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Suitability of Pangasius as a source for salt fermentation and its physicochemical and microbiological changes during fermentation were evaluated for a period of 150 days. Biochemical and microbiological parameters such as proximate composition, pH, non-protein nitrogen, total volatile base nitrogen, free α-amino nitrogen, free fatty acid, peroxide value, thiobarbutric acid reactive substances, salt content, total titratable acidity, total viable count, and Escherichia coli were analyzed during the fermentation. Peroxide value and thiobarbutric acid reactive substances indicated that maturation started on the 90th day of fermentation. The highest non-protein nitrogen (NPN)/total nitrogen (TN) ratio was observed on the 120th day and the highest sensory scores were observed on the 150th day of fermentation. NPN/TN ratio and sensory scores showed that salt fermentation accelerate from the 90th day and attains maturation on the 120th day. The study revealed that Pangasius can be an ideal fish for salt fermentation, and this technique can be adopted by small-scale farmers. [ABSTRACT FROM AUTHOR]

In this study, different solvents were screened for the extraction of phenolic compounds from brown seaweed (Padina tetrastromatica). Among the methods, 50% (v/v) methanol gave maximum yield having higher phenolic content with antioxidant and antimicrobial activities. The methanol free crude extract was used as a natural preservative for chilled stored tilapia by giving dip treatment at different concentrations as control (T0), 0.5% (T1) 1% (T2) 1.5% (T3), and 2% (T4) (v/v) before chilled storage. Sampling was done on the 0th, 7th, 14th, 17th, 21st, 23rd, and 25th days, respectively. The changes in proximate composition, total volatile base nitrogen, free fatty acid, peroxide value, thiobarbituric acid reactive substance, total viable count and sensory evaluation were analyzed. The onset of spoilage was delayed in seaweed treated samples. Tilapia got 6 days' shelf life extension, when treated with 1%–1.5% of seaweed extract as compared to the control sample. Novelty impact statement: The present study showed the potential of seaweed as a natural preservative in chilled stored fish. Seaweed is a good source of phenolic compounds that has potent antioxidant and antimicrobial properties, which is expected to be responsible for the preservative effect. [ABSTRACT FROM AUTHOR]

Background: Indiscriminate use of harmful synthetic preservatives to extend the shelf life of fish needs to be avoided. The objective of the present work was to study the qualitative and quantitative properties and bioactive properties of black tea powder found in local markets of Maharashtra. Methods: Low-value tea powder was selected through market survey and proximate analysis, total phenolic (Folin-Ciocalteau) and qualitative analysis (Agilent LC-MS system) for phenolic compounds including antioxidant properties was carried out using standard methods. Result: The results for proximate content were protein (21.15%), lipids (1.3%), total ash (9.91%), crude fibre (18.35%) and moisture (3.3%). While total phenolic content was 220.02 mg GAE/g dry tea powder. Total 12 different bioactive compounds were identified by HR-LCMS. The antioxidant properties were DPPH (88.84%), ABTS (74.94%), FRAP (1398.24 µ mol Trolox/gram dry tea powder) and metal chelating activity (25.13%). Based on the findings of this preliminary study it is opined that, black tea powder can act as a promising source of low-cost tea polyphenols for incorporation as antioxidant and antimicrobial agent for fish meat value addition. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Functional extruded snacks were prepared using paste shrimp powder (Acetes spp.), which is rich in protein. The process variables required for the preparation of extruded snacks was optimized using response surface methodology. Extrusion temperature (130–144 °C), level of Acetes powder (100–200 g kg−1) and feed moisture (140–200 g kg−1) were selected as design variables, and expansion ratio, porosity, hardness, crispness and thiobarbituric acid reactive substance value were taken as the response variables. RESULTS: Extrusion temperature significantly influenced all the response variables, while Acetes inclusion influenced all variables except porosity. Feed moisture content showed a significant quadratic effect on all responses and an interactive effect on expansion ratio and hardness. Shrimp powder incorporation increased the protein and mineral content of the final product. The extruded snack made with the combination of extrusion temperature 144.59 °C, feed moisture 178.5 g kg−1 and Acetes inclusion level 146.7 g kg−1 was found to be the best one based on sensory evaluation. CONCLUSION: The study suggests that use of Acetes species for the development of extruded snacks will serve as a means of utilization of Acetes as well as being a rich source of proteins for human consumption, which would otherwise remain unexploited as a by‐catch. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Background: Tea polyphenols are extracted from top two-four young leaves and leaf buds of tea plant, while the bottom leaves of tea shrub are considered as an agricultural waste. Hence, an attempt has been made to utilise them as an alternate source of low-cost natural antioxidant. Methods: Green tea shrub bottom leaves of Camellia sinensis Var. assamica/TV-23 were procured from Estate-Seni Mora Bagan, Karanga kamar, Hazarika Gaon, Tal. Karga, Dist. Jorhat, Assam. Proximate analysis, total phenolic (Folin-Ciocalteau) and qualitative analysis (Agilent LC-MS system) for phenolic compounds including antioxidant properties was carried out using standard analytical methods. Result: The results for proximate content were protein (14.43%), lipids (4.44%), total ash (4.94%), crude fibre (33.63%) and moisture (3.20%). A total phenolic content of dry green tea powder extracts prepared by using ethanol was 105.68 mg GAE/g dry tea powder. Total 12 different bioactive compounds were identified by HR-LCMS. The antioxidant properties were DPPH (89.82%), ABTS (74.71%), FRAP (1053.92 µ mol Trolox/gram dry tea powder) and metal chelating activity (17.51%). Based on the study it is opined that; tea shrub bottom leaves can act as a promising source of low-cost tea polyphenols when extracted with ethanol as a solvent for value added fish product shelf life extension. [ABSTRACT FROM AUTHOR]

The high-performance liquid chromatography with dual Agilent jet stream electrospray ionization- quadrupole time of flight-mass spectrometry method enabled the identification of 10 and 13 phenolic compounds from lyophilized aqueous and 60% ethanol extracts of coconut husk. Different compounds such as catechin, 4-methoxy cinnamic acid, salicin, chlorogenic acid, naringins, madecassic acid, myricetin and quercetin were detected. The effect of extracts at different levels on the gel properties of tilapia surimi were studied. An increase in the gel strength, textural properties and water holding capacity of surimi gels was observed at 0.05% of aqueous and 0.075% of ethanol extracts. Higher concentrations of both extracts had a negative effect on the gel strength of surimi gels. Thermal transition of myosin tail of ethanol extract treated gels ranged in 64–66°C. As a result, at an optimal ratio, coconut husk extracts can improve the quality of freshwater fish surimi gel. [ABSTRACT FROM AUTHOR]

Background: This is the first study in Indian context where underutilized fish species pony fish (Leiognathus sp.) has been used for the preparation of surimi and surimi gel and its textural and spectral images were analysed. Methods: Textural profile analysis for estimating the hardness, gumminess and chewiness parameters and colour analyser for measuring the difference in whiteness among samples were used. FTIR (Fourier Transform Infrared Spectroscopy) was used to estimate the percentage of proteins folded during heat denaturation process. Result: Textural parameters of CWS (Conventional Washed Surimi) gel showed ideal gel strength of 191.06 g cm, hardness of 46.48 N, gumminess of 30.75 N and chewiness of 28.70 N. Colour analysis of UM (Unwashed Mince), CWS and CWS gel showed whiteness of 38.59, 61.45 and 72.07. FTIR analysis of UM, CWS and CWS gel shows unfolding of protein structures in the wavelength of 1688.07 cm-1, 1665.34 cm-1 and 1653.20 cm-1. This study reveals the potential use of pony fish (Leiognathus sp.) as one of the favorable fish species for surimi and sausage production showing virtuous instrumental quality attributes. [ABSTRACT FROM AUTHOR]

Biofloc technology is a modern-day high-density fish culture system employing heterotrophic conversion of nitrogenous waste into useful flocs for water quality control and improved welfare. However, optimization of the stocking density for the target species during seed rearing is the key to a successful farming operation. The study evaluated the effect of different stocking density on the growth, feed utilization, digestive physiology and economics in a biofloc-based seed rearing of butter catfish, O. bimaculatus. Advanced fry (1.21 ± 0.08 g) was reared in a zero-water exchange biofloc system for 90 days at stocking densities of 0.5 g/L(T1), 1.0 g/L(T2), 1.5 g/L(T3) and 2.0 g/L(T4). The observed water quality indicates a reduction in DO and pH in T4, while the total ammonia nitrogen and nitrite levels remained low in T1. Among the groups, highest weight gain was noticed in the lowest stocking density (0.5 g/L) (p < 0.05), which coincides with a better feed conversion ratio. Similarly, the digestive enzyme (protease, amylase, and lipase) secretion was higher in T1. Profitability assessment describes the possibility of low profit in T4, in the case where the fish's sale price is based on harvested size. T1 showed higher individual growth and higher profit. Overall, a low stocking density of 0.5 g/Lis optimum for augmenting growth, feed utilization, physiological function and economic performance of O. bimaculatus. The study provides direction for a low-stocking oriented ecological and economically sustainable method of seed production of butter catfish in a biofloc system. [ABSTRACT FROM AUTHOR]

Carotenoprotein, a complex of carotenoids and protein, extracted from shrimp shell waste can be an effective source of carotenoid as well as antioxidant in fish diets. In the present study, the nutritional potential of carotenoprotein extracted from shell wastes of Parapeneopsis stylifera on growth, physiometabolic changes and coloration in high-value ornamental fish, oscar (Astronotus ocellatus) was assessed in a 120 days feeding trial. Four iso‑nitrogenous (30–31% CP) and isolipidic (11.34–11.55% CL) diets were formulated with graded levels of carotenoprotein inclusion like 0%, 5%, 10% and 15% and designated as Control, T1, T2 and T3 respectively. At the end of the feeding trial, growth indices such as final body weight, weight gain, and specific growth rate indicated that fish fed with 10 and 15% levels of carotenoprotein incorporated diet showed higher growth compared to control and T1. Oxidative stress enzymes like SOD and Catalase were lower in 15% and 10% carotenoprotein incorporated diets respectively in both gills and liver. Stress indicators like serum glucose and cortisol activity were found to be higher in control than in diets with 10% (T2) as well as 15% (T3), suggesting the stress-reducing ability of the carotenoprotein in fish feed. Relatively higher respiratory burst activity in fishes of T3 group indicated higher immunity status of the fish. Quantitative colour values in terms of redness, chroma in the fin region as well as carotenoid content in scale, skin and muscle of fish were higher in T2 (10% carotenoprotein incorporated diet) as compared to T3 (15% carotenoprotein incorporated diet). Overall, this study clearly showed that dietary incorporation of as little as 10% carotenoprotein is advisable to ornamental fish farmers for enhanced growth, colouration, as well as antioxidant activity in this popular high value ornamental fish for maximizing their profit. • Dietary supplementation of shrimp carotenoprotein on ornamental fish was studied. • Improved growth, better feed utilization and antioxidant activity observed. • Higher level of carotenoprotein up to 10% significantly improved the immune status. • Instrumental L*, a*, b* values, chroma, hue angle was superior in 10% inclusion level. • Inclusion of carotenoprotein is cost effective as evaluated by BCR against their costs. [ABSTRACT FROM AUTHOR]

Breading and battering of fish results in a physically superior product with a higher economic value from low-value fish. The present work was undertaken to evaluate three conventional breading materials for fish cutlets. Standard sized fish cutlets were molded with and dipped in a batter mix, followed by breading with bread crumbs (CB), pressed rice (PR), or noodle vermicelli (NS). The products were evaluated for coating parameters such as pickup, adhesion degree, cooking loss, and frying yield. The coating pickup ranged from 10.95% to 36.00%, and a maximum pickup was found with pressed rice (PR). Similarly, the adhesion degree in PR was 26.47%, which was highest among the three. Cooking loss was highest with control (conventional breadcrumb) at 15.92%. After analyzing the frying yield, it was found that PR yielded the maximum at 16.75% and less oil absorption. PR also had significantly (p <.05) higher hue angle value than both the NS and CB. Maximum browning and tough texture was observed in the NS sample. Frying tolerance was better with PR breading, which maintained better color during deep frying operations. This study can help industries to utilze low-cost breading material in preparing enrobed snack products. [ABSTRACT FROM AUTHOR]