Fermentation - Science topic
Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.
Questions related to Fermentation
Based on the literature, some foam is hard to break down once produced at the end of the fermentation process, even adding some defoamer. According to your expertise, what kind of procedure we can use to prevent such foam? Increase internal pressure of fermenter? Decrease airflow and temperature by time?
I've encountered an unexpected issue while attempting to multiply bacteriophages from soil samples that were previously isolated. During the double-plate assay, I observed the formation of bubbles. Initially, I assumed they were typical bubbles caused by improper preparation of the culture medium. However, these bubbles exhibited an inhibition halo against Pseudomonas syringae, and over the course of three days, they have grown, burst, and given rise to new ones.
I hypothesize that this could be a contamination from a fermentative bacteria or possibly the bacteriophages themselves being carried by the bubbles. However, I'm not entirely certain. Any suggestions or insights into this phenomenon would be greatly appreciated.
Productivity in case of filamentous fungi is heavily depend upon the morphology of the fungi. But during submerged fermentation, morphology is function of impeller design, speed and orientation of the impeller, besides other factors like pH. Right now, my fermentation 3L is equipped with the fixed blade rushton impeller due to which I have observed a lot of shearing. Is there any impeller which is suitable for the fungal fermentation specifically in chemostat mode?
I am working on bioethanol production from lignocellulosic biomass. However, I require some clarification on the methods for calculating initial sugar concentration, sugar consumption rate, ethanol yield (in g/g and g/l). Could you please recommend simple calculations or protocols?
please cite some reference papers also if possible which clears this concept
How to calculate pectinase enzyme activity as, we have values of OD @540 nm obtained from DNS method of different Ph and Temp of sub merged fermentation using wheat bran and citrus peel ? please let me know the calculation of total activity and specific activity by using standard curve?
We investigate the ability of some Streptomyces isolates to produce various bioactive molecules, primarily antibiotics. We know that fermentation conditions and extraction methods are crucial at this stage. We see that many different media and techniques are used in the literature. What do you think about the most suitable medium, incubation time, and other factors for fermentation?
Respected sir/mam, the alcohol that needs seperation must be seperated within the bioreactor( no other seperate bioreactor should be used for the extraction process other than the bioreactor with organism).
During the extraction process the safety of the organism should also be ensured.
Please kindly provide us with a solution for this at the earliest convenience. Thank you!
For my research I have to optimize the growth in liquid cultures of a bacterium for which oxygen availability is very important. Long story short, there will be other factors to test later (I need decent throughput) and space is an issue, so I need/want to keep working volumes low, let's say max 10mL.
I am considering batch fermentation strategies such as the use of baffled Erlenmeyer flasks; however, they do not seem to come in volumes lower than 250mL. Pre-experiments in round 24-well plates were unsuccessful, and I know that the round base plays a big role in limiting gas exchange. I have used plastic cell culture flasks with vented caps such as the ones used for eukaryotic tissue cultures and they work very well, but they are disposable (and expensive) and I am producing a looot of waste. I was wondering if anyone has had the same issue and has used, for instance, square-base plates or similar, and if it worked. Or can you please suggest alternative strategies?
Thanks in advance.
The fermentation in question takes place in a vat of 1 cubic meter of very dense substrate and buffering the inoculum would aim at ensuring optimal pH for a longer period of time. Is it something that could be done ?
I'm very new to this field of activity.
To understand my Bioprocessing module and better, I have been reading a lot about bacterial fermentation. I came across a lot of literature that either stuck to heat induction or biochemical induction for the expression of recombinant proteins in the form of inclusion bodies. However, I have also heard and read about processes that use a combination of both. For example, perform biochemical induction at 37 degree C and after 4-5 hours increase the temperature to 42 degree C and run the process for another 9-10 hours. In such cases where a combined approach is taken, is heat induction done to promote inclusion body formation? Does increasing temperature promote better IB formation or does it allow for more prolonged expression of the recombinant protein? Hit a dead end thinking about this and would appreciate any responses. Thank you in advance.
I am in the process of setting up an industrial enzyme production facility, initially for producing poultry feed enzymes. Does anyone have a contact of where I can procure the strains for the following enzymes? I am trying not to do R&D initially as we would like to be production ready ASAP.
I am working on a project to use bacterial fermentation of proteins from plant-based resources. I was wondering if anyone comment on which lactic acid bacteria i.e. Lactobacillus helveticus or L. delbrueckii has better proteolytic activity.
Under anaerobic conditions organic acids are secreted into the culture media. Also corynebacterium glutamicum is known for producing aminoacids. I am not sure if the color change from yellow to brown and finally to purple has a biological or chemical reason. Has anyone experienced such thing?
We're making an E. coli intracellular expression product. In one batch of fermentation, OD was reduced by half within one hour, and phage contamination was found by post-electron microscopy. Subsequently, the entire fermentation system and workshop were treated, such as autoclave, formaldehyde fumigation, and ozone disinfection. Subsequent fermentation showed no contamination. But bacteriophage contamination was found again this week. Would like to ask how to do follow-up prevention? We found that the two fermentation contamination were both cultured at 30 degrees, while the intermediate culture at 37 degrees did not show contamination. Are there any temperature-sensitive phages?
Hello, so i am scaling up a 10 L biorector to 1000 L bioreactor for enzyme production using corncob-based media. The product increased, but there's a lot of excess media left in the product. So, i want to minimize the media impurities before purifying the product. What should i assess regarding this matter? Thank you
I am in the process of setting up an industrial enzyme production facility, initially for producing poultry feed enzymes. Does anyone have a contact of where I can procure the strains for the following enzymes? I am trying not to do R&D initially as we would like to be production ready ASAP.
As a guest editor of special issue on Enzyme in Biorefinery in the journal Fermentation (https://susy.mdpi.com/academic-editor/special_issues/process/1215191) I invite submission of the articles related to the theme of this special issue.
The special issue is aimed to collect articles describing role of enzymes in biorefinery processes.
Fermentation is an open access journal and hence incurs article processing charges.
Some discounts in APC are available.
I will be delighted to respond to quries in this regard.
I'm currenty transitioning into using a microplate reader. Right now, I use DNS to determinate reducing sugars from a fermentation supernatant. Recently the lab acquired a microplate reader and I would love to use it for all my analysis. Any sugestions?
Therapeutics such as probiotics exert a beneficial effect on host gut microbiota after consumption and may be capable to prevent several diseases such as Alzheimer’s disease. Fermented dairy foods, cheese whey and buttermilk whey offer suitable matrices for the growth and viability of probiotic microorganisms and are potential sources for the development of probiotic dairy-based beverages. The literature shows that the heterogeneous food matrices of non-dairy food carriers are the major constraints for the survival of the probiotics and the use of antioxidants in yogurt manufacture. Dairy consumption such as sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula need to be assessed for the content of microbial diversity. The role of fermentation, freezing/thawing, room temperature modification and probiotic shelf life may have a critical effect on the generation of LPS from gram negative bacteria that may lead to dysbiosis. The association between high fat/high cholesterol diets have been shown to be linked to the increased incidence for Alzheimer’s disease (AD). The literature shows strong evidence with relevance to changes in cholesterol metabolism and transport that is associated with AD pathogenic processes. The safety of probiotic therapy for AD patients requires investigation with relevance to the induction of dyslipidemia and the release of bacterial lipopolysaccharides and amyloid beta from gram-negative bacteria needs to be controlled in these probiotic formulations.
- The role of Microbiota in the pathogenesis of Alzheimer’s disease. https://www.researchgate.net/publication/370691497_The_role_of_Microbiota_in_the_pathogenesis_of_Alzheimer's_disease
- Food and Nutrition cause liver and brain diseases ... - Atlas of Science: Another Veiw on Sciencehttps://atlasofscience.org/food-and-nutrition-cause-liver-and-brain-diseases-with-diabe... Mar 11, 2016 –
- Bacterial Lipopolysaccharides and Neuron Toxicity in Neurodegenerative Diseases. Neurology Research and Surgery. 2018; 1(1): 1-3.
- Overnutrition Determines LPS Regulation of Mycotoxin Induced Neurotoxicity in Neurodegenerative Diseases. Int J Mol Sci.2015;16(12): 29554–29573.
- Functional Foods and Active molecules with relevance to Health and Chronic disease: Editorial. Functional Foods in Health and Disease 2017; 7(10): 833-836.
- Food Quality and Advances in Pharmacological Management Prevent Mitochondrial Apoptosis and Epilepsy Induced Stroke. Research and Reveiws: Neuroscience. 2018;2:7-9.
- Food quality induces a miscible disease with relevance to Alzheimer’s disease and Neurological diseases. J Food Research, vol. 5, pp.45-52, 2016.
India’s Green House Gas emissions calculation of livestock specifically enteric fermentation. These queries are related to -
• Methodology used to calculate emission from livestock in India
• What are the parameters used to calculate emissions from livestock – considering different - sub category of cattle and buffalo, breed, non-descript animals, feeding practices and rearing practices across India
• Emission factors – how are these arrived at for different cattle and buffalo breed including non-descript, what were the formula and sub formula used
• Details of various parameters used in the above formula and sub formula to arrive at the emission factor for each category
• Details of any model that is currently being used for emission factor estimation
• State wise enteric fermentation data for the last five years based on the emission factors currently used
• Activity Data – details of the activity data used to calculate the enteric fermentation
• How are we calculating emission for different rearing practices, stall fed, stall fed and grazing, grazing or pastoral and their details
• How are we calculating emission for the non-descript cattle and buffalo
• Are we factoring in the draught power in the emissions
• What are the factors contributing to the Uncertainty as per BUR3, what are the ongoing efforts to reduce these uncertainty
• Details of GHG inventory improvement practices adopted by the country
• Details of the effects of adaptation and mitigation actions related to productivity improvements in the livestock sector is adopted to estimate GHG emissions and its sustainability
End of last year I have developped an indirect ELISA method to detect a couple of caseins in fermentation supernatants. It worked great until a couple of weeks ago.
Since then, for each plate we are running (6 plates as of today), their are black aggregates developping after the addition of H2SO4 (stop solution). They are increasing with time starting from the addition. They are not present after incubation with TMB.
Does anybody experienced the same thing? And/or does somebody knows what it could be and how to fix it?
Thanks in advance,
If the media is placed in a shaker during the fermentation time, ethanol production increase or decreae??
So I'm running some experiments where I will need to record growth profile data, and collect samples for glucose, ethanol and volatiles analysis. My strategy is always to use use fresh cells from a plate (so, streaked in the afternoon to fresh plate, let grow overnight at 29 degrees, and inouclate pre-culture next day, 8 hours, start culture by dilution, calculating a certain Od next day based on the 2x time). When diluting the pre-culture, I assure that they are in the beggining of exponential phase, to avoid any kind of lag-phase. I send you a figure where there are curves using the same strain and same media, but with different final biomass concentrations. From my pre-culture, I also tested dilluting the strains to a culture or actually put them in the microplate reader. I observed that, from the same pre-cutlure, when cells are dilluted something happens, since on the microplate reader, where I just loaded the pre-culture directly, cells grow like in curve 1. However, this does not happen every time, as you can see in curve 1. On curve 1, cells were treated the same way as in curves 2 and 3, but they grew just fine. Additionally, we also measured glucose. As you see, on cultures where growth arrest occurs faster and earlier, glucose takes much longer to be consumed. The growth rates between all the curves, however, are equal, it's just the exit from exponentil growth that occurs earlier. Of curse, for the cutlures 2 and 3, the glucose concentration when cells shift from exponential growth is quite high. I always use same flasks, same amount of media per flask (1/5 of the volume of the flask), fresh cells, etc. I have no clue why are they exiting exponential growth so fast and early. Hope somebody can help me! Thank you in advance.
In recent years, fermentation has evolved into a prominent method for the production of bioactive peptides particularly for the development of novel nutraceuticals and functional foods. Microbial proteases breakdown protein into peptides during fermentation, but what happens to the other non-protein components of the fermentation medium? Can microorganisms be grown solely on protein substrate? Milk fermentation, for example, results in the breakdown of milk proteins into peptides; but what about other components? Bacteriocins, which are antimicrobial peptides synthesized by ribosomes rather than milk proteins, are also produced by lactic acid bacteria. Can we claim bioactivity of fermented milk due to bioactive peptides in this case? Other metabolites and bacteriocins have bioactivities as well.
I'm currently growing E. coli in bioreactor and I have experience only with P. pastoris in bioreactor, so I'm not sure, how should it behave. With Pichia, one can try hard to imrove the conditions and it will grow very well to very high cell density (something like OD600 of hundreds), so I had similar approach with E. coli.
I usually grow E. coli (in flasks) in LB medium supplemented with 0.1M K-phosphate pH 7.0; 1% glycerol; 2mM magnesium.
I grew it for the first time in this medium, but the pH shifted up to 8.x after switching the temperature to 18°C (after induction). We thought it was because of the phosphate, although from what I found on the internet, the phosphate buffer shall not be so much sensitive to temp change as other buffers. Anyway, we grew it without the phosphate the second time, but the pH increased anyway (not that much though). Moreover, it was slowly increasing over time, rather than decreasing. It was about 7.2 in the morning (maybe more). What could be the cause of the pH increase?
Second- what is the usual OD600 after overnight growth in bioreactor? The first time we got around 8, but the pH was slowly increasing. At that time I thought it's because of cell lysis, but now in retrospect, it could be related to the changes in pH as mentioned above. The second time we got OD600 around 3, but it was after shorter time (because we thought it's lysing) and the culture grew slower in general in comparison with the first one.
Thank you for your suggestions.
I require small amounts of sodium lactate from a fermentation broth for laboratory exercises. I would like to avoid evaporating off a lot of water so tried precipitation. Most catalysts for this were not appropriate for the end use as they were slightly toxic.
What is the mechanism by which the microorganisms in the pulp during the fermentation process of cocoa/coffee affect the quality of the bean and/or cotyledon?
If it is an indirect influence, what is the significance of inoculating fermentation starters?
I did ethanol production using 50g/L of glucose and xylose in fermentation broth. Now need to find ethanol productivity, their theoretical yield and fermentation efficiency, also consumption of pentose and hexose sugars. Kindly help me to get clear calculation (any papers or protocols) for all of this especially ethanol productivity calculation
I would like to know the existence of possible ways to separate mycelium after the solid-state fermentation of waste material.
I know about the membrane culture process for mycelium but couldn't find a good source/way to separate mycelium biomass from solid-state fermented materials other than agar mediums.
I'm trying to determine an anaerobic bacterial cell growth curve. The substrate of the medium is lignocellulose. I also add some dark soluble substance in the medium. So I can't measure OD. I tried to measure the total protein of bacterial. But I can't fully washed the dark soluble substance absorbed on the cellulose. It had a great influence on the method of protein measurement, including BCA, lorry and bradford.
How can we predict the bioethanol yield from simulated fermentation parameters concerning yeast fermentation of lignocellulosic biomass by using recently developed machine learning techniques of Artificial Intelligence technology? Please define the research question Clearly articulate the research question you want to answer with your machine learning models.
#Artificial intelligence #ML Models
The conversion of sugars into bioethanol occurred in the fermentation medium. However for GC analysis, in capillary or packed column, water is biggest enemy for instrument. still in need of ethanol quantification so kindly suggest methods to remove or reduce water content without affecting ethanol in the fermentation medium
can anyone help me in the recovery of citric acid from fermentation broth
I want to recover citric acid using Ca(OH)2 when add Ca(OH)2 in it. how much Ca(OH)2 i should add to get pure calcium citrate and at which temperature i should heat it to precipitate Calcium citrate as calcium (OH)2 is also slightly soluble in water. there is a chance of preciptation of Ca(OH)2
I was wondering if it's possible to evaluate the amount of oligosaccharides (stachyose and raffinose) in soybean meal using the dinitrosalicylic method. I have dinitrosalicylic acid and alpha-galactosidase (enzyme that digests oligosaccharides), but I'm unsure if this method is applicable.
Any insight is appreciated.
I would like to come up with the fermentation volume required for an enzyme manufacturing project.
I have the volume/concentration necessary and I have the fermentation activity of the strains.
Ex. If the fermentation activity of the strain is 5000 u/ml and if I need to produce 20000 Kgs of enzyme with an activity of 50000 U/g then what would be my fermentation volume?
TIA for all the help
When the recombinant E. coli was cultivated in a 3L fermenter, the growth of the bacteria was normal before induced by lactose, and the parameters such as pH and DO were normal. But about 5 h after induction, the bacteria would autolyze at a fast rate, and the final OD600 is also low.
Is there any laboratory test that I can use to identify if two or more microorganisms will be compatible as a mixed culture for fermentation purposes?
How aeration and agitation can influence the mixing of liquid in vortex fermenter?
what are the other significant factors that can influence the mixing capacity in vortex fermenter.
I am looking for a simple spreadsheet for calculating the feeding regime for biomass production in a fed-batch mode.
Basically, I am growing baker's yeast and looking for a simple spreadsheet that I can provide my volumes, substrate concentrations, specific growth rate, starting biomass and target biomass So I can get feeding rate and time of fermentation required without going through the complex calculations and equations that I am not good at. I am using sucrose and 10L steered/controlled bioreactor. Anyone can help with this? I will be very much grateful.
I am planning to produce a recombinant protein by fermentation using Pichia pastoris (mut+) as the host and methanol as the inducer/carbon source at the protein production stage. For the fermentation, I am looking at the scales at 1 L, 20 L and possibly 200 L, with which the main challenge is how to safely manage the flammable and toxic methanol within the lab. When working with the 1 L bioreactors, I can place 1-2 bioreactors and methanol in a fume hood. But I have no idea on how to scale up when both the bioreactors and the volume of methanol to be used are beyond this option with a fume hood. I have searched online for a solution or reference, no expected information has been found so far. Though some people just mentioned using methanol is a risk, no people talked about the solutions for the management of methanol during fermentation. So I present here the challenge I have now, and If I could get some ideas or suggestions from the colleagues here who have worked or have been working with P. pastoris and methanol for scale-up fermentation, that will be very graceful. Thanks in advance. Shuguang
I am currently completing a design project, part of which requires cellulase to produce glucose for fermentation. 37 tons/hr of cellulose is the input for the process. We have found that 10 FPU/g cellulase is feasible for the process. How do I go about working out exactly how much cellulase we need? I don’t particularly understand FPU.
Biochem major here. Just a bit perplexed as to why my Kimchi and Sauerkraut produce bubbles when this is not a direct by-product of lactic acid fermentation. Are other bacteria involved, or perhaps ethanoic fermentation?
I want to culture the different lactic acid bacteria that are present in fermented vegetables, i saw that MRS medium is mostly selective for lactobacillus, but there are many more types of bacteria present in the fermented vegetables. Would it be possible to grow the whole array by simply removing sodium acetate? How big is the risk of contamination from other sources?
I want to dissolve heptadecanoic acid for microbial fermentation at around 5g/L in the fermentation broth. I dissolved it in ethanol however when I added fermentation broth at 5 g/L of the heptadecanoic acid, it was precipitated. How can I use the final concentration of 5g/L of heptadecanoic acid in fermentation broth?
I was about to do R. oryzae fermentation in 500 mL flask. The Culture medium (g l−1): corn stover hydrolysate 22·4, KH2PO4 0·6, MgSO4·7H2O 0·5, FeSO4·7H2O 0·0088, ZnSO4·7H2O 0·11, urea 2.
it was all fine until i autoclaved the medium for 15 mins, there was white insoluble precipitate.
and the fermentation was slow (72h of incubation in waterbath shaker, 100rev/min), rather than a big ball of mycelia formed, it was like cloudy small dots mycelia. I have to extract the mycelia and the amount of those cloudy dots mycelia was too small.
is there any way to solve this?
additional info: the hydrolysis of corn stover was carried by 2h of autoclaves in 2% H2SO4 with the ratio of corn stover : sulfuric acid (1:10).
after that, detoxification was done by adding 2N of Ca(OH)2 until the pH of 8, centrifuged, and the supernatant was taken to be the carbon source.
I didn't adjust the hydrolysate pH bcs when the medium is done, the overall pH was 5,6 and I thought that's a pretty ideal pH.
The tested species are growen in broth and they incubated for fermentation optimicaly
The Fermentor is in the form of fed batch. In primary and secondary inoculum, growth is normal, but after feeding (about 1/6 of that) about 4 hours later, The fermentor get foamy, the morphology of the cells becomes round and the cells burst and OD reaches to 5 (These events happen in less than 5 minutes). What could be the reason?
Do the corresponding carbon and nitrogen source concentrations need to be synchronized when the concentration at the shaker level is enlarged to the fermenter level?e.g. the carbon concentration is 1g/L in the shaker level and 5 g/L in the fermentation tank?
In fermentation (fermentation time is 144h), nitrogen source (consumed in 12-24h fermentation), secondary metabolites start to be synthesized at about 48h fermentation, excuse me, do we represent that nitrogen source has no influence on secondary metabolites synthesis? The fermentation strains are Gram-negative bacteria.
The literature on cyclic β-1,2 glucans mainly uses glutamate as nitrogen source, but it does not explain why glutamate is chosen. Want to ask for advice, you know? (Glutamate concentration is positively correlated with pigment production ability, and pigment will interfere with the synthesis and purification of target sugars.)
I am trying to optimize fermentation conditions in my enzymatic hydrolysate obtained after cellulase treatment. I am using S. cerevisiae MTCC 36 to carry out the experiment. Even though this strain has previously reported a high ethanol conversion rate, I am only getting 0.7% ethanol yield in a solution containing 13.4g/L of glucose. I am carrying out the experiment by supplementing the enzymatic hydrolysate (1L) with yeast extract (10 g) and peptone (20 g) adjusted to pH 5. Incubation is carried out at 30 degrees with 150 rpm in a baby modular fermenter. My culture volume was 300 ml and the fermentation rate started decreasing after 6 h.
I hope this is enough information. Thanks in advance.
I am carrying out fermentations in bioreactors using the haloarchaea strain Haloferax Mediterranei for the production of PHA with short fatty acids as the carbon substrate in a saline medium. The bacterial growth at the early stage is similar to what I obtained when the experiment was conducted in flasks. After several hours of fermentation (usually around 60h), an excessive foaming takes place, making the culture medium overflowing and disturbing pH and dissolved oxygen control. Nevertheless, the culture should be able to grow further and consume remaining substrate, as it is the case in flasks experiments. To prevent foaming, I used a solution of Antifoam A Concentrate (Sigma Aldrich) diluted in propylene glycol at 1%w. For a 2L bioreactor fermentation, up to 20mL of this antifoam solution was added, and foaming still could not be prevented after some time.
It is expected that exopolysaccharides are concomitantly produced during fermentation, which can increase viscosity of the medium and thus cause foaming.
Is it possible that antifoam is consumed or adsorbed by the microorganisms ?
Should I use a more concentrated antifoam solution, eventhough antifoam A concentrate (Sigma Aldrich) is hard to dissolve properly in propylene glycol (even worse in water as it is a silicon based polymer) ?
Should I reduce the airflow in the bioreactor (currently at 1vvm) to reduce foaming ?
Is it mandatory to add antifoam in a continuous way with an antifoam probe rather than add a consequent volume each day (10mL the first day, 5mL the other days) ?
Lucas Bonnet, PhD student
Mostly of my research was carried out by two- or three-stage reactor that operated under mesophilic temp., anaerobic digestion process via dark fermentation which I found that the concentration of hydrogen sulfide (H2S) will decrease when increasing the stage of reactor (H2S in first reactor > H2S in second reactor).
So, how possible that H2S will increase its concentration (H2S in first reactor < H2S in second reactor) in anaerobic digestion process and why?
Thank you in advance for your kindly guidance.
I inoculated a 200 ml minimal medium with 50g/L glucose with an unknown yeast (shown in figures).
After an incubation of 72 hours, at 180 RPM and 28 C, the broth containing the yeast turned very viscous, slippery liquid. In HPLC, using H column with 5mM Sulphuric Acid as mobile phase and RID as well as UV detector, nothing was detected.
The colour of the yeast is not cream or white, but its like cantaloupe colour.
Any type of help in identifying this yeast or the viscous product shall be highly appreciated.
I am using vegetable oil as a carbon source for the bacteria and supplying air in the fermenter. During the course of fermentation, it is causing heavy foaming in reactor which is not getting controlled by 30% silicone antifoam. So, what can be the alternative for this?
I want to carry out a lab-scale fermentation of endophytic microorganisms in primary conical flasks. Please suggest a single fermentation media which would be suitable for both bacteria and fungi for metabolite production. thank you! :)
I am processing some organic wastes with bacteria and yeasts I want to stop the fermentation after I get the end product, can I depend only on PH, or boiling or add some chemical to stop fermenation to preserve the final product for months.
Milk fermentation increased my samples' L* and whiteness index (WI) values.
I want to write a discussion sentence about it. I have found some papers which give the whiteness values of milk and fermented milk, but I couldn't see any technical description.