Physicochemical properties, gel-forming ability and myoglobin content of sardine (Sardinella gibbosa) and mackerel (Rastrelliger kanagurta) surimi produced by conventional method and alkaline solubilisation process

Characteristics and gel properties of sardine and mackerel surimi produced by conventional washing process and alkaline solubilising process were investigated. The decrease in Ca²⁺-ATPase activity with the changes in the surface hydrophobicity was found in surimi produced by alkaline solubilising process (p<0.05), suggesting the denaturation of protein induced by this process. The alkal-ine solubilising process with prewashing could remove myoglobin most effectively from sardine muscle, whereas the process without prewashing resulted in the greatest myoglobin removal in mackerel muscle (p<0.05). Surimi conventionally prepared by water or NaCl washing showed the gel with greater breaking force and deformation than that from alkaline solubilising process (p<0.05). The hig-her expressible moisture was found in the gels of surimi pre-pared by alkaline process, indicating the poor water holding capacity of the gel matrix. The highest whiteness was found in the gel of sardine surimi produced by alkaline process with prewashing but the highest whiteness was obtained in the gel of mackerel surimi washed with distilled water.     

Biochemical property and gel-forming ability of surimi-like material from goat meat

Biochemical and gel properties of surimi-like material from goat meat (SMGM) as affected by washing solutions including tap water, NaCl, sodium bicarbonate, aluminium sulphate and sodium pyrophosphate, with the same ionic strength of 0.15 for all salt solutions, were investigated. Three-cycle washing (cold solution/water/water; mince:solution ratio of 1:5; 10 min/cycle) was used. Washing solutions differently altered the pH, Ca²⁺-ATPase activity, reactive sulfhydryl, TCA-soluble peptide, total volatile base nitrogen (TVB-N), myoglobin, lipid and thiobarbituric acid reactive substances (TBARS) content of SMGM. Washing can eliminate undesirable lipid, myoglobin, TVB-N and TCA-soluble peptide from goat meat. SMGM washed with water and NaCl can form stable gels whereas SMGM washed with bicarbonate, pyrophosphate and aluminium sulphate formed very mushy gel/aggregate with high released water. SMGM gels particularly that washed with NaCl had higher breaking force, deformation and whiteness with lower TBARS content, species odour and expressible drip than unwashed mince. Therefore, SMGM can be optimally produced by washing with NaCl solution.     

Effect of oxidised tannic acid on the gel properties of mackerel (Rastrelliger kanagurta) mince and surimi prepared by different washing processes

Effect of oxidised tannic acid (OTA) at different levels (0, 0.25, 0.50 and 0.75% of protein content) on the gel properties of mackerel (Rastrelliger kanagurta) mince and surimi prepared by different washing processes was investigated. Breaking force and deformation of gels varied with washing processes and concentrations of OTA. The gel of alkaline-saline washing process surimi (ASWPS) added with 0.25% OTA had the increases in breaking force and deformation by 166.2 and 45.9%, respectively, compared with that of conventional washing process surimi (CWPS) without OTA addition. Those increases were associated with the lowered expressible moisture content. Electrophoretic studies revealed that the greater polymerisation was found in ASWPS added with 0.25% OTA. Slight retention of myosin heavy chain (MHC) with lowered trichloroacetic acid (TCA) soluble peptide contents was observed in ASWPS gel added with 0.25% OTA, suggesting the decreased degradation induced by indigenous proteases. The microstructure of ASWPS gels became more ordered, compact and denser with the addition of 0.25% OTA. The use of OTA in conjunction with alkaline-saline washing process could improve the properties of gel from mackerel surimi without adverse effect on sensory properties.     

Decoloration and Gel-forming Ability of Horse Mackerel Mince by Air-flotation Washing

ABSTRACT: The decoloration effects and gel-forming ability of horse mackerel mince by air-flotation washing (AFW) was investigated. The lowest residual myoglobin content (RMb) and relative fluorescence intensity (RFI), the highest metmyoglobin (metMb) content and best decoloration effects were recorded for the mince washed with AFW. AFW also effectively improved gel strength in heated surimi. No significant difference in RMb was found when mince was treated with flotation washing using nitrogen, air and ozone. Although the highest metMb content and the lowest RFI were found for the mince washed with ozone, significant differences in whiteness were observed only when the mince was treated with a different gas at 10 or 20 L/min for 5 to 10 min. The physical removal of myoglobin was suggested to be the main factor contributing to accelerated decoloration with AFW.     

New processing technology of small pelagic fish protein

Abstract

Small pelagic fishes, such as sardine and mackerel, generally rich in lipid, have a large amount of superficial dark muscle. The proportion of dark to ordinary muscle is 20–30%. Since the dark muscle is red‐colored due to high myoglobin content and different in protein properties from the ordinary muscle, there have been many difficulties in the efficient utilization of small pelagic fish proteins as food resources.

Effective processing of frozen surimi from small pelagic fishes is as follows: 1) washing of meat with NaHCO₃ solution to remove fat, 2) mechanical removal of dark muscle to make use of only ordinary muscle. However, it is impossible to make surimi from small pelagic fishes that are not fresh, even if the effective processing technique is applied. Frozen minced fish block can be made from sardine and mackerel meats to employ the washing technique and mixing of suitable additives. Recently, fish protein concentrate (Marinbeef) from small pelagic fishes has been developed. It can be rehydrated easily and cooked to acceptable foods. In the processing of Marinbeef, a wider margin of freshness of material fish can be allowed.     

Properties of a protein-based film from round scad (Decapterus maruadsi) as affected by muscle types and washing

The effects of muscle types and washing on the properties of a protein-based film from round scad (Decapterus maruadsi) mince were investigated. Washing resulted in an increase in the protein content with a coincidental decrease in the fat content of mince, especially from whole muscle and dark muscle. Among all types of muscle (ordinary, dark and whole muscle), the ordinary muscle rendered the film with the highest tensile strength (TS) (p < 0.05). TS of films from washed mince was greater than that of films prepared from unwashed mince for the same type of muscle used (p < 0.05). Nevertheless, the water vapour permeability (WVP) of films from unwashed mince was higher than that of films prepared from washed mince (p < 0.05). Films from washed mince had higher solubility but lower protein solubility than those from unwashed mince (p < 0.05). Regardless of washing, films from ordinary muscle showed the highest L^∗-value (p < 0.05). However, films prepared from dark muscle were more yellowish than those prepared from other muscles, as evidenced by the greater b^∗-value. Films from round scad mince and washed mince had excellent barrier properties to UV light at the wavelength of 200–280 nm. Generally, films from round scad mince had a lower preventive effect on visible light transmission than had those from unwashed mince. Among films from all muscles, those prepared from dark muscle exhibited the highest barrier to visible light transmission (p < 0.05). Therefore, the properties of films from round scad meat were governed by muscle type as well as by washing.     

Impact of microbial transglutaminase on gelling properties of Indian mackerel fish protein isolates

Impacts of microbial transglutaminase (MTGase) (0–0.6 units/g sample) on gel properties of Indian mackerel unwashed mince, surimi and protein isolates with and without prewashing were studied. Generally, lower myoglobin and lipid contents were found in protein isolate with and without prewashing, compared to those of unwashed mince and surimi (P < 0.05). Protein isolate had the decreased Ca²⁺-ATPase and protein solubility, indicating protein denaturation. When MTGase was incorporated, breaking force and deformation of all gels markedly increased, especially as MTGase levels increased (P < 0.05). At the same MTGase level, gel from protein isolate with prewashing exhibited the highest breaking force and deformation (P < 0.05). The addition of MTGase could lower the expressible moisture content of most gels. No change in whiteness of gel was observed with the addition of MTGase (P > 0.05), but gel from protein isolate gels had decreased whiteness as MTGase at high level was added. The microstructure of protein isolate gels without prewashing showed a similar network to unwashed mince gels, whilst a similar network was observed between surimi gel and gel from protein isolate with prewashing. Nevertheless, a larger void was noticeable in gels from protein isolates. All gels incorporated with MTGase (0.6 units/g) showed a slightly denser network than those without MTGase. Thus, gel with improved properties could be obtained from protein isolate from Indian mackerel with added MTGase.     

漂洗工艺对鲢鱼鱼糜凝胶强度和色泽的影响

探讨清水漂洗次数、盐水漂洗次数和漂洗温度对鲢鱼鱼糜凝胶强度和白度的影响。结果表明:清水漂洗和盐水漂洗可以显著的提高鲢鱼鱼糜的凝胶强度和白度,采用清水漂洗2次再用盐水漂洗1次的漂洗处理,得到的鲢鱼鱼糜凝胶强度和色泽较好。漂洗温度对鲢鱼鱼糜的凝胶强度和白度无显著影响,但为保持鱼肉的新鲜,漂洗温度不宜过高。     

Biochemical and gelling properties of tilapia surimi and protein recovered using an acid-alkaline process

The biochemical and gel properties of tilapia surimi prepared by a conventional washing method and protein isolated using alkaline-acid-aided processes were studied. Solubility and recovery of protein was found to be highest by using a conventional method, followed by an alkaline- and acid-aided process, respectively. Decreases in myoglobin and lipid contents were found in alkaline- or acid-aided process when compared to the conventional process (p < 0.05). The highest breaking force and deformation of kamaboko and modori gels was found in the gels prepared by the conventional washing method. Higher expressible water and whiteness were found in modori gels when compared to kamaboko gels. TCA-soluble peptide contents of conventional surimi gels were lower than those of acid- and alkaline-recovered protein gels. Degradation of myofibrillar protein was observed in acid-isolated protein. Microstructure of kamaboko gels showed more compact network than in modori gels in both conventional surimi and protein recovered using the pH-shift process.     

Physicochemical properties and gel-forming ability of surimi from three species of mackerel caught in Southern Thailand

Physicochemical and gelation properties of surimi prepared from three species of mackerel were investigated. The highest whiteness with the lowest redness index corresponding to the lowest myoglobin content especially its oxidised form, metmyoglobin, was found in short-bodied mackerel (Rastrelliger brachysoma) surimi (p < 0.05). Frigate mackerel (Auxis thazard) surimi contained the highest lipid content (p < 0.05). The pH of all surimi was in the range of 6.58–6.80. The highest sulfhydryl group and Ca²⁺-ATPase activity was found in natural actomyosin extracted from short-bodied mackerel surimi (p < 0.05). The highest TCA-soluble peptide content was found in frigate mackerel surimi gels (p < 0.05). Kamaboko gel of short-bodied mackerel surimi exhibited the highest breaking force with the lowest expressible drip (p < 0.05). Heating regime had no effect on deformability of gels from Indian mackerel (Rastrelliger kanagurta) and short-bodied mackerel but not for frigate mackerel. The highest metmyoglobin content with the lowest whiteness was found in frigate mackerel surimi gel (p < 0.05). Therefore, short-bodied mackerel was the best suited for the production of surimi with superior functional attributes including whiteness and gel-forming ability.     

Color and Gel-forming Properties of Horse Mackerel (Trachurus japonicus) as Related to Washing Conditions

A beneficial decoloration effect resulted for horse mackerel mince washed with ozonized water within 10–20 min, but a longer washing time was required to improve the color properties when cold water or alkaline solution was used. Increase in pH as well as improvements in gel-forming ability occurred for mince washed with alkaline solution. The maximal gel strength of surimi was found when washed for 90 min. A marked decrease in pH and an undesirable gel strength of mince, as well as oxidation of the fish oil occurred during ozone treatment. Since the salt-soluble protein concentration increased for all minces washed with the three methods, improvement in gel-forming ability of washed mince was attributed to the increase in pH rather than to oil removal.     

Gel-forming ability of small scale mud carp (Cirrhiana microlepis) unwashed and washed mince as related to endogenous proteinases and transglutaminase activities

Gel-forming ability of small scale mud carp (Cirrhiana microlepis) mince and washed mince was investigated with respect to their proteinase and transglutaminase (TGase) activities. Proteinases in sarcoplasmic fluid showed the optimum activity at 65 °C and pH 9, whereas autolytic activity was maximum at 70 °C and pH 10, indicating the presence of heat-stable alkaline proteinases. When mince was washed with three volumes of water twice, TGase and proteinases were mainly removed in the first washing cycle, resulting in a decreased autolytic activity of washed mince. Breaking force of the single washed mince gels was greater than the twice washed mince and the unwashed mince gels (p<0.05). Pre-incubation of mince pastes at 40 °C for 1 h prior to cooking (90 °C/30 min) increased breaking force of all samples, particularly the single washed mince (p<0.05). This coincided with an increase of higher molecular weight polymers observed on SDS-PAGE. Washing did not completely eliminate proteinases as it was evident by an increased trichloroacetic acid (TCA)-soluble oligopeptides of washed gels pre-incubated at 55 °C. Whiteness values of washed mince gels were greater than that of mince gels.     

CHANGES IN PROXIMATE COMPOSITION OF THORNBACK RAY (RAJA CLAVATA, L. 1758) SURIMI DURING WASHING AND FROZEN STORAGE

The effects of frozen storage of surimi produced from thornback ray and the washing of mince on the chemical composition were investigated. The crude ash content which was initially found as 1.38% in raw thornback ray decreased approximately 12 and 80% after the first and second washing, respectively. After the third washing, crude ash content increased to 207% of the amount in the second washing because of addition of salt to the last washing water. The crude protein content of mince also decreased approximately to 28 and 20% after the first and second washing, respectively. After the third washing, the decrease in the lipid levels was approximately 30%. At the end of 6 months of frozen storage at − 23.8  ±  2C, dry matter, crude ash and crude protein contents increased in a greater ratio in surimi containing 4% sorbitol, 4% sucrose and 0.3% Na-tripolyphosphate than surimi prepared with 8% sorbitol and 0.3% Na-tripolyphosphate.

PRACTICAL APPLICATIONS

In the present study, the effects of frozen storage of surimi produced from thornback ray and the washing of mince on the chemical composition were investigated. Washing procedure significantly decreased crude ash, crude protein and crude fat content of mince. There were significant differences in moisture, crude ash, and crude protein contents during the 6 months storage period of frozen surimi obtained by using different cryoprotectant mixtures. The folding test scores were highest in fresh surimi and during the first two months of storage. Thornback ray can be used for the production of surimi.     

Impact of salted duck egg albumen powder on proteolysis and gelling properties of sardine surimi

The influences of salted duck egg albumen powder (SDEAP) as salt replacer at various levels (0.5–2.5%) on autolysis and gelling properties of sardine surimi were investigated. SDEAP had high salt (33.67%) and protein contents (64.52%) with trypsin inhibitory activity of 5,975 kunits/g solid. SDEAP was white in color with L*‐value of 96.72. It had low moisture content (3.98%) and water activity (0.38). Autolysis of sardine surimi was drastically inhibited when SDEAP was incorporated with increasing levels as indicated by the more retained myosin heavy chain and the reduced trichloroacetic acid‐soluble peptide content. Breaking force and deformation of surimi gel increased, while expressible moisture content decreased as the levels of SDEAP added were increased (p < .05). Gumminess, hardness, chewiness, springiness, and cohesiveness of surimi gels also increased as SDEAP levels increased (p < .05). Lightness and whiteness were higher in all surimi gels incorporated with SDEAP than the control (p < .05). For microstructure, surimi gels incorporated with SDEAP at all levels used had finer gel network with smaller voids and more connectivity than the control gel. Thus, SDEAP could be used as a salt replacer for sardine surimi gel preparation and it could improve the properties of resulting gel.     

Thermal gelation properties of surimi-like material made fromsheep meat

Thermal gelation properties of surimi-like material made from sheep meat were investigated. The sheep meat was ground, washed 3 times at a meat to water ratio of 1:5 and dewatered by centrifugation. The effects of washing on the composition, functional properties and colour of the mince, were studied. The washing method resulted in a sharp reduction of the fat content and an increase of the water content and pH of the mince. Lightness (L*) and yellowness (b*) of the mince were improved by washing. A significant reduction (p<0.001) of a* (redness) value and a decrease in the a*/b* ratios and saturation index value of the washed mince were recorded. Gels were prepared from washed and unwashed mince after being blended with 2% NaCl and heated at 75°C for 20 min. The washed mince produced excellent gels as measured by the fold test, elasticity modulus and the percentage recovery. The gels made of washed mince had lower expressible fluid compared to that of unwashed mince. A fibrous protein network structure was evidenced in the gel made from washed mince while observed under a transmission electron microscope.     

Gelation properties of previously cooked minced meat from Jonah crab (Cancer borealis) as affected by washing treatment and salt concentration

The influence of washing treatment (dewatered only, one wash, and three washes) and sodium chloride (NaCl) concentration (0%, 2%, and 4%) on the gelation properties of crab mince was investigated. This previously cooked muscle mince is a low-value by-product of the crab processing industry, considered to have little or no functional properties. Crab mince gels were produced and tested for water-holding capacity (WHC), gel strength, colour, and electrophoretic profile. Wash treatment and NaCl concentration significantly affected gelation. Washed samples exhibited significantly higher WHC than dewatered samples. The 4% NaCl treatment decreased WHC compared to lower NaCl levels. Multiple washing steps increased the force to gel deformation. Wash treatment and NaCl concentration also affected the colour of gels. Based on these results, cooked crab meat mince treated with three washes and 0% NaCl resulted in the strongest gels with the best water-holding capacity, which can be used in the development of value-added products.     

Comparative Study of Washing Treatments and Alkali Extraction on Gelation Characteristics of Striped Catfish (Pangasius hypophthalmus) Muscle Protein

ABSTRACT:  The effect of washing treatments (water and alkali washing) and alkali extraction/acid precipitation on the physicochemical and textural properties of striped catfish ( Pangasius hypophthalmus ) muscle protein was compared. Alkali extraction/acid precipitation process resulted in the highest protein recovery of 98.77% (dry weight basis) and lowest fat content of 0.98% (dry weight basis). The extractable proteins of fish protein isolates (FPI) at various ionic strengths (0 to 0.6 M NaCl) exhibited majority of protein at 38 kDa with trace amount of others. Unsaturated fatty acids, namely, oleic, linoleic, and docosahexaenoic acid, were greatly reduced in FPI. Water-washed mince (W) exhibited higher autolytic activity than mince (M), suggesting the presence of myofibril-bound proteinase(s). Autolytic activity was lowest in the FPI. Breaking force of striped catfish gels was greatly improved when set at 40 °C for 30 min, regardless of preparation treatment. The typical water washing process was effective to improve gel-forming ability of striped catfish. FPI gels contained the lower total sulfhydryl content, indicating the greater extent of disulfide bond formation as compared to that of washed mince. The FPI gels showed higher breaking force but lower deformation values than W and alkali-washed (AW) gels. Addition of NaCl improved deformation, but adversely affected breaking force of FPI gel. Whiteness of FPI gel increased with NaCl addition.     

Oxidative stability of lipids and cholesterol in salame Milano, coppa and Parma ham: dietary supplementation with vitamin E and oleic acid

Spent hen (98 weeks) and broiler (12 weeks) breast and thigh muscles were minced (1 mm orifice diameter) and washed with 0.1% NaCl. A portion of both unwashed and washed mince was mixed with cryoprotectants (CP) at the rate of 4% sucrose, 4% sorbitol, and 0.2% Na-tripolyphosphate to produce surimi and kept frozen at -20°C. The mince and surimi were ground with 3% NaCl and a small amount of water to adjust the final moisture content of 80%. The pastes were stuffed into the sausage casing and heated at 90°C for 15 min to produce gel. The effects of washing, heating and CP on colour composition and thermal gelation properties of hen and broiler minces and surimi were compared. Broiler mince was lighter and less red in colour, higher in protein and lower in moisture, lipid and collagen. Gel strength and breaking strength were higher in spent hen surimi compared to broiler surimi under similar gelation conditions. Gel elasticity, springiness and water retention properties were almost identical in two surimi. Gel quality was markedly deteriorated in spent hen surimi but not so in broiler surimi after 8 weeks frozen-storage. Although CP increased the gel strength of fresh surimi (non-frozen, 0 week storage) from both hen and broiler, they were more effective in broiler surimi than hen surimi in protecting the functional quality of gel.     

Gel properties of croaker–mackerel surimi blend

Gel properties of croaker surimi blended with three types of mackerel surimi at different ratios were evaluated. The gel strength of the croaker–mackerel surimi blend was higher than that of the original mackerel surimi (p < 0.05). The presence of croaker surimi in the blend resulted in the increase in myosin heavy chain (MHC) band intensity. No differences in deformation of gels were observed in croaker surimi and croaker-short-bodied mackerel blend at all ratios (p > 0.05). The addition of short-bodied mackerel surimi into croaker surimi up to a ratio of 1:2 had no effect on whiteness and metmyoglobin content of the gel (p > 0.05). Marked decrease in expressible drip and TCA-soluble peptide of gel was noticeable in croaker–frigate mackerel surimi blend (p < 0.05). Therefore, the gel properties of croaker–mackerel surimi blend were governed by the type and content of mackerel surimi used.     

Inhibition of Lipid Oxidation during Processing of Washed, Minced Atlantic Mackerel

An antioxidative system that was designed to maintain heme iron reduced, nonheme iron as an inactive chelate, and provide free radical scavenging in the aqueous and lipid phases, was most effective when added early in the processing of washed, minced mackerel muscle. Mince prepared from mackerel dark muscle showed greater propensity to oxidize than did the mince from light muscle. Washed mince from light muscle in the presence of the antioxidative system showed no loss of odor quality during 24 wk at -20°C. Postmortem age of the mackerel muscle had little effect on initial odor quality of the washed mince.