The effectiveness of edible chitosan coating (1 and 2%) on the quality changes of Indian oil sardine (
Sardinella longiceps) in iced condition was assessed. The chitosan prepared in the study had ...higher degree of deacetylation (83%). Edible coating with chitosan was effective in inhibiting bacterial growth and reduced the formation of volatile bases and oxidation products significantly. The muscle pH increased with the storage period for all the samples. On the day of sensory rejection for untreated samples, the formation of total volatile base nitrogen and trimethylamine nitrogen was less by 14.9 and 26.1% for 1% chitosan treated sardine and 32.7 and 49% for 2% chitosan treated samples respectively. The chitosan coating improved the water holding capacity, drip loss and textural properties significantly compared to untreated sample. The eating quality was maintained up to ∼8 and 10 days for 1 and 2% chitosan treated sardine respectively, compared to only 5 days for untreated samples.
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Presently, in food industry, microwave energy is increasingly finding applications in various processing technologies. The dielectric heating properties of microwave enabled its wide use in cooking, ...blanching, pasteurization, thawing, baking, drying, etc. Many reviews suggest that microwave processing is energy efficient and time saving, producing high quality products.
Microwave energy has potential applications in diversified seafood processing applications including cooking, sterilization, drying, thawing, extraction of bioactive components, gelation of surimi etc. This review delves with the past and recent developments in the diversified use of microwave in fish processing. The mechanism of microwave heating and successful employment of microwave energy for various seafood processing applications is discussed. The impacts of microwave heating on the nutritional quality of fish and fish products, advantages of microwave processing over traditional processing methods and future research directions for further improvement of microwave's efficiency are also presented.
In general, microwave processing is time saving, energy efficient and yields good quality fish products with high nutritional value. Microwave cooking or blanching does not alter the nutritional composition of fish. Apart from preserving the sensory attributes, microwave drying creates a porous structure, enhancing the water absorption characteristics. Microwave in combination with conventional or advanced technologies further augmented the quality of fish products by alleviating the shortcomings of microwave.
•Microwave heating reduces time and energy consumption.•Microwave assisted drying enhances the physicochemical characteristics of fish products.•Yield and performance of bioactive compounds extracted by microwave are superior to conventional methods.•Nutritional quality of fish products is not altered by microwave heating.
•Sage polyphenols along with gum arabic strengthened shell matrix.•Sage polyphenols improved encapsulation efficiency.•The stabilised structure reduced oil oxidation.•In vitro release kinetics ...confirmed controlled release of oil in modified encapsulates.
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.
Changes in consumer preference for safe food have led to innovations in packaging technologies. This article reviews about different smart packaging systems and their applications in food packaging, ...packaging research with latest innovations. Active and intelligent packing are such packaging technologies which offer to deliver safer and quality products. Active packaging refers to the incorporation of additives into the package with the aim of maintaining or extending the product quality and shelf life. The intelligent systems are those that monitor the condition of packaged food to give information regarding the quality of the packaged food during transportation and storage. These technologies are designed to the increasing demand for safer foods with better shelf life. The market for active and intelligent packaging systems is expected to have a promising future by their integration into packaging materials or systems.
Phlorotannins, a seaweed based class of polyphenolic compounds, have proven to possess potential bioactivities such as antioxidant, antimicrobial, anti-allergic, anti-diabetic, anti-inflammatory, ...anti-cancerous, neuroprotection etc. These bioactivities have further increased demand globally and sustainable techniques such as supercritical fluid extraction, microwave assisted extraction, enzyme assisted extraction, extraction using deep eutectic solvents etc. are being explored currently for production of phlorotannin-rich extracts. In spite of such well documented bioactivities, very few phlorotannin-based nutraceuticals are available commercially which highlights the significance of generating consumer awareness about their physiological benefits. However, for industry level commercialization accurate quantification of phlorotannins with respect to the different classes is vital requiring sophisticated analytical techniques such as mass spectrometry,
1
H-NMR spectroscopy etc. owing to the wide structural diversity. This review summarizes the extraction and bioactivities of phlorotannins based on the findings of in vivo and in vitro studies.
Seventh pandemic Vibrio choleare O1 El Tor strain is responsible for the on-going pandemic outbreak of cholera globally. This strain evolved from non-pathogenic V. cholerae by acquiring seventh ...pandemic gene (VC 2346), pandemic Islands (VSP1 and VSP2), pathogenicity islands (VP1 and VP2) and CTX prophage region. The cholera toxin production is mainly attributed to the presence of ctx gene in these strains. However, several variants of this strain emerged as hybrid strains or atypical strains. The present study aimed to assess the aquatic environment of Cochin, India, over a period of 5 years for the emergence of multidrug resistant V. cholerae and its similarity with seventh pandemic strain. The continuous surveillance and monitoring resulted in the isolation of ctx negative, O1 positive V. cholerae isolate (VC6) from coastal water, Cochin, Kerala. The isolate possessed the biotype specific O1 El Tor tcpA gene and lacked other biotype specific ctx, zot, ace and rst genes. Whole genome analysis revealed the isolate belongs to pandemic sequence type (ST) 69 with the possession of pandemic VC2346 gene, pathogenic island VPI1, VPI2, and pandemic island VSP1 and VSP2. The isolate possessed several insertion sequences and the SXT/R391 family related Integrative Conjugative Elements (ICEs). In addition to this, the isolate genome carried virulence genes such as VgrG, mshA, ompT, toxR, ompU, rtxA, als, VasX, makA, and hlyA and antimicrobial resistance genes such as gyrA, dfrA1, strB, parE, sul2, parC, strA, VC1786ICE9-floR, and catB9. Moreover, the phylogenetic analysis suggests that the isolate genome is more closely related to seventh pandemic V. cholerae O1 N16961 strain. This study reports the first incidence of environmental ctx negative seventh pandemic V. choleare O1 El Tor isolate, globally and its presence in the aquatic system likely to induce toxicity in terms of public health point of view. The presence of this isolate in the aquatic environment warns the strict implementation of the epidemiological surveillance on the occurrence of emerging strains and the execution of flagship program for the judicious use of antibiotics in the aquatic ecosystem.
Effect of high pressure in inducing textural and functional modification has been investigated in pink perch (
Nemipterus japonicus
) mince. Fish mince undergone pressurization at 200, 400 and ...600 MPa for a holding period of 10 min and was compared against cooked mince (90 °C; 40 min). The treated mince at 400 and 600 MPa lost its natural viscosity and behaved like cooked mince through denaturation and formation of protein aggregates. Textural characterisation showed the retention of tenderness in 200 MPa treated samples, but become harder on application of higher pressures. Unlike heat gels, pressure induced gels were more smooth, white and elastic in nature. A decreased in reactive SH groups was observed in 400 and 600 MPa treated samples due to the formation of disulfide bonds. Hydrophobic concentration was higher in cooked and 600 MPa treatments whereas Ca
2+−
ATPase activity decreased after pressurization. On application of different pressures microbial reduction of 2–3 log cycles was achieved in the mince samples. Hence pressure treatments at lower ranges cannot alter the texture and functionality of protein and the mince can undergo processing as required. Besides extending shelf life, the treatments above 400 MPa can make irreversible effect on texture quality and protein functionality which is similar to that of cooking.
Biogenic amines in seafood: a review Biji, K. B.; Ravishankar, C. N.; Venkateswarlu, R. ...
Journal of Food Science and Technology,
05/2016, Letnik:
53, Številka:
5
Journal Article, Book Review
Recenzirano
Odprti dostop
The biogenic amines are low molecular weight organic bases present normally in the body with biological activity influencing important physiological functions. The physiological functions of these ...molecules are achieved by very low concentrations in the tissues. However, significantly high amounts of biogenic amines are produced during processing and storage of seafood as a result of microbial contamination and inadequate storage conditions. Microorganisms having decarboxylase enzyme activity convert amino acids to their respective biogenic amines. Biogenic amines in seafood have been implicated as a major causative agent of food borne illness, where intoxication results from the ingestion of foods containing higher amount of biogenic amines. Hence its identification, quantitation and awareness of this food borne toxin are important in relation to food safety and spoilage. The aim of this paper is to review the basic concepts of seafood quality and safety in relation to biogenic amines along with its control measures and future areas for research.
An edible composite film was prepared from an emulsion system based on chitosan and virgin coconut oil (VCO). The effect of incorporation of VCO was evaluated at various concentrations and the ...optimum concentration was chosen based on resultant changes in the properties of the film. Addition of VCO in film forming solution resulted in increase in film thickness and marginal reduction in film transparency. Compatibility of VCO with chitosan was better at lower concentration of VCO as indicated by the microstructure of composite film in scanning electron micrographs. Phase separation was evident at higher level of oil incorporation and the optimal oil/chitosan ratio was determined to be at 0.5 to 1 mL/g chitosan. Furthermore, chemical interaction took place between VCO and chitosan as revealed by Fourier transform infrared spectroscopy data. Even though control chitosan films exhibited superior gas barrier properties, composite film with optimum VCO concentration revealed better mechanical and moisture sorption properties.
Practical Application
The results of this study provide a practically viable technique to improve the moisture barrier properties of chitosan films making them more suitable for food packaging applications. The results indicate that chitosan films incorporated with virgin coconut oil at selected optimum concentration can be ideally used as an edible film for packing dry as well as moist foods.
•New antioxidant wall material for microencapsulation of PUFA rich marine oil.•Rheological behaviour of vanillic acid grafted chitosan is suitable for spray drying.•Improved oxidative stability of ...microencapsulated sardine oil during storage.•Improved microencapsulation and loading efficiency achieved in the developed process.
Vanillic acid grafted chitosan (Va-g-Ch) was evaluated as a new antioxidant wall material for microencapsulation of polyunsaturated fatty acid rich sardine oil. A high grafting ratio of 305mg vanillic acid equivalent/g of polymer was achieved using a free radical mediated grafting reaction. Oil in water emulsion was prepared with an optimised combination of Va-g-Ch and Tween 20 (3.2:1). Sardine oil loaded microparticles (SO-M) were produced (∼75% yield) by spray drying. The average diameter and polydispersity Index (PDI) of the particles were found to be 2.3μ and 0.345. XRD spectra of SO-M showed reduction in crystallinity due to microencapsulation. After four weeks of storage, a moderate (∼12%) decrease in the EPA and DHA content and a low PV of 5.5±0.51meq/kg oil in SO-M demonstrated good oxidative stability. Satisfactory encapsulation efficiency (84±0.84%) and loading efficiency (67±0.51%) values, also demonstrated the suitability of Va-g-Ch for microencapsulation of sardine oil.
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