

Table IV shows the effect of protein concentration on foam volume and stability compared with egg white and soy isolate. Foam volumes for the hydrolyzed, succinlyated fish protein were highest at 3 g protein/ 100 ml, but decreased at 4 g/100 ml. Compared with egg white and soy isolate, the hydrolyzed succinylated fish protein yielded a more stable, but less voluminous foam.

One of the current approaches to the improvement of the functional properties of proteins is enzymatic hydrolysis [148], The emulsifying ability of soy protein isolate can be increased by treatment with neutral fungal protease however, this treatment decreases emulsion stability [163], Partial hydrolysis of fish protein concentrate improves both emulsification and stability [164]. On the other hand, treatment of whey protein concentrate with pepsin, pronase, and pro-lase leads to a decrease in emulsification ability, suggesting that there... 

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