Search

Surimi or fish mince gel are popular seafood products worldwide. Lean fish are commonly used as raw material, while dark fleshed fish, especially Indian mackerel, has high fat content and dark color associated with poor gel quality. To improve gel strength, plant extract, particularly from duea ching (Ficus botryocarpa Miq.), rich in polyphenols and calcium could be used as natural protein cross-linker to strengthen gel network. Effect of ethanolic duea ching extract (EDCE) at varying levels in the absence and presence of microbial transglutaminase (MTGase) on gel property of Indian mackerel mince gel prepared from fillets pre-washed for different times (1 and 3 times) was studied. Heat-induced aggregation of myofibrillar protein (MP) from Indian mackerel fillets under different conditions was also investigated. Mince gel prepared from fillets pre-washed for 3 times added with 0.10 % EDCE and 0.5 unit/g of MTGase (3-PWM-MT-0.10) showed the highest breaking force, deformation and textural properties (P

The present study aims to analyze the biological aspects and population dynamics of Indian mackerel in Barru waters. Data was collected in Barru for 11 months, from June 2022 to April 2023. The observed parameters of biological aspects included gonadal maturation stages (GMSs), size at first gonadal maturation, and length-weight relationship. Meanwhile, the aspects of population dynamics encompass age group, growth, mortality rate, and exploitation rate. Data analysis consisted of morphological selection of general maturation stages, Spearman-Kärber method in estimating gonadal first maturation size, Bhattacharya method in identifying age group, von Bertalanffy function through FISAT II to measure growth (L∞ and K), Pauly Model to estimate mortality rate, Beverton & Holt Model to estimate Y/R, and virtual population analysis (VPA) analysis to estimate stock and fish yield. The results demonstrated that GMS I was observed to be dominant, followed by stages II and III. The initial gonadal maturation was estimated to be 17.98–19.28 cm (FL) for females and 17.98–19.27 cm (FL) for males. The length-weight relationship in male and female Indian mackerels indicated a positive allometric growth. The mode grouping analysis results from the fork length measurement revealed three age groups. It was also identified that the asymptotic length (L∞) = 29.5 cm (fork length), growth rate coefficient (K) = 0.46 per year, and theoretical age at zero length (t0) = –0.3576 per year. Total mortality (Z) = 2.67 per year, natural mortality (M) = 1.10 per year, fishing mortality (F) = 1.57 per year, and exploitation rate (E) = 0.59, the actual Y/R = 0.083 gram/recruitment, and optimal Y/R 0.03 gram/recruitment. Fishing mortality is higher than the natural mortality rate, and a high exploitation value (E > 0.5) also reflects over-exploitation. VPA analysis on fish yields and stock estimation reported a highly exploited rate between the 11.5 cm and 14.5 cm length classes and an exceeding current yield of 467.07 tons/year with a recom-mended yield of 233.53 tons/year to ensure population sustainability.

The present study was designed with an attempt to explore therapeutic potential of Indian mackerel against carbon tetrachloride (CCl4) induced hepatic damage in rats. Male Wistar albino rats (n=18), weighing about 150-200 g, were randomly assigned to 3 groups of six each. Rats of Group I (control) received 1% DMSO daily orally for 3 weeks and olive oil I/P twice a week in the 2nd and 3rd week. Group II and III received CCl4 @ 1 mL/kg b.wt. in olive oil (1:1) I/P twice a week in 2nd and 3rd week, whereas, Group III rats were also administered with fish extract @ 300 mg/kg b.wt. orally daily in 1% DMSO for 3 weeks. The extent of CCl4 induced damage was measured by estimating ALT, AST, ALP, bilirubin in serum, total protein and albumin in plasma, SOD, CAT, GSH, GPx and TBARS in liver tissue homogenate and histopathological examination of liver. CCl4 induced oxidative damage was evidenced by elevated levels of ALT, AST, ALP, TBARS and reduced levels of GSH, SOD, CAT, GPX and total protein. Treatment with fish extract along with CCl4 led to reversal in the altered hepatic biomarkers and a significant reduction in the MDA levels, improvement in antioxidant markers when compared to CCl4 induced hepatotoxic group. Thus, results of the present study indicated that fish extract offered protection against CCl4-induced hepatic damage in rats due to its antioxidant effect. [ABSTRACT FROM AUTHOR]

In this study, Indian mackerel (Rastrelliger kanagurta) waste protein hydrolysate was produced using two enzymes, alcalase and flavourzyme, at different times of hydrolysis (10, 20 and 30 minutes) and then its antimicrobial properties against Gram-positive Escherichia coli and Gram-negative Staphylococcus aurous were examined. The results showed that the highest values of nitrogen recovery (89.88%) and degree of hydrolysis (38.70%) were observed by alcalase enzyme during 30 minutes of hydrolysis (P <0.05). The composition of amino acids also showed that the proteins hydrolyzed with both enzymes have a relatively similar composition. The highest levels of essential amino acids for alcalase and flavourzyme were lysine 7.99%, 7.19% and arginine 7.55% and 8.21%, respectively. The highest levels of non- essential amino acids were glutamic acid 12.55%, 11.79% and then aspartic amino acid were 7.99% and 6.98%, respectively. The chemical index showed that both hydrolyzed proteins could well meet an adult human need for most amino acids. The highest antimicrobial activity was observed in the hydrolyzed protein produced by alcalase (P <0.05). Staphylococcus aureus had lower resistance to Escherichia coli. Overall, it seems that Indian mackerel waste protein hydrolysate can be used as protein supplements in food and in diet formulas as a natural antimicrobial. [ABSTRACT FROM AUTHOR]

The present study aimed to assess the size-selectivity of Rastrelliger kanagurta (Indian mackerel) caught in encircling gill nets of 5.1, 5.7 and 6.3 cm mesh sizes. Fishing experiments were carried out in Huamual Belakang coastal waters of West Seram during the period from October to December 2022. The captured Indian mackerel were measured to determine their total length, and size-frequency distributions were generated for each mesh size category. The selectivity curve was analysed by Kitahara methods using MS Excel. The results indicate that encircling gill nets with 5.1 cm mesh sizes tend to capture smaller Indian mackerel individuals, potentially leading to a bias in the catch composition. Conversely, 6.3 cm mesh sizes exhibited a higher likelihood of capturing larger individuals while allowing smaller fish to escape, suggesting a potential strategy for size-focused fisheries management. The outcomes of this study have implications for optimizing fishing gear design and enhancing the selectivity of catches to support sustainable fisheries management in the Huamual Belakang Waters. [ABSTRACT FROM AUTHOR]

Gelling behaviors of partially purified myofibrillar proteins (PPMP) extracted from Indian mackerel (IM) and threadfin bream (TB) as a function of heating temperatures (20–75°C) were comparatively studied. PPMP obtained from IM (IM‐MP) showed lower turbidity and surface hydrophobicity as compared to those extracted from TB (TB‐MP). Moreover, lower disulfide bond content was noticed in IM‐MP (7.7–9.46 mol/106 g protein) as compared to TB‐MP (10.99‐13.95 mol/106 g protein) during the heating process. There was no major difference in the amino acid profile noticed between PPMP from both the species, except lysine and glutamine contents, which were higher in TB‐MP. Structural analysis, FTIR spectra, amide I band, and fluorescence intensity substantiated those changes. The protein pattern also revealed autolysis of IM‐MP. The transmission analysis also showed lower aggregation and crosslinking ability of IM‐MP than TB‐MP. Therefore, poorer gelling behavior of IM‐MP reconfirmed the inferior gel property of surimi gel from IM to gel from TB. Potential development is still required for the improvement of the gel properties of dark‐fleshed fish surimi such as IM. Practical Application: Indian mackerel (IM) is an abundant and widely captured fish species. Due to overexploitation of lean fish, pelagic fish could be explored as a potential raw material for surimi production. However, poor gelling properties of IM limit its use in the surimi industry. This study provides an insight into the gelling behavior of myofibrillar proteins from IM during the gelation process in comparison with the lean fish (threadfin bream). Overall, structural and rheological changes of myofibrillar proteins play a role in gelation, thus affecting gel properties between two species. Further improvement of the gel of IM is still required. [ABSTRACT FROM AUTHOR]

The two main small pelagic fishes along the southwest coast of India in the eastern Arabian Sea, the Indian oil sardine (Sardinella longiceps) and the Indian mackerel (Rastrelliger kanagurta) were studied to see if there was any notable long-term alteration in phytoplankton in their diets. The basic oceanographic features and the long-term sea surface warming in the study region are first examined using satellite data, which reveals clear seasonality in the wind, sea surface temperature, sea surface salinity, and chlorophyll-a as well as long-term ocean surface warming. We then considered a recent gut content data set of Indian oil sardine and Indian mackerel from the 2010–2011 period from two landing places along India's southwest coast, which was compared with numerous historical data sets to find out if there was any long-term phytoplankton compositional change in the diet. The recent data revealed the same dominant phytoplankton as those collected decades ago, such as Coscinodiscus, Nitzschia, Pleurosigma, and Thalassiosira in sardines and Coscinodiscus, Thalassiosira, Ceratium, Dinophysis, Protoperidinium, and Pyrophacus in mackerel. This suggests the lack of any significant long-term qualitative shift of phytoplankton in the Indian oil sardine and Indian mackerel over the last several decades. However, several phytoplankton genera found present in the recent data were absent in the historical data, including 10 genera for mackerel and 17 for Indian oil sardine. These recent phytoplankton records are intriguing, and we feel they could be an early sign of long-term phytoplankton compositional or relative abundance shift, although additional research is needed to confirm this.

Indian Mackerel (Rastrelliger kanagurta) is an essential small pelagic fishery resource, contributing to nearly 30 % of India's total marine fish landing. However, this species' life cycle and stock status are poorly understood and data deficient. Ocean mesoscale events are also known to influence their landing, besides the environmental factors like- salinity, chlorophyll, and sea surface temperature, affecting these small pelagic fishes' availability, migration, feeding, and reproductive activity. The Malabar upwelling region (southwest coast of India) is a significant upwelling system where upwelling occurs during the monsoon months. The nutrient-rich water increases the productivity of surface water, leading to plankton abundance. This productivity sustains a fishery for several commercially important fishes, mainly small pelagics such as sardines, mackerels, and anchovies, supporting India's most significant coastal pelagic fishery. For understanding the relationship between the target fish and the oceanographic events, in the present study, Pearson's correlation has been estimated between Indian Mackerel landing, rainfall, Sea water temperature at 0, 10, 20, 30, 45, and 50 m depths, mixed layer depth (MLD), their anomalies and occurrences of potential fishing zone (PFZ) lines along the Malabar upwelling region and corresponding coasts of Karnataka and Kerala. Mackerel landing time series showed a significant autocorrelation in four-quarter lag, correlation with rainfall anomaly in one-quarter lag, with PFZ line and MLD in three-quarter lag, and with SWT@50 (Seawater temperature@50 m depth) and SST anomaly in two-quarter lag both in Karnataka and Kerala. Upwelling events, as indicated by the presence of PFZ lines, were found to significantly impact the landings of Indian mackerel along the Karnataka and Kerala coasts. Polynomial equations were used to model the relationship between mackerel landings and these environmental factors, effectively capturing the influence of these parameters on mackerel catch trends. • MUR, fuelled by nutrient-rich water, enhances plankton abundance, supporting a thriving fishery for small pelagic species like Indian mackerel. • Pearson's correlation revealed significant relationships between mackerel landings, rainfall, SST, MLD, and PFZ lines along SW coast of India. • Polynomial equations developed here provided a quantitative framework for understanding the impact of these factors on mackerel landings. • Rainfall anomaly, PFZ lines, MLD, SST, and SWT@50 exhibited significant correlations suggesting their influence on the fishery. [ABSTRACT FROM AUTHOR]

Indian mackerel and Pangasius fish fillets were both subjected to a hot smoking procedure, and their products were used in the spread preparation. Proximate analysis, physicochemical, microbial and sensory properties were monitored before and after frozen storage for three months. The fat content (12.1%) and nutritional value (215.3 Kcal/100g) of the smoked Pangasius fillets were more than those recorded for smoked Indian mackerel fillets (2.5% & 144.1 Kcal/100g, respectively). During frozen storage of smoked Indian mackerel and Pangasius fillets, moisture content was reduced to 61.25 and 51.8%, while an increment was noticed in salt content (2.73 & 2.45%), pH (6.7 & 6.82), TVB-N (24.94 & 18.55 mgN/100g), TBA (2.4 & 2.98 mgMDA/kg), TPC counts (2.5×10³ & 5.3×10³ CFU/g), and yeast and mold counts (0.97×102 & 1.3×10² CFU/g), respectively. Sensory scores for smoked Indian mackerel and Pangasius fillets ranged between very good and good, and the overall acceptability scores became 38 and 35, respectively, at the end of frozen storage period. By adding feta cheese and ketchup to produce Indian mackerel and Pangasius spreads, the protein content decreased to 21.5 and 19.8%, while carbohydrates (10.2 & 8.5%), fat (4.1 & 13.3%) and nutritional value (163.7 & 232.9 Kcal/100g) increased, respectively. At the end of frozen storage, moisture content decreased to 58.08 and 50.97%, while salt content (3.81 & 2.85%), pH (5.84 & 6.72), TVB-N (33.44 & 23.91 mg N/100g), TBA (2.03 & 2.67 mg MDA/kg), TV counts (7.9×103 & 9.2×103 CFU/g), and yeast and mold counts (3.1×102 & 3.8×10² CFU/g) increased, respectively. Sensory scores for the Indian mackerel and Pangasius spreads ranged between very good and good, and the overall acceptability scores became 39 and 37, respectively. The quality of hot smoked fillets and spreads coincides with Egyptian standards for smoked products. [ABSTRACT FROM AUTHOR]

Simple Summary: Mackerel species are commercially important marine species in Southeast Asia, especially short mackerel and Indian mackerel. However, genomic information about them is still limited. Genome survey of these two mackerel species was reported in this study. Next-generation sequencing and comprehensive bioinformatics were performed to obtain the genetic information. The estimated genome size of both species is around 680 Mbp. The heterozygosity of these species was very similar, while the repeat content for Indian mackerel was slightly higher than for short mackerel. Functional annotation also was reported in this study. This is the first reported genome survey and assembly of species in the genus Rastrelliger and could be useful for future comparative genomic studies. Rastrelliger brachysoma (short mackerel) and Rastrelliger kanagurta (Indian mackerel) are commercially important marine species in Southeast Asia. In recent years, numbers of these two species have been decreasing in the wild, and genomic information about them is still limited. We conducted a genome survey of these two mackerel species to acquire essential genomic information using next-generation sequencing data. To obtain this genetic information, comprehensive bioinformatics analyses were performed, including de novo assembly, gene prediction, functional annotation, and phylogenetic analysis. The estimated genome sizes were around 680.14 Mbp (R. brachysoma) and 688.82 Mbp (R. kanagurta). The heterozygosity of these species was very similar (≈0.81), while the repeat content for R. kanagurta (9.30%) was slightly higher than for R. brachysoma (8.30%). Functional annotation indicated that most of the genes predicted in these two species shared very close average amino acid identities (94.06%). The phylogenetic analysis revealed close phylogenetic relationships between these two species and other scombrids. This is the first reported genome survey and assembly of species in the genus Rastrelliger and could be useful for future comparative genomic studies. [ABSTRACT FROM AUTHOR]

Metal pollution has always been a major cause of contamination of the environment and is considered a major concern for food health. In this study, the human health risk due to the consumption of muscle of Rastrelliger kanagurta was evaluated by measuring the concentrations of copper and zinc in caviar and muscle samples. After preparation operation, biometry, and digestion of muscle parts, measurement of heavy metal concentrations were done using atomic absorption spectrophotometer (AAS). Mean concentrations of copper and zinc were lower than the international standard limits. In addition, the calculations indicated that daily and weekly copper and zinc uptake for the Iranian consumers, according to Statistical Yearbook of Iran Fisheries organization (the amount consumed per capita), is lower than the guideline values (PTWI and PTDI) provided by WHO, USEPA. In general, the THQ and total THQ measured in this study were

Summary: In this study, a film was developed for packaging fish that not only enhanced its shelf life but also was visually receptive to its spoilage. Rose petal extract (RPE) having excellent bioactivity was used as the functional component in carboxymethyl cellulose‐poly vinyl alcohol packaging film. Due to its high anthocyanin content, RPE could be used as a pH indicator, as its colour changed from bright red (pH 2) to yellow (pH 10). The developed film was used for packing Indian Mackerel and assessing its quality during chilled storage. Mackerel packed in neat film spoiled in 3 days while that in RPE containing films had shelf life of 12 days. Total bacterial count, pH, total volatile basic nitrogen and thiobarbituric acid reactive substance of fish in control were higher as compared to in RPE films. On spoilage RPE containing films showed visible colour response from red to green. [ABSTRACT FROM AUTHOR]

Rastrelliger brachysoma (short mackerel) and Rastrelliger kanagurta (Indian mackerel) are commercially important marine species in Southeast Asia. In recent years, numbers of these two species have been decreasing in the wild, and genomic information about them is still limited. We conducted a genome survey of these two mackerel species to acquire essential genomic information using next-generation sequencing data. To obtain this genetic information, comprehensive bioinformatics analyses were performed, including de novo assembly, gene prediction, functional annotation, and phylogenetic analysis. The estimated genome sizes were around 680.14 Mbp (R. brachysoma) and 688.82 Mbp (R. kanagurta). The heterozygosity of these species was very similar (≈0.81), while the repeat content for R. kanagurta (9.30%) was slightly higher than for R. brachysoma (8.30%). Functional annotation indicated that most of the genes predicted in these two species shared very close average amino acid identities (94.06%). The phylogenetic analysis revealed close phylogenetic relationships between these two species and other scombrids. This is the first reported genome survey and assembly of species in the genus Rastrelliger and could be useful for future comparative genomic studies.

Fish quality is important in the food industry. Studies on the nutritional, microbial and minerals in Indian mackerel fish are limited. Therefore, this study was carried out to assess the quality and production of fish products (balls and fingers). Additionally, the effect of frozen storage for six months on the microbial, nutritional and sensory evaluation of fish balls and fingers was studied. The obtained results showed that the estimated minerals (zinc, cadmium, chromium, copper, lead and mercury) contents in Indian mackerel muscles were lower than the maximum permissible limits for human consumption. The levels of total bacterial counts and total yeast counts in Indian mackerel purchased from three different stores varied. After 6 months of storage, the microbial content decreased in Indian mackerel fish balls and fingers to less than 2.0×10² CFU/g, which was due to the effect of freezing on the growth and activity of microorganisms, while the carbohydrate, fat and energy contents increased, and the ash, protein and moisture contents decreased; however, Indian mackerel fish fingers had elevated ash, carbohydrate, fat, protein and energy contents and a reduced moisture content after freezing. Sensory evaluation of Indian mackerel balls and fingers at the start and end of the storage period (6 months) revealed good scores for appearance, odor, texture, taste and acceptability. These results provide insights into the benefits of good-quality Indian mackerel fish in the fish product industry and their availability after storage for six months. [ABSTRACT FROM AUTHOR]

Collagen is an extracellular matrix protein which plays a vital role in the wound healing process. Wound healing properties of papaya leaf extract have been well studied. Therefore, the synergistic effect of papaya leaf phytoconstituents and isolated collagen was evaluated for its wound healing properties. In the present study, acid-soluble collagen (ASC) was isolated from the skin of Indian mackerel (Rastrelliger kanagurta) and characterized. Along with isolated ASC, major papaya leaf constituents including caffeic acid, coumaric acid, quercetin and oleic acid were added to study their effects on wound healing. The ASC was isolated with a yield of 3.57 %. On the basis of SDS-PAGE analysis, the isolated ASC was identified as type I collagen. In the FTIR spectra, five amide groups were identified as major bands, which represents the triple helical nature of the collagen. By SEM analysis, the collagen fibers were found to be densely packed. Different combinations of collagen gel and papaya leaf compounds were prepared by one-to-one combination as well as mixed combinations. These test compounds were screened by in vitro scratch wound assays using the NIH3T3 cell line. Among all the test compounds, collagen with quercetin (0.04 mg) was the most effective in enhancing wound closing, with 100 % migration of fibroblasts. [ABSTRACT FROM AUTHOR]

Fish is always cooked in different methods before consumption. Cooking improves hygienic quality of the fish by inactivation of pathogenic microorganisms and enhances digestibility of nutrients in the digestive tract. The aim of this study was to evaluate the physico-chemical and nutritional properties of Indian Mackerel (Rastrelliger kanagurta) for different cooking methods (Boiling, Frying and Microwave). The Proximate composition of fresh Indian mackerel was observed to be moisture 70.90%, crude protein 20.5%,crude fat 7.40% andash 1.20%. The yield percentage of fresh Indian mackerel was observed to be whole dressed mackerel was 60%. The proximate composition of Indian mackerel for different cooking methods (boiling, frying and microwave) was found to be moisture 70.26%, 67.95%, 65.73%, protein content was found to be 20.8%, 21.78%, 27.46%, fat content was found to be 7.7%, 8.9%, 5.6%, ash content was found to be 1.2%, 1.3%, 1.1% and the yield percentage was observed for Indian mackerel for different cooking methods (boiling, frying and microwave) was 84.82, 84.60, 85.67%, respectively. Organoleptic evaluation score for different cooking methods (boiling, frying and microwave) from Indian mackerel i. e. based on organoleptic characteristics like colour, odour, taste, texture and appearance was found to be overall acceptability for Indian mackerel (boiling, frying and microwave) rated 6.6, 7.6, and8.3 respectively. Using sensory evaluation by trained panellists, the microwave method from Indian mackerelgained higher acceptability as compared to other cooking methods. While cooking methods affected mineral content of Indian mackerel did not affect. The highest value of saturated, polyunsaturated, omega 6 and omega 3 fatty acids was found for mackerel in microwave method. Similarly colour, TPA, peroxide value (PV) and Total Plate Count (TPC) changed significantly (p<0.05) between fresh fish and cookingmethods. Effect of different cooking methods for Indian mackerel in microwave method was found greater values than those parameters as compared to other methods. Therefore, it is concluded from present study that good yield and desirable physico-chemical and nutritional properties of microwave cooking method is the best method for Indian mackerel. These findings may recommend for healthy consumption. [ABSTRACT FROM AUTHOR]

In the present study, Indian mackerel was dried by microwave vacuum drying (MVD) method and compared its physico chemical quality to mackerel dried by hot air drying (HAD) method. Antioxidant effects of thyme oil (TMO) and clove leaf oils (CLO) during storage were also evaluated. Brine salted mackerel was dried in hot air oven (50–55 °C) and microwave vacuum dryer (600 W and 600 Hg mm). For essential oil treatment, mackerel was dipped in 0.75% TMO and CLO for 5 min. Moisture content of MVD and HAD samples was reduced to 30–32% in 1.2 h and 12 h, respectively. Rehydration ability and water absorption index of MVD samples were significantly higher to that of HAD samples. Mackerel dried by HAD showed significantly higher salt soluble and water soluble protein nitrogen fractions than that of MVD samples. Significantly higher hardness and chewiness values were observed for HAD samples. Color and appearance of uncooked MVD sample was superior to that of HAD samples. As per the results of PV and TBARS, TMO exhibited better antioxidant effect compared to CLO. The study demonstrated that fast drying can be achieved by microwave vacuum dryer and it can produce dried fish having better sensory and textural attributes. [ABSTRACT FROM AUTHOR]

Population dynamics parameters of Rastrelliger kanagurta (Cuvier, 1816) were analyzed from January to December 2008 in coastal waters of Pakistan. FiSAT software was used to assess growth population dynamics parameters. The growth parameters K = 0.84 year–1 and L∞ = 24.57 cm were estimated with the aid of von Bertalanffy growth function. The natural mortality rate (M), the fishing mortality rate (F), and the total mortality rate (Z) were calculated as 1.682, 2.208, and 3.890 year–1, respectively. The annual instantaneous fishing mortality rate in our study was considerably greater than both the target (Fopt = 0.841 year−1) and limit (Flimit = 1.121 year−1) biological reference points, suggesting that this species is being over-exploited in the waters of Pakistan. An exploitation rate (E) was estimated to be 0.567 year–1and longevity (tmax) was calculated as 3/K equal to 3.57 years. The fishery of R. kanagurta by the gillnet catches in our study are of ages 2 to 3 years which indicated a reasonable mesh size for the catch. [ABSTRACT FROM AUTHOR]

Flake ice refrigeration is a conventional but commonly employed technique to slow down fish spoilage and deterioration of nutritional values and sensory properties during chilled storage. In the present study, a methanolic extract of red alga Gracilaria verrucosa was characterised, and functional groups, such as alkenes, aldehydes, nitriles, galactans and galactose-4-sulphate were found. Subsequent identification of active compounds revealed the presence of potent preservative agents, such as butylated hydroxytoluene, sulfurous acid, 1,2-propanediol, benzeneacetic acid, cyclononasiloxane and tetracosamethyl-cyclododecasiloxane. The effect of incorporating G. verrucosa at two different concentrations (0.67 and 2.5 g lyophilised alga/L aqueous solution) in the icing medium was tested for the preservation of Indian mackerel (Rastrelliger kanagurta), compared to preservation in traditional ice prepared only from water. Microbial, chemical and sensory qualities were monitored in Indian mackerel chilled in ice with and without G. verrucosa during 15 days storage period. Inhibitory effects (p < 0.05) on the microbial proliferation (mesophilic and psychrophilic bacteria) and chemical markers of fish deterioration (pH, TVB-N, TMA-N and biogenic amines) were evidenced for ice containing both concentrations of G. verrucosa, respectively, relative to the control medium. The sensory score acceptability limit reached 11 days for Indian mackerel stored in traditional ice and 15 days for Indian mackerel stored in ice with G. verrucosa extract. Thus, the icing medium containing G. verrucosa extract improves the quality and safety of Indian mackerel during storage and can be explored by the seafood industry as a biopreservative. [ABSTRACT FROM AUTHOR]

Investigation of fecundity and gonado somatic index (GSI) of Rastrelliger kanagurta were carried out from March 2011 to February 2012. Fecundity was determined at different length, weight and ovary ranges of different individual fishes. Study revealed that at 5% significant level significant average absolute fecundity was found to be 1,08,266 and relative fecundity ranged from 407 to 1499. The number of ova generally increased with increase in length and weight. However, variations in fecundity with respect to length and weight were also noticed. The gonado- somatic index (GSI) was calculated for each individual fish (592 numbers) and was averaged for each month. The average GSI values were plotted against each month to analysed monthly variations. GSI showed wide variations between sex and it was highest for both males and females during the month of April and September, showing occurrence of more ripe individuals. Analysis of regression showed that there were significant relationship between the fecundity with the fish length, body weight and ovary weight. [ABSTRACT FROM AUTHOR]

Effects of serine protease inhibitor from squid ovary (SOSPI) and egg white powder (EWP) on gel properties of surimi from Indian mackerel ( Rastrelliger kanagurta) were investigated. Breaking force of gel increased when SOSPI levels increased up to 2%. However, EWP showed higher efficiency in increasing breaking force of resulting surimi gel. Nevertheless, SOSPI (0.5-3%) had no effect on deformation. Trichloroacetic acid-soluble peptide content in surimi gel decreased when the levels of SOSPI and EWP increased ( p < .05). This was coincidental with more retained myosin heavy chain. Water holding capacity was increased with the addition of these protein additives, but resulted in lower whiteness. Microstructure study revealed that surimi gel added with 2% EWP was denser and had higher connectivity as compared to that containing 2% SOSPI. The SOSPI had no negative effect on sensory attributes and could serve as the alternative protein additive to improve gel strength of surimi. Practical applications Surimi from dark-fleshed fish is prone to degradation of myofibrillar proteins caused by the endogenous proteases, thereby lowering textural property. To tackle the problem, protease inhibitors (egg white, porcine plasma protein, and bovine plasma protein) have been used by the surimi industries. Due to drawbacks of some particular inhibitors (religious constraints, off-white color, off odor, etc.), the novel additives are still in demand. Ovary from squid processing industry, commonly discarded as the waste, can be an alternative natural protease inhibitor, which can improve the gel properties of surimi, especially produced from dark-fleshed fish. [ABSTRACT FROM AUTHOR]

The current study was conducted to evaluate the nutritional characteristics (moisture, protein, lipids, ash and fatty acid composition) of the flesh of oil sardine (Sardinella longiceps) and Indian mackerel (Rastrelliger kanagurta) caught from Hadhramout coast of the Arabian Sea. The protein content was 21.6% and 18.1% (wet weight basis) for mackerel and sardine, respectively. The lipid content was much higher in sardine (10.1%) compared with mackerel (1.7%). The fatty acid composition showed that total saturated fatty acids had the highest relative value (37.5%) among other fatty acid groups in the flesh lipids of sardine, followed by polyunsaturated fatty acids (29.9%) and monounsaturated fatty acids (23.4%). In mackerel, polyunsaturated fatty acids was present at 37.4%, followed by saturated fatty acids (36.7%) and then monounsaturated fatty acids (14.3%). The majority of polyunsaturated fatty acids in both fish were deposited as omega-3 (89.8% in sardine and 87.9% in mackerel), of which docosahexaenoic acid and eicosapentaenoic acid were the most abundant. In conclusion, oil sardine and Indian mackerel which are locally available and affordable fish in Yemen can be considered valuable sources of nutrients particularly protein and health-beneficial omega-3 long chain polyunsaturated fatty acids. [ABSTRACT FROM AUTHOR]

The antioxidant activity and efficacy of pomegranate (Punica granatum) peel extract (PPE) to retard lipid oxidation in mackerelcooked meat model was evaluated. The PPE was extracted using ethanol and crude extracts were obtained in flash evaporator under low pressure and low temperature. The antioxidant activity of extract was evaluated by DPPH (2, 2- diphenyl-1-picrylhydrazyl) radical scavenging and ABTS+ 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid). The minced meat of Indian mackerel (Rastrelliger kanagurta) was treated with different concentration of PPE (1000, 1500 and 2000 ppm) and cooked at 80-85 °C in water bath, cooked sampled were packed in polythene bags and stored at 4 °C. Oxidative stability was measured by the PV (Peroxide value) and TBARS (Thiobarbituric acid reactive substances). Results obtained were compared with the samples containing commonly used synthetic antioxidants, BHA and control sample. The results of DPPH radical scavenging activity of PPE at a concentration 35µg/mL showed inhibition of 92.37 %, which was equivalent to results of BHA at a concentration of 200µg/mL. Results of ABTS+ radical activity at a concentration 1000 µg/mL showed an inhibition of 80.45 %.Results of oxidative rancidity of meat showed that, the sample treated with PPE at a concentration 2000 ppm showed significantly higher reduction (p<0.05)in primary and secondary oxidation products compared to other two concentrations of extracts. The sample treated with pomegranate peel was acceptable till 8th days of storage compare to control of 4 days of storage. The result of the present investigation suggested that the pomegranate peel obtained as a by-product of fruit processing industry can be used as a natural antioxidant for controlling the oxidative rancidity in fish and fishery products. [ABSTRACT FROM AUTHOR]

The present study was aimed to investigate the combined effects of vacuum packaging and mint extract treatment on the quality changes of gutted Indian mackerel ( Rastrelliger kanagurta) during storage at 0-2 °C for 22 days. Biochemical, total viable count and sensory quality of chill stored mackerel were analysed at periodic intervals. Mint extract treated [dipping in 0.5% (w/v) solution of mint extract for 30 min] and vacuum packed fishes (MEVP) had significantly lower total volatile base nitrogen and trimethyl amine nitrogen compared to those packed under vacuum (CVP) and air (CAP) without mint extract treatment. Nucleotide degradation rate was lower in MEVP followed by CVP and CAP. Vacuum packaging in combination with ME treatment significantly inhibited lipid hydrolysis and lipid oxidation in mackerel as observed from its lower free fatty acid, peroxide value and thiobarbituric acid reactive substances values. Synergistic use of mint extract and vacuum packaging has markedly controlled microbial proliferation in the samples. Based on sensory evaluation, shelf life of Indian mackerel stored at 0-2 °C was determined as 13 days for CAP group, 16 days for CVP group and 21 days for MEVP group, respectively. The present study revealed that combination of vacuum packaging and mint extract treatment can be a promising technology to improve the storage quality of chill stored gutted mackerel. [ABSTRACT FROM AUTHOR]

In this study, Nickel (Ni), Lead (Pb), Cadmium (Cd) and Chromium (Cr) concentrations were determined in muscle, liver, kidney, gills and gonads of Indian mackerel (Rastrelliger kanagurta) collected from Karachi fish Harbour, Karachi coast, Pakistan, during August 2006 and December 2011. Generally, the fish showed the highest level of Ni (2.26+0.89 μg g-1), Pb (1.45+0.40 μg g-1), Cd (2.07+0.75 μg g-1) and Cr (1.52+0.69 μg g-1) in the liver. The studied metals were the most abundant in the liver than the other organs of the fish. The amount of metal accumulation in fish tissues was evaluated in terms of human health. It was seen that bioaccumulations in muscle tissues of the fish caught from Karachi coast of Pakistan did not exceed the limit values. [ABSTRACT FROM AUTHOR]

The effect of edible coating using gum arabic on biochemical, microbiological, textural and sensory characteristics of fresh gutted mackerel stored at 4 °C was investigated. The results were further compared against the samples packed under vacuum (VP) and conventional polyethylene pouches (CP). Coating with gum arabic (GC) markedly retarded lipid oxidation process in gutted mackerel compared to VP and CP samples. Moreover, VP and CP samples showed higher degree of textural deterioration compared to GC samples. Microbiologically, the shelf life of chilled gutted Indian mackerel was estimated to be 7-8, 17 and 19-20 days for CP, GC and VP samples, respectively. The sensory analysis scores confirmed the efficacy of gum coating in retarding the spoilage process during chilled storage. The current study identifies the potential of edible coating with gum arabic to improve the overall quality of Indian mackerel and extend its storage life during chilled storage. [ABSTRACT FROM AUTHOR]

BACKGROUND Fish proteases, especially trypsin, could be used to prepare fish protein hydrolysates with antioxidative activities. In this study, trypsin from the pyloric caeca of unicorn leatherjacket was purified by ammonium sulfate precipitation and soybean trypsin inhibitor ( SBTI)-Sepharose 4B affinity chromatography. Hydrolysate from Indian mackerel protein isolate with different degrees of hydrolysis (20, 30 and 40% DH) was prepared using the purified trypsin, and antioxidative activities (1,1-diphenyl-2-picrylhydrazyl and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging activities, ferric-reducing antioxidant power and ferrous-chelating activity) of the hydrolysate were determined. RESULTS Trypsin was purified 26.43-fold with a yield of 13.43%. The purified trypsin had a molecular weight ( MW) of 23.5 kDa and optimal activity at pH 8.0 and 55 °C. It displayed high stability in the pH range of 6.0-11.0 and was thermally stable up to 50 °C. Both SBTI (0.05 mmol L−1) and N-p-tosyl- l-lysine-chloromethylketone (5 mmol L−1) completely inhibited trypsin activity. Antioxidative activities of the hydrolysate from Indian mackerel protein isolate increased with increasing DH up to 40% ( P < 0.05). Based on sodium dodecyl sulfate polyacrylamide gel electrophoresis, the hydrolysate with 40% DH had a MW lower than 6.5 kDa. CONCLUSION The purified protease from unicorn leatherjacket pyloric caeca was identified as trypsin based on its ability to hydrolyze a specific synthetic substrate and the response to specific trypsin inhibitors. The purified trypsin could hydrolyze Indian mackerel protein isolate, and the resulting hydrolysate exhibited antioxidative activity depending on its DH. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]