Annual Review of Food Science and Technology - Volume 8, 2017
Volume 8, 2017
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Who Would Have Thought? The Story of a Food Engineer
Vol. 8 (2017), pp. 1–20More LessFood engineering is a hybrid of food science and an engineering science, like chemical engineering in my particular case, resulting in the application of chemical engineering principles to food systems and their constituents. With the complexity of food and food processing, one generally narrows his or her interests, and my primary interests were in the kinetics of reactions important in foods, thermal processing, deposition of unwanted materials from food onto heated surfaces (fouling), and microwave heat transfer in baking. This review describes how I developed an interest in these topics and the contributions I have hopefully made to understanding food and to the application of engineering.
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Enzyme-Based Strategies for Structuring Foods for Improved Functionality
Vol. 8 (2017), pp. 21–34More LessEnzyme technologies can be used to create food dispersions with novel functional attributes using structural design principles. Enzymes that utilize food-grade proteins and/or polysaccharides as substrates have gained recent interest among food scientists. The utilization of enzymes for structuring foods is an ecologically and economically viable alternative to the utilization of chemical cross-linking and depolymerization agents. This review highlights recent progress in the use of enzymes to modify food structures, particularly the interfacial and/or bulk properties of food dispersions with special emphasis on commercially available enzymes. Cross-linking enzymes such as transglutaminase and laccase promote the formation of intra- and intermolecular bonds between biopolymers to improve stability and functionality, whereas various degrading enzymes such as proteases alter the native conformation of proteins, leading to self-assembly of hierarchically ordered colloids. Results of this bio-inspired approach show that rational use of structure-affecting enzymes may enable food manufacturers to produce food dispersions with improved physical, functional, textural, and optical properties.
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Bioavailability of Nutrients and Micronutrients: Advances in Modeling and In Vitro Approaches
Vol. 8 (2017), pp. 35–55More LessThe bioavailability of food nutrients and microconstituents is recognized as a determinant factor for optimal health status. However, human and animal studies are expensive and limited by the large amount of potential food bioactive compounds. The search for alternatives is very active and raises many questions. On one hand, in vitro digestion systems are good candidates, but to date only bioaccessibility has been correctly assessed. To go further, to what degree should natural processes be reproduced? What techniques can be used to measure the changes in food properties and structures in situ in a noninvasive way? On the other hand, modeling approaches have good potential, but their development is time-consuming. What compromises should be done between food and physiology realism and computational ease? This review addresses these questions by identifying highly resolved analytical methods, detailed computer models and simulations, and the most promising dynamic in vitro systems.
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Food Analysis Using Organelle DNA and the Effects of Processing on Assays
Vol. 8 (2017), pp. 57–74More LessExtrachromosomal DNA such as organelle DNA are increasingly targeted in molecular detection assays where samples have been degraded by physical or chemical means. Owing to multiple organelles per cell and greater copy numbers than nuclear genes, organelle gene targets provide a more robust signal in polymerase chain reaction (PCR), quantitative PCR (qPCR), and other emerging molecular technologies. Because of these advantages, direct analysis of organelle DNA in food matrices is used for detection of contaminants and identification and authentication of food ingredients and allergens. Non-nuclear DNA is also used as an assay normalizer for detection of genetically modified organisms (GMOs) in foods. This review describes these protocols plus the effects of processing on efficacy, with special emphasis on thermally produced DNA fragmentation. Future research may incorporate molecular techniques beyond detection, used instead as time-temperature indicators in thermal food processing or quality indicators in food fermentation or acidification.
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Legumes as Functional Ingredients in Gluten-Free Bakery and Pasta Products
Vol. 8 (2017), pp. 75–96More LessThe increasing demand for gluten-free food products from consumers has triggered food technologists to investigate a wide range of gluten-free ingredients from different sources to reproduce the unique network structure developed by gluten in a wheat-dough system. In recent times, the attention has been focused on novel application of legume flour or ingredients. The interest in this crop category is mainly attributed to their functional properties, such as solubility and water-binding capacity, which play an important role in gluten-free food formulation and processing. Their nutritional profile may also counteract the lack of nutrients commonly highlighted in commercial gluten-free bakery and pasta products, providing valuable sources of protein, dietary fiber, vitamins, minerals, and complex carbohydrates, which in turn have a positive impact on human health. This review reports the main chemical and functional characteristics of legumes and their functional application in gluten-free products.
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Side Streams of Plant Food Processing As a Source of Valuable Compounds: Selected Examples
Vol. 8 (2017), pp. 97–112More LessIndustrial processing of plant-derived raw materials generates enormous amounts of by-products. On one hand, these by-products constitute a serious disposal issue because they often emerge seasonally and are prone to microbial decay. On the other hand, they are an abundant source of valuable compounds, in particular secondary plant metabolites and cell wall materials, which may be recovered and used to functionalize foods and replace synthetic additives with ingredients of natural origin. This review covers 150 references and presents select studies performed between 2001 and 2016 on the recovery, characterization, and application of valuable constituents from grape pomace, apple pomace, potato peels, tomato pomace, carrot pomace, onion peels, by-products of citrus, mango, banana, and pineapple processing, side streams of olive oil production, and cereal by-products. The criteria used were economic importance, amounts generated, relevance of side streams as a source of valuable compounds, and reviews already published. Despite a plethora of studies carried out on the utilization of side streams, relatively few processes have yet found industrial application.
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Translating Omics to Food Microbiology
Vol. 8 (2017), pp. 113–134More LessThis review examines the applications of omics technologies in food microbiology, with a primary focus on high-throughput sequencing (HTS) technologies. We discuss the different sequencing approaches applicable to the study of food-related microbial isolates and mixed microbial communities in foods, and we provide an overview of the sequencing platforms suitable for each approach. We highlight the potential for genomics, metagenomics, and metatranscriptomics to guide efforts to optimize food fermentations. Additionally, we explore the use of comparative and functional genomics to further our understanding of the mechanisms of probiotic action and we describe the applicability of HTS as a food safety measure. Finally, we consider the use of HTS to investigate the effects that ingested microbes have on the human gut microbiota.
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A New Look at Kinetics in Relation to Food Storage
Vol. 8 (2017), pp. 135–153More LessModern mathematical software and user-friendly interactive programs can simplify and speed up kinetics calculations. They also open the way for new approaches to storage data gathering and analysis. This is demonstrated with a recently introduced simple exponential model that is interchangeable with the Arrhenius equation and endpoints and successive points methods and that estimates chemical degradation kinetics parameters from a small number of isothermal or nonisothermal experimental data. Also presented are a method to determine shelf life using two chemical markers and a global phenomenological model for peaked reactions, such as those encountered in lipid oxidation. Also recently introduced are freely downloadable Wolfram Demonstrations and other interactive software to generate, visualize, examine, and/or compare actual or hypothetical storage scenarios in minutes. They include programs that solve pairs of simultaneous nonlinear algebraic or differential rate equations by passing two reconstructed degradation curves, or a single nonisothermal curve, through two entered experimental points by moving the degradation parameters’ sliders on the screen.
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Anthocyanins and Flavanones Are More Bioavailable than Previously Perceived: A Review of Recent Evidence
Vol. 8 (2017), pp. 155–180More LessThis review considers recent investigations on the bioavailability of anthocyanins and flavanones. Both flavonoids are significant dietary components and are considered to be poorly bioavailable, as only low levels of phase II metabolites appear in the circulatory system and are excreted in urine. However, when lower molecular weight phenolic and aromatic ring-fission catabolites, produced primarily by the action of the colonic microbiota, are taken into account, it is evident that anthocyanins and flavanones are much more bioavailable than previously envisaged. The metabolic events to which these flavonoids are subjected as they pass along the gastrointestinal tract and are absorbed into the circulatory system prior to their rapid elimination by renal excretion are highlighted. Studies on the impact of other food components and the probiotic intake on flavonoid bioavailability are summarized, as is the bioactivity of metabolites and catabolites assayed using a variety of in vitro model systems.
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Strategies for Producing and Incorporating Conjugated Linoleic Acid–Rich Oils in Foods
Vol. 8 (2017), pp. 181–204More LessConjugated linoleic acid (CLA) is in ruminant-derived foods and is known to combat obesity-related diseases. However, CLA levels in a healthy diet are too low to produce a clinical effect. Therefore, CLA has been produced by linoleic isomerization through fermentation and chemical catalysis. Many of these techniques are not practical for food production, but a recent development has enabled production of CLA-rich triglyceride vegetable oils from high linoleic acid oils by a minor modification of conventional food-oil processing techniques. These oils were used to produce common lipid-based food, such as margarine, shortenings, and salad dressings, whose quality was enhanced by the presence of CLA-rich oil and provided a significant CLA source. Meat and egg CLA content and subsequent food quality can also be increased by addition of dietary CLA. However, consumer awareness of CLA benefits needs to increase prior to commercial-scale production of CLA-rich oil.
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Recent Advances in the Utilization of Natural Emulsifiers to Form and Stabilize Emulsions
Vol. 8 (2017), pp. 205–236More LessConsumer concern about human and environmental health is encouraging food manufacturers to use more natural and sustainable food ingredients. In particular, there is interest in replacing synthetic ingredients with natural ones, and in replacing animal-based ingredients with plant-based ones. This article provides a review of the various types of natural emulsifiers with potential application in the food industry, including phospholipids, biosurfactants, proteins, polysaccharides, and natural colloidal particles. Increased utilization of natural emulsifiers in food products may lead to a healthier and more sustainable food supply. However, more research is needed to identify, isolate, and characterize new sources of commercially viable natural emulsifiers suitable for food use.
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In Vitro Release Kinetics of Microencapsulated Materials and the Effect of the Food Matrix
Vol. 8 (2017), pp. 237–259More LessMany biomaterials are encapsulated to preserve their health-promoting properties and promote targeted delivery. Numerous papers have been published about extraction and purification methods, encapsulation techniques, and release properties of encapsulated biomaterials. Despite the abundant information, the food applications of encapsulated materials are currently limited. One approach to increase the food applications is to investigate the mathematical aspects of release behavior and the effect of the food matrix. Such information is useful in evaluating suitable food matrices and predicting the extent of bioavailability of the biomaterial. This review aims to discuss the kinetic models of release, current efforts to promote sustained release, and food matrices currently used in in vitro investigations. Information from pharmaceutical studies is integrated and reviewed to determine possible food applications. Future research on microencapsulated biomaterials conducted along these aspects may hopefully hasten nutraceutical applications.
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Natural Colorants: Food Colorants from Natural Sources
Vol. 8 (2017), pp. 261–280More LessThe color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.
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Cyanobacterial Toxins in Freshwater and Food: Important Sources of Exposure to Humans
Vol. 8 (2017), pp. 281–304More LessA recent ecological study demonstrated a significant association between an increased risk of nonalcoholic liver disease mortality and freshwater cyanobacterial blooms. Moreover, previous epidemiology studies highlighted a relationship between cyanotoxins in drinking water with liver cancer and damage and colorectal cancer. These associations identified cyanobacterial blooms as a global public health and environmental problem, affecting freshwater bodies that are important sources for drinking water, agriculture, and aquafarms. Furthermore, as a result of climate change, it is expected that our freshwater environments will become more favorable for producing harmful blooms that produce various cyanotoxins. Food is an important source of cyanotoxin exposure to humans, but it has been less addressed. This paper synthesizes information from the studies that have investigated cyanotoxins in freshwater and food on a global scale. We also review and summarize the health effects and exposure routes of cyanotoxins and candidates for cyanotoxin treatment methods that can be applied to food.
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From Bits and Pieces to Whole Phage to Nanomachines: Pathogen Detection Using Bacteriophages
Vol. 8 (2017), pp. 305–329More LessThe innate specificity of bacteriophages toward their hosts makes them excellent candidates for the development of detection assays. They can be used in many ways to detect pathogens, and each has its own advantages and disadvantages. Whole bacteriophages can carry reporter genes to alter the phenotype of the target. Bacteriophages can act as staining agents or the progeny of the infection process can be detected, which further increases the sensitivity of the detection assay. Compared with whole-phage particles, use of phage components as probes offers other advantages: for example, smaller probe size to enhance binding activity, phage structures that can be engineered for better affinity, as well as specificity, binding properties, and robustness. When no natural binding with the target exists, phages can be used as vehicles to identify new protein-ligand interactions necessary for diagnostics. This review comprehensively summarizes many uses of phages as detection tools and points the way toward how phage-based technologies may be improved.
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Carbohydrates as Fat Replacers
Xingyun Peng, and Yuan YaoVol. 8 (2017), pp. 331–351More LessThe overconsumption of dietary fat contributes to various chronic diseases, which encourages attempts to develop and consume low-fat foods. Simple fat reduction causes quality losses that impede the acceptance of foods. Fat replacers are utilized to minimize the quality deterioration after fat reduction or removal to achieve low-calorie, low-fat claims. In this review, the forms of fats and their functions in contributing to food textural and sensory qualities are discussed in various food systems. The connections between fat reduction and quality loss are described in order to clarify the rationales of fat replacement. Carbohydrate fat replacers usually have low calorie density and provide gelling, thickening, stabilizing, and other texture-modifying properties. In this review, carbohydrates, including starches, maltodextrins, polydextrose, gums, and fibers, are discussed with regard to their interactions with other components in foods as well as their performances as fat replacers in various systems.
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Engineered Probiotics: Applications and Biological Containment
Vol. 8 (2017), pp. 353–370More LessBioengineered probiotics represent the next generation of whole cell–mediated biotherapeutics. Advances in synthetic biology, genome engineering, and DNA sequencing and synthesis have enabled scientists to design and develop probiotics with increased stress tolerance and the ability to target specific pathogens and their associated toxins, as well as to mediate targeted delivery of vaccines, drugs, and immunomodulators directly to host cells. Herein, we review the most significant advances in the development of this field. We discuss the critical issue of biological containment and consider the role of synthetic biology in the design and construction of the probiotics of the future.
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The Challenges of Eliminating or Substituting Antimicrobial Preservatives in Foods
Vol. 8 (2017), pp. 371–390More LessConsumers’ criteria for evaluating food safety have evolved recently from considering the food's potential to cause immediate physical harm to considering the potential long-term effects that consumption of artificial ingredients, including antimicrobial preservatives, would have on health. As bacteriostatic and bactericidal agents to prevent microbial spoilage, antimicrobials not only extend shelf life, but they also enhance the product's safety. Antimicrobials and their levels that may be used in foods are specified by regulatory agencies. This review addresses the safety of antimicrobials and the potential consequences of removing those that are chemically synthesized or replacing them with antimicrobials from so-called natural sources. Such changes can affect the microbiological safety and spoilage of food as well as reduce shelf life, increase wastage, and increase the occurrence of foodborne illnesses.
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Mass Transport Phenomena in Lipid Oxidation and Antioxidation
Vol. 8 (2017), pp. 391–411More LessIn lipid dispersions, the ability of reactants to move from one lipid particle to another is an important, yet often ignored, determinant of lipid oxidation and its inhibition by antioxidants. This review describes three putative interparticle transfer mechanisms for oxidants and antioxidants: (a) diffusion, (b) collision-exchange-separation, and (c) micelle-assisted transfer. Mechanism a involves the diffusion of molecules from one particle to another through the intervening aqueous phase. Mechanism b involves the transfer of molecules from one particle to another when the particles collide with each other. Mechanism c involves the solubilization of molecules in micelles within the aqueous phase and then their transfer between particles. During lipid oxidation, the accumulation of surface-active lipid hydroperoxides (LOOHs) beyond their critical micelle concentration may shift their mass transport from the collision-exchange-separation pathway (slow transfer) to the micelle-assisted mechanism (fast transfer), which may account for the transition from the initiation to the propagation phase. Similarly, the cut-off effect governing antioxidant activity in lipid dispersions may be due to the fact that above a certain hydrophobicity, the transfer mechanism for antioxidants changes from diffusion to collision-exchange-separation. This hypothesis provides a simple model to rationalize the design and formulation of antioxidants and dispersed lipids.
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CRISPR-Cas Technologies and Applications in Food Bacteria
Vol. 8 (2017), pp. 413–437More LessClustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins form adaptive immune systems that occur in many bacteria and most archaea. In addition to protecting bacteria from phages and other invasive mobile genetic elements, CRISPR-Cas molecular machines can be repurposed as tool kits for applications relevant to the food industry. A primary concern of the food industry has long been the proper management of food-related bacteria, with a focus on both enhancing the outcomes of beneficial microorganisms such as starter cultures and probiotics and limiting the presence of detrimental organisms such as pathogens and spoilage microorganisms. This review introduces CRISPR-Cas as a novel set of technologies to manage food bacteria and offers insights into CRISPR-Cas biology. It primarily focuses on the applications of CRISPR-Cas systems and tools in starter cultures and probiotics, encompassing strain-typing, phage resistance, plasmid vaccination, genome editing, and antimicrobial activity.
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