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Showing papers in "Journal of Food Science in 2006"


Journal ArticleDOI
TL;DR: The Institute of Food Technologists has issued a Scientific Status Summary to update readers on the applications of nanotechnology in the food industry as discussed by the authors, which can be found in this issue.
Abstract: The Institute of Food Technologists has issued this Scientific Status Summary to update readers on the applications of nanotechnology in the food industry.

969 citations


Journal ArticleDOI
TL;DR: In this article, the molecular mechanisms involved in the formation and stability of protein-stabilized foams and emulsions has been reviewed, and recent progress in the understanding of the molecular mechanism involved in protein formation and stabilization has been made.
Abstract: Proteins play an important role as macromolecular surfactants in foam and emulsion-type food products. The functioning of proteins in these applications is determined by their structure and properties in the adsorbed layers at air-water and oil-water interfaces. In addition, because typical food proteins are mixtures of several protein components, interaction between these components in the adsorbed layer also impacts their ability as surfactants to stabilize dispersed systems. In this paper, recent progress in our understanding of the molecular mechanisms involved in the formation and stability of protein-stabilized foams and emulsions has been reviewed.

591 citations


Journal ArticleDOI
TL;DR: In this paper, the water activity of eight salt solutions was determined at three temperatures (25, 30, 45°C) using a pressure transducer-vapor pressure manometer.
Abstract: The water activity (aw) of eight salt solutions was determined at three temperatures (25, 30, 45°C) using a pressure transducer-vapor pressure manometer. The aws of the salts showed a decrease with increasing temperature, which was explained with the help of a thermodynamic equation. This is opposite to the increase in aw with increase in temperature for foods. Moisture sorption data for fish flour and cornmeal were obtained at 25–65°C. The Guggenheim-Anderson-deBoer model was evaluated and shown to be comparable to the Brunauer-Emmett-Teller model for prediction of the monolayer. Product was equilibrated at different aws at 25°C then subsequently shifted to 30°C and 45°C in a sealed chamber. The resultant a, change, measured on the Kaymont-Rotronics, was predictable from the isotherm at each temperature using the Clausius Clapeyron relationship.

547 citations


Journal ArticleDOI
TL;DR: The Institute of Food Technologists has issued this Scientific Status Summary to update readers on the science of fungal toxins.
Abstract: The Institute of Food Technologists has issued this Scientific Status Summary to update readers on the science of fungal toxins.

452 citations


Journal ArticleDOI
TL;DR: In this paper, protein hydrophobicity of 42 native and partially denatured milk and soy protein samples was determined fluorometrically by using three probes, 1-anilino-8-naphthalenesulfonate (ANS), cis-parinarate (CPA) and chromatographically by using Phenyl Sepharose CL-4B (PSC).
Abstract: Protein hydrophobicity of 42 native and partially denatured milk and soy protein samples was determined fluorometrically by using three probes, 1-anilino-8-naphthalenesulfonate (ANS), cis-parinarate (CPA) and 1,6-diphenyl hexatriene (DPH), and chromatographically by using Phenyl Sepharose CL-4B (PSC). PSC and ANS hydro- phobicities correlated well to the protein insolubility determined at zero zeta potential, whereas no significant correlation was observed between CPA. hydrophobicity and protein insolubility. When backwards stepwise regression analysis was applied to 189 data of protein insolubility, a significant correlation (P < 0.001) was obtained between PSC hydrophobicity, zeta potential and protein insolubility. It is suggested that the aromatic hydrophobicity, in conjunction with zeta potential, may play a more important role in protein solublity than the aliphatic hydrophobicity.

445 citations


Journal ArticleDOI
TL;DR: In this article, a review of betalain degradation mechanisms and conditions governing their stability in a beneficial or an unfavorable way is presented. And strategies for maintaining the chromatic properties and tinctorial strength of the pigment preparations as well as tools for color modulation by targeted betacyanin degradation are discussed.
Abstract: In recent years, food coloring with artificial colorants has been increasingly disapproved by consumers In return, application of coloring foodstuffs, among them betalain-containing fruits and vegetables, has gained importance for the food industry As commonly true for natural pigments, betalains are afflicted with inferior stability compared to synthetic dyes Especially temperature, oxygen, and light are known to exhibit detrimental effects on betalain integrity, while certain antioxidants and chelating agents may act as stabilizers Only recently, several studies expanded the knowledge on betalain degradation pathways, especially focusing on betacyanin decomposition Additionally, new findings on stability and stabilization of betalains in cactus fruit juices extended the application range of betalainic foodstuffs Focusing on betacyanins, the present review discusses betalain degradation mechanisms and provides a survey of compounds and conditions governing betalain stability in a beneficial or an unfavorable way Finally, strategies for maintaining the chromatic properties and tinctorial strength of betalain-based juices and pigment preparations as well as tools for color modulation by targeted betacyanin degradation are discussed

422 citations


Journal ArticleDOI

389 citations


Journal ArticleDOI
TL;DR: In this paper, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruit extracts was tested.
Abstract: Total polyphenols, total anthocyanins, and reduced ascorbic acid were evaluated in berries belonging to the genera Rubus, Ribes, and Aronia by means of spectrophotometric and high-performance liquid chromatography (HPLC) techniques. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruit extracts was tested. Total polyphenols ranged from 140.6 to 888.5 mg/100 g fresh weight (FW), total anthocyanins ranged from 22.0 to 460.5 mg/100 g FW, and reduced ascorbic acid ranged from 12.4 to 153.8 mg/ 100 g FW. The average EC50 values for Aronia melanocarpa, Ribes nigrum, Ribes rubrum, Rubus fruticosus, and Rubus idaeus were 1.8, 2.8, 5.3, 6.4, and 8.2 mg FW, respectively. The results indicate that the fruits tested are good sources of natural antioxidants.

365 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of acid (acetic, formic, lactic, propionic) concentrations, plasticizer concentrations, and storage time (up to 9 wk) on mechanical properties, water vapor permeability, and oxygen permeability of solution-cast chitosan films were determined.
Abstract: The effects of acid (acetic, formic, lactic, propionic) concentrations, plasticizer concentrations, and storage time (up to 9 wk) on mechanical properties, water vapor permeability, and oxygen permeability of solution-cast chitosan films were determined. Measured water vapor permeability coefficients ranged from 5.35 to 13.20 x 10 -1 g/m.day.atm. Oxygen permeated coefficients ranged from 0.08 to 31.67 x 10 -3 cc O 2 / m.day.atm. Neither property was affected by storage time. Tensile strength (6.85-31.88 Mpa) also was not time dependent, but elongation (14-70%) decreased with storage time. Lactic acid solutions produced the lowest oxygen permeability values, formic acid the highest. Films formed with 7.5% lactic acid solutions had uniquely high values for elongation at break.

318 citations


Journal ArticleDOI
TL;DR: In this article, the combination of a spouted bed with microwave heating to improve heating uniformity was evaluated on a laboratory system in which evaporated diced apples of about 24% moisture were dried to about 5% at 70°C air temperature using four levels of microwave power density.
Abstract: The combination of a spouted bed with microwave heating to improve heating uniformity was evaluated. Experiments were performed on a laboratory system in which evaporated diced apples of about 24% moisture were dried to about 5% at 70°C air temperature using four levels of microwave power density (0 to 6.1 W/g). With the combination method, temperature uniformity in diced apples was greatly improved as compared to that with a stationary bed during microwave drying. Products had less discoloration and higher rehydration rates as compared to conventional hot air drying or spouted bed (SB) drying. Drying time could be reduced by >80% compared with SB drying without microwave heating.

308 citations


Journal ArticleDOI
TL;DR: The thermal degradation pathways of acylated and nonacylated anthocyanins from three commercial sources have been investigated in this article, where Strawberry, elderberry, and black carrot concentrates were purified on XAD-16-HP and Sephadex-LH-20 columns to remove sugars, amino acids, salts, and phenolic compounds, respectively.
Abstract: The thermal degradation pathways of acylated and nonacylated anthocyanins from 3 commercial sources have been investigated. Strawberry, elderberry, and black carrot concentrates were purified on XAD-16-HP and Sephadex-LH-20 columns to remove sugars, amino acids, salts, and phenolic compounds, respectively. The so obtained anthocyanin isolates were heated at 95 °C at pH 1, the optimum stability condition for the flavylium cation. During 7 h of thermal exposure, the samples were monitored by HPLC-DAD-MS3 at 280, 320, and 520 nm, respectively, together with spectrophotometric color and anthocyanin assessment. Total anthocyanin content lightness, and chroma, but not hue angle, were appropriate parameters to monitor anthocyanin loss on a statistically significant level. Anthocyanin glycosides were generally cleaved by successive loss of sugar moieties and pentoses were more readily split off than hexoses. Anthocyanin aglycones were further degraded by scission into phloroglucinaldehyde (cyanidin, pelargonidin), 4-hydroxybenzoic acid (pelargonidin), and protocatechuic acid (cyanidin), the residues of the A- and B-rings, respectively. Most interestingly, acylated cyanidin-triglycosides from black carrot were degraded into their corresponding diglycoside derivatives, which are not genuine carrot pigments. Moreover, hydroxycinnamic acid glycosides were generated. It is therefore assumed that the thermal burden during processing of anthocyanic food can be deduced by monitoring the colored and colorless compound profiles.

Journal ArticleDOI
TL;DR: In this paper, a computer vision system was implemented to identify the ripening stages of bananas based on color, development of brown spots, and image texture information using nine simple features of appearance (L*, a*, b* values; brown area percentage; number of brown spot per cm2; and homogeneity, contrast, correlation, and entropy of image texture) extracted from images of bananas were used for classification purposes.
Abstract: A computer vision system was implemented to identify the ripening stages of bananas based on color, development of brown spots, and image texture information. Nine simple features of appearance (L*, a*, b* values; brown area percentage; number of brown spots per cm2; and homogeneity, contrast, correlation, and entropy of image texture) extracted from images of bananas were used for classification purposes. Results show that in spite of variations in data for color and appearance, a simple classification technique is as good to identify the ripening stages of bananas as professional visual perception. Using L*, a*, b* bands, brown area percentage, and contrast, it was possible to classify 49 banana samples in their 7 ripening stages with an accuracy of 98%. Computer vision shows promise for online prediction of ripening stages of bananas.

Journal ArticleDOI
TL;DR: In this article, the authors found that the singlet oxygen reaction rate was the highest in β-carotene followed by tocopherol, riboflavin, vitamin D, and ascorbic acid.
Abstract: Reactive oxygen species (ROS) is formed enzymatically, chemically, photochemically, and by irradiation of food. It is also formed by the decomposition and the inter-reactions of ROS. The hydroxy radical is the most reactive ROS and then followed by singlet oxygen. Reactions of ROS with food components produce undesirable volatile compounds and carcinogens, destroy essential nutrients, and change the functionalities of proteins, lipids, and carbohydrates. Lipid oxidation by ROS produces low-molecular-weight volatile aldehydes, alcohols, and hydrocarbons. ROS causes crosslink or cleavage of proteins. ROS produces low-molecular-weight carbonyl compounds from carbohydrates. Vitamins are easily oxidized by ROS, especially singlet oxygen. The singlet oxygen reaction rate was the highest in β-carotene followed by tocopherol, riboflavin, vitamin D, and ascorbic acid.

Journal ArticleDOI
TL;DR: The use of Maillard reaction products for encapsulation of fish oil was investigated in this article, where the authors measured solvent-extractable fat and the oxidative stability of the fish oil powder, which was determined by assessment of headspace propanal after storage of powders at 35 °C for 4 wk.
Abstract: The use of Maillard reaction products for encapsulation of fish oil was investigated. Fish oil was emulsified with heated aqueous mixtures comprising a protein source (Na caseinate, whey protein isolate, soy protein isolate, or skim milk powder) and carbohydrates (glucose, dried glucose syrup, oligosaccharide) and spray-dried for the production of 50% oil powders. The extent of the Maillard reaction was monitored using L*, a*, b* values and absorbance at 465 nm. Encapsulation efficiency was gauged by measurement of solvent-extractable fat and the oxidative stability of the fish oil powder, which was determined by assessment of headspace propanal after storage of powders at 35 °C for 4 wk. Increasing the heat treatment (60 °C to 100 °C for 30 to 90 min) of sodium caseinate-glucose-glucose syrup mixtures increased Maillard browning but did not change their encapsulation efficiency. The encapsulation efficiency of all heated sodium caseinate-glucose-glucose syrup mixtures was high, as indicated by the low solvent-extractable fat in powder (<2% powder, w/w). However, increasing the severity of the heat treatment of the sodium caseinate-glucose-glucose syrup mixtures reduced the susceptibility of the fish oil powder to oxidation. The increased protection afforded to fish oil in powders by increasing the temperature-time treatment of protein-carbohydrate mixtures before emulsification and drying was observed irrespective of the protein (sodium caseinate, whey protein isolate, soy protein isolate, or skim milk powder) and carbohydrate (glucose, glucose/dried glucose syrup, or oligosaccharide/dried glucose syrup) sources used in the formulation. Maillard reaction products produced by heat treatment of aqueous protein-carbohydrate mixtures were effective for protecting microencapsulated fish oil and other oils (evening primrose oil, milk fat) from oxidation.

Journal ArticleDOI
TL;DR: A review of mechanisms of microbial reduction, enzyme inactivation, DPCD treatment systems, both experimental and commercial, and examples of applications with effects on quality attributes is given in this paper.
Abstract: Dense phase CO2 (DPCD) is a non-thermal technology that can inactivate certain microorganisms and enzymes at temperatures low enough to avoid the thermal effects of traditional pasteurization. This technology has been investigated over the past 50 y, particularly in the past 2 decades, and its effects on vegetative cells and spores of various microorganisms including pathogens, spoilage bacteria, yeasts, and molds, and various enzymes of importance to foods have been demonstrated. Many liquid foods retained freshlike sensory, nutritional, and physical properties after DPCD treatment. This article is a review of mechanisms of microbial reduction, enzyme inactivation, DPCD treatment systems, both experimental and commercial, and examples of applications with effects on quality attributes.

Journal ArticleDOI
TL;DR: In this paper, two groups of plasticizers (polyols and monosaccharides) were compared to compare their plasticizing efficiency and found that polyols have several hydroxyl groups and a compatible structure with starch polymers resulting in effective plasticization in starch films.
Abstract: Monosaccharides have several hydroxyl groups and a compatible structure with starch polymers resulting in effective plasticization in starch films. Two groups of plasticizers (polyols and monosaccharides) were used to compare their plasticizing efficiency. Fructose, glucose, mannose, galactose, glycerol, sorbitol, ethylene glycol, and maltitol were selected at 13.031 mmol per 100 g of pea starch. Edible starch films were produced after heat gelatinization and dehydration of the 3% starch dispersion. The microstructure, attenuated total reflection foorier transform infrared (ATR-FTIR) characteristics, thickness, moisture content, tensile strength, modulus of elasticity, elongation-at-break, water vapor permeability, and transparency of films were determined. Microstructure of the film solutions showed that some swollen starch granules and their remnants existed in the film. Compared to the FTIR spectra of pure starch films, the spectra of plasticized films showed that more hydrogens bound hydroxyl groups and more water molecules were attracted around starch polymer chains. Ethers were produced in glycerol-plasticized films. Monosaccharide-plasticized films were comparable to the polyol-plasticized films in tensile test, but more resistant in moisture permeation than the polyol-plasticized films. It was assumed that the structural compatibility of monosaccharides with starch might result in denser polymer-plasticizer complex, smaller size of free volume, and less segmental motions of starch chains. In conclusion, monosaccharides were identified as effective plasticizers for starch film.

Journal ArticleDOI
TL;DR: The potential of SEM techniques as a tool for selection of wall materials, for the study of core materials distribution in microcapsules, and for elucidating the mechanisms of capsule formation and the effects of water-vapor uptake on microcapsule properties are demonstrated.
Abstract: Scanning Electron Microscopy (SEM) has been applied to the morphological study of various microcapsule systems. In addition to using standard preparation techniques for the examination of the outer structure of microcapsules, a new embedding and microtoming technique has been developed to allow the study of the inner structure of fractured capsules. The technique uses a new nonpolar embedding resin, Lowicryl HM-20, which is compatible with the microcapsule shell material, and does not introduce artifacts associated with the use of epoxy resins. We demonstrate the potential of SEM techniques as a tool for selection of wall materials, for the study of core materials distribution in microcapsules, and for elucidating the mechanisms of capsule formation and the effects of water-vapor uptake on microcapsule properties.

Journal ArticleDOI
TL;DR: In this article, Krzywicki's equations were modified by using wavelength maxima at 503, 557, and 582 nm, representative for metmyoglobin, deoxymyoglobin and oxymyoglobin.
Abstract: Krzywicki's equations have been widely used for estimating the relative proportions of myoglobin (Mb) redox forms in aqueous solution. However, these equations have generated negative values for some redox forms, and total Mb estimates obtained by summation of the individual redox forms have deviated from unity. The inappropriate selection of wavelengths (545, 565, and 572 nm) used to generate these equations appears to have been responsible for these problems. Therefore, Krzywicki's equations were modified by using wavelength maxima at 503, 557, and 582 nm, representative for metmyoglobin, deoxymyoglobin, and oxymyoglobin, respectively. Millimolar extinction coefficients at these wavelengths were calculated, and a set of modified equations was established for determining the relative proportions of Mb redox forms in aqueous solution. The new equations demonstrated improved performance in decreasing the occurrence and magnitude of negative values and in estimating total Mb, when compared with Krzywicki' original equations.

Journal ArticleDOI
TL;DR: Malic acid-incorporated soy protein film had the fewest survivors of L. monocytogenes, S. gaminara, and E. coli O157:H7 and has the potential to inhibit a wide spectrum of microbes in product application.
Abstract: We studied the effectiveness of partial replacement of glycerol with citric, lactic, malic, and tartaric acids on the antimicrobial activities of nisin (205 IU/g protein)-incorporated soy protein film against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella gaminara. S. gaminara inoculated into 2.6% malic acid-incorporated films and lactic acid-incorporated films with nisin (5.7 and 3.4 log number colony-forming units (CFU)/mL, respectively) and without nisin (3.2 and 3.0 log number CFU/mL, respectively) had fewer survivors than HCl-incorporated film with and without nisin (8.6 and 7.9 log number CFU/mL, respectively). Malic acid (2.6%)-incorporated soy protein film had the fewest survivors of L. monocytogenes, S. gaminara, and E. coli O157:H7 (5.5, 3.0, and 6.8 log number CFU/mL, respectively) and has the potential to inhibit a wide spectrum of microbes in product application.

Journal ArticleDOI
TL;DR: A large body of knowledge on anthocyanin chemistry can be found in the literature that includes established, systematic methods for identifying Anthocyanins and measuring their concentration and color properties as discussed by the authors.
Abstract: Anthocyanin pigments are responsible for the attractive red to purple to blue colors of many fruits, vegetables, flowers, and cereal grains. In plants they serve as attractants for pollination and seed dispersal, give protection against the harmful effects of UV irradiation, and provide antiviral and antimicrobial activities. Anthocyanin-based colorants are commercially manufactured for food use from horticultural crops and from processing wastes. There is a large body of knowledge on anthocyanin chemistry in the literature that includes established, systematic methods for identifying anthocyanins and measuring their concentration and color properties. Structural variation (B-ring substitution, glycosidic substitution, and acylation) produces a multiplicity (over 400) of anthocyanins. Color intensity and hue, as well as stability, are markedly affected by pH, which can be a major limitation for many food applications. Increased glycosidic substitution and acylation with cinnamic acids will improve pigment stability. However, the matrix in which the pigments exist can have a much greater impact on pigment degradation. Anthocyanin pigments are very effective scavengers of free radicals. Currently, there is much research activity on their possible health benefits. While anthocyanin-based colorants are universally approved for food use, there are considerable regulatory differences among countries.

Journal ArticleDOI
TL;DR: In this paper, a review of the development in the field of non-invasive techniques for quality analysis of fresh fruit and vegetables over the past decade up to the year 2005 is presented.
Abstract: This review covers developments in the field of noninvasive techniques for quality analysis of fresh fruit and vegetables over the past decade up to the year 2005. A chapter on the concept of quality is followed by a discussion of various methods and applications including optical, spectroscopic, and mechanical techniques but also the application of X-rays and some noninvasive methods of minor dispersal. An extra section on research needs reflects on possible future developments. It is concluded that during the last year, much progress has been made in developing nondestructive techniques for the assessment or inspection of quality parameters of fruits including internal disorders but also taste, sugar content, and so forth. As sensors often measure only a single constituent or quality property, combined techniques have to be optimized to measure overall quality. Commercial application of these techniques will be beneficial for the consumer as well as the producer and for trades in which merchants will be able to comply with consumer demands for uniform high-quality products.

Journal ArticleDOI
TL;DR: In this article, the effect of blends with different ratios of sorbitol and glycerol, at 2 plasticizer concentrations, on mechanical, viscoelastic, and water vapor barrier properties of films based on gelatin was evaluated.
Abstract: The addition of plasticizers increases the flexibility and workability of films based on biopolymers. However, the use of some plasticizers cause undesirable results, such as the migration of these additives out the film or crystallization during shelf life. Thus, the aim of this study was to evaluate the effect of blends with different ratios of sorbitol and glycerol, at 2 plasticizer concentrations, on mechanical, viscoelastic, and water vapor barrier properties of films based on gelatin. The films were prepared with 2 g gelatin/100 mL of water and with 25 or 55 g plasticizer/100 g gelatin. The ratio, glycerol to sorbitol, was studied as 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. The increase of plasticizer concentration from 25 to 55 g plasticizer/100 g gelatin caused an increase of flexibility and reduction of resistance and water vapor barrier as expected. In relation to the effect of the mixture, the increase in the proportion of glycerol caused a reduction of the puncture force, tensile strength, modulus of elasticity, and an increase of the puncture deformation, elongation at break, and water vapor permeability due to the higher plasticizing effect of glycerol. This behavior was explained in terms of molecular weight of the plasticizers, which demonstrated that the studied properties could be considered as functions of the number of molecules of plasticizers in the films.

Journal ArticleDOI
TL;DR: In this article, the effects of viscosity reduction of spray-dried sweetpotato powder with alpha-amylase, maltodextrin (MD) addition, and inlet air temperature on physicochemical characteristics of powder were investigated.
Abstract: Spray-drying, which has been used for commercial production of functional ingredients from several fruits and vegetables, has not yet been studied for sweetpotato processing. Thus, the objective was to determine the effects of viscosity reduction of sweetpotato puree with alpha-amylase, maltodextrin (MD) addition, and inlet air temperature on the physicochemical characteristics of spray-dried sweetpotato powder. A face-centered cube design was used to evaluate the effects of amylase level (0, 3.75, and 7.5 mL/kg puree), MD concentration (0%, 10%, and 20%), and inlet air temperature (150 ◦ C, 190 ◦ C, and 220 ◦ C) on powder characteristics. Model-fitting using response surface methodology was performed to examine the effects of independent variables on the moisture content, color, water absorption, solubility, particle size, bulk density, and glass transition temperature. The data were fit to a full second order polynomial equation. However, only the linear and quadratic terms proved to be significant for most dried powder attributes. MD significantly increased powder solubility, altered the hue value, and raised the glass transition temperature of the powder. Pretreatment with alpha-amylase resulted in a lower glass transition temperature and a decrease in particle size. Overall, results show that good quality sweetpotato powders can be produced using this drying method, with potential applications in food and nutraceutical products.

Journal ArticleDOI
TL;DR: The foods fortified with marine n-3PUFA and their role in meeting daily requirements are reviewed, and the need for further research in this important area of functional foods is highlighted.
Abstract: n-3 Polyunsaturated fatty acids (n-3PUFA) of marine origin have been shown to be essential for brain development and cognitive function. In addition to their essentiality, the scientific literature is full of evidence to suggest that regular consumption and/or dietary supplementation with long chain n-3PUFA give several health benefits including: prevention of cardiovascular diseases, inflammatory diseases, dyslexia, and depression. Long chain n-3PUFA intake in the Western countries, including Australia, has been shown to be inadequate. This is largely due to the fact that the Western populations do not eat seafood on a regular basis because of its cost and availability, and many individuals do not like the flavor/taste/odor of seafood. Foods fortified with long chain n-3PUFA could play an important role in meeting the demands for optimal health. Marine n-3PUFA are not likely to compete with saturated, monounsaturated, and n-6PUFA as a major source of dietary fat; however, increasing the intake of foods containing marine n-3PUFA is an important strategy for the prevention of chronic illnesses. Recent developments in food technology allow fortification of foods, such as bread, dairy products, eggs, pasta, biscuits, margarines, and other spreads, without the undesirable fish odor/taste and with reasonable shelf life. There is a need to increase the amount of long chain n-3PUFA consumed per serve and optimize their bioavailability. This article reviews the foods fortified with marine n-3PUFA and their role in meeting daily requirements, and highlights the need for further research in this important area of functional foods.

Journal ArticleDOI
TL;DR: A review of the factors that can influence the final color of cooked meats can be found in this article, where the authors suggest that the color of a product is not a good indicator of adequate cooking, and the use of a food thermometer is recommended.
Abstract: Adequate cooking of meat is necessary to inactivate microbial pathogens. This is particularly important for ground meat products and some variety meats where pathogens can be present internally. Consumers are being advised on appropriate temperatures to which meat products should be cooked, and to use a meat thermometer to ensure these temperatures are reached. However, consumers are more likely to assess cooking status by the color of the meat or juice. This article reviews the factors that can influence the final color of cooked meat. In most instances, these factors influence color by modifying the meat pigment myoglobin prior to and during cooking. Many factors can prolong the pink "uncooked" color in meat, including high pH, modified atmosphere packaging, rapid thawing, low fat content, nitrite, and irradiation. Such factors may lead to overcooking and loss of food quality, and consumer rejection. Alternatively, factors that cause "premature browning" of meat, where the interior of the product looks cooked but a microbiologically safe temperature has not been reached, are food safety issues. Pale, soft exudative meats can prematurely brown, as can meats packaged under oxygenated conditions, frozen in bulk or thawed over long periods, or those that have had salts or lean finely textured beef added. Meats cooked from a frozen state or irradiated in aerobic conditions might also be at risk, but this might depend on meat species. In summary, the color of cooked meat is not a good indicator of adequate cooking, and the use of a food thermometer is recommended.

Journal ArticleDOI
TL;DR: In this paper, the acid-aided and alkali-assisted protein extraction and precipitation techniques were compared using acid and alkaline (pH 2.5 and 11) pH and compared with surimi processing.
Abstract: Channel catfish muscle was subjected to 2 novel protein extraction and precipitation techniques using acid (pH 2.5) or alkaline (pH 11) pH and compared with surimi processing (3 wash cycles). Solubility of catfish proteins was found to be highest at pH 2.5 and 11, and at these pH levels, viscosity was found to be low enough to cause separation of proteins from insoluble materials via centrifugation. Both the acid-aided and alkali-aided processes led to higher recoveries (P < 0.05) of protein and larger reduction (P < 0.05) in lipids compared with surimi processing. The protein recovery could be increased even more with a modified version of the acid-aided and alkali-aided processes. There was no hydrolytic breakdown detected during low and high pH. The acid-aided process recovered more protein types than the alkali-aided process during isolelectric precipitation (pH 5.5), which indicated that it led to more protein denaturation and thus more aggregation at pH 5.5. The alkali-aided process had more soluble proteins (including heme proteins) at isoelectric precipitation than the acid-aided process, and the soluble proteins were of the same type as the soluble proteins for non-pH-treated catfish muscle at pH 5.5. This suggested the alkali-aided process led to less denaturation than the acid-aided process. Both acid-aided and alkali-aided processes recovered proteins of higher (P < 0.05) whiteness scores than surimi. The alkali-aided process recovered proteins of higher whiteness (P < 0.05) than the acid-aided process. The acid-aided process led to higher yellowness (P < 0.05) than the other 2 processes. All processes led to minimal levels of lipid oxidation as assessed by secondary oxidation products.

Journal ArticleDOI
TL;DR: The combination of an alkaline pretreatment followed by an acid pretreatment not only removed the noncollagenous proteins, but also provided the proper pH condition for extraction, during which some cross-linkages could be further destroyed but with less breakage of polypeptide chains.
Abstract: Pretreatments with different alkalis and acids at different concentrations were used to determine their effects on gelatin extraction from Alaska pollock skin. The alkaline pretreatments with the OH concentrations lower than 0.5 mol/L removed noncollagenous proteins without significant loss of skin collagen. The acid pretreatments caused loss of collagen, even using a weak acid with a low H concentration at a low temperature. The presence of proteases might cause degradation of gelatin extract, but the pretreatments with NaOH or Ca(OH)2 at 0.1 mol/L OH concentration, or acetic acid at 0.05 mol/L H concentration could significantly decrease the degradation by proteases. The combination of an alkaline pretreatment followed by an acid pretreatment not only removed the noncollagenous proteins, but also provided the proper pH condition for extraction, during which some cross-linkages could be further destroyed but with less breakage of polypeptide chains.

Journal ArticleDOI
TL;DR: To monitor the underlying structural alterations of betalains, a new high-performance liquid chromatography separation compatible with mass spectrometry was developed and neobetanin formation resulting from heat exposure was proven for the 1st time.
Abstract: The impact of heating at 85°C during 8 h on overall color and betalain pattern of red beet (Beta vulgaris L. ssp. vulgaris) juice was investigated. Although the hue angle of 358° in fresh juice was indicative of the typical red-purple appearance, heating for 8 h induced an unexpected shift to 62° resulting in a yellow-orange solution. To monitor the underlying structural alterations of betalains, a new high-performance liquid chromatography separation compatible with mass spectrometry was developed. Applying this method, 2 novel yellow neobetanin structures and 2 orange-red betanin degradation products were preliminarily identified, and neobetanin formation resulting from heat exposure was proven for the 1st time. These 5 compounds were held responsible for the orange shift of red beet juice during thermal treatment. The relevance of these findings for industrial beet processing was demonstrated by comparison of pigment patterns of heated red beet juice samples and a commercial concentrate. On the basis of these results, a scheme for the thermal degradation of betanin is proposed.

Journal ArticleDOI
TL;DR: Lower water vapor permeability of fish gelatin films can be useful particularly for applications related to reducing water loss from encapsulated drugs and refrigerated or frozen food systems.
Abstract: Water vapor permeability of cold- and warm-water fish skin gelatins films was evaluated and compared with different types of mammalian gelatins. Alaskan pollock and salmon gelatins were extracted from frozen skins, others were obtained from commercial sources. Water vapor permeability of gelatin films was determined considering differences on percent relative humidity (%RH) at the film underside. Molecular weight distribution, amino acid composition, gel strength, viscoelastic properties, pH, and clarity were also determined for each gelatin. Water vapor permeability of cold-water fish gelatin films (0.93 gmm/m2hkPa) was significantly lower than warm-water fish and mammalian gelatin films (1.31 and 1.88 gmm/m2hkPa, respectively) at 25 °C, 0/80 %RH through 0.05-mm thickness films. This was related to increased hydrophobicity due to reduced amounts of proline and hydroxyproline in cold-water fish gelatins. As expected, gel strength and gel setting temperatures were lower for cold-water fish gelatin than either warm-water fish gelatins or mammalian gelatins. This study demonstrated significant differences in physical, chemical, and rheological properties between mammalian and fish gelatins. Lower water vapor permeability of fish gelatin films can be useful particularly for applications related to reducing water loss from encapsulated drugs and refrigerated or frozen food systems.

Journal ArticleDOI
TL;DR: Certain marine foods have often been considered as heart food because of their omega-3 constituents which are known to lower blood triacylglycerol and, possibly, cholesterol levels, and food factors from both plants and animals may be participating in human health promotion.
Abstract: ; The effect of food factors on health status has been recognized since antiquity. More recently, epidemiological studies have led to fundamental research for unraveling the chemistry and mechanism of action of dietary phytochemicals and bloactives. Functional foods and natural health products encompass a wide range of food and ingredients, with a variety of bioactives responsible for their efficacy in health promotion and disease prevention. Phenolic and polyphenolic compounds constitute an important class of secondary plant metabolites that act as free radical scavagers and inhibitors of LDL chelesterol oxidation and DNA breakage, among others. Thus, the role of food phenolics and polyphenolics in the prevention of cardiovascular disease and certain types of cancer is well recognized. In addition, certain marine foods have often been considered as heart food because of their omega-3 constituents which are known to lower blood triacylglycerol and, possibly, cholesterol levels. Thus, food factors from both plants and animals may be participating in human health promotion.