Light, Riboflavin Degradation And Their Interaction In Milk

Amazoniac

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Food Packaging: Principles and Practice
Gordon L. Robertson

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Food Packaging and Preservation
M. Mathlouthi

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Destruction of Riboflavin in Milk by Light | Nutrition Reviews | Oxford Academic
Photo, thermal and chemical degradation of riboflavin

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For those that are wondering about @haidut and his Energin, I think that he has already been trying to find an opaque bottle for some time now, and the reason why he didn’t change it immediately was to make sure that it’s reliable in a sense that it doesn’t leach anything known as unsafe.

Powdered b vits is also an option because they tend be more stable since those degradations usually occur faster in water.
@healthnatura
 
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Amazoniac

Amazoniac

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RF is among the most widely studied compounds in terms of photostability and degradation in aqueous and organic solvents. It shows strong absorption at 223, 267, 373 and 444 nm in the UV and visible regions in aqueous solution and is degraded into various photoproducts on exposure to light [1].
Around 30% of RF is destroyed by sunlight in milk within only 30 minutes of exposure [63]. In the dark, RF is stable and remains unchanged under specified conditions for prolonged periods of time [11,36,64]. In the dry form, RF is not much affected by light while in the solution form it is rapidly degraded to various photoproducts through a variety of reactions under aerobic and anaerobic conditions [11,14,15,18,20,21,23-35,65].
A comparison between UV and visible radiation sources for the photodegradation of RF has been made by Ahmad et al. [24,26]. Similar photoproducts were formed when the aqueous solutions of RF were exposed to either of the radiation source, however, the rate of reaction was higher on UV irradiation as compared to that of the visible irradiation. Similarly, the magnitude of the formation of the photoproducts was higher in solutions exposed to UV light as compared to the visible light. The difference in rates might be due to the higher intensity of the UV radiation (medium pressure mercury vapor lamp, 125 W), i.e., 2.19 ± 0.12 × 1018 quanta s−1 as compared to the visible sources (high pressure mercury vapor fluorescent lamp, 125 W and tungsten lamp, 150 W), i.e., 1.14 ± 0.10 × 1017 and 1.06 ± 0.11 × 1016 quanta s−1, respectively [24,26]. Previously it was reported by Sattar et al. [72] that the wavelengths in the range of 350–520 nm are damaging to RF solution especially in the range of 415–455 nm [11,72]. However, the method of analysis performed by these workers was not selective as that of Ahmad and Rapson [34] and Ahmad et al. [24,26], and therefore, an accurate determination of the vitamin content may not have been made to assess the rate of degradation.
The pH of the solution has a significant effect on the photostability of RF. Under acidic and neutral pH conditions, RF is photodegraded to LC whereas in alkaline media it forms LC along with LF. [..] LC and LF are non-volatile and are biologically inactive [10,11,59]. They also degrade under light once they reach their respective maximum concentrations at various pH values. However, LC is more stable at lower pH than at a higher pH [36], probably due to its protonation. LF is further degraded in the alkaline solution in the pH range of 14–14.6 at room temperature
RF shows higher photostability in less polar solvents [96]. When RF was irradiated anaerobically in alcohols and alcohol/water mixtures, a slightly different photochemistry was observed which does not involve any primary photoreduction in the solvents. The major photodegradation products formed in alcohols were LC and FMF [83]. LC has also been identified as the major photoproduct of RF in various organic solvents such as acetic acid, acetone, dioxane and its mixtures with water, ethanol and pyridine [96-98]. The photodegradation of RF has been found to be more rapid in organic solvents as compared to aqueous solutions [97,99]. This could be linked to the physical properties of the solvents such as polarity, dielectric constant, viscosity, etc. [27,32,83,100,101]. The dielectric constant of the medium has been shown to affect complexation between RF and cloxacillin sodium in aqueous–ethanol media and found to decrease with an increase in temperature [102].
The use of various complexing agents is another way of RF photostabilization. Caffeine (CF) is known to form molecular complexes with RF [10,40,106-110] and thus slow down its rate of chemical [76] and photodegradation reactions [29,68].
Photodegradation of aqueous solutions of RF has already been discussed in the previous sections. However, moisture can affect the stability of RF in dried form as acceleration in the photodegradation of RF in powder and tablets has been reported [73,134]. When the RF tablets were irradiated, a color change was noted immediately which was enhanced after 24 hours of storage in ambient conditions in dark. When similar samples were stored after irradiation in a sealed container with dried silica, no further modifications were observed in the samples. The analysis of the samples indicated the presence of loosely adsorbed moisture in the RF powder [134].
Packaging material plays an important role in the photostability of RF. If RF is not packed in a suitable container even after storing at optimum conditions of pH, temperature, humidity, etc., it may degrade on exposure to light. A rapid loss of RF in milk has been reported in clear bottle or white sachet as compared to the milk packed in a brown bottle or carton [144]. Mestdagh et al. [145] performed a comparative study of RF photodegradation in milk by using four different types of polyethylene terephthalate (PET) packages. Their results indicated that the packages provided with additional light protection and triple white–black–white layers protected RF more efficiently from light exposure as compared to those with transparent appearance even if provided with a UV-absorbing additive. A similar type of RF photoprotection in milk and cheese has been reported by blocking all UV and visible excitation wavelengths by overwrapping the package [146] and storing the samples under colored filters [147] or using vacuum packaging [148]. Therefore, RF should always be stored in containers protected from air and light [1,73,149]. Alternatively, the tablets could be packed in unit dose containers or in the presence of a desiccant like dried silica to prevent moisture adsorption from the environment [73].
RF is a heat stable compound and little information is available regarding its thermal degradation in aqueous solution. However, some degradation pathways and products have been reported for the thermal destruction of RF [150-152].

The thermal degradation of RF is known to occur with a rise in temperature and exposure time [150,157-162]. When aqueous solutions of RF were heated for 40 min at 100, 120 and 150 °C, a degradation of 4, 7 and >20% was observed, respectively. Similarly, an increase of exposure time from 20 to 60 min at a constant temperature of 150 °C resulted in an enhanced thermal degradation of RF from approximately 15 to 42% [162]. [..] However, RF is thermally more stable to heat as compared to other vitamins such as thiamine and ascorbic acid [158,159].
Although RF is a thermostable substance, the temperature may greatly affect its stability if the pH of the medium is varied from the acidic to the alkaline region [11] or it is exposed to light [71,160]. Rapid destruction of RF in buffered solutions has been reported from pH 1.3–6.5 at 80 °C, pH 1.7–5.5 at 100 °C, pH 2.0–5.0 at 120 °C and below pH 1 and above pH 5.4 when heated at 121–123 °C for 1 hour [150,151].
 
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Amazoniac

Amazoniac

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That's the advantage of plastic owa glass bottles for supplements. Not only you can find completely opaque plastic bottles, but their dropper is usually attached to the container, so there's no need to keep opening it on every use and renewing the air inside..
 

Waynish

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Here's older vs a new energin - all three have been kept out of sunlight. The one in the middle is middle-aged :P
 

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milk_lover

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I have tried two brands of B2 with almost no fillers and I reacted badly to both. I am from those people that Peat mentioned could be allergic to it :(
 
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Amazoniac

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Here's older vs a new energin - all three have been kept out of sunlight. The one in the middle is middle-aged :p
For some reason they degrade very fast for me, every time, in less than 2 months. It will be nice to compare with the new bottle.
Hopefully haidut's inbox explodes with messages, so many of them that he will start shaking and sweating thinking how to answer them all without standarized replies.
But I know that it's on its way. I think that he's waiting for pboy to smell the bottle to inspect it for undesirable stuff, certifying it as safe.
 
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haidut

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For some reason they degrade very fast for me, every time, in less than 2 months. It will be nice to compare with the new bottle.
Hopefully haidut's inbox explodes with messages, so many of them that he will start shaking and sweating thinking how to answer them all without standarized replies.
But I know that it's on its way. I think that he's waiting for pboy to smell the bottle to inspect it for undesirable stuff, certifying it as safe.

Lol, thanks for the studies and the reminder. Yes, as you said, new bottles for Energin are in the works. The first batch will probably use white, less transparent bottles that I have already tested for leechables. If those seem to work then we may stay with them. I have also ordered a batch of brown plastic bottles, which should stop the degradation of B2 altogether but those will have to be tested for leechables and whether then actually leech...liquid when put under duress :): Durability is also a factor given the "stress" they endure during shipping and the old bottles are very good at that and one of the reasons we went with them.
 
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Amazoniac

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Lol, thanks for the studies and the reminder. Yes, as you said, new bottles for Energin are in the works. The first batch will probably use white, less transparent bottles that I have already tested for leechables. If those seem to work then we may stay with them. I have also ordered a batch of brown plastic bottles, which should stop the degradation of B2 altogether but those will have to be tested for leechables and whether then actually leech...liquid when put under duress :) Durability is also a factor given the "stress" they endure during shipping and the old bottles are very good at that and one of the reasons we went with them.
There's a good mechanical stress test: hire your kids and challenge them to spill the liquid by throwing the bottles on the wall or jumping multiple times on them.
 
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Amazoniac

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Food Packaging and Preservation
M. Mathlouthi
"Butter is particularly susceptible to photodegradation because it is rich in fatty acids especially unsaturated fatty acids. It contains enough riboflavin and water to dissolve the oxygen and thus to generate excited oxygen. Further factors add to the risk of photodegradation, namely low storage temperatures, which increase the solubility of oxygen, long storage times (several months) and deep penetration of light (less light scattering potential than cheese)."
 
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Amazoniac

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Food Packaging and Preservation
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"Light protection seems to be much more important than oxygen protection, particularly during the first two weeks of storage as the active yoghurt flora has a reducing effect on oxygen (redox potential). Protection against oxygen is nevertheless essential because of its synergistic effect with light. Light protection is best afforded by opaque materials (cardboard wrapped polystyrene) or brown-red materials (glass or polystyrene). Glass offers the best protection against oxygen."

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Influence of light transmittance of packaging materials on the shelf-life of milk and dairy products — a review - Springer
 
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Amazoniac

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"Raw milk or milk pasteurised at relatively low temperatures (72-75°C) is more sensitive to photooxidation than milk subjected to higher temperatures. The latter is protected by its increased content of reducing agents and the antioxidant effect of the sulfhydryl groups liberated by heat. The photosensitivity of milk depends therefore to a great extent on the temperature applied during its processing. 10,135 Today's milk pasteurisation technology aims at a mild treatment of the milk in order to preserve its natural properties. Since this increases the photosensitivity of pasteurised milk and limits its shelf life (approx. 5 days), it is particularly important to protect the milk against light. Ecological considerations should not therefore override the need for effective light protection when choosing the packaging for pasteurised milk."
 

Antonello

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"Raw milk or milk pasteurised at relatively low temperatures (72-75°C) is more sensitive to photooxidation than milk subjected to higher temperatures. The latter is protected by its increased content of reducing agents and the antioxidant effect of the sulfhydryl groups liberated by heat. The photosensitivity of milk depends therefore to a great extent on the temperature applied during its processing. 10,135 Today's milk pasteurisation technology aims at a mild treatment of the milk in order to preserve its natural properties. Since this increases the photosensitivity of pasteurised milk and limits its shelf life (approx. 5 days), it is particularly important to protect the milk against light. Ecological considerations should not therefore override the need for effective light protection when choosing the packaging for pasteurised milk."
Thank you a lot for those studies.
Because I tend to pour my milk from the refrigerator to a jar and let it sit at room temperature for as long as it get enough warm to drink it for a better digestion does it mean that during the time is in my room obviously in contact with oxygen and blue light the riboflavin content has decrease?
Also I don't understand if the study refer only for sunlight or blue light is damaging too.
And of course oxigen is inevitable, the only way to avoid oxigen would be drink it straight from the cow :)
 
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Amazoniac

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Thank you a lot for those studies.
Because I tend to pour my milk from the refrigerator to a jar and let it sit at room temperature for as long as it get enough warm to drink it for a better digestion does it mean that during the time is in my room obviously in contact with oxygen and blue light the riboflavin content has decrease?
Also I don't understand if the study refer only for sunlight or blue light is damaging too.
And of course oxigen is inevitable, the only way to avoid oxigen would be drink it straight from the cow :)
Given that milch is meant to pass directly from the mother to the fetus, it's worth doing whatever's possible to minimize damage.

The most concerning part is the one that you don't have control over. But in case the farm uses shady (?) bottles, you can pick those that are the farthest from the shelf's light source, carry them in insulated bags, and transfer it to opaque bottles with decent lids for storage (there are coated ceramic bottles if you search for it, some were maded with milch in the mind). You can pour it in those ceramic jugs if you plan to leave it outside for a while.

Your milch is whole, isn't it? The cream helps to delay these reactions.

Having light inside the refrigerator is unnecessary, there isn't much point in having it if the room already has. Not that it will be on all the time, but some have a light intensity that makes them look like a portal to heaven when open.
 

Antonello

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Given that milch is meant to pass directly from the mother to the fetus, it's worth doing whatever's possible to minimize damage.

The most concerning part is the one that you don't have control over. But in case the farm uses shady (?) bottles, you can pick those that are the farthest from the shelf's light source, carry them in insulated bags, and transfer it to opaque bottles with decent lids for storage (there are coated ceramic bottles if you search for it, some were maded with milch in the mind). You can pour it in those ceramic jugs if you plan to leave it outside for a while.

Your milch is whole, isn't it? The cream helps to delay these reactions.

Having light inside the refrigerator is unnecessary, there isn't much point in having it if the room already has. Not that it will be on all the time, but some have a light intensity that makes them look like a portal to heaven when open.
So is not just sunlight that damage the riboflavin but all the artificial light as well?
Thanks for the tips on the ceramic jugs I'll switch my glass jar for one of those that is more protective for the milk.
Yes my milk is whole and the fact that is raw...well I don't know if is more protective because it can change in taste and texture very quickly in contact with oxigen.
 
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