George Ninan

Structural and oxidative stabilization of spray dried fish oil microencapsulates with gum arabic and sage polyphenols: Characterization and release kinetics.

The synergistic efficacy of gum arabic and sage polyphenols in stabilising capsule wall and protecting fish oil encapsulates from heat induced disruption and oxidative deterioration during spray drying was assessed. The emulsions prepared with sodium caseinate as wall polymer, gum arabic as wall co-polymer and sage extract as wall stabiliser was spray dried using a single fluid nozzle. Fish oil encapsulates stabilised with gum arabic and sage extract (SOE) exhibited significantly higher encapsulation efficiency compared to encapsulates containing gum arabic alone (FOE). Scanning electron microscopic and atomic force microscopic images revealed uniform encapsulates with good sphericity and smooth surface for SOE, compared to FOE powder. In vitro oil release of microencapsulates indicated negligible oil release in buffered saline whereas more than 80% of the oil loaded in encapsulates were released in simulated GI fluids. The encapsulates containing sage extract showed a lower rate of lipid oxidation during storage.

Physical, mechanical, and barrier properties of carp and mammalian skin gelatin films.

Films of 0.11 to 0.13 mm thickness were prepared using gelatins from the skins of cultured freshwater carp species and mammalian gelatins viz., porcine and bovine skin gelatin. A comparative study was made on the physical, mechanical, and barrier properties of these films. The amino acid composition, gel strength, clarity, and gel setting point of the gelatins were also determined. Carp skin gelatins had a lower imino acid content (19.16% to 20.86%) than mammalian skin gelatins (22.91% to 23.7%). Grass carp gelatin had gel strength of 230.2 B that is comparable to the reported value for bovine skin gelatin (227.2 B). The bloom values of rohu and common carp skin gelatins were 188.6 B and 181.3 B, respectively, which were significantly lower than mammalian gelatins. Mammalian gels have significantly higher (P < 0.05) setting temperatures (23.7 to 24.2 °C) than carp skin gelatins. Tensile strength (TS) was lowest for films from common carp and rohu skin gelatin (490 and 497 kg/cm(2), respectively) and highest for porcine skin gelatin film. The degree of transparency (L*) was significantly higher for films from grass carp, bovine hide, and pork skin gelatin films. Carp skin gelatin films had significantly lower water vapor permeability (WVP) and oxygen permeability (OP) than mammalian skin gelatin films, which indicated that carp skin gelatin based films have superior barrier properties than mammalian skin gelatin films.

Effect of Freezing Time on the Quality of Indian Mackerel (Rastrelliger kanagurta) during Frozen Storage

The present study aims to find the effect of freezing methods on the quality of mackerel (Rastrelliger kanagurta) in commercial plate and air blast freezers during freezing and subsequent frozen storage (-18 degrees C). Total time for freezing was significantly different (P < 0.05) between the plate and air blast freezers (90 and 220 min, respectively). This difference in the freezing time could be attributed to the varied quality of the 2 samples. Upon freezing, the moisture content decreased in air blast frozen samples compared to plate freezer where protein content decreased in both the samples. Upon freezing and during frozen storage, lipid oxidation products (peroxide value, thiobarbutiric acid value, and free fatty acid value) and volatile bases (total volatile base nitrogen and trimethyl amine nitrogen) showed an increasing trend in both the samples with values slightly higher in air blast frozen samples compared to plate frozen samples. The total plate counts showed a significantly (P < 0.05) decreasing trend in both the samples. K value did not show any significant (P < 0.05) difference between the samples where as the histamine formation was significantly (P < 0.05) increased in air blast frozen samples compared to plate frozen samples. The taste and overall acceptability was significantly different (P < 0.05) in plate frozen samples compared to air blast frozen samples on 3rd month. Both samples were in acceptable condition up to 3 mo but the plate frozen samples quality was slightly better than the air blast frozen samples.

A comparative study on the physical, chemical and functional properties of carp skin and mammalian gelatins.

Carp species forms the bulk of the aquaculture production in India and studies have shown that the filleting waste of these species, particularly skin can be a good source of gelatin. This study is a comparison of the gelatins from these unexploited sources with that of mammalian gelatins to get a better understanding of their physicochemical and functional properties with respect to mammalian gelatins. The study showed that mammalian gelatins had significantly superior physical properties viz., higher viscosity, melting & setting temperature and faster setting time. The odour scores were significantly higher (P < 0.05) for bovine and porcine skin gelatins (3.1–3.12), indicating that they had a distinguishable odour and hence can be considered as inferior to fish skin gelatins in organoleptic qualities. The gel strengths of rohu and common carp skin gelatins were significantly lower than mammalian gelatins. Among the carp skin gelatins, grass carp skin gelatin was found to have better compatibility with gelatin from bovine and porcine skins.

Effect of chitosan on shelf life of restructured fish products from pangasius (pangasianodon hypophthalmus) surimi during chilled storage

In the present study, restructured products were prepared from pangasius surimi and their qualities were analysed under chilled storage. Pangasius surimi had 75.82 % moisture, 16.91 % protein, 2.76 % fat and 0.95 % ash. Restructured products were prepared in three different formulations by incorporating corn starch (10 %) and chitosan (0.75 %). Formulation containing only corn starch (10 %) was served as control. In all the formulations, mono unsaturated fatty acids were higher (45.14 %). The total volatile base nitrogen (TVB-N) showed an increasing trend and it was found to be higher in control (4.8 mg/100 g) on 10th day than the chitosan incorporated sample (3.5–4.2 mg/100 g) on 17th day during chill storage. Similarly, peroxide value (PV) was found to higher (8.85 milliequivalent of O2/kg) in control than the chitosan incorporated sample (4.5–6.8 milliequivalent of O2/kg) on 10th day. All the three formulations had an acceptable level of thiobarbituric acid (TBA) value that ranged between 0.023–0.098 mg of malanoldehyde/kg during chilled storage. Based on the sensory and microbiological analysis, products prepared without chitosan had a shelf life of 10 day whereas, products incorporated with chitosan had an extended shelf life of 17 day.

Quality of Monosex Tilapia Under Ice Storage: Gutting Effects on the Formation of Biogenic Amines, Biochemical, and Microbiological Characteristics

ABSTRACT Effects of gutting on biogenic amine (putrescine, cadaverine, histamine, agmatine, tyramine, spermidine, and spermine) formation, biochemical (pH, TVBN, K value), microbial (APC, H2S producing, Coliform bacteria), and sensory quality of farmed monosex tilapia (Oreochromis niloticus) was studied during ice stored at 4 ± 2ºC. Spermine and spermidine levels were high with cadaverine reached 4.66 ppm in gutted sample. The other amines were detected at relatively low level. K value of both samples crossed 60% on 15th and 18th day, respectively. The total phenolic content exceeded 7 log cfu/g after sensory rejection. The shelf life of whole and gutted samples was estimated to be 24 and 21 days, respectively.

Effect of Chilling on Microbiological, Biochemical and Sensory Attributes of Whole Aquacultured Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792)

The effect of chilling (0-2oC) on the quality deterioration of whole ungutted aquacultured rainbow trout ( Oncorhynchus mykiss , Walbaum,1792) was studied by integrated evaluations of microbiological, biochemical, and sensory attributes. The counts of aerobic mesophilic, psychrotrophic bacteria and Pseudomonas increased exponentially. An initial lag phase was noticed for H2S producing bacteria, Aeromonas and Enterobacteriaceae. Presence of pathogens such as Aeromonas hydrophila and A. sobria are of concern in the case of delay in icing or temperature abuse during storage. The pH values increased from an initial value of 6.74 to 7.13. PV showed fluctuations. Of the chemical indicators of spoilage, Thiobarbituric acid (TBA) values increased very slowly reaching final value of 16.56 μg MA g -1 . Total Volatile Base Nitrogen (TVB-N) values exceeded 27. 87 mg N 100 g -1 on day 14 when the psychrotrophic counts exceeded 10 7 cfu g -1 indicating that this value may be useful as a measure of degree of freshness for whole ungutted rainbow trout. Based on the TVB-N and microbiological limits, the shelf life of trout at 0-2o C was 9-12 days.

Influence of sea grapes (Caulerpa racemosa) supplementation on physical, functional, and anti-oxidant properties of semi-sweet biscuits

Seaweeds present a promising option for inclusion in the human diet through supplementation in various food systems. Sea grapes (Caulerpa racemosa), a common tropical green seaweed, has immense nutritional potential. An attempt was made to utilize the health benefits of sea grapes in human diet via biscuit as carrying medium. The effect of C. racemosa incorporation on nutritional, physical, anti-oxidative and sensorial characteristics of biscuits was assessed. Functional properties of seaweed-flour mix along with the electrophoretic pattern of dough were evaluated. Caulerpa racemosa addition increased water and oil absorption capacity of flour mix. Likewise, increase was noticed in solvent retention capacities (sodium carbonate, lactic acid, and sucrose) of flour mix. Inclusion of C. racemosa in biscuit enhanced the nutritive potential. Protein and fiber content of biscuits increased with rising level of C. racemosa incorporation. With increase in the concentration of seaweed in biscuits, the phenolic content and anti-oxidant activities (DPPH, ABTS, H2O2 radical scavenging activity and ferric reducing anti-oxidant power) increased. The sensory rating of biscuits varied from “neither like nor dislike” to “like slightly” on 9-point Hedonic scale. The study demonstrated the positive nutritional effect of C. racemosa inclusion in biscuits. Further, the health benefits of different seaweeds can be explored via incorporation in various other food systems. This could give rise to new and significant segment of health foods—“composite seaweed food products.”

Enrobed Snack Product from Devis’s Anchovy (Stolephorus commersonnii) and its Quality Evaluation during Frozen Storage

ABSTRACT Enrobing of fish improves physical as well as consumer acceptance of low value fish. The present work was undertaken to utilize a low value fish with its bones by enrobing with cereal flour based coating. Three combinations of batters were prepared, and the fish was coated and fried; based on the sensory quality, 1:2 batter to water ratio was selected for product preparation. To determine the storage life, frozen par-fried samples were prepared and stored at −18°C. Quality parameters such as pH, total volatile basic nitrogen, free fatty acids, peroxide value, thiobarbituric acid reactive substances, color, and sensory attributes were evaluated on a monthly basis. It was observed from chemical parameters and sensory scores of the product that the par-fried form can be stored for up to 5 months. This technology will provide a better opportunity for employment of coastal women.

Biochemical and Microbiological Assessment of Crucifix Crab (Charybdis feriatus) Stored at 4°C

ABSTRACT Charybdis feriatus is a highly prized crab in the local and international markets of East Asian countries. In local markets, crabs are sold live, iced, or refrigerated at 2°C – 4°C. The present study was carried out to determine the shelf life of whole crab stored at 4°C for 192 h using a set of biochemical, microbiological, and sensorial parameters. Biochemical indicators such as the total volatile base nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) increased significantly during storage and within an acceptable limit up to 144 h. Regarding the biogenic amines, cadaverine and spermidine increased significantly (p < 0.05) during the storage period. Among them, cadaverine could be proposed as a useful spoilage indicator for this crab species. The mesophilic and psychotropic bacterial count exceeded the limit of acceptance after 144 h of storage. Sensory attributes were gradually diminished with the storage time. Sensory scores were found to correlate well with both mesophiles and psychrotrophs. Based on the results of this study, the meat quality of Charybdis feriatus can be maintained up to 144 h when properly stored at a temperature of 4°C ± 1°C.