Loss Of Riboflavin Research Articles

Shelf life of whole pasteurized milk in Greece: effect of packaging material

Chemical, microbiological and sensorial changes in whole pasteurized milk stored under fluorescent light at 4 °C in 500 ml bottles, made of: (a) multilayer pigmented [HDPE + 2% TiO 2/HDPE + 4% carbon black/HDPE + 2% TiO 2], 550–600 μm in thickness, (b) monolayer pigmented [HDPE + 2% TiO 2], 550–600 μm in thickness, (c) clear PET, 300–350 μm in thickness and (d) pigmented [PET + 2% TiO 2], 300–350 μm in thickness, were monitored for a period of 7 days. Milk packaged in coated paperboard cartons and stored under the same experimental conditions served as the “control” sample. Data were obtained for lipid oxidation, lipolysis, proteolysis, vitamin A and riboflavin contents, microbial growth including mesophilic and psychrotrophic counts and sensorial attributes (odour and taste) of whole pasteurized milk. Results showed satisfactory protection of milk packaged in all packaging materials with regard to microbiological and chemical parameters assessed over the 7 day period. Vitamin A losses, recorded after 7 days of storage, were, respectively, 8.8%, 10.5%, 29.8%, 50.9% and 14.0% in samples packaged in multilayer HDPE, monolayer HDPE, pigmented PET, clear PET bottles and control samples. Respective losses of riboflavin were 18.4%, 20.6%, 30.9%, 47.1% and 19.8%. Based on organoleptic analysis, the shelf life of whole pasteurized milk in Greece is 5 days. The best overall protection to the product was provided by the multilayer and monolayer pigmented HDPE bottles at a thickness of 550–600 μm. Such packaging materials are currently finding their way into the fresh milk packaging market.

Light-induced quality changes in plain yoghurt packed in polylactate and polystyrene

The potential of using materials based on polylactate (PLA) for packaging of plain yoghurt has been demonstrated in the present study. Plain yoghurt (3.5% fat) was stored for 5 weeks in PLA or polystyrene (PS) cups under fluorescent light (3500 lux) or in darkness. Quality changes were studied by determination of color stability, formation of lipid hydroperoxides, development of volatile products (secondary oxidation products and release of styrene and lactate from the packaging materials) and degradation of β-carotene, and riboflavin was determined. For light-exposed yoghurts, PLA was at least as effective in preventing color changes and formation of lipid hydroperoxides as PS. During storage under fluorescence light, concentrations of n-hexanal, n-heptanal, n-octanal, n-nonanal, 3-methyl-butanal, dimethyl disulfide, and 1-octen-3-ol were lower in yoghurts packed in PLA than in PS. Furthermore, losses of riboflavin and β-carotene were less in light-exposed yoghurt packed in PLA than in PS. The amount of styrene in yoghurt stored in PS cups increased during storage, whereas lactate was not found in yoghurts stored in PLA. Practically no development of lipid hydroperoxides and secondary oxidation products or loss of riboflavin and β-carotene were observed in yoghurts stored in darkness. Thus, it can be concluded that light exposure reduced the quality of plain yoghurt and that PLA provided a better protection against photo-degradation processes than PS.

Limiting light‐induced lipid peroxidation and vitamin loss in infant parenteral nutrition by adding multivitamin preparations to Intralipid

Parenteral lipids are susceptible to light-induced peroxidation, particularly under phototherapy. Ascorbic acid is protective. The aim of this study was to investigate whether dark delivery tubing and/or coadministration of multivitamin preparations could prevent peroxidation of Intralipid without undue vitamin loss. In experiments carried out on the benchtop, lipid peroxidation occurred in ambient light and was more extensive under phototherapy. Dark tubing decreased peroxide formation, but only by about 65%. In simulated clinical conditions in which solutions were pumped through standard clear or dark minibore plastic tubing. Intralipid accumulated lipid peroxides as measured by the FOX assay (280 microM) or as triglyceride hydroperoxides (52 microM). Multivitamin preparations (MVIP or Soluvit/Vitlipid) inhibited peroxide formation almost completely, and were fully protective when used with dark tubing. There was loss of riboflavin (65% from Soluvit and 35% from MVIP) in clear tubing but this was decreased to 18% and 11%, respectively, in dark tubing. Ascorbate loss was 20% (MVIP) and 50% (Soluvit) and only slightly less in dark tubing. Ascorbate loss was also seen in the absence of Intralipid and is due to riboflavin-induced photo-oxidation. Multivitamin preparations protect Intralipid against light-induced formation of lipid hydroperoxides, and administering multivitamins with Intralipid via dark delivery tubing provides a practical way of preventing peroxidation of the lipid while limiting vitamin loss. This procedure should be considered for routine use as well as with phototherapy.

Modification of vitamins B1 and B2 by culinary processes: traditional systems and microwaves

Abstract Loss of thiamin and riboflavin is studied in Swiss chard and green beans. The processes of boiling and boiling and frying lightly in two systems, traditional and microwaves, both cause loss of these two vitamins, but vitamin B 1 shows a higher loss in traditional boiling. Leaching of both vitamins into the boiling water occurs and, in general, Swiss chards show higher leaching losses, mainly in the traditional system.

STABILITY OF B-VITAMINS IN MEATS PREPARED BY FOODSERVICE. 2. RIBOFLAVIN

The influence of foodservice preparation techniques on the riboflavin content in beef, pork and chicken cuts was studied, and its stability after preparation methods compared to steam/convection oven preparation methods has been evaluated. For that, the samples were grilled, fried, roasted and cooked without being immersed in water, using a steam/convection oven and traditional equipment. Results by HPLC have shown that the stability of riboflavin varied (69.3% to 91.4%; 71.8% to 92.7% and 60.1% to 92.3% in beef, pork and chicken, respectively). For most of the preparation techniques used, a higher vitamin stability in the meats was associated with the use of the steam/convection oven. Riboflavin losses were clearly associated with the moisture losses and with the meats cuts preparation conditions, specially type of traditional equipment used, cooking time and temperature.

Light-induced vitamin deficiency in Drosophila melanogaster.

Illumination by visible light (400 Ix) of cultures containing larvae of Drosophila melanogaster can reduce survival (Bruins et al., Insect Biochemistry 21:535-539, 1991). Here we show that the effect of light depends on the presence of propionic or acetic acid in the food medium. We also show that survival is far more affected by illumination of the yeast food media than by direct illumination of the eggs and developing larvae. It is shown that addition of antioxidants to the food prevents light induced mortality. The action of antioxidants suggests that free radicals are important in light induced mortality. We also showed that both yeast and riboflavin (vitamin B2) solutions illuminated with visible light (400 Ix) generate hydrogen peroxide. Other vitamin and amino acid solutions do not produce peroxide in measurable amounts. However, the concentration of photogenerated hydrogen peroxide is far too low to explain the death of eggs and developing larvae upon exposure to light. A 400 Ix light treatment destroys the capability of yeast food media to support survival of larvae. Addition of vitamin C, carotene, tryptophan, nipagin, uric acid, or sucrose to the light treated medium does not restore viability. It is restored when riboflavin is added to the photo-inactivated yeast. A high concentration of pyridoxine also produced an improvement in survival. When riboflavin is treated with light, it cannot support survival on synthetic food media nor can it restore survival on light treated yeast food media. These results show that riboflavin (or a derivative) is a major light sensitive compound of yeast, which can be degraded by light. Light induced loss of riboflavin leads to mortality, because this is an essential dietary vitamin. The vitamin degradation can be prevented by dietary antioxidants. A chromatographic analysis confirms this conclusion.

Cowpea Flour Vitamins and Trypsin Inhibitor Affected by Treatment and Fermentation with Rhizopus microsporus

ABSTRACTSoaking cowpeas (25°C, 24 hr) decreased folacin content but did not affect thiamin, niacin, and riboflavin. Boiling soaked seeds for 45 min sharply decreased thiamin, folacin, niacin, and riboflavin. Losses of folacin, niacin, and riboflavin were recovered during fermentation. Soaking reduced trypsin inhibitor activity (TIA) by ∼20%, whereas boiling of soaked seeds decreased TIA by ∼85%. A slight increase in TIA occurred in soaked, cooked cowpeas after 18 hr fermentation.

Gamma Irradiation Effects on Thiamin and Riboflavin in Beef, Lamb, Pork, and Turkey

ABSTRACTA study was made of the loss of thiamin and riboflavin due to gamma irradiation of beef, lamb and pork longissimus dorsi, turkey breast and leg muscles. Thiamin losses averaged 11%/kiloGray (kGy) and riboflavin losses 2.5%kGy above three kGy. The rate of loss of thiamin in beef was higher than that in lamb, pork and turkey leg, but not turkey breast. with losses of 16%/kGy in beef and 8%/kGy in lamb. The rate of thiamin loss was not related to sulfhydryl, protein, moisture, fat or water content, pH or reducing capacity by redox titration. Loss of riboflavin was not different among species. Any detriment from such slight losses would seem to be more than compensated by the advantage of controlling bacteriological contamination by irradiation processing.

Stability of vitamins in soybean oil fat emulsion under conditions simulating intravenous feeding of neonates and children.

The stability of the fat-soluble vitamins and thiamine, riboflavin, pyridoxine, ascorbate, and folic acid when administered as part of Intralipid 10% was evaluated. Intravenous pediatric vitamin formulations (Vitalipid N Infant and Soluvit Infant) containing the daily dose for term neonates were diluted with Intralipid to final volumes of 12.5 mL or 260 mL. The volumes were then delivered for 24 hours via dihexylethyl-phthalate-free in vitro infusion systems that simulated clinical conditions. The first vitamin-Intralipid admixture (12.5-mL volumes) was pumped (by syringe) during 24 hours through neonatal infusion sets placed in an incubator (37 +/- 1 degree C, bilirubin light). Aliquots were collected at the beginning of the experiment and after 24 hours of infusion. The second admixture (260-mL volumes) was pumped (by a peristaltic pump) through infusion sets during 24 hours and was exposed to periodic indirect sunlight and to continuous fluorescent light to stimulate the feeding of a child. Aliquots were collected at 0, 8, and 24 hours during administration of the admixtures. The vitamin concentrations were measured by high-performance liquid chromatography. The effect of the vitamins on the stability of the emulsion was also assessed by visual inspection, lipid globule size distribution, and pH change. Losses of vitamins vary from different experimental conditions and were for the fat-soluble vitamins essentially nil, except for phylloquinone, which was 5% to 17% below the initial level. Thiamine, pyridoxine, and folic acid were stable. Losses of riboflavin and ascorbate amounted to 10% to 20% and 9% to 52%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of light on the vitamin B2 and the vitamin A content of cheese.

Edam type cheese was exposed to sunlight at ambient temperature and to fluorescent light at 5 degrees C. The loss of vitamin B2 (riboflavin) and vitamin A was monitored in both the surface and inner layers of the cheese and the results compared with control samples kept in the dark. The loss of riboflavin when exposed to sunlight was shown to be primarily a surface effect but losses of vitamin A were similar throughout the cheese. When exposed to fluorescent light at 5 degrees C and monitored at intervals for 10 days the loss of riboflavin was still greatest at the surface but a trend to lower values than the control was evident throughout the cheese. Vitamin A losses followed a different pattern in both sunlight and fluorescent light. There was a heavy initial loss throughout the cheese. Under fluorescent light this was followed by a period in which further loss was mainly in the surface layer. Vacuum packaging reduced the loss of riboflavin but had no effect on the loss of vitamin A.

Determination by HPLC of changes in riboflavin levels in milk and nondairy imitation milk during refrigerated storage

Riboflavin, a water-soluble light-sensitive vitamin, was determined in milks and nondairy imitation milks, by HPLC with ultraviolet-visible detection. The riboflavin content ranged from 1·16 to 1·31 μg ml −1 in cows' milk, and from 1·33 to 1·44 μg ml −1 in nondairy imitation milks. When the opened containers were stored in a refrigerator at 8°C, in the dark, the loss of riboflavin in cows' milk samples ranged from 16·0 to 23·4%, and nondairy imitation milk samples ranged from 12·5 to 16·5% of the initial values.

Kinetic analysis of the loss of some B-vitamins during the cooking of macaroni.

The kinetics of the losses of thiamin, niacinamide, and riboflavin were investigated during the cooking of macaroni at 50, 75, 80, 85, and 90 degrees C. Simultaneous analysis of the vitamins was achieved by HPLC using a mu-Bondapak column. The activation energies for the losses of thiamin, niacinamide, and riboflavin were determined as 25 kJ/mol, 22 kJ/mol, and 11 kJ/mol, respectively. It was concluded that the leaching of these vitamins into cooking water was the main pathway for their loss during macaroni preparation.

Microwave Heating of Infant Formula: A Dilemma Resolved

Microwave heating of infant formula is a common practice despite concerns of infant scalding. Beyond the issue of physical safety, little is known about the effects on nutrient content of microwave heating of infant formula. Casein-predominant infant formula in 120- and 240-mL glass and plastic nursing bottles of varying colors were heated for 40 seconds and 60 seconds, respectively. Temperature profiling was monitored during the heating cycle. Analysis of riboflavin and vitamin C was made prior to and after heating. Topmost portions reached a mean temperature of 44.7 +/- 1.7 degrees C and 43.0 +/- 2.4 degrees C for all types of 240-mL and 120-mL bottles, respectively. Topmost temperatures were significantly hotter than temperatures reached at other sites. Routine mixing resulted in formula temperatures which could safely be fed to infants (35.4 +/- 0.3 degrees C and 33.9 +/- 0.2 degrees C for 240-mL and 120-mL bottles, respectively). There was no significant loss of either riboflavin or vitamin C. Protocols for microwave heating are given.

EFFECTS OF OVEN TEMPERATURE AND TIME ON THE LOSSES OF SOME B VITAMINS IN ROASTED BEEF AND PORK

The study was carried out to enumerate the effect of thermal process variables on the losses of some B vitamins and moisture from roasted beef and pork of various sizes in a hot air oven. The roasting temperature and time of both samples were varied from 100-160°C and 15 min to 1 h, respectively. Thiamin losses were between 20-40% (0.116-0.232 mg/100 g) in pork and between 15-25% (0.006-0.011 mg/100 g) in beef at the same period. The loss of riboflavin was between 10-25% (0.019-0.047 mg/100 g) in beef when compared with the 15-40% (0.023-0.061 mg/100 g) in pork. Niacin was more stable than other vitamins at all temperature-time combinations used. The losses of niacin ranged from between 5-10% (0.193-0.386 mg/100 g) in beef and 10- 16% (0.431-0.689 mg/100 g) in pork. Also, moisture losses from pork (22-45%) were greater than from beef (15-30%) during the same period of roasting. Generally, the losses of thiamin and riboflavin appeared to be closely dependent on both heat and loss of moisture (or drip) and sample size. However, the values of niacin losses were considerably less than thiamin, riboflavin and moisture losses, and no strong dependence of niacin loss on heat was observed. The results also confirmed higher retention of these vitamins as the ratio of the mass of meat to its exposed surface area increases.

Effect of Gamma Irradiation on the B Vitamins of Pork Chops and Chicken Breasts

A study was made of the effect of low-dose gamma irradiation on the content of thiamine (B1), riboflavin (B2), niacin, pyridoxine (B6) and cobalamin (B12) in pork chops, and thiamine, riboflavin and niacin in chicken breasts. Gamma irradiation from a caesium-137 source was used to irradiate the samples in a range of 0.49 to 6.65 kGy from -20 to +20 degrees C. Over the range of dose and temperature studied it was possible to derive a mathematical expression for predicting the losses. A calculation was made of the effect of the loss of thiamine, riboflavin and niacin due to irradiation on the overall loss of these vitamins in the American diet. The losses of riboflavin and niacin were of the order of a fraction of a per cent. Pork is an important source of thiamine, but the calculated loss at 1.0 kGy of this vitamin in cooked pork was only 1.5 per cent. There were initial increases with radiation doses up to 2-4 kGy in the measured concentrations of riboflavin and niacin in both pork and chicken. The increases were highly significant, and are of concern both to the study of radiation effects and the chemical method of the determination of these two vitamins.

Industrial processing of palm juice and riboflavin loss

The effect of processing or season, or exposure to atmospheric temperature on riboflavin content of industrially bottled palm juice was studied. Losses occurred in riboflavin content throughout the processing stages but loss was more pronounced after the filtration stage. The pasteurized palm juice contained about 60% of the initial riboflavin while the riboflavin content of fermenting palm juice increased significantly (P < 0·01) with time of exposure. Losses occurred in pasteurized ‘non-fermenting’ samples similarly exposed. On the other hand, losses were not observed in pasteurized samples stored in the dark for 6 weeks. Sun-inactivation may explain the significantly lower riboflavin content of samples processed in the dry compared to those processed in the rainy season. Findings from the study suggest that the nutritional value of processed palm juice may be raised if fermentation is allowed to proceed for 10 h before processing commences. Also, synthetic riboflavin may be incorporated at the pasteurization stage in non-fermenting juice.

Effect of Processing and Storage Conditions on the Fate of Vitamins B1, B2, and C and on the Shelf‐Life of Goat's Milk

ABSTRACTGoat's milk was heat‐processed under different time‐temperature conditions of pasteurization and sterilization. Losses of thiamin, riboflavin, and total vitamin C in HTST, Flash, and UHT were less than that by LTLT and Autoclave. Also residual oxygen in the milk affected the loss of total vitamin C during storage. A longer shelf‐life of pasteurized milk was obtained with HTST, HTST overpasteurization, and Flash process; however, there was no significant difference between UHT and Autoclave sterilized products. From the above results, HTST pasteurization was considered the best process to preserve milk quality.

Effect of Agitation, Sampling Location and Protective Films on Light‐Induced Riboflavin Loss in Skim Milk

ABSTRACTPhotodegradation of riboflavin in skim milk as influenced by continuous agitation, location within the container and protective films was studied. High performance liquid chromatography was used to monitor the riboflavin concentration in the milk. Retention of riboflavin in light‐exposed, continuously agitated milk samples was significantly lower than in unagitated samples. Sampling positions within blow‐molded polyethylene milk containers also had a significant effect on light‐induced riboflavin loss. After 5 days of light exposure, riboflavin retention at the top of the unagitated milk containers averaged 58% compared to 92% retention for milk located at the bottom of the containers. Metallized‐oriented, polyethylene‐terephthalate films used as overwraps decreased penetration of visible light into milk samples and decreased the riboflavin photodegradation.

Effect of Fluorescent Light on Flavor and Riboflavin Content of Milk Held in Modified Half-Gallon Containers

A study was conducted to evaluate the ability of aluminum and oriented polypropylene film to protect milk in half-gallon polyethylene containers from light radiation and thereby stabilize it from light-induced off-flavor (LIOF) and riboflavin loss. Both films, applied to the major portion of the outer surface of the containers, protected milk from light radiation better than when applied only to the container top.

Influence of Milk Fat, Milk Solids, and Light Intensity on the Light Stability of Vitamin A and Riboflavin in Lowfat Milk

Retinyl palmitate and riboflavin were quantified in milk samples exposed to fluorescent light. Effects of compositional factors were determined by comparing rates of loss of riboflavin and vitamin A in milks with different amounts of milk fat and milk solids. Upon exposure to fluorescent light, rates of vitamin A and riboflavin loss were lower in whole milk than in skim milk. Riboflavin degraded more slowly in skim milk with 1% added nonfat dry milk than in skim milk with no added solids. No additional protective effect for riboflavin was found when added solids were increased from 1 to 3%. Compared with milk with no added solids, 1% added nonfat dry milk did not increased protection for vitamin A, but a protective effect was noted when the skim milk was fortified with 3% nonfat dry milk. Increasing light intensity increased the rates of loss of both vitamins, and riboflavin was lost at a greater rate.