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Physicochemical properties of x-carrageenan (KC) molecules and their aqueous solutions were determined using molecular dynamics modeling and experimental techniques. Chain conformations, the end-to-end distance, the gyration radiu...
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Physicochemical properties of x-carrageenan (KC) molecules and their aqueous solutions were determined using molecular dynamics modeling and experimental techniques. Chain conformations, the end-to-end distance, the gyration radius and the density of the molecule were theoretically calculated. Experimentally, the diffusion coefficient and electrophoretic mobility of the molecules were measured for ionic strength range 10(-4) to 0.15 M and different pHs. Using these data, the hydrodynamic diameter, the electrokinetic charge and the effective ionization degree of KC molecules were determined. The dynamic viscosity measurements for dilute KC solutions enabled to determine of its molecule intrinsic viscosity for various ionic strengths. The viscosity attained 50,000 for dilute electrolyte solutions compared to the Einstein value for spheres equal to 2.5. This confirmed that KC molecules assumed extended conformations in accordance with theoretical modeling. It is concluded that the application of complementary theoretical and experimental methods furnishes reliable information about KC molecule conformations in electrolyte solutions.
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Extraction of Furcellaria lumbricalis by potassium hydroxide solution shows that the maximum gel strength of polysaccharides separated is attained by extraction at concentration 0.16 M KOH. Crude extract from this algal species ha...
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Extraction of Furcellaria lumbricalis by potassium hydroxide solution shows that the maximum gel strength of polysaccharides separated is attained by extraction at concentration 0.16 M KOH. Crude extract from this algal species has a complicated monosaccharide composition; a drastic increase of gel strength by alkaline extraction of the polysaccharide mixture cannot be explained through the composition of a major (kappa) fraction described earlier. Alkaline treatment is also suitable for accelerating the extraction of polysaccharides from Coccotylus truncatus overlaid with thick epithelium. Viscous galactans from C. truncatus are more stable to alkali, their composition is simpler and close to iota carrageenan. The formation of mixed kappa and iota carrageenan gels as a result of simultaneous extraction of both seaweeds causes levelling of rheological properties of different extraction fractions. (C) 1997 Elsevier Science B.V. [References: 25]
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In this instance, the researchers used the temperate redseaweed Chondrus crispus (commonly known as Irish moss)in their attempt to determine if dark treatment can improvethe gel quality of carrageenan extracted from the seaweed.Th...
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In this instance, the researchers used the temperate redseaweed Chondrus crispus (commonly known as Irish moss)in their attempt to determine if dark treatment can improvethe gel quality of carrageenan extracted from the seaweed.This type of seaweed produces two types of carrageenandepending on its life stage, one that is produced by thegametophytes and another by the tetrasporophytes. Theformer has recently been applied in the food industry as agelling agent. After harvesting from natural stocks, femalegametophytes of C. crispus were cultured for several daysunder a light-deprived regime. Amylase treatment wasemployed during the extraction process to eliminate anyFloridean starch contaminating the carrageenan extracts.
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Standard oligo-i-carrageenans were produced with t-carrageenases isolated from the marine bacteria Alteromonas fonts and Pseudolalteromonas atlantica. The carrageenans were then desulfated using a 4S-carrageenan-sulfatase purified...
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Standard oligo-i-carrageenans were produced with t-carrageenases isolated from the marine bacteria Alteromonas fonts and Pseudolalteromonas atlantica. The carrageenans were then desulfated using a 4S-carrageenan-sulfatase purified from P. atlantica. Using chromatography and NMR analyses, we characterized a series of new standard neo-α-carrageenan oligosaccharides.
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Carrageenan (CGN) is a common food additive that has been widely used for decades as a gelling, thickening and stabilizing agent. Carrageenan has been proven safe for human consumption; however, there has been significant confusio...
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Carrageenan (CGN) is a common food additive that has been widely used for decades as a gelling, thickening and stabilizing agent. Carrageenan has been proven safe for human consumption; however, there has been significant confusion in the literature between CGN and the products of intentional acid-hydrolysis of CGN, which are degraded CGN (d-CGN) and poligeenan (PGN). In part, this confusion was due to the nomenclature used in early studies on CGN, where poligeenan was referred to as ?degraded carrageenan? (d-CGN) and ?degraded carrageenan? was simply referred to as carrageenan. Although this nomenclature has been corrected, confusion still exists resulting in misinterpretation of data and the subsequent dissemination of incorrect information regarding the safe dietary use of CGN. The lack of understanding of the molecular weight distribution of CGN has further exacerbated the issue. The significant differences in chemistry, manufacture, and protein reactivity of CGN versus d-CGN and PGN are reviewed, in addition to the in vivo toxicological profiles of CGN, d-CGN, and PGN. As CGN cannot be hydrolyzed to PGN in vivo, concerns over the use of CGN as a food additive are unfounded, particularly since current studies support the lack of oncogenic and tumorigenic activity of CGN in humans.
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Carrageenan (CGN) is a widely used food additive commonly found in dairy products, dairy substitutes (such as almond milk and soy milk), deli meats, nutritional supplements, beverages, and infant formula. It is typically used as a...
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Carrageenan (CGN) is a widely used food additive commonly found in dairy products, dairy substitutes (such as almond milk and soy milk), deli meats, nutritional supplements, beverages, and infant formula. It is typically used as a gelling, thickening, emulsifying and stabilizing agent and to improve the mouthfeel of the product. Decades of research on CGN safety has been reviewed by numerous regulatory bodies across the world. These regulatory bodies have all agreed on the safety status of CGN used as a food additive. Despite this, a few groups have continually published reports using misinformation and misinterpretation of results to suggest that CGN is harmful. The study reviewed here, “A randomized trial of the effects of the no-carrageenan diet on ulcerative colitis disease activity (Bhattacharyya et al. Nutr. Healthy Aging. 2017; 4(2): 181–192)” from Joanne Tobacman’s group, is an example of this. In this study, Bhattacharyya et al. set out to assess the impact of CGN in the diet on the interval to relapse in patients with ulcerative colitis (UC) who were currently in remission. For the study, UC patients in remission were instructed to participate in a “no carrageenan” diet. Some of the participants also received placebo capsules while others received CGN capsules. CGN, being a food additive, is mostly ingested as part of the diet, and typically bound to food protein. It is never ingested as a bolus in capsule form. The study contains errors in the interpretation of CGN literature and has cited studies that used degraded CGN, not food grade CGN. There are also issues with the use of statistical tests and data interpretation. In one instance, the authors seemed to ignore their own study results, suggested that CGN in the diet had no effect. Here we will review these issues as well as discuss how this study could have been approached to eliminate obvious bias.
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This work reports a chemical and rheological study of the carrageenans from Hypnea musciformis, a red seaweed commercially known for its production of K-carrageenan. The polysaccharides were extracted with water both at room tempe...
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This work reports a chemical and rheological study of the carrageenans from Hypnea musciformis, a red seaweed commercially known for its production of K-carrageenan. The polysaccharides were extracted with water both at room temperature and at 90 °C: the yield of the latter was about six times larger than the former. Fractionation with KC1 yielded a large proportion (50-67%) of a precipitate with 0.125 M of this salt for both extracts, with characteristics of a nearly pure K-carrageenan, as determined by methyla-tion analysis and NMR spectroscopy. Smaller amounts of fractions precipitating at higher concentrations showed a basic K-carrageenan structure, but included some i-carrageenan diads.The KCl-soIuble polysaccharides showed a larger complexity, containing d-and L-galactans or D/L-hybrids. Some differences in the rheological properties of these carrageenans have been found. Although all KCl-precipitating polysaccharides form true gels at 10 °C in presence of KG, those extracted with hot water form stronger gels than those extracted at room temperature. Both purified K-carrageenans show lower gelling and melting temperature than the whole polysaccharides from which they were originated.
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The aim of this work was to study the influence of iota- and kappa-carrageenan addition to strawberry sorbet prepared by various freezing methods (cryostat and conventional freezer) on freezing kinetics and ice crystals structure....
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The aim of this work was to study the influence of iota- and kappa-carrageenan addition to strawberry sorbet prepared by various freezing methods (cryostat and conventional freezer) on freezing kinetics and ice crystals structure. Four variants of strawberry-based sorbet were prepared: with no additive, with 0.1% addition of iota- and kappa-carrageenan, and 1:1 blend of both. Freezing curves and freezing time, as well as the size and morphology of ice crystals, were analyzed. The addition of carrageenan stabilizers resulted in freezing process elongation. Reference samples were characterized by different dynamics of the freezing process. The addition of carrageenan increased the final temperature of the samples, compared to the reference sample (even 2.6 degrees C of difference). Additives reduced ice crystals growth. The most efficient was mixture of both fractions of carrageenan--the samples in this variant frozen in conventional freezer were characterized by the smallest ice crystals diameter--average 5.44 mu m, while for the reference sample it was 17.79 mu m. Practical Application This research can give a new path for the carrageenan's hydrolysates application--not only for dairy products. Iota carrageenan fraction was recommended for dairy products according to its water-holding capacity in the presence of calcium ions. This study showed that mix of iota- and kappa-carrageenan could bring positive results to such product as sorbet without any milk proteins addition. This experiment data could also be helpful when optimizing frozen desserts production in small gastronomy--especially the temperature and time of freezing modifications.
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The aim of this work was to study the influence of l- and κ-carrageenan addition to strawberry sorbet prepared by various freezing methods (cryostat and conventional freezer) on freezing kinetics and ice crystals structure. Four ...
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The aim of this work was to study the influence of l- and κ-carrageenan addition to strawberry sorbet prepared by various freezing methods (cryostat and conventional freezer) on freezing kinetics and ice crystals structure. Four variants of strawberry-based sorbet were prepared: with no additive, with 0.1% addition of l- and κ-carrageenan, and 1:1 blend of both. Freezing curves and freezing time, as well as the size and morphology of ice crystals, were analyzed. The addition of carrageenan stabilizers resulted in freezing process elongation. Reference samples were characterized by different dynamics of the freezing process. The addition of carrageenan increased the final temperature of the samples, compared to the reference sample (even 2.6 ℃ of difference). Additives reduced ice crystals growth. The most efficient was mixture of both fractions of carrageenan—the samples in this variant frozen in conventional freezer were characterized by the smallest ice crystals diameter—average 5.44 jum, while for the reference sample it was 17.79 μm.
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The radiation degradation yield (G_d) of kappa, iota and lambda carrageenans was compared in solid and in 1% aqueous solution in air at ambient temperature. C_ds obtained in solid and aqueous form did not vary with the different t...
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The radiation degradation yield (G_d) of kappa, iota and lambda carrageenans was compared in solid and in 1% aqueous solution in air at ambient temperature. C_ds obtained in solid and aqueous form did not vary with the different types of carrageenan.The chemical structural changes of carrageenans were accompanied by appearance of UV absorbance peak at 260 nm and a characteristic FT-IR band at 1728 cm~(-1). Changes in the FT-IR finger print regions were observed at high doses of the aqueous solution.Radiation-induced desulfation increased the acidity of the carrageenans. The number of reducing end groups increased with dose with greater susceptibility in K-carrageenan.
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