Riboflavin Content Research Articles

P3C101 - Effects of high-level lead exposure on NK cell and T-lymphocyte functions and some important cytokine levels in man

We have shown previously that riboflavin is stored in chloragosomes of chloragocyte-derived earthworm eleocytes what may have an adaptive value for worms vulnerable to soil-derived pathogen invasion. Thus, it is important to determine whether riboflavin stores are also present in earthworm species with low eleocyte counts, especially in the chloragocytes of their chloragogen tissue that surrounds the coelomic site of the intestine, and find out its putative roles in earthworm immunity. Experiments were performed on adult worms from 6 species. Freely floating coelomocytes (consisting of amoebocytes plus species-specific numbers of eleocytes) were extruded by mild electric shock and then chloragocytes from the same anaesthetized worm were mechanically detached into buffer. Both cell suspensions were analyzed by spectrofluorometry for riboflavin content. It turned out that riboflavin is stored in species-specific quantities in all investigated species. Riboflavin storage predominates in free coelomocytes of eleocyte-rich species (Eisenia andrei, Dendrobaena veneta, Allolobophora chlorotica) while in chloragocytes of species with few eleocytes (Lumbricus terrestris, L. rubellus, and Aporrectodea caliginosa). Upon a massive microbial impact, the coelomocytes (both amoebocytes and eleocytes) are involved in the formation of multicellular bodies encapsulating soil-derived pathogens, what is connected with enhanced coelomocyte mobility. Thus the second aim of the present investigation was to check if riboflavin can participate in coelomocyte accumulations. Tests performed in a 48-well chemotaxis chamber revealed that riboflavin behave as chemoattractant for coelomocytes of all investigated earthworm species, which may be one of mechanisms underpinning its immunomodulatory functions.

Effect of ripening stage on thiamin and riboflavin levels in lupin, pea and faba bean seeds

Seeds of yellow pea lupin (Lupinus luteus L., cv. Juno), pea (Pisum sativum L., cv. Ergo) and faba bean (Vicia faba sp. minor Harz., cv. Tibo) were harvested at different stages of seed maturity. Changes in thiamin and riboflavin levels during growth and maturation were studied. The results obtained showed that thiamin and riboflavin were found in high abundance early in the development of lupins and peas, but that their content decreased during maturation. The thiamin content of faba bean seeds increased from 33 to 47 days after flowering (DAF), then a decrease was observed until 61 DAF; however, no significant differences between these levels in faba bean seeds harvested from 61 to 89 DAF were found. The riboflavin content of faba beans increased after 54 DAF, and no significant changes were observed between then and 89 DAF. The thiamin and riboflavin contents in lupin, pea and faba bean seeds during development were fitted to modelling curves in order to predict the vitamin content at different stages of maturity.

Effects of Ascorbic Acid on the Light-Induced Riboflavin Degradation and Color Changes in Milks.

Effects of ascorbic acid (0.025, 0.05, and 0.1%, w/v) on the light-induced riboflavin degradation and color changes in whole and skim milks were studied during 10 h fluorescent light illumination at 7 +/- 2 degrees C. As the time of light illumination increased, the riboflavin content in milks greatly decreased, resulting in 30.1 and 59.1% reduction of riboflavin in whole milk and skim milk after 10 h exposure to fluorescent light, respectively. The ascorbic acid treatment effectively protected the photodegradation of riboflavin in both whole milk and skim milk, and its effectiveness is concentration dependent. The 0.1% ascorbic acid treatments resulted in 50.0 and 25.5% inhibition of riboflavin reduction in whole milk and skim milk after 10 h fluorescent light illumination, respectively. The color parameters of lightness (L), greenness (-a), and yellowness (b) in both whole milk and skim milk decreased after light illumination. Ascorbic acid treatment also protected effectively the changes in greenness and yellowness in both milks during the light illumination.

Nutrient composition, amino acid and vitamin contents of malted sorghum, pearl millet, finger millet and their rootlets

Sorghum, pearl millet and finger millet were allowed to germinate up to 96 h and samples were withdrawn from the germinating bed at every 24 h intervals, dried at 50°C and derooted to prepare the malt. The native and the malt samples were analysed for the proximate principles, and amino acids, thiamine, riboflavin, niacin and ascorbic acid contents. Protein, fat, ash and crude fibre contents of the rootlets separated from the malt were also determined. Protein content of finger millet malt was considerably less than the native millet, but the protein, fat and mineral contents of native and malted sorghum and pearl millet were almost the same. A noticeable increase in lysine content and decrease in sulphur-containing amino acids were also recorded only in the case of finger millet on malting. Malting enhanced riboflavin, niacin and ascorbic acid contents but slightly reduced the thiamine content of sorghum as well as both the millets. The SEM photomicrographs of the endosperm portion of sorghum and pearl millet exhibited visible pitting of starch granules, but contrary to this in the case of finger millet, only surface erosion was noticed. The rootlets from sorghum as well as the millets were rich sources of protein and the essential amino acids.

Natural fermentation of lentils

Lentils (Lens culinaris, var. vulgaris cultivar Magda-20) were naturally fermented for 96 h at different lentil flour concentrations (79, 150 and 221 g/l) and temperatures (28, 35 and 42°C). During fermentation, samples were taken at 24-h intervals and the changes in thiamin (vitamin B1), riboflavin (vitamin B2) and total and available niacin (vitamin B3) were investigated. Preparation of the lentil flour suspension to be fermented (i.e. the process of mixing the flour and sterilized tap water) caused an increase of the available niacin content in all batches, while changes in thiamin and riboflavin content were related to the conditions in which the preparation of the suspensions was carried out. The whole natural fermentation process (from the raw state to after 96 h of fermentation), either did not affect or produced a slight decrease in the thiamin content of lentils. In contrast, riboflavin, available niacin and total niacin contents increased throughout the 96 h period, which ended with a 35 – 82% increase of riboflavin, a 24 – 91% increase of available niacin and a 20 – 58% increase of total niacin. The temperature during the fermentation procedure had significant effect on the levels of thiamin and riboflavin in fermented lentils. To obtain lentil flours with an improved amount of riboflavin and available niacin with a minimum loss of thiamin, the natural fermentation of lentils should be carried out for 96 h at 42°C and with a lentil flour concentration of 221 g/l.

Simultaneous square-wave voltammetric determination of riboflavin and folic acid in pharmaceutical preparations

The square-wave voltammetric (SWV) behaviour of riboflavin and folic acid was studied at a static mercury drop electrode by square wave voltammetry. In 0.05M KCl (pH 5.89) a cathodic scan gave peaks at — 0.56 and — 0.87 V vs. Ag/AgCl for riboflavin and folic acid, respectively. The reduction peak currents are linearly dependent on the concentration of vitamins. Both vitamins can be simultaneously determined from the same voltammogram. The method proposed for the determination of riboflavin and folic acid in multivitamin tablets is very simple, rapid and does not involve time-consuming separation steps. The average contents of riboflavin and folic acid were found to be 14.8 ± 1.26% and 1.46 ± 2.66%, for tablet A and 9.86 ±1.40% and 1.47 ± 2.0% for tablet B, respectively.

Animal species and muscle related differences in thiamine and riboflavin contents of Swiss meat

Animal species and muscle related differences in thiamine and riboflavin contents were studied in pork, chicken, veal and beef. Pork was the best thiamine source and there was no significant difference in thiamine content of longissimus dorsi and shoulder muscles. Also, no difference in thiamine content of chicken breast and thigh was found. In contrast, the riboflavin content significantly differed between the muscles within species (pork and chicken) examined. With the average daily lean meat consumption in Switzerland (105 g day −1), thiamine and riboflavin intakes were approximately 0.5 mg day −1 and 0.2mgday −1, respectively. The recommended daily thiamine intake was met up to 25% for men and 29% for women. Pork itself contributed about 23% (men) and 27% (women). The recommendation for riboflavin intake was met up to 10% for men and 11% for women.

Effect of germination on the thiamine, riboflavin and niacin contents in legumes

The effect of germination on the thiamine, riboflavin, as well as the available and total niacin contents in two varieties of lentils (Lens culinaris, var. vulgaris, Lens culinaris, var. variabilis) and faba beans (Vicia faba, L., var. major) were investigated. Germination of the three legumes, carried out for 6 days at 20 °C in the dark and with daily rinsing, led to a significant reduction of the thiamine content and a significant increase of the riboflavin as well as the total and available niacin contents. For Lens culinaris, var. vulgaris the effect of different conditions during the germination procedure (light, time and number of rinses) on water-soluble vitamins was studied. The presence or absence of light had no significant effect on the thiamine and riboflavin contents in germinated lentils, while the niacin content was higher when germination was conducted in the light. The increased number of rinses during the germination process had no significant effect on the thiamine content in lentils, whereas a significant decrease in the riboflavin and available niacin contents was observed, except for riboflavin when germination was carried out for 6 days and for available niacin when germination was carried out for 3 days without light, where no significant changes were detected. A longer germination time led to a recovery of the decrease in the thiamine content that was observed to occur during the initial period of germination, and significant increases of the riboflavin and available niacin contents in lentils, independently of other conditions (light and number of daily rinses), were observed. When germination was carried out for 10 days in the dark and with daily rinsing, maximal increases of the riboflavin and available niacin contents with minimal decreases in the thiamine content were observed.

Removal of Vitamin and Trace Mineral Supplements from Broiler Finisher Diets

In one experiment, supplemental vitamins and trace minerals were removed from a 20% CP corn-soybean meal broiler diet during the period 35 to 42 days posthatching. Vitamin and trace mineral withdrawal reduced daily weight gain and slightly decreased the bio-available riboflavin content of breast and thigh muscle. Another experiment involved removal of supplemental riboflavin, only, from broiler diets during the periods 8 to 22, 22 to 42, or 42 to 56 days posthatching. Only during the first period did riboflavin removal reduce weight gain and feed efficiency. Feeding at 18% CP diet with no supplemental riboflavin during the 42 to 56-day period caused a 43% reduction in bio-available riboflavin in breast muscle.

In vitro protein digestibility and content of thiamin and riboflavin in extruded tarhana, a traditional Turkish cereal food

Tarhana, a traditional Turkish yogurt-wheat flour mixture, was extruded using a twin-screw extruder. The effects of extrusion variables and post-extrusion process on the in vitro digestibility (PD) of the protein and contents of thiamin and riboflavin in the extruded samples were measured and the results were compared with those of an unextruded control sample. The changes in barrel temperature (60–120°C), feed rate (10–20 kg/h, wb) and screw speed (10–300 rpm) did not have any significant ( p > 0.05) detrimental effect on the PD and thiamin and riboflavin contents of tarhana at constant moisture content (43%, wb). However, oven-drying at 55 °C for 48 h after extrusion caused approximately 30% thiamin losses in the samples while the in vitro protein digestibility and riboflavin content of the samples did not change significantly ( p > 0.05).

The fate of thiamin and riboflavin during the preparation of couscous

Couscous is an agglomerated and steamed product usually made from durum semolina. The processing of couscous consists of traditional or commercial manufacture followed by preparation in the home prior to consumption. The proximate and particle size analysis of five traditional and four commercial samples is given. Characteristically, the commercial samples were less homogeneous than the traditional ones. The initial thiamin content for both sets of samples was similar (0.26 ± 0.07 mg/100 g and 0.22 ± 0.02 mg/100 g). The riboflavin content of the traditional sun-dried samples tended to be lower than that of the commercial samples (0.037 ± 0.006 g/100 g and 0.066 ± 0.01 μg/100 g). Average losses during steaming amounted to 15.4 ± 2.7% for thiamin and 36.1 ± 5.7% for riboflavin. It is suggested that eye problems common in supra-Saharan Africa are caused by the sun-drying of couscous which is the cereal staple.

Proximate composition and mineral content of selected Tanzanian vegetables and the effect of traditional processing on the retention of ascorbic acid, riboflavin and thiamine.

Proximate composition, mineral content and the effect of traditional processing practices on the retention of ascorbic acid, riboflavin and thiamine were studied using amaranth, cowpea, peanut, pumpkin and sweetpotato leaves. Results of this study indicated that, crude protein, crude fat, carbohydrate and ash contents were in the range of 20.64--46.56 percent, 2.57--4.34 percent, 35.43--63.50 percent and 8.92--15.69 percent respectively. The mineral content per 100 g of fresh vegetables was in the range of 83.64--229.34 mg, 145.97--780.19 mg, 11.5--2l.31 mg, 43.02--110.30 mg, 0.96--5.90 mg and 0.40--2.24 mg for Ca, K, Na, Mg, Fe and Zn respectively. For ascorbic acid, riboflavin and thiamine, concentrations in 100 g of fresh vegetables were in the range of 43.78--89.00 mg, 0.62--1.71 mg and 0.09--0.30 mg respectively. The traditional processing practices of sun/shade drying and storing in ventilated containers resulted in a significant (P <0.05) decrease in ascorbic acid, riboflavin and thiamine for all vegetables. Conventional blanching and cooking for up to 15 minutes resulted in a significant (P <0.05) increase in riboflavin content in cowpea, peanut and pumpkin greens while in amaranth and sweetpotato leaves, thermal processing resulted in a significant (P <0.05) decrease in the vitamin. Based on the results of this study, the vegetables were good dietary sources of minerals, carbohydrate and protein.

Chemical, nutritional and sensory evaluation of green beans fermented with and without starter culture.

Two varieties of green bean locally known as Binz and Mangtout were fermented with and without starter culture. During fermentation pH changes, total reducing sugars, total acids, thiamine, riboflavin and protein contents were determined. After the pH of the beans had fallen to below 4.0 the beans were pasteurized and sensory evaluation was carried out to assess the taste, texture, aroma and overall acceptability using a 5 point hedonic scale. The pH of the beans fermented with starter culture fell to below 4.0 after 4 days whereas the samples fermented without starter culture took 8 days. In both cases a sharp decrease in sugars and increase in acids were observed within the first two days of fermentation but samples fermented without starter produced significantly less acids. Although there was a significant decrease (p < 0.05) of the vitamins and protein with fermentation period, there were no significant differences between samples fermented with and without starter culture. Overall both varieties produced acceptable fermented products but samples fermented without starter culture were more acceptable than those fermented with starter culture.

Chemical composition of cyanobacteria grown in diluted, aerated swine wastewater

The chemical composition of Spirulina maxima and Phormidium sp. biomasses grown on pretreated and diluted swine wastewater was determined. Analyses were carried out on lyophilized samples and compared with data from mineral media (controls). Analyses of Phormidium grown on aeration-stabilized wastewater (ASSW) were: protein (N × 6·25) 62%, lipids 11%, carbohydrates (calculated by difference) 16%. For Spirulina in the same effluent, data were: protein 36%, lipids 6% and carbohydrates 44%. No crude fiber was found in any of the samples. The fatty acid profiles of both biomasses showed important differences when compared to controls. The biomasses contained all the essential amino acids. The Spirulina biomass had a significantly higher content of pyridoxine, riboflavin and pantothenic and nicotinic acids than Phormidium when grown on ASSW, but in general the vitamin content of both biomasses was practically the same as their respective controls. The results suggest that Phormidium and Spirulina biomasses could be used as dietary supplements in animal feed, but further studies are needed to determine the nutritional value of the product.

Riboflavin-sensitized photooxidation of ascorbic acid: kinetics and amino acid effects

The study on the effects of riboflavin contents and light intensity on the riboflavin-sensitized decomposition of ascorbic acid indicated that light and riboflavin accelerated the decomposition of ascorbic acid. The relative photosensitizing activity of riboflavin, methylene blue and protoporphyrin IX was 21:15:1 at 1–2 ppm. The rate constants for reaction of ascorbic acid with singlet oxygen at pH 7·5, 6·0 and 4·5 were 6·63 × 10 8, 5·77 × 10 8 and 5·27 × 10 8 M −1 s −1, respectively. Cysteine showed strong antioxidant activity on both riboflavin- and methylene blue-sensitized photooxidation of ascorbic acid and its antioxidant effect was concentration-dependent. Alanine and phenylalanine at 0·1% concentration showed antioxidant effects on the riboflavin-sensitized photooxidation of ascorbic acid but prooxidant effects on the methylene blue-sensitized photooxidation. Tyrosine (0·1%) exhibited strong prooxidant activity on both the riboflavin- and methylene blue-sensitized photooxidation of ascorbic acid. However, tryptophan (0·1%,) showed antioxidant or prooxidant activity on the photooxidation of ascorbic acid depending on the storage time.

Thiamine and Riboflavin Contents in Finnish Pig, Heifer, and Cow Livers and in Pork Loin

Thiamine and riboflavin contents were determined in Finnish pig, heifer, and cow livers and in pork loin. The average thiamine contents were 0.33 ± 0.02 mg/100 g fresh weight (FW) in pig liver, 0.22 ± 0.02 mg/100 g FW in heifer liver, and 0.24 ± 0.02 mg/100 g FW in cow liver. Pork loin contained 1.10 ± 0.15 mg/100 g FW thiamine on average. Average riboflavin contents were 2.69 ± 0.13 mg/100 g FW in pig liver, 2.56 ± 0.16 mg/100 g FW in heifer liver, and 2.67 ± 0.18 mg/100g FW in cow liver. Pork loin contained 0.14 ± 0.01 mg/100 g FW riboflavin on average.

Determination of thiamine (vitamin B,) and riboflavin (vitamin B2) in meat and liver by high-performance liquid chromatography

HPLC methods described so far for the determination of thiamine and riboflavin in meat samples have used mostly fluorescence detection. The aim of this work was to elaborate a suitable method with UV detection for this purpose and to compare the thiamine and riboflavin contents obtained for meat and liver samples from various pig groups. Homogenized spare rib, chop, ham and fiver samples were treated with acid and heated (at 121°C, 30 min), followed by enzymatic digestion to release the vitamins. After a clean-up procedure the simultaneous determination of thiamine and riboflavin was performed with a Nucleosil ODS (3 μ m) packed column at 45°C. The mobile phase was phosphate buffer (pH 3.0)-acetonitrile (84:16, v/v) containing 5 m M sodium heptanesulphonate. The relative standard deviation was 5% for thiamine and 12% for riboflavin in meat and 8% for thiamine and 5% for riboflavin in liver for four parallel determinations.

Thiamine and Riboflavin Contents of Finnish Breads and Their Corresponding Flours

Thiamine and riboflavin contents were determined in breads from six large-scale and three small-scale bakeries in Finland. Thiamine content of French bread ranged from 0.28 to 0.54 mg/100 g fresh wt with an average of 0.45 mg/100g, and riboflavin content ranged from 0.07 to 0.10 mg with an average of 0.08 mg/100 g. Thiamine content of rye bread ranged from 0.20 to 0.25 mg/100 g and riboflavin content ranged from 0.09 to 0.12 mg/100 g. Thiamine content in oat breads ranged from 0.21 to 0.43 mg/100 g with an average of 0.36 mg and riboflavin content from 0.08 to 0.18 mg with an average of 0.10 mg. Freezing did not significantly affect the thiamine and riboflavin contents of bread. Thiamine and riboflavin contents were also determined in pooled flour and corresponding bread samples. Thiamine content ranged in rye bread from 56 to 76%, in French bread from 58 to 75%, in coffee bread from 51 to 73%, and in oat bread from 52 to 66% of the thiamine content in corresponding flours, respectively. Different thiamine contents in breads among bakeries were mostly due to differences in the thiamine contents of flours. Riboflavin content in breads was not dependent only on the riboflavin content of the flour. Riboflavin content was usually lower in the flour than in the bread, except for rye bread, for which the riboflavin content was higher in the flour.

Vitamin C and riboflavin content in camels milk: effects of heat treatments

Vitamin C and riboflavin content in dromedary camels milk and in milk heated at 63, 80, 90 and 100°C for 30 min, 73°C for 15 s and 90°C for 10 min were studied. Results showed that the levels of vitamin C and riboflavin in raw camels milk were 24.9 ± 2.75 and 0.56 ± 0.11 mg/kg and in cows milk were 14.3 ± 1.12 and 1.84 ± 0.16 mg/kg, respectively. Heating of camel milk at 63, 80, 90 and 100°C for 30 min results in a loss of vitamin C content of about 27, 41, 53 and 67%, respectively. The corresponding figures for cows milk were 18, 26, 36 and 48%. However, the heat treatments caused a negligible amount of destruction (0–7%) of the riboflavin content in camels and cows milk.

Riboflavin, α-tocopherol and retinol retention in milk after microwave heating

5ummary The effect of microwave heating during 2-4 min on the riboflavin, a-tocopherol and retinol content of milk, with three different fat levels, was studied by HPLC. The riboflavin content was not significantiy modified by this treatment. Heating during 2 min did not modify the atocopherol content of whole milk, but in the case of low fat milk, the a-tocopherol content significantly decreased. The effect on the retinol content was less pronounced but still significant (P < 0.05). Further heating (up to 4 min) did not modify the vitamin content in any case.