Keith W. Gates

Quantification of enterococci and bifidobacteria in Georgia estuaries using conventional and molecular methods.

Fecal pollution is a serious threat to the estuarine environment along the Georgia coast. Culture-dependant and molecular methodologies were utilized to compare and evaluate the abundance of fecal indicator bacteria in four Georgia estuaries (Darien River, Frederica River, Gulley Hole Creek, and St. Marys River). The functionality of enterococci and bifidobacteria as indicator organisms in marine environments was assessed, as well as Bifidobacterium adolescentis densities. At each study site, enterococci were enumerated as colony forming units (CFU) on mEI agar. For quantitative polymerase chain reaction (qPCR), genus- and species-specific primer sets were used to quantify bifidobacteria and B. adolescentis as 16S rRNA gene copies and enterococci as tuf gene copies. A high correlation (r=0.925) was observed between CFU and qPCR enumeration of enterococci. Enterococci densities in the estuarine rivers ranged from 3-449CFU/100ml on mEI plates and 4.58-5.39Log(10) gene copies/100ml by qPCR. Bifidobacteria densities ranged from 3.62-4.14Log(10) gene copies/100ml and suggested the Frederica River as least affected by fecal bacteria and the Darien River as most affected by fecal pollution. A correlation of 0.46 was observed among qPCR densities of enterococci and bifidobacteria at all sample sites. Quantitative polymerase chain reaction detection of B. adolescentis was a rapid (i.e., less than 2h) indicator of presumptive human fecal pollution and suggested that Gulley Hole Creek, the Darien River, and the St. Marys River were affected by fecal bacteria derived from a human source. Gulley Hole Creek and the Darien River had the highest levels of fecal pollution detected in the studied estuaries. Molecular quantification of bifidobacteria may be a more accurate method of determining immediate health risks associated with fecal pollution in estuarine water than traditional and contemporary assessments of enterococci.

Fate of Staphylococcus aureus, Salmonella enterica serovar typhimurium, and vibrio vulnificus in raw oysters treated with chitosan.

The fate of Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio vulnificus in oysters treated with chitosan was investigated. Three concentrations (0.5, 1.0, and 2.0%) of chitosan in 0.5% hydrochloric acid were prepared and coated onto raw oysters, which were then stored at 4 degrees C for 12 days. Untreated oysters and oysters coated with 0.5% hydrochloric acid without chitosan were used as controls. S. aureus cells were most sensitive to 2.0% chitosan followed by 0.5 and 1.0%. In general, chitosan treatment of oysters produced a decline in the population of S. aureus by 1 to 4 log CFU/ml compared with the untreated control. Chitosan treatment had no influence on the reduction of Salmonella Typhimurium over the 12-day storage period; inhibition of Salmonella Typhimurium growth was similar in both the control samples and the chitosan-treated samples. However, time of storage had a major effect on the survival of Salmonella Typhimurium on oysters. Neither time nor chitosan concentration had a significant effect on the growth of V. vulnificus during storage. All treatments were similar in inhibiting V. vulnificus growth.

Risk of Clostridium botulinum Type E Toxin Production in Blue Crab Meat Packaged in Four Commercial-Type Containers

The aim of this investigation was to determine if a risk of Clostridium botulinum growth and toxin production existed in four different packaged crabmeat products. Freshly picked blue crab meat was inoculated with 10(3) to 10(4) spores per g of a mixed pool of four strains of C. botulinum type E (Beluga, Minnesota, G21-5, and 070). The lump crabmeat was packaged in four different packaging containers: (i) 12-oz copolymer polyethylene cups currently used by most crab processors; (ii) 12-oz copolymer polyethylene cups with heat-shrink, tamper-evident low-density polypropylene seals; (iii) 8-oz copolymer polyethylene cups with easy-open aluminum ends: and (iv) 8-oz copolymer polypropylene cups with integral tamper-evident pull-tabs. The packages were stored at either 4 degrees C for 21 days or 10 degrees C for 15 days. Storage at 10 degrees C was used to simulate temperature abuse. The mouse bioassay was used to detect the presence of C. botulinum toxin. Psychotrophic and anaerobic populations were enumerated and were found to increase with time regardless of packaging type. No botulinum toxin was detected in any of the four packaging types stored at 4 degrees C or 10 degrees C throughout the entire storage period.

Marine Polysaccharides—Food Applications. Vazhiyil Venugopal

The author presents a down-to-earth comprehensive review of current and potential food and medical research and commercial applications for marine polysaccharides including analyses of economic viability for products derived from such diverse sources as fishery products, seaweeds, microalgae, microorganisms, and corals. Many consumers now view processed foods as a convenient vehicle for the delivery of bioactive compounds and nutraceuticals. Introduced to food processing in the early 1940s, “Polysaccharides are water-soluble biopolymers (also referred to as hydrocolloids or gums), derived from diverse renewable sources such as seeds, fruits, vegetables, plant exudates, microorganisms, and animals, that can meet most of these requirements for food additives.” Naturally originating marine polysaccharides are considered edible, safe, and an effective means to impart many appealing properties to foods including modified texture, stability, foam and emulsion capacities, water retention, fat replacement, microbial protection, rancidity control, and fiber content enhancement. The book consists of three sections covering eleven chapters: I. Isolation and Properties of Marine Polysaccharides, (Chapters 1–5), II. Food Applications (Chapters 6–10), and III. Biomedical Applications (Chapter 11).

Bioactive Compounds from Marine Foods: Plant and Animal Sources, by Blanca Hernández-Ledesma and Miguel Herrero (Editors)

The volume, part of the IFT Press series, delivers a wide-ranging comprehensive review of research efforts exploring the substantial number of bioactive compounds found in marine foods harvested from the world’s oceans. The well-referenced chapters provide comprehensive literature reviews facilitating additional detailed investigations springing from the book’s thorough historical and contemporary summaries pertinent to both academic research and product development’s pursuit of unique plant and animal bioactive ingredients that support and drive the rapidly expanding world demand for new functional foods. The book targets food scientists, food technologists, and food engineers working in academia, industry, and government. The authors concentrate on descriptions of foods demonstrating active biological properties coupled with identifiable isolated compounds that are potentially valuable and effective in the prevention of hypertension, oxidative stress, inflammation, cardiovascular diseases, cancer, and other human diseases. Bioactive materials addressed in the following 18 chapters include PUFAs (polyunsaturated fatty acids), oils, phospholipids, proteins and peptides, fiber, carbohydrates, chitosan, vitamins and minerals, fucoxanthin, polyphenols, phytosterols, and taurine.

Marine Nutraceuticals: Prospects and Perspectives Edited by Se-Kwon Kim

On a world scale, consumers show increasing interest in bioactive materials, driving the rapidly expanding demand for nutritional and pharmacological substances isolated from natural sources capable of providing verifiable health benefits. Complex, diverse, and novel marine-derived compounds serve as abundant, virtually untapped, sources of biologically active agents available for extraction from marine algae, invertebrates, vertebrates, and microorganisms. The authors penned the first volume in the CRC Press Series, Nutraceuticals Basic Research/Clinical Applications, introduced by the “Series Preface” with a synopsis of the nutraceutical and functional food industries, expected health benefits of marine-derived medicines, projected industry growth, unique marine organisms, habitats, and areas of promising research. The Preface alludes to a “ . . . new generation of foods, which will certainly cause the interface between foods and drugs to become increasingly permeable” . . . and provide . . . “alternative sources for synthetic ingredients that can contribute to the consumers’ well-being and play a vital role in human health and nutrition.” The editor’s biographical sketch and a list of 41 contributors with their professional affiliations lead to 24 topical chapters assembled by a group of international experts who offer a thorough review of marine-derived nutraceuticals with promising antioxidant, anticancer, antiviral, anticoagulant, antidiabetic, antiallergic, anti-inflammatory, antihypertensive, antibacterial, and radioprotective properties. The work, an excellent companion to Bioactive Compounds from Marine Foods: Plant and Animal Sources (2014) published through IFT Press and reviewed previously, frequently provides multiple supportive references and details for the concise overviews developed by editors Blanca Hernández-Ledesma and Miguel Herrero.

Environmental Effects on Seafood Availability, Safety, and Quality (Chemical & Functional Properties of Food Components). Edited by E. Grażyna Daczkowska-Kozon and Bonnie Sun Pan

The authors provide an excellent wide-ranging historical and up-to-the-minute literature review of seafood quality, safety, environmental concepts, and the impacts of both intrinsic and extrinsic factors on the marine environment. Seafood organisms are especially vulnerable to changes in their natural habitats that affect their reproductive abilities, growth rates, and mutual interand intra-species interactions. The concept of sustainability is skillfully woven through 22 comprehensive chapters that discuss fishery populations and management options, wild seafood harvesting, aquaculture production, processing, transportation, marketing, sensory quality, nutritional values, health promoting activity, overfishing, seafood authentication, quality and freshness concepts, toxic compounds, marketing chain logistics, and product tracking and recalls.

Rapid Detection and Characterization of Foodborne Pathogens by Molecular Techniques

Penned by a distinguished and internationally respected authority on food safety, the book provides a detailed assessment and summary of hundreds of contemporary studies focusing on the molecular detection, quantification, and subspecies differentiation of pathogens isolated from foods. The author concentrates on the genes linked to bacterial pathogenicity that have been used for Polymerase Chain Reaction (PCR) detection and identification including discussions of extractions from complex food matrices and DNA purification techniques. The review includes method limitations for certain pathogens or food matrices prefaced by a comprehensive assessment of real-time PCR, including theoretical and operational concepts. A separate chapter is dedicated to each reviewed pathogen.

Seafood Science: Advances in Chemistry, Technology and Applications, Edited by Se-Kwon Kim

The author provides a topical review of wide-ranging subjects pertinent to commercial wild-caught and cultured seafood species, their production on both regional and global scales, processing, marketing, both health risks and benefits associated with seafood consumption, and methods to assess product quality and safety. Professor Kim prefaces the work noting seafood is simply “food from the sea,” referencing fish, crustaceans, mollusks, and seaweeds followed by brief descriptions of the book’s 21 chapters. He states that the work offers essential “state-of-art” readings for seafood scientists and students working in the field. Following the index, the book is appended by a brief statement about the editor and 21 pages of color plates referring to specific chapters. Individual chapter reviews follow.

Food Allergen Testing: Molecular, Immunochemical, and Chromatographic Techniques, by George Siragakis and Dimosthenis Kizis

“Food allergens are a series of agents, mainly proteins, which cause various unpleasant and sometimes clinical symptoms in humans through consumption of foods.” Twenty international experts contributed to a work that reviews and defines recent strides in food allergen detection and screening techniques needed to address a growing awareness by consumers and government regulators of health and economic consequences attributed to food allergies that impact nearly 2% of the world’s adult population and 6–8% of children under 3 years of age. The scope of individual responses to a given allergen varies greatly in reaction and severity, vastly complicating the difficult task of developing and applying effective treatments to control allergies. Targeting food scientists and technical staff, the book provides a current, comprehensive, and muchneeded source to assist with the development of testing protocols that will effectively determine the presence of allergens. The authors provide practical information on the major methodologies and approaches available to validate food allergen analytical techniques applicable to the food industry and to supporting analytical laboratories, including contemporary analyses appropriate for fundamental and applied research. The book’s 11 chapters and eight color plates afford an inclusive review of food allergens including molecular biology and immunochemical detection techniques. However, there are no evaluated treatments designed to counter food allergies that are 100% effective.