Production of valued materials from squid viscera by subcritical water hydrolysis (original) (raw)
Related papers
Journal of Agricultural and Food Chemistry, 2005
The squid (Loligo pealei) byproduct composed of heads, viscera, skin, fins, and small tubes was subjected to hydrolysis at 55°C and natural pH (6.8) using endogenous proteases. Squid hydrolysate was characterized during the course of hydrolysis for changes in the degree of hydrolysis, viscosity, electrophoretic pattern of proteins and peptides, and amino acid and fatty acid profiles. The change in viscosity can be used to monitor the progress of protein hydrolysis up to the molecular mass of 26.63 kDa. The 2 h hydrolysis resulted in a 2-fold increase in the total free amino acids and yielded hydrolysate with protein molecular mass of e45 kDa having feed attractability and good amino acid and fatty acid profiles with high contents of essential amino acids and fatty acids. Such hydrolysisinduced changes can make squid byproduct hydrolysate a good source of aquaculture feed ingredient, especially for a starter diet for larval fish.
Food Science and Technology International, 2014
Jumbo squid is an important fishery resource in Mexico, and its muscle is lean and white and it has a very low price in the market. It is abundant, but with little or nothing added value, therefore is necessary to search alternatives of processing. Due to muscle characteristics, the aim of this study was to obtain protein concentrates using different methods. They were obtained by means of acidic (acid protein concentrates) and alkaline (alkaline protein concentrates) dissolution. Moreover, a protein concentrate was obtained by direct isoelectric precipitation and by the traditional method (neutral protein concentrates). The yield with better results was alkaline protein concentrates (63.58 AE 1.8%). The gel hardness was significantly different (p < 0.05), especially for the alkaline protein concentrates. The acid protein concentrates, isoelectric precipitation and alkaline protein concentrates were better with regard to the neutral protein concentrates, concerning the emulsifying and foaming properties. The protein concentrates by means of alkaline dissolution gave a better gelling property, but all the processes had the potential to obtain protein with emulsifying and foaming properties.
Food Biophysics, 2014
The physicochemical characteristics of protein hydrolysates of jumbo squid (Dosidicus gigas) byproducts (JSBP) produced by endogenous proteases at two different pH values (5.0 and 7.0) were studied using destructive and nondestructive methods. Reaction mixture samples were collected at different interval times during hydrolysis to monitor changes in the level of hydrolysis (DH) using the OPA method, the protein peptide molecular masses (MM), and SDS-PAGE. The DH increased from 3.5 to 11.2 % at pH 5.0 and from 4.8 to 17.5 % at pH 7.0. Both pH treatments exhibited similar degradation patterns with progressive proteolysis and, after 120 min of hydrolysis, yielded hydrolysates that contained MM <45 kDa proteins. It was detected lower hydrophobic amino acid exposure for the protein hydrolysates prepared at pH 5.0 compared with the hydrolysates at pH 7.0. In several wavebands, higher wavenumbers were observed in the FT-IR spectra for the pH 5.0 hydrolysates. Nine different equivalent protons were observed in the NMR spectra for both hydrolysates; these protons might belong to amino acid side chains. SEM showed substantially lower particle size for the JSBPs after hydrolysis at pH 7.0. The hydrolysate zeta potentials were −29.4 mV at pH 7.0 and −10.5 mV at pH 5.0. The pH 5.0 hydrolysates exhibited lower endothermic resistance and hydrophobicity (SoANS) compared with the pH 7.0 hydrolysates. This biophysical characterization enhances the understanding of jumbo squid byproduct hydrolysate physiochemical properties, which will aid in determining the proper use of these hydrolysates.
… and Bioprocess Engineering, 2009
Three major classes of digestive enzymes of squid viscera were characterized following extraction of oil by supercritical carbon dioxide (SCO 2) and organic solvent, n-hexane. Squid viscera were extracted at temperature, 35~45°C and pressure, 15~25 MPa for 2.5 h by SCO 2 with a constant flow rate of 22 g/min. Oil extraction yield increased with the increasing of extraction pressure and temperature. The highest oil extracted residues of squid viscera were used for characterization of digestive enzymes. The activities of protease, lipase, and amylase were highest in n-hexane treated squid viscera samples and lowest in SCO 2 treated samples. The crude extracts of SCO 2 and n-hexane treated squid viscera samples showed almost same optimum pH and pH stability for each of the digestive enzymes. The optimum temperature of protease, lipase, and amylase were found to almost similar in SCO 2 and n-hexane treated samples. But the thermal stability for each digestive enzyme in SCO 2 treated squid viscera were slightly higher than that of n-hexane treated squid viscera. Studies using SDS-PAGE showed no significant differences in protein patterns of the crude extracts of untreated and SCO 2 and n-hexane treated squid viscera indicating no denaturation of proteins. © KSBB
日本冷凍空調学会論文集, 2003
The concentration dependent (2.5-10% of dry weightywet weight) protective effect of squid protein hydrolysate (SPH), extracted from Japanese flying squid and swordtip squid by protease treatment, on the state of water and denaturation of frozen lizardfish (Saurida wanieso) myofibrillar protein (Mf) were assessed on the basis of the amount of unfrozen water in Mf by differential scanning calorimetry and Mf Ca-ATPase inactivation during freezing at y25 8C for 90 days; the effects were compared with those of sodium glutamate. The Mf showed a higher amount of unfrozen water upon addition of SPH, regardless of level of addition and species differences, resulting in a markedly decreased inactivation of Mf Ca-ATPase throughout the freezing period. The Ca-ATPase activity in the Mf without SPH (control) dropped drastically from the beginning of the freezing. These findings suggest that the functional side chains of the peptides of SPH produce bound water in the Mf structure, which provides a structural alteration of the hydrate water that has a capacity to suppress the freeze-induced denaturation of Mf. An addition of 5.0-7.5% concentration of SPH is found to be suitable to increase the amount of unfrozen water and to prevent the freeze-induced denaturation of Mf. ᮊ Industrial relevance: The present study is an interesting approach to improve the physico-chemical and nutritional properties of frozen fish via the addition of protein hydrolysates from low-cost squid. The data suggest that squid protein hydrolysates compare well with other antidenaturants reported in the literature on the folding and the structured stability of protein during freezing.
Production of Organic Acids and Amino Acids from Fish Meat by Sub-Critical Water Hydrolysis
Biotechnology Progress, 1999
Fish meat was easily liquefied by hydrolysis under subcritical conditions without oxidants, and aqueous phase and water-insoluble phase containing oil and fat-like solid were formed. Lactic acid found in the raw fish meat (about 0.03 g/g-dry meat) was stable up to the reaction temperature 513 K (3.35 MPa). Pyroglutamic acid was produced with a yield of 0.095 kg/kg of dry meat by 30 min reaction at 553 K (6.42 MPa). Amino acids such as cystine, alanine, glycine, and leucine were produced in the temperature range 513-623 K with a maximum peak at 543 K. Amounts of cystine, alanine, glycine, and leucine produced in 5 min at 543 K (5.51 MPa) were 0.024, 0.013, 0.009, and 0.004 kg/kg of dry meat, respectively. The oil extracted with hexane contained useful fatty acids such as eicosapentanoic acid (EPA) and docosahexianoic acid (DHA). Thus, subcritical water hydrolysis would be an efficient process for recovering useful substances from organic waste such as fish waste discarded from fish market.
EFFECT OF pH AND TEMPERATURE ON JUMBO SQUID PROTEINS
Journal of Food Biochemistry, 2009
Evaluation of the effect of pH (2 to 13) and temperature (0 to 50C) on functional properties of jumbo squid proteins was performed, followed by a 2 ¥ 3 factorial design for producing squid protein hydrolysates bearing useful functional properties. In particular, the effects of pH (8, 9 and 10) and temperature (30, 35, 40C) were evaluated. Alcalase and papain were tested on each treatment. The protein recovery, whippability and emulsifying capacity of the hydrolysates were evaluated. Almost 80% of the proteins were recovered in water-soluble form after hydrolysis with papain at pH 10 at the three temperatures. The highest values of whippability (245 Ϯ 17.7%), foam stability (100%), emulsion-forming capacity (27 Ϯ 0.97%) and stability (99.99 Ϯ 8.8%) occurred with papain-produced hydrolysates. When squid protein was treated at 50C and pH 8, the highest whippability value (390.0 Ϯ 0.1%) and foam stability (100%) were obtained when no enzyme was added. PRACTICAL APPLICATIONS This paper assesses how process variables, particularly temperature and pH, affect the functional properties of squid proteins. Making use of such process variables will produce more useful and efficient processes, as the application of a hydrolysis system. The processing of jumbo squid protein to obtain proteins bearing adequate functional properties would be an inexpensive way to provide added value to this marine resource and the production of a high-quality protein ingredient. These results hold promise for jumbo squid proteins as useful food ingredient because of their functional properties.
International Aquatic Research
Nowadays, there is a growing interest on how to utilize fish materials remaining from the main production and considered as unappropriated for a direct human consumption. There are numbers of possible solutions to recover valuable nutrients from that matter and one of the most efficient is the production of fish protein hydrolysate. This article is devoted to overview existing information about the production of dried fish protein hydrolysates with a focus on dehydration process during production and equipment used for moisture removal. Drying step of the production is considered as the most energy demanding and, therefore, described in detail. Questions considering energy demands of the drying are highlighted in the article together with the proposals for the improvement of energy efficiency. This work also describes source of the raw material, the main steps of the technological scheme with the equipment used and valuable information on the intermediate state of fish protein hydrolysate between the process operations.
The fish processing industry is a major exporter of seafood and marine products in many countries. About 70% of the fish is processed before final sale. Processing of fish involves stunning, grading, slime removal, deheading, washing, scaling, gutting, cutting of fins, meat bone separation and steaks and fillets. During these steps significant amount of waste (20-80% depending upon the level of processing and type of fish) is generated which can be utilized as fish silage, fishmeal and fish sauce. Fish waste can also be used for production of various value added products such as proteins, oil, amino acids, minerals, enzymes, bioactive peptides, collagen and gelatin. The fish proteins are found in all parts of the fish. There are three types of proteins in fish: structural proteins, sacroplasmic proteins and connective tissue proteins. The fish proteins can be extracted by chemical and enzymatic process. In the chemical method, salts (NaCl and LiCl) and solvents (isopropanol and aezotropic isopropanol) are used, whereas during the enzymatic extraction, enzymes (alcalase, neutrase, protex, protemax and flavorzyme) are used to extract proteins from fish. These fish proteins can be used as a functional ingredient in many food items because of their properties (water holding capacity, oil absorption, gelling activity, foaming capacity and emulsifying properties). They can also be used as milk replacers, bakery substitutes, soups and infant formulas. The amino acids are the building blocks of protein. There are 16-18 amino acids present in fish proteins. The amino acids can be produced from fish protein by enzymatic or chemical processes. The enzymatic hydrolysis involves the use of direct protein substrates and enzymes such as alcalase, neutrase, carboxypeptidase, chymotrypsin, pepsin and trypsin. In the chemical hydrolysis process, acid or alkali is used for the breakdown of protein to extract amino acids. The main disadvantage of this method is the complete destruction of tryptophan and cysteine and partial destruction of tyrosine, serine and threonine. The amino acids present in the fish can be utilized in animal feed in the form of fishmeal and sauce or can be used in the production of various pharmaceuticals. The fish oil contains two important polyunsaturated fatty acids called EPA and DHA or otherwise called as omega-3 fatty acids. These omega-3 fatty acids have beneficial bioactivities including prevention of atherosclerosis, protection against maniac-depressive illness and various other medicinal properties. Fish oil can also be converted to non-toxic, biodegradable, environment friendly biodiesel using chemical or enzymatic transesterification.