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Effects of Microwave Heating on the Loss of Vitamin B12 in Foods
Abstract
To clarify the effects of microwave heating on the loss of vitamin B(12) in foods, raw beef, pork, and milk were treated by microwave heating and then their vitamin B(12) contents were determined according to a chemiluminescent vitamin B(12) assay with hog intrinsic factor. Appreciable loss ( approximately 30-40%) of vitamin B(12) occurred in the foods during microwave heating due to the degradation of vitamin B(12) molecule by microwave heating. When hydroxo vitamin B(12), which predominates in foods, was treated by microwave heating and then analyzed by silica gel 60 thin layer chromatography, two vitamin B(12) degradation products were found. One of the compounds with a R(f)() of 0.16 was purified and partially characterized. The vitamin B(12) degradation product did not show any biological activity in the growth of a vitamin B(12) requiring microorganism, Euglena gracilis Z, and was not bound to hog intrinsic factor, a mammalian vitamin B(12) binding protein. Intravenous administration of the compound (1 µg/day) for 7 days to rats showed that the compound neither has toxicity nor acts as a vitamin B(12) antagonist in mammals. These results indicate that the conversion of vitamin B(12) to the inactive vitamin B(12) degradation products occurs in foods during microwave heating.
... (no. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]2010). ...
... no. 7870) (28). The total nicotinamide content in the whole blood samples was measured using the method of Shibata et al (29). ...
... The protocol for this study was approved by the Institutional Review Board of the Shiga University of Medical Science (no. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]2010). Written informed consent was obtained from the individual participants included in the study. ...
Few studies have investigated the association between dietary intake and blood concentrations of water-soluble vitamins in patients with ulcerative colitis (UC). In the present study, vitamin concentrations were measured in the blood and urinary excretion of 23 outpatients with UC and compared against a control group of 20 healthy participants. A weighed food record procedure was used to ensure controlled macronutrient and vitamin intakes of the UC cohort. Individuals in the control group were given a semi-purified diet for 8 days prior to assessment. Multiple linear regression analysis was used to identify important differences in vitamin concentrations, independent of sex, age and other confounding variables. The blood concentrations of vitamins B2, C, niacin and folate were markedly lower in the patients with UC than those in the control group, and the renal clearance of vitamins B1, B6, B12 and folate was notably higher in the UC cohort. It was concluded that vitamins B2, C, niacin and folate were at significantly lower concentrations in patients with UC following adjustment for coexisting factors. The lower levels of niacin may be partially due to impaired reabsorption. Chronic inflammation, common in patients with UC, with may contribute to the lower levels of other vitamins by rendering amino acid and carbohydrate metabolism into a hypermetabolic state. As the role of vitamins in metabolic activity is constant and pervasive, nutritional management including the application of water-soluble vitamins appears important for patients suffering from UC.
... Various factors have been suggested to afect the structural integrity and conformation of vitamin B 12 such as heat, light, and microwaves, and to lead to vitamin B 12 defciency [32][33][34][35][36]. Likewise, cigarette smoking has been proposed to be a causative agent of vitamin B 12 defciency by possibly converting the active forms of vitamin B 12 into cyanocobalamin. ...
... Vitamin B 12 defciency is a worldwide health concern and plays a vital role in many metabolic pathways in the human body [38][39][40][41][42]. Many pieces of evidence in the literature suggest that the structure of vitamin B 12 is afected by several factors such as heat and UV light [32,43]. Other studies reported an association between vitamin B 12 defciency and smoking. ...
Vitamin B12 (cobalamin) is a water-soluble molecule required for the proper functioning of metabolism, blood and DNA synthesis, and neurological development. Vitamin B12 exists in several forms: methylcobalamin (MeCbl), adenosylcobalamin (AdoCbl), hydroxycobalamin (OHCbl), and cyanocobalamin (CNCbl). This study aimed to evaluate the effect of cigarette smoke on the chemical structure of methylcobalamin and hydroxycobalamin forms of vitamin B12. MeCbl and OHCbl were markedly affected by exposure to cigarette smoke. The resemblance of the Rt between MeCbl and OHCbl and CNCbl indicates that exposure to cigarette smoke extracts chemically alters MeCbl and OHCbl to CNCbl, warranting in vivo research investigations.
... The amount of B12 ultimately delivered by an infant formula or other fortified food will depend on B12 stability during production, storage, and/or preparation; accordingly, studies have been performed to assess B12 stability in various foods. B12 losses ranging from 0% to 100% have been reported for sterilisation and storage studies of milk, where the greatest losses occurred at elevated temperatures and times (e.g., 110-115°C for 20-40 min) and/or at higher dissolved oxygen levels (e.g., 8 mg kg À1 ) (Rolls & Porter, 1973;Oamen et al., 1989;Andersson & Oeste, 1992;Watanabe et al., 1998;Gille & Schmid, 2015). B12 losses of 10-40% occurred during the cooking of meat (beef, pork), and losses as high as 62% were measured after cooking herring; however, no B12 loss occurred when the herring was cooked in vacuum pouches (Bennink & Ono, 1982;Watanabe et al., 1998;Nishioka et al., 2011;Gille & Schmid, 2015). ...
... B12 losses ranging from 0% to 100% have been reported for sterilisation and storage studies of milk, where the greatest losses occurred at elevated temperatures and times (e.g., 110-115°C for 20-40 min) and/or at higher dissolved oxygen levels (e.g., 8 mg kg À1 ) (Rolls & Porter, 1973;Oamen et al., 1989;Andersson & Oeste, 1992;Watanabe et al., 1998;Gille & Schmid, 2015). B12 losses of 10-40% occurred during the cooking of meat (beef, pork), and losses as high as 62% were measured after cooking herring; however, no B12 loss occurred when the herring was cooked in vacuum pouches (Bennink & Ono, 1982;Watanabe et al., 1998;Nishioka et al., 2011;Gille & Schmid, 2015). Studies of CN-B12 stability in baked bread found losses ranging from 0% to 45%; notably, the hydroxocobalamin loss consistently exceeded the CN-B12 losses in straight dough bread (21% vs. 0%), in sponge dough bread (31% vs. 0%), and in sourdough bread (44-55% vs. 23-26%) (Czernichow et al., 2003;Winkels et al., 2008;Edelmann et al., 2016). ...
Losses of vitamin B12 during the processing and/or storage of foods and supplements have been associated with both reducing and oxidising agents. We evaluated the effects of six redox active (Cu²⁺, Fe²⁺, Fe³⁺, Mn²⁺, Ce³⁺, and Cr⁶⁺) and one redox inactive (Zn²⁺) metal ions on cyanocobalamin stability in heat‐treated, milk protein‐based matrices. The metal ion could either decrease (by ≤76%) or increase (by ≤56%) cyanocobalamin loss, depending on metal ion concentration and redox potential, as well as on matrix properties (metal ion binding, redox activity, and reactive oxygen species generation) and on protein properties (cysteine content, conformation, and charge density). The largest losses of cyanocobalamin appeared to be caused by redox cycling mechanisms (for Cu²⁺ and Fe²⁺); however, indications were that such losses could be mitigated by metal ion modification of the matrix. Only the redox inactive metal ion Zn²⁺ inhibited cyanocobalamin loss in all experimentally evaluated matrices.
... Among important PUFAs, linolenic acid (18:3 ω3) is present in high amount only in wild type cells grown in the light with any of the tested carbon sources. The content of other Onishi, T.;Nakano, Y.; Kitaoka, S.; 1986; "The contents and subcellular distribution of tocopherols in Euglena gracilis";Agric. Biol. ...
... Chem. 50: 1063-1065 Yokota, A.;Nakano, Y.; Kitaoka, S.;1979; "The effect of illumination on the L-ascorbic acid content in Euglena gracilis Z"; Agric.Biol. Chem. ...
This e-book is a review about the state-of-the art about Euglena in 2007
... Among important PUFAs, linolenic acid (18:3 ω3) is present in high amount only in wild type cells grown in the light with any of the tested carbon sources. The content of other Onishi, T.;Nakano, Y.; Kitaoka, S.; 1986; "The contents and subcellular distribution of tocopherols in Euglena gracilis";Agric. Biol. ...
... Chem. 50: 1063-1065 Yokota, A.;Nakano, Y.; Kitaoka, S.;1979; "The effect of illumination on the L-ascorbic acid content in Euglena gracilis Z"; Agric.Biol. Chem. ...
... Human transcobalamin (TC), which subsequently binds cobalamin forms that have entered the bloodstream and facilitates uptake into various tissues, is also highly selective against cobinamide, but less selective than IF for AdoCbl over other cobamides (30)(31)(32). The selectivity of both proteins is considered important for preventing cobinamide, inactive cobamides, and cobamide degradation products from reaching MS and MMUT (18,27,(33)(34)(35)(36). Haptocorrin, a cobalamin-binding protein that binds structurally diverse cobamides and cobinamide with high affinity, might play an additional role in clearing non-cobalamin analogs from the body (30). ...
... In addition to cobalamin, however, the human diet can contain other cobamides, as well as cobamide precursors and degradation products (33,40,41,58). The selectivity of the cobamide uptake system is considered to be important for protecting human cells from analogs that inhibit MS and MMUT (18,27,(33)(34)(35)(36). However, it is conceivable that cobamide cofactors other than cobalamin reach human cells, given the ability of IF and TC to bind multiple cobamides (31,32). ...
Cobalamin, commonly known as vitamin B12, is an essential micronutrient for humans because of its role as an enzyme cofactor. Cobalamin is one of over a dozen structurally related compounds – cobamides – that are found in certain foods and are produced by microorganisms in the human gut. Very little is known about how different cobamides affect B12-dependent metabolism in human cells. Here, we test in vitro how diverse cobamide cofactors affect the function of methylmalonyl-CoA mutase (MMUT), one of two cobalamin-dependent enzymes in humans. We find that, although cobalamin is the most effective cofactor for MMUT, multiple cobamides support MMUT function with differences in binding affinity (Kd), binding kinetics (kon), and concentration dependence during catalysis (KM, app). Additionally, we find that six disease-associated MMUT variants that cause cobalamin-responsive impairments in enzymatic activity also respond to other cobamides, with the extent of catalytic rescue dependent on the identity of the cobamide. Our studies challenge the exclusive focus on cobalamin in the context of human physiology, indicate that diverse cobamides can support the function of a human enzyme, and suggest future directions that will improve our understanding of the roles of different cobamides in human biology.
... En effet, une teneur sérique en vitamine B12 dans les limites basses (154 à 300 pmol/L) et donc classée comme « normale » pourrait en réalité masquer une déficience en vitamine B12 active (Čabarkapa, Stošić, Žeravica, Ilinčić, & Filipović, 2007). (Nishioka et al., 2011;Prodanov, Sierra, & Vidal-Valverde, 2004;Riccio, Mennella, & Fogliano, 2006;Watanabe et al., 1998). ...
... Ainsi, pour les aliments ne subissant pas de cuisson à l'eau, des taux de rétention des folates de 98 % pour les oeufs(Bassett & Sammán, 2010), 87 % pour les petits pois(Stea, Johansson, Jägerstad, & Frølich, 2007) et 97 % pour les brocolis(Petersen, 1993) ont été observés.Des pertes plus élevées ont été constatées pour la vitamine B12, allant de 9% pour le Flan à 31 % pour la Génoise. Des pertes en vitamine de l'ordre de 30 à 40 % ont été observées lors de la cuisson au micro-ondes de viandes de boeuf, de porc ou de lait(Watanabe et al., 1998). Dans une étude ultérieure portant sur la cuisson de la viande de hareng, des taux de rétention variables ont été observés selon le procédé utilisé: 99,5 % lors d'une cuisson sous vide, 98,7% à la vapeur, et seulement 55,7 % lorsque les harengs étaient grillés(Nishioka, Kanosue, Yabuta, & Watanabe, 2011). ...
Un tiers de la population mondiale souffrirait d’une carence en micronutriments entraînant des conséquences à court et long terme sur la vie des individus. L’enrichissement des aliments est une des pistes de l’optimisation nutritionnelle visant à lutter contre ces carences, mais les conditions de son efficacité maximale restent à définir au regard de la biodisponibilitéréelle de ces micronutriments. L’impact de la structure des aliments sur la cinétique de digestion des macronutriments a été largement démontré. En revanche, en ce qui concerne les micronutriments, les études ne permettent pas toujours de distinguer les effets composition et structure de la matrice sur leur biodisponibilité. L’objectif principal de cette thèse est d’évaluer l’impact de la seule structure d’aliments réels sur le processus de digestion et la biodisponibilité des micronutriments.Quatre aliments de même composition mais de structures et textures variables ont été conçus et enrichis en micronutriments (lutéine et vitamines D, B9 et B12). La structure de la matrice alimentaire a effectivement influencé la biodisponibilité de la lutéine et des vitamines D et B9 chez l’Homme, et ce de manière quantitative et cinétique, apportant ainsi une preuve de concept. Les études in vitro ont permis de confirmer l’effet structure observé in vivo et d’étudier en détail la dégradation de la matrice alimentaire, la libération des micronutriments et donc leur bioaccessibilité.Ce travail souligne l’importance de l’effet matrice dans la digestion des aliments. Il suggère aussi que la compréhension fine des mécanismes de digestion pourrait permettre, à terme, la maîtrise du déroulement de la digestion par un design ciblédes aliments.
... CN-B12 loss in fortified, extruded rice was found to increase linearly (R 2 = 0.975) from 23% to 64% over the temperature range 126-180°C, and extensive losses of B12 (30%-100%) have been reported for milk sterilized at 110-115°C for 20-40 min, for baked bread, for cooked beef and herring, for UHT milk stored for 20 weeks at 24°C, for wheat flour stored in paper bags at 25°C and 65% relative humidity for 1.5 M, and for multivitamin (with B1 = B6 >> B12) parenteral solutions stored at 25-28°C for 12 M and at 40°C for 9 weeks. By contrast, no significant B12 loss occurred in pasteurized milk, in cooked vacuum-packed herring, or in wheat flour packaged in moisture/oxygen impermeable multilayer PET/aluminium bags, only minor losses of CN-B12 losses were reported for extrusion at 91-95°C (3%) and for boiled (100°C) CN-B12 fortified rice (11%), and CN-B12 recoveries were ≥95% in single vitamin (B12 only) parenteral solutions stored at 25-28°C for 12 M and at 40°C for 9 weeks (Rolls & Porter, 1973;Bennink & Ono, 1982;Oamen et al., 1989;Andersson & Oeste, 1992;Ahmad & Hussain, 1993;Watanabe et al., 1998;Czernichow et al., 2003;Riaz et al., 2009;Nishioka et al., 2011;Monajjemzadeh et al., 2014;Wieringa et al., 2014;Gille & Schmid, 2015;Edelmann et al., 2016;Bajaj & Singhal, 2019;Hemery et al., 2020;Rakusa et al., 2023). The results of these and related studies have implicated temperature, time, oxygen, redox active agents (including ascorbic acid, thiols, polyphenols, bisulphite, ferrous salts and hydrogen peroxide), other vitamins (B1, B2, B3 and B6), pH and light as potentially significant contributors to B12 decomposition (Schnellbaecher et al., 2019;Rakusa et al., 2023). ...
Reducing agents and oxidizing agents have been identified as contributors to vitamin B12 losses associated with food processing and/or storage. We evaluated the effects of redox active agents on cyanocobalamin stability in heat‐treated non‐fat milk and neutral pH buffers. The largest average cyanocobalamin losses occurred in the presence of an added thiol (glutathione, cysteine, dithiothreitol and the thiamine decomposition product 2‐methyl‐3‐furanthiol) or dithionite, whereas cyanocobalamin recoveries generally increased in the presence of an added oxidizing agent. Cyanocobalamin instability in the heat‐treated, non‐fat milk (~40% loss after 90 min at 100 °C) was attributed to a combination of heat, cystine/cysteine, oxygen and a low‐level presence of transition metals, a combination also found in many other foods for which B12 instability has been reported. The proposed cyanocobalamin decomposition pathway – complexation with heat‐exposed cysteine thiolate, cobalt reduction, hydrolysis of the complex, conversion to hydroxocobalamin and irreversible oxidation – follows the sequence described by others.
... Cobalamin is considered very stable in foodstuffs [2]; however, it is thermolabile. Cooking can inactivate it, depending on the temperature and the type of food [12][13][14]. Homemade cooked diets should be supplemented with vitamin B12 accordingly, while raw diets should not be provided unless the recommended intake is achieved. While vitamin B12 content in food for human consumption is well reported [15], it is not well described in pet food. ...
Simple Summary
We review the role of vitamin B12 in cats. Cobalamin is an essential part of enzymes involved in multiple metabolic reactions. In mammals, two enzymes are cobalamin-dependent: methionine synthase and methylmalonyl-CoA mutase. Cats are obligate carnivores and have an essential requirement for certain nutrients present only in animal tissues, including vitamin B12, which cannot be synthesized by cats. The serum cobalamin concentration can be measured by an automated chemiluminescence competitive binding immunoassay system but does not accurately reflect the real availability of cobalamin, because cobalamin-dependent metabolic reactions occur within cells. A lack of intracellular cobalamin leads to reduced enzyme activity and methylmalonic acid accumulation. The serum cobalamin concentration is particularly useful for detecting deficiency, as it is directly related to the real bioavailability of the vitamin for intracellular enzymatic reactions. Several diseases of the gastrointestinal tract, pancreas, and liver are associated with hypocobalaminemia in cats. Treatment with parenteral cobalamin is always recommended for cats with gastrointestinal disease and low serum cobalamin concentrations. A recognized guideline for cobalamin supplementation does not yet exist for cats, so the recommendations are mainly based on clinical experience.
Abstract
Cobalamin is a water-soluble molecule that has an important role in cellular metabolism, especially in DNA synthesis, methylation, and mitochondrial metabolism. Cobalamin is bound by intrinsic factor (IF) and absorbed in the ileal tract. The IF in cats is synthesized exclusively by pancreatic tissue. About 75% of the total plasma cobalamin in cats is associated with transcobalamin II, while in this species, transcobalamin I is not present. In cats, the half-life of cobalamin is 11–14 days. Diagnostic biomarkers for B12 status in cats include decreased levels of circulating total cobalamin and increased levels of methylmalonic acid. The reference interval for serum cobalamin concentrations in cats is 290–1500 ng/L, and for the serum methylmalonic acid concentration, it is 139–897 nmol/L. Therapy for hypocobalaminemia mainly depends on the underlying disease. In some cases, subcutaneous or intramuscular injection of 250 μg/cat is empirically administered. In recent years, it has been demonstrated that oral cobalamin supplementation can also be used successfully in dogs and cats as a less invasive alternative to parental administration. This review describes the current knowledge regarding B12 requirements and highlights improvements in diagnostic methods as well as the role of hypocobalaminemia in its associated diseases.
... Food processing has also been reported to significantly affect vitamin B 12 stability, with a typical maximum vitamin B 12 loss of up to 45% after cooking, 50% after cooking and draining, and 45% after reheating, as reported by Devi [204]. The effect of microwaving on vitamin B 12 stability in foods was initially evaluated by Watanabe et al., who reported up to 40% total vitamin B 12 loss after 6 min of microwave heating of beef, pork, and cow milk [205]. Similar conclusions were reached by Czerwonka et al. [206] and Bennink and Ono [207]. ...
Vitamin B12, also known as the anti-pernicious anemia factor, is an essential micronutrient totally dependent on dietary sources that is commonly integrated with food supplements. Four vitamin B12 forms—cyanocobalamin, hydroxocobalamin, 5′-deoxyadenosylcobalamin, and methylcobalamin—are currently used for supplementation and, here, we provide an overview of their biochemical role, bioavailability, and efficacy in different dosage forms. Since the effective quantity of vitamin B12 depends on the stability of the different forms, we further provide a review of their main reactivity and stability under exposure to various environmental factors (e.g., temperature, pH, light) and the presence of some typical interacting compounds (oxidants, reductants, and other water-soluble vitamins). Further, we explore how the manufacturing process and storage affect B12 stability in foods, food supplements, and medicines and provide a summary of the data published to date on the content-related quality of vitamin B12 products on the market. We also provide an overview of the approaches toward their stabilization, including minimization of the destabilizing factors, addition of proper stabilizers, or application of some (innovative) technological processes that could be implemented and contribute to the production of high-quality vitamin B12 products.
... Temperatures of 76 • C for 16 s and 96 • C for 5 min did not cause B12 losses. However, high losses were observed in other studies [30,31]: boiling milk for 2-5 min and 30 min resulted in vitamin B12 reductions of 30% and 50%, respectively, as were minor losses (less than 10%) of vitamin B12 after pasteurization and 0-20% loss after ultra-high-temperature treatment. Packaging and storage can also alter vitamin B12 concentration; ultra-high-temperature-treated milk stored at 7 • C for 18 weeks did not show losses of vit B12, while storage at 23 • C and 35 • C for 18 weeks caused a significant reduction of up to 33% of the vitamin B12 concentration. ...
The analysis of natural cobalamins in dairy products still represents an analytical challenge. The matrix’s complexity, low concentration level, light sensitivity, and binding to proteins are just some of the aspects that make their quantification a difficult goal to achieve. Vitamin B12 plays a fundamental role in human nutrition, and its intake is closely linked to a diet that includes the consumption of food of animal origin. In the current literature, few studies have been carried out on the quantitation of cobalamin in ripened cheeses. A sensitive, selective, and robust ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) method was developed, validated, and applied on ripened cheeses from different species (cow, sheep, and goat) purchased from local Italian markets, highlighting species-dependent differences in vitamin B12 concentrations. The vitamin B12 extraction procedure was performed by converting all cobalamins to the cyanocobalamin form. Furthermore, solid-phase extraction was used for matrix clean-up and analyte preconcentration. The proposed method showed good performance in terms of linearity, sensitivity, reproducibility, and repeatability. The mean vitamin B12 content ranged from <LOQ to 38.9 ng/g. Sheep cheese showed the highest concentrations of vitamin B12, with a mean content of 29.0 ng/g.
... When the dielectric heating method is used instead of other conventional heating strategies, as an effect, the process provides bacterial destruction while minimizing sensory and nutritional damage (Martin et al., 2019). Various researchers found that the loss of vitamin C (ascorbic acid) and B 12 could occur when conventional methods were used for heating (Watanabe et al., 1998). As compared to traditional methods, high rates of heat transfer for a specified degree of microbial or enzyme destruction could result in reduced loss of heatsensitive nutrients in pasteurization and blanching applications. ...
The new era of processed food consumer is demanding quality food with minimum processing technologies and have similar sensorial acceptance as that of fresh food. Nonthermal processing technologies of food full fill these demands along with preservation of food quality as well as some essential nutrients. This chapter describes five methods based on electric and magnetic field for processing of food. It consists of dielectric heating, Ohmic heating, infrared heating, oscillating magnetic field, pulsed electric field, induction heating. It describes equipment used for each technology and working principle along with the effect of each technology on microorganisms.
... Thermal processing causes almost 33% vitamin B12 loss in meat [36]. Analysis of 100 g of mutton using radioactive vitamin B12 showed its bioavailability between 56% and 77% [37], while in chicken, it was 65% [38]. ...
Vitamin B12 is one of the most important B vitamins. This vitamin has an important role in cellular metabolism and is also associated with folate and vitamin B6 metabolism. Vitamin B12 deficiency occurs as a result of some diseases, the use of certain medications, or inadequate nutrition. It primarily affects the elderly and women, but is also common among the pediatric population. The B12 deficiency mostly affects the functions of the nervous and hematopoietic systems but it can also affect the skin, heart, bones, and eyes. The treatment of vitamin B12 deficiency includes oral or intramuscular vitamin B12 supplementation according to different treatment regimens.
... Evidence shows that B12 losses depend also on cooking temperature and time of cooking [65]. Heat processing of milk causes appreciable B12 losses, up to 30% and 50% when milk is boiled for 2-5 min and 30 min, respectively, 50% losses when microwaved for 5 min and 5-10% losses when pasteurized [66,67]. Those data suggested that changes in Vitamin B12 bioavailability due to time and cooking processes of food need to be considered in addition to the absolute amount of vitamin B12 content in food, when assessing dietary B12 intake. ...
Vitamin B12 (also known as cobalamin) is an essential water-soluble vitamin that plays a pivotal role for several physiologic functions during one’s lifespan. Only certain microorganisms are able to synthetize B12, thus humans obtain cobalamin exclusively from their diet, specifically from animal-derived foods. Specific sub-group populations are at risk of vitamin B12 subclinical deficiency due to different factors including poor intake of animal source foods and age-dependent decrease in the capacity of intestinal B12 uptake. Consumption of animal products produces some negative health issues and negatively impacts sustainability while a plant-based diet increases the risk of B12 deficiency. Taking a cue from the aforementioned considerations, this narrative review aims to summarize facts about B12 deficiency and the burden of inadequate dietary intake in elderly population, as well as to discuss sustainable approaches to vitamin B12 deficiency in aging population.
... Riboflavin resulted more stable to heat, showing a retention value close to 70%; these results confirmed the findings of Lombardi-Boccia et al. [31], who found in roast beef a complete riboflavin retention, a severe loss in niacin, while thiamine was basically undetectable. Vitamin B 12 showed a significant decrease in cooked donkey meat, confirming the results obtained in cooked beef [43] and in grilled fish [44]; the Authors in both the cited studies attributed the loss of vitamin B 12 to the destruction of this vitamin caused by the heating. ...
Human health is deeply affected by nutrition. The most important nutritional property of a good diet, able to provide an adequate amount of nutrients, to fulfill growth and development requirements, permitting also health maintenance, is variety of foods. Meat can be included in several diets, particularly when they are based on a restricted choice of plant foods. The inclusion of meat and meat products, even in small amounts, can significantly improve many diets; in fact, meat and derived products are good sources of proteins, vitamins and mineral salts. Thermal processes used for cooking meats represent an important factor which affects the minerals and vitamins meat content. Loss of minerals and water-soluble vitamins in cooked meat may occur, depending on the cooking method used. Previous studies investigated on donkey meat nutritional properties, described interesting characteristics of this alternative red meat, rich in protein and in iron, and with low-fat content. This chapter describes the donkey meat chemical composition, showing a comparison with other traditional red meats. The effects of cooking methods on donkey meat vitamins and minerals content will be also evaluated.
... The serum vitamin B12 assay does not discriminate between these two forms, so that the test may overestimate the amount of vitamin B12 available for metabolism (Harrington 2017;Chandy 2019). In addition, microwave cooking may cause a loss of 30-40% of vitamin B12 activity (Watanabe et al. 1998). Furthermore, oxidation of the cobalt in vitamin B12 inactivates the vitamin (Bratman and Harkness 2000;Selzer et al. 2003). ...
In Part I of this Review we evaluated the scientific evidence for a Metabolic Model of multiple sclerosis (MS). Part II outlines the implementation of an adaptive pathology-supported genetic testing (PSGT) algorithm aimed at preventing/reversing disability in two illustrative MS cases, starting with a questionnaire-based risk assessment, including family history and lifestyle factors. Measurement of iron, vitamin B12, vitamin D, cholesterol and homocysteine levels identified biochemical deficits in both cases. Case 1, after following the PSGT program for 15 years, had an expanded disability status scale (EDSS) of 2.0 (no neurological sequelae) together with preserved brain volume on magnetic resonance imaging (MRI). A novel form of iron deficiency was identified in Case 1, as biochemical testing at each hospital submission due to MS symptoms showed low serum iron, ferritin and transferrin saturation, while hematological status and erythrocyte sedimentation rate measurement of systemic inflammation remained normal. Case 2 was unable to walk unaided until her EDSS improved from 6.5 to 4.0 over 12 months after implementation of the PSGT program, with amelioration of her suboptimal biochemical markers and changes to her diet and lifestyle, allowing her to regain independence. Genotype-phenotype correlation using a pathway panel of functional single nucleotide variants (SNVs) to facilitate clinical interpretation of whole exome sequencing (WES), elucidated the underlying metabolic pathways related to the biochemical deficits. A cure for MS will remain an elusive goal if separated from nutritional support required for production and maintenance of myelin, which can only be achieved by a lifelong investment in wellness.
... Similar result for microwave drying was observed by Tian et al. (2015), however, for hot air drying the result was different. Watanabe et al. (1998) also studied the effect of microwave drying on several foods (milk, beef, pork) and reported that microwave heating causes an appreciable degradation (30-40%) of the vitamin B 12 molecules. ...
Aegle marmelos (L.) is a seasonal fruit that contains significant amounts of bioactives like, phenolic acids (gallic acids, 2,3-dihydroxy benzoic acid, chlorogenic acid, p-coumaric acid, vanillic acid), flavonoid (rutin), organic acids (oxalic acid, tartaric acid, malic acid, lactic acid, acetic acid, citric acid, propionic acid, succinic acid, fumaric acid), vitamin C, vitamin B group (thiamine, niacin, pyridoxine, pantothenic acid, biotin, cobalamins, riboflavin), tocopherols (α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol), carotenes (α-carotene, β-carotene, γ-carotene, δ-carotene) and also rich in essential minerals (potassium, calcium, phosphorus, sodium, iron, copper, manganese). This study provides a comprehensive composition analysis (determined using RP-HPLC and Energy Dispersive X-Ray Fluorescence (EDXRF) Spectroscopy). In vitro medicinal activities (antioxidant activity, anti-inflammatory activity, anti-diabetic activity) are quantified for different bael samples. The study also investigates the changes of these bioactive components with freeze, sun, hot air, and microwave drying. The study gives a proper vision to preserve the nutraceutically rich pulp by converting it into fruit leather.
... For example, the heat necessary for canning pickled vegetables destroys much of the vitamin C. Light destroys riboflavin. The storage of pickled vegetables in a cellar or dark room serves to reduce exposure to light, and the subsequent destruction of riboflavin [26]. ...
... Its stability depends also from the food processing and the type of food. Microwave heating reduced appreciable (30-40%) vitamin B12 in raw beef and pork [63] while and higher degradation (62%) was observed in fish [64]. In our case the significant reduction was probably caused by the heat in combination with the specific process techniques. ...
This work explores the feasibility to apply supercritical CO 2 (SC−CO 2 ) drying alone or in combination with High-Power Ultrasounds (SC−CO 2 +HPU) to improve the shelf life and safety of raw chicken meat. SC−CO 2 +HPU drying process revealed the fastest water removal and higher rehydration capacity. A complete inactivation (6 log CFU/g) of mesophilic bacteria and yeasts and moulds was achieved with both the SC−CO 2 processes, while oven drying at 75 °C, used as control, showed only a limited inactivation (4 log CFU/g). The SC−CO 2 processes were efficient also for the inactivation of inoculated Salmonella. The retention of Vitamins B1, B2, B3 and B12 after the SC−CO 2 drying demonstrated the preservation of fresh like properties in terms of nutrients. Colour analysis showed a change in colour comparable to traditional cooking techniques. Results demonstrate that SC−CO 2 -based processes may be used as innovative technologies to dry chicken and make it microbiologically safe, while maintaining nutritional properties.
... Many studies showed equal or better retention of some vitamins (B 1 , B 2 , B 6 , C and folic acid) after MW heating compared with conventional heating (CROSS & FUNG 1982;HOFFMAN & ZABIK 1985). However, conversion of vitamin B 12 to inactive degradation products occurs in foods during MW heating (WATANABE et al. 1998). The efficiency of drying of grains and seeds is improved by microwave finishing and consequent reduction of drying time. ...
The effect of microwave treatment on wet rice was studied. Power output used was 90, 160, 350 or 500 W; final heating temperatures were 40, 60 and 80°C; initial moisture content of rice was 11, 21 or 30%. Temperature of treated sample during microwave heating was measured by means of NoEMI fiber-optic temperature system. Temperature of rice gelatinization, expressed as alkali spreading values and total starch content, was used to evaluate the influence of microwave heating on physicochemical properties of rice. Drying time reduction and the stability of total starch content during microwave treatment of rice makes it possible to recommend the combination of microwave and conventional rice drying for further use.
... There are several candidates and of course there are likely many more. The advent of the microwave is one possibility: microwaving destroys vitamin B12, causing a 30-40% loss of the vitamin in foods [98]. Could the increased use of the microwave in the late 1980s have precipitated more methylation problems in mothers, with a resultant effect on fetal palatal growth and based on this theory, autism rates? ...
The ASD/OSA hypothesis as proposed in this paper will incorporate over 90 pieces of the "autism puzzle". It is suggested that the cause of autism is four-fold, requiring that: 1) the mother has sleep disordered breathing (SDB) during her pregnancy, 2) the infant is born with sleep disordered breathing, 3) both mother and infant have polymorphisms of the methylation pathway which are then triggered by the SDB, and 4) the infant is prone to intracranial hypertension. This theory can explain many, if not most, of the pieces of information that we currently know about the biology of autism. The fact that the sleep disordered breathing (SDB) in autism and in the mothers of autistic children has not been previously noted is due to flaws in the current methods for detecting SDB. Esophageal manometry is much more sensitive for detecting SDB but is not used routinely, however it may be more accurate than the apnea hypopnea index in terms of correlation with disruptive behavior disorders. There is evidence that SDB is much more common than previously believed. Apneas are known to increase intracranial pressure, and intracranial hypertension can be caused by obstructive sleep apnea. Recent studies showing behavioral problems and special needs correlated with SDB urge further evaluation of autistic children for SDB. The ASD/OSA hypothesis suggests that autism might be primarily prevented by detecting and treating SDB in women prior to conception, and in infants shortly after birth.
... The cooking methods are majorly categorized into water media based (steaming, boiling, poaching, stewing, braising);fat media based (roasting, frying); heat media based (grilling/ boiling, baking) and smoke media based (braising, roasting, grilling and smoking) of which the most preferred mode used for vegetables is boiling 6 . Phytonutrients or phytochemicals are mostly water soluble 7 and tend to leach out when vegetables are submerged in water for prolonged period 8,9 ; their thermo labile nature also lead to the loss duringexposure toheat [10][11][12] . Apart from these detriments, bactericidal activity enabling food consumption without harmful microbes, improved digestibility and increased availability of nutrients are beneficial factors credited to cooking 13,14 . ...
The culinary arts across continents have provided a whole range of variant practices that now concentrate to contain the essential components of the nutriment used. Among the disparate healthy cooking practices, boiling is considered as a quick and effortless way for both preserving and extracting the water soluble vitamins. In this study, an attempt was carried out to correlate the extent of phytochemical release and antioxidant activity in raw and cooked food items. Common vegetables that form any part of appetizer, entrée or main course of food were targeted for this swot. Extracts obtained after 20 min of cooking showed increased phytochemical contents with corresponding free radical scavenging activity. Based on the targeted food samples an ideal cooking duration for each is recommended in accordance to their scavenging property.
Vitamin B 12 , cobalamin, is indispensable for humans owing to its participation in two biochemical reactions: the conversion of l -methylmalonyl coenzyme A to succinyl coenzyme A, and the formation of methionine by methylation of homocysteine. Eukaryotes, encompassing plants, fungi, animals and humans, do not synthesise vitamin B 12 , in contrast to prokaryotes. Humans must consume it in their diet. The most important sources include meat, milk and dairy products, fish, shellfish and eggs. Due to this, vegetarians are at risk to develop a vitamin B 12 deficiency and it is recommended that they consume fortified food. Vitamin B 12 behaves differently to most vitamins of the B complex in several aspects, e.g. it is more stable, has a very specific mechanism of absorption and is stored in large amounts in the organism. This review summarises all its biological aspects (including its structure and natural sources as well as its stability in food, pharmacokinetics and physiological function) as well as causes, symptoms, diagnosis (with a summary of analytical methods for its measurement), prevention and treatment of its deficiency, and its pharmacological use and potential toxicity.
Microwave technology effectively cooks, heats, or thaws food by using electromagnetic waves. Its use has shown a variety of advantageous impacts on different thermophysical, physicochemical, and sensory qualities of food, making it a promising tool in the culinary world. We can learn a lot about how food changes during microwave heating by knowing the changes that take place in the protein, lipid, and carbohydrate contents. The accessibility and ease of microwave technology are two of its main benefits. Microwaves provide a secure and effective way to prepare food for people with restricted movement, such as the elderly or people with disabilities. This is especially crucial because it eliminates the need for heavy manual labour in the kitchen, fostering independence and raising standard of living. Despite these benefits, it is important to be aware of the restrictions and issues related to microwave technology in the food processing industry. The technology’s inability to lessen allergenicity in some food products is a notable downside. This chapter aims to explore the numerous changes in food quality that have been noticed when the meal is being heated in the microwave. Understanding these modifications can lead to the development of microwave cooking methods that maximise nutritional value while lowering hazards.
Vitamin B12 deficiency and insufficiency can lead to both hematological and neurological impairments. This review examines nondisease causes and risk factors associated with dietary availability, such as eating habits, food processing, cooking techniques, and bioavailability, as well as increased physiological needs and iatrogenic factors linked to medication use or surgical procedures. As a result of these nondisease influences, groups at higher risk include vegans, vegetarians, older adults, individuals with limited diets, breastfed and preterm infants, and those who primarily consume foods prepared or cooked in ways that reduce vitamin B12 content, as well as individuals on certain medications or who have undergone specific surgeries. Recognizing these diverse risk factors helps develop strategies for prevention and intervention to minimize the adverse health effects related to B12 deficiency and insufficiency.
Edible wild-grown mushrooms, plentiful in resources, have excellent organoleptic properties, flavor, nutrition, and bioactive substances. However, fresh mushrooms, which have high water and enzymatic activity, are not protected by cuticles and are easily attacked by microorganisms. And wild-grown mushroom harvesting is seasonal the harvest of edible wild-grown mushrooms is subject to seasonality, so their market availability is challenging. Many processing methods have been used for postharvest mushroom processing, including sun drying, freezing, packaging, electron beam radiation, edible coating, ozone, and cooking, whose effects on the parameters and composition of the mushrooms are not entirely positive. This paper reviews the effect of processing methods on the quality of wild and some cultivated edible mushrooms. Drying and cooking, as thermal processes, reduce hardness, texture, and color browning, with the parallel that drying reduces the content of proteins, polysaccharides, and phenolics while cooking increases the chemical composition. Freezing, which allows mushrooms to retain better hardness, color, and higher chemical content, is a better processing method. Water washing and ozone help maintain color by inhibiting enzymatic browning. Edible coating facilitates the maintenance of hardness and total sugar content. Electrolytic water (EW) maintains total phenol levels and soluble protein content. Pulsed electric field and ultrasound (US) inhibit microbial growth. Frying maintains carbohydrates, lipids, phenolics, and proteins. And the mushrooms processed by these methods are safe. They are the focus of future research that combines different methods or develops new processing methods, molecular mechanisms of chemical composition changes, and exploring the application areas of wild mushrooms.
The potential of microwave (MW) energy to offer significant reductions in heating time and load during commercial preservation operations such as drying, blanching, pasteurization and sterilization, and food preparation in domestic and commercial ovens makes it attractive to food and food service industry in terms of possibility of achieving better quality and sensory attributes of products. Microwave-processed foods may also have better texture, taste, and appearance than products processed by conventional methods. The objective of this chapter is to present overall effects of microwave heating on food physical properties, quality and nutritional attributes, composition, enzymes in different foods, proteins, lipids, carbohydrates as well as the formation of undesirable chemical compounds such as acrylamides (AAs) and compare those effects with other heating modes in various food processing operations.
Microwave (MW) is considered one of the most sustainable technologies in the food and agriculture sector with zero residual waste. Microwave radiation can heat food particles with dielectric properties. Food particles absorb that energy and convert it into heat energy, enabling its potential usage in food processing and preservation. The primary aim of this article is to provide an overview of current trends in the application of MW treatment to food products. Treatment includes sterilization, pasteurization, thawing, blanching, stunning, drying, and assisting with MW. Several advantages, including low processing time (50%), minimum production cost, and effect on food products, have also been described. Recent studies about the ability of MW to extract bioactive compounds from various biomass sources are also discussed, along with its advantages, drawbacks, and prospects.
Although fish roes (or the egg-laden ovary) are seafood products with high nutritional value and are considered abundant in vitamins including vitamin B12, nevertheless, the detailed properties of vitamin B12 have not been fully elucidated in fish roe products. Vitamin B12 content was determined using C18-reversed-phase high-performance liquid chromatography after purification of samples from immunoaffinity columns. Salmon egg-laden ovary products (sujiko), salmon roe products (ikura), dried mullet roe products (bottarga), and white sturgeon roe products (caviar) were found to contain substantial levels of vitamin B12 (more than approximately 15 µg/100 g wet weight). Interestingly, high levels of vitamin B12 per 100 g wet weight have been measured in pollack roe products (tarako) and flying fish roe products (tobiko). Liquid chromatography–electrospray-ionization/tandem mass spectrometry analysis revealed that vitamin B12 was the predominant corrinoid in the evaluated fish roe products examined, while no inactive corrinoid compounds were identified. These results suggest that commercially available fish roe products could be an important source of vitamin B12 for use as a dietary product for humans.
This chapter describes the uses of dielectric and infrared electromagnetic waves that penetrate food and are absorbed and converted to heat. They are compared with ohmic heating which uses the electrical resistance of foods to directly convert electricity to heat. Each section explains the theory of heating and the equipment used. The applications of dielectric heating to baking, dehydration, tempering and thawing of foods, and the use of ohmic heating for aseptic processing are described. Each section describes the effects of the type of heating on both foods and microorganisms.
Vitamin B12 is assimilated and transported by complex mechanisms that involve three transport proteins, intrinsic factor (IF), haptocorrin (HC) and transcobalamin (TC) and their respective membrane receptors. Vitamin deficiency is mainly due to inadequate dietary intake in vegans, and B12 malabsorption is related to digestive diseases. This review explores the physiology of vitamin B12 absorption and the mechanisms and diseases that produce malabsorption. In the stomach, B12 is released from food carrier proteins and binds to HC. The degradation of HC by pancreatic proteases and the pH change trigger the transfer of B12 to IF in the duodenum. Cubilin and amnionless are the two components of the receptor that mediates the uptake of B12 in the distal ileum. Part of liver B12 is excreted in bile, and undergoes an enterohepatic circulation. The main causes of B12 malabsorption include inherited disorders (Intrinsic factor deficiency, Imerslund-Gräsbeck disease, Addison's pernicious anemia, obesity, bariatric surgery and gastrectomies. Other causes include pancreatic insufficiency, obstructive Jaundice, tropical sprue and celiac disease, bacterial overgrowth, parasitic infestations, Zollinger-Ellison syndrome, inflammatory bowel diseases, chronic radiation enteritis of the distal ileum and short bowel. The assessment of B12 deficit is recommended in the follow-up of subjects with bariatric surgery. The genetic causes of B12 malabsorption are probably underestimated in adult cases with B12 deficit. Despite its high prevalence in the general population and in the elderly, B12 malabsorption cannot be anymore assessed by the Schilling test, pointing out the urgent need for an equivalent reliable test.
Risk for colorectal cancer (CRC) is increased in adults with poor diet quality, low socioeconomic status, and increased body mass index (BMI). Cooked meats contain high contents of mutagenic compounds related to CRC risk. To explore differences in meat-based carcinogen exposure, a 99-item Qualtrics survey was issued to 1648 US adults. Average monthly serving size, degree of doneness, and cooking methods of meat products were obtained. The National Cancer Institute CHARRED database was used to quantify exposure to HCAs, PAHs, and Ames Predicted and Estimated mutagenicity. Questions from validated instruments assessed food security status (FSS) and demographic variables, while height and weight were self-reported to calculate BMI. Sex, FSS and obesity status (BMI > 30 kg/m²) were compared using two-sample t-tests and multivariate regression models to determine differences in meat intake and carcinogen exposure. Statistical significance was set at P < 0.05. Eight hundred fifty-six valid responses (57.4% female and 81.8% white) were obtained. Non-obese males consumed more white meat and were exposed to greater amounts of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline. Food insecure and obese females consumed more red meat and had higher exposure rates of several carcinogens. Pan-frying and BBQ were the primary sources of meat-derived carcinogens. Greater disparities in carcinogen exposure were observed in females regarding BMI and FSS. Public health messages to modify meat cooking methods may be most effective for CRC prevention.
Specifically, the objective of food preservation is to slow down or stop (kill) bacterial spoilage activity that would otherwise exhibit loss of taste, textural quality, or nutritive value of food. Techniques of food preservation include heating, cold refrigeration, freezing, freeze drying, dehydration, concentrating, microwave heating, salting, or pickling, both nonthermal methods, or other means as discussed in this chapter.
We comprehensively searched the available databases, such as Igaku Chuo Zasshi, CiNii, and PubMed, for literatures about the loss of vitamins from food during cooking that were published in or before April 2014. In total, 148 pieces of literatures, including 113 reports from academic journals, 31 bulletin reports, 3 lecture abstracts, and a section of an electronic book, were found out. From the literatures, we extracted data on the loss of these vitamins in various cooking conditions, and made tables in which food groups, food names, cooking methods, the retention rate of each vitamin, and bibliographic information were summarized. Based on the tables, the general characteristics of the vitamin loss such as fat-solubule vitamins and vitamins B1, B2, B6 and B12 during cooking were cleared up as follows: Thermal cooking causes a larger reduction in the level of vitamin B1 and B2 than non-thermal cooking. Boiling causes the elution of water-soluble vitamins from food into the cooking water, resulting in significant losses of vitamins B1, B2, and B6. Overall data on the loss of fat-soluble vitamins in cooking are limited. The tables made in this study allow us to make out menu to take appropriate amounts of vitamins from food. Future studies should be needed to collect data on vitamin loss in different cooking conditions and develop novel analytical methods.
As an efficient heating method, microwave processing has attracted attentions both in academic research and industry. However, the mechanism of dielectric heating is quite distinct from that of the traditional conduction heating, and is widely applied as polar-molecules and charged ions interaction with the alternative electromagnetic fields, resulting in fast and volumetric heating through their frication losses. Such a heating pattern would cause a certain change in microwave treatment, which is unarguable reality. In this review, we made a retrospect of the essential knowledge about dielectric properties and summarized the concept of microwave heating, and the impact of microwave application on the main components of foods and agricultural products, which are classified as carbohydrates, lipids, proteins, chromatic/flavor substances, and vitamins. Finally we offered a way to resolve the drawbacks of relevant microwave treatment and outlined the directions for future research.
The PDF of the thesis can be found here.
http://urn.fi/URN:ISBN:978-951-51-2753-2
Preservation by heat, cold refrigeration, freezing temperature, or other means and application of the preservation techniques are introduced in this chapter. Storage conditions and preservation processes are subject to Food and Drug Administration (FDA) inspection and enforcement. Preservation from microbial, chemical, and physical contamination, as well as enzymatic activity, is necessary for preserving and extending the shelf life (time a product can be stored without significant change in quality) of food. Adequate packaging is important in preserving food (Chapter 19).
This chapter is in the newly named Aspects of Food Processing section of the text. The chapters covering food additives and food packaging components of the food processing section appear in Chaps. 17 and 18, respectively.
Cobalamin or B12 is an important group of water-soluble compounds belonging to the cobalt corrinoid family. This chapter provides an overview of B12 chemistry and physical properties, its occurrence in natural sources and quantification of B12, mainly in foods. A summary of key nutritional aspects of B12 in humans is also given, that is, absorption and uptake, metabolic cofactor functions and the current context of B12 deficiencies and their detection, with references to detailed reviews. The chapter presents the current state of B12 production by Propionibacterium and Pseudomonas, including genetic engineering of producing strains, downstream processing (DSP) of fermentation products, B12 purification and future directions for industrial B12 production. Future demand for B12 will likely continue to increase in both developed and developing countries, mainly due to increases in human and animal populations and the ageing population with higher needs for B12-fortified food.
Vitamin B12 exists naturally in foods of animal origin and is synthesised only by
certain bacteria. New food sources are needed to ensure vitamin B12 intake in risk groups.
This study aimed to investigate the stability of added cyanocobalamin (CNCbl, chemically
modified form) and hydroxocobalamin (OHCbl, natural form) and in situ-synthesised vitamin
B12 in breadmaking. Samples were analysed both with a microbiological (MBA) and a liquid
chromatographic (UHPLC) method to test applicability of these two methods.
This chapter describes the uses of dielectric and infrared electromagnetic waves that penetrate food and are absorbed and converted to heat. They are compared with ohmic heating, which uses the electrical resistance of foods to directly convert electricity to heat. Each section explains the theory of heating and the equipment used. The applications of dielectric heating to baking, dehydration, tempering and thawing of foods, and the use of ohmic heating for aseptic processing are described. Finally the effects of each type of heating on both foods and micro-organisms are discussed.
Pasteurization of freshly milked cows' milk was carried out by microwave-based treatment and traditional heat transfer. The efficiency of heat treatments were compared with the analysis of the total viable cell count and the peroxidase enzyme activity. In case of the latter the authors found that the peroxidase enzyme activity was detectable even at higher temperatures (T>80 °C) during the microwave heat treatment, as opposed to the convective heat treatment where the enzyme was inactivated at Ta≈8 °C. This was the first time that a significant difference was demonstrated between the effects of heat treatments.
This review apprises the reader of recent advances in cobalamin absorption and transport since 1970. This field has been of interest to gastroenterologists, hematologists, and biochemists as well as nutritionists. Clinical conditions leading to cobalamin deficiency present especially to the first two of these specialties. Many recent advances involve biochemical definition of the specific transport proteins themselves. Full understanding of the multiple clinical conditions associated with cobalamin deficiency requires some knowledge of these proteins. We do not discuss every paper in the field, especially the early literature (see 47, 61, 150). Despite rapid strides in understanding the mechanism of absorption and transport of cobalamin both in prokaryotic and eukaryotic cells, the complete sequence of events during cellular absorption at the plasma membrane level and events in the cells that mediate intracellular movement of cobalamin have not been elucidated completely. Here we emphasize the current state of knowledge about cobalamin absorption and transport in man and other mammalian systems, particularly the physiological role and biochemical nature of proteins involved (intrinsic factor, intrinsic factor-cobalamin receptor, transcobalamins).
A variety of cobalamin analogues synthesized chemically or microbiologically were used to study the corrinoid specificities of cell growth and the cobalamin uptake system in Euglena gracilis z. Although Euglena could not utilize most of the analogues for cell growth, benzimidazolyl cobamide, cyanocobalamin-O(5')-phosphate, and cyanocobalamin-b-, -d- and -e-monocarboxylates had effects similar to that of cyanocobalamin on cell growth. It is suggested that Euglena cells have the ability to synthesize 'complete cobalamin' from the acid derivatives (amidation reaction) and/or the phosphate derivative (dephosphorylation reaction). Inhibition of uptake of radiolabelled cyanocobalamin caused by addition of various analogues indicates that both the α-lower axial ligand (the cobalt-coordinated nucleotide) and the (b)-propionamide side-chain of the cobalamin molecule are essential for the cobalamin uptake system in Euglena. These results indicate that there are different corrinoid specificities for cell growth and the cobalamin uptake system in E. gracilis z.
An assay for urinary methylmalonic acid by high-pressure liquid chromatography was devised. Methylmalonic acid could be assayed over a range of 5–80 μg by this method, which is one of the most convenient and useful assays for the acid in urine as an index of cobalamin deficiency.
The relationship of carcass grade, primal cuts and cooking to vitamin B 12 , E and D in separable lean beef was studied. The average vitamin B ¹² content in 471 samples of raw and cooked beef was 3.17 μg/100g. The vitamin B 12 content of raw and cooked beef was similar; however, on considering the moisture and fat losses during cooking, there was a 27–33% loss of B 12 . The vitamin E content of raw and cooked beef was similar and averaged 133 μg/100g for 464 samples. From 33–44% of the original vitamin E in the meat was lost upon cooking. Raw and cooked beef contained 80–100 ng of vitamin D/100g, with 35–42% of the original vitamin D content being lost upon cooking. The content of vitamins E and D in beef is low and of little nutritional importance; however, beef is an important dietary source of vitamin B 12 .
SUMMARY & CONCLUSIONS
RAW OR COOKED separable lean contained approximately 80–100 ng of vitamin D/100g, with 35–42% of the original vitamin D being lost upon cooking. Raw and cooked separable lean contained approximately 40–800 μg of vitamin E/100g with a mean value of 133 μg for 464 samples. From 33–44% of the original vitamin E was lost during cooking. Fat trim contained 300–350 μg of vitamin E/100g. HPLC showed that α‐tocopherol was the major E vitamer in meat. Vitamin B‐12 content of raw and cooked separable lean ranged from 1 – 10 μg/100g, with a mean value of 3.17 μg B‐12/100g for 471 samples. Fat trim contained approximately 1.5 μg of B‐12/100g. RID was a feasible method for determining B‐12 in meat, with the B‐12 values reported herein being appreciably greater than typical values reported for B‐12 in beef as determined by microbiological assays. Beef consumption makes an important contribution towards meeting an individual's dietary requirement for B‐12.
Thesis (M.S.)--Kansas State University, 1980. Includes bibliographical references (leaves 52-60). Typescript (photocopy).
Rat liver contains both NADH- and NADPH-linked aquacobalamin reductases, which are involved in the synthesis of the vitamin B-12 coenzymes and are distributed in both the mitochondrial and microsomal membranes. To clarify the physiological roles of these hepatic enzymes, vitamin B-12-deficient rats were used to study the effect of the deficiency on the enzyme activities. Male rats fed a vitamin B-12-deficient diet for 11 wk developed a severe vitamin B-12 deficiency with a high urinary methylmalonate excretion (214.3 +/- 115.2 mumol/d) and approximately 96% lower hepatic vitamin B-12 content. Tissues of the vitamin B-12-deficient rats were assayed for NADH- and NADPH-linked aquacobalamin reductase activities. The specific activities of both enzymes in homogenates of liver, kidney or upper intestine were shown to be three- to 20-fold greater in the vitamin-deficient rats than in the control rats. In liver, the vitamin deficiency specifically elevated the specific activities of the mitochondrial NADH-linked and microsomal NADPH-linked enzymes. These are likely the isozymes involved in vitamin B-12 coenzyme synthesis.
Microwave-oven technology has been improved by the use of low power. With the utilization of low-power techniques, studies showed equal or better retention of nutrients for microwave, as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folacin, and ascorbic acid. Beef roasts microwaved at "simmer" were comparable with conventionally cooked roasts in sensory quality, while vegetables cooked by an institutional (1,150 w) microwave oven were superior to those cooked in a domestic (550 w) microwave oven. Microwave-cooked bacon had lower levels of nitrosamines than conventionally cooked bacon; however, the use of a new alpha-tocopherol coating system has been found to be a safe N-nitrosamine inhibitor regardless of cooking method used.
Microwave cooking has gained considerable importance as an energy-saving, convenient, and time-saving cooking method. This article reviews the state of the art of microwave cooking and the existing publishing data on the effects of microwave cooking on nutritive values of moisture, protein, carbohydrate, lipid, minerals, and vitamins. Most reports indicated that microwave cooking resulted in higher moisture losses compared with conventional methods. Overall, the nutritional effects of microwaves on protein, lipid, and minerals appear minimal. There is no report on the effects of microwaves on carbohydrate fraction in foods. A large amount of data is available on the effects of microwaves on vitamins. It is concluded that there are only slight differences between microwave and conventional cooking on vitamin retention in foods. In conclusion, no significant nutritional differences exist between foods prepared by conventional and microwave methods. Any differences reported in the literature are minimal.
This chapter discusses the measurement of tissue vitamin B12 by radioisotopic competitive inhibition assay and quantitation of tissue cobalamin fractions. In this method, the measurement of tissue vitamin B12 by the competitive inhibition approach requires an initial complete separation of all endogenous B12 from the tissue binders and the removal or inactivation of these binders. Because B12 in tissue exists as a group of coenzyme forms with differing affinities for tissue binding proteins and subcellular moieties, extraction of the tissue B12 from these binders is accomplished by vigorous boiling of the homogenate of tissue in an acetate–cyanide buffer. This also results in the conversion of all the B12 forms into that of cyanocobalamin. Prior to this extraction, addition of radiolabeled vitamin B12 ([57Co]B12) permits the determination of the recoverable B12 originally present. Analysis is accomplished by the subsequent incubation of these extracts with a predetermined amount of material with unsaturated B12 binding sites. The percentage of [57Co]B12 that is protein bound is inversely proportional to the total B12 concentration. The bound B12 can be removed by batch adsorption onto diethylaminoethyl (DEAE) cellulose and subsequent centrifugation or by adsorption onto coated charcoal. The percentage binding of any unknown can then be determined from previously prepared standard curves.
Cobalamin uptake by Euglena mitochondria is a biphasic process, consisting of energy-independent cobalamin-binding to mitochondrial membranes and energy-dependent active transport. The energy-dependent phase of cobalamin uptake is not dependent on mitochondrial respiration, but on the presence of ATP within the mitochondrial matrix. The dissociation constant of the energy-independent cobalamin-binding reaction is estimated to be 0.45 nM. Inhibition of the mitochondrial cobalamin uptake by a variety of cobalamin analogues indicates that Euglena mitochondria have an absolute requirement for the complete cobalamin molecule with an alpha-axial ligand (the cobalt-coordinated nucleotide) and an intact b-propionamide side-chain. Thus, the Euglena mitochondrial cobalamin uptake system is highly specific for the cobalamin structure. The cobalamin taken up by the Euglena mitochondria cannot be exchanged with exogenous cobalamin. All of the mitochondrial cobalamin is associated with three proteins with molecular masses of > 700,000 (16.3%), 160,000 (7.4%), and 35,000 (76.3%). They occur in the soluble fraction of mitochondria, suggesting that these cobalamin-binding proteins or cobalamin-dependent enzymes play an important role in cobalamin accumulation and metabolism within the mitochondria.
The photosynthetic protozoon Euglena gracilis Z contains adenosylcobalamin-dependent methylmalonyl-CoA mutase (MCM) involved in propionate metabolism. The specific activity of the Euglena mutase was about 6.5-fold greater in propionate-adapted Euglena cells than in photoautotrophic cells (control). Although the control cells contained only one mutase (apparent M(r) 72,000), the propionate-adapted cells contained two mutases with M(r) values of 72,000 and 17,000; both enzymes were located in the mitochondria. These results provide evidence that propionate-adapted Euglena contains two MCM isozymes. The induced mutase (M(r) 17,000) permits photoassimilation of propionate.
Cobalamin in food and feeding stuff
- Z Schneider
Schneider, Z. Cobalamin in food and feeding stuff. In Com-prehensive B12; Schneider, Z., Stroiñ ski, A., Eds.; de Gruyter: Berlin, 1987; pp 194-198.
X JF970670X X Abstract published in Advance ACS Abstracts
- Watanabe
Received for review August 4, 1997. Accepted October 14, 1997. X JF970670X X Abstract published in Advance ACS Abstracts, December 1, 1997. 210 J. Agric. Food Chem., Vol. 46, No. 1, 1998 Watanabe et al.