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I am interested in doing my research thesis on ice cream, but I am not sure of the exact process, which takes place at both large scale and small scale. Can you please tell me the process and the temperature which is followed on a standard basis?
Try KU Leuven in Belgium for NIR specroscopy. It is headed by Bart Nicolai, one of the top specroscopist of our time. For hyperspectral and multispectral imaging, you can try South China University of Technology under leadership of Prof. Zeng Xin An (Andy). More on hyperspectral and multispectral imaging you can try the Department of Agricultural and Food Engineering at the University College Dublin, in Ireland, headed by Da Wen Sun.
Tomatine and Glucosinolates are claimed to be used as pestcide and cancer drug ingredients. However, I couldn't find info in terms of their market value such as market demand, and $ value. Any clue? Thanks.
Indonesia is a country known for its coffee quality, especially specialty coffee. Kopi Luwak (Luwak Coffee), Mandheling Coffee, Sumatra Coffee, and Bali Kintamani Coffe are good examples of Indonesian specialty coffees. As we know, there are two main ways for coffee processing: dry and wet. In regards to that, I got a project for processing coffee with several fermenter/fermentor (or starter) agents for wet-processing. Some of the fermenters I want to use are Lactobacillus sp., Aspergillus sp., etc. The problem is, I need your suggestion for the other types of starters that can be used in this project. Moreover, it's preferable if that starter has been used for 'local wisdom' based coffee-processing in your area. I plan to use GC-O (Gas Chromatography-Olfactometry) and Cup-Testing (a sensory evaluation method for coffee).
Though , I am not sure about the offshelf(commercial) available wireless aroma/taste sensors, We can design and develop wireless sensing system by interfacing the sensors(aroma,.....chemical sensors,....) with XBee radio module for wireless operations. The conditioning circuit can transmit the sensed data in ADC form. The collected (sensed) data can be anayzed for detecting appropriate color, smells,..etc.,
Instron is a company that makes materials testing instruments in sizes/ capacities from very small to quite large (The largest ones are capable of ripping apart/ compressing iron bars, concrete slabs, etc). Many institutions/ companies use one of their smaller models to test the material properties of foods. A texture analyzer is an instrument designed specifically to test the textural properties of foods. From a practical standpoint, as long as the probes/fittings are comparable, the load cells have the same (or similar) sensitivities and capacities, and one uses the same procedure (specifically setting the probe/ crossarm speeds, deflection or maximum force, and pauses (if any) to the same values) you should see no difference in material properties measured by either.
The edibility of food other than microbial analysis is its texture, test and smell. If the texture is such that it can not be ground by teeth or elastic in nature then it is described as non edible. Same way the taste and smell should be within the threshold limit to human sensory organ perception.
I weighed the sample of meat (5 g +- 0.1) than was homogenate with 10 mL of TCA/DTPA. After centrifugation and filtration 5 mL of the liquid extracted was mixed with 2.5 mL of TBA solution. Then the solution was heated at 95°C and after cooling Abs was recorded.
A calibration curve was plotted with 1,1,3,3-tetraethoxypropane (TEP) and the slope was recorded.
To calculate mg MDA in Kg of fresh meat I used that formula:
(Abs sample*Volume extraction*Volume dilution)/(slope*weigh of sample)
That formula with numbers becomes:
(Abs sample*10*1.5)/(0.23*weigh of sample)
where 10 is the 10 mL of TCA/DTPA and 1.5 is the dilution from 5 mL of extracted sample plus 2.5 of TBA solution (5+2.5=7.5 mL; 7.5/5= 1.5)
where volumes are in mL and the weigh of sample is in grams.
Spray-drying is an effective, efficient means of producing peptide/protein-loaded powders suitable for pulmonary delivery. In addition, fine powders of proteins have application in other delivery systems (e.g., implantable pumps). If the correct formulation and spray-drying conditions can be identified, then a product can be obtained with a high yield and having a large fine-particle dose. Spray-drying is therefore a realistic alternative to the widespread practice of air-jet milling used to produce powders of low molecular-weight actives for inhalation. Indeed, air-jet milling should probably be avoided with peptides or proteins, because of possible problems of physical instability and inactivation. Apart from these considerations, spray-drying is also a suitable technique for embedding sensitive peptides or proteins in stabilizing excipients (“carriers”) such as disaccharides or amino acids.
In a study, the efficiency of drying carrier, whey protein isolate (WPI) was evaluated during spray-drying of honey. No powder was recovered when pure honey was spray-dried. Honey powders were successfully obtained (powder recovery >50%) by adding WPI alone at a ratio of Honey:WPI ratio of 70:30. The mechanisms of such a significant effect of WPI on spray-drying of honey are attributed to the preferential migration of protein to the droplet/air interface and the limited inward movement of protein during moisture evaporation, in conjunction with excellent skin-forming properties of protein upon drying. Powders' moisture content, water activity, and hygroscopicity were negligibly influenced by carriers.
Other carrier agents such as maltodextrins, gum Arabic, waxy starch, and microcrystalline cellulose, when introduced into the feed solution, influence the properties and stability of the powder. Crystalline and amorphous forms of the same material powder show differences in particle size, particle shape, bulk density, physicochemical properties, chemical stability, water solubility, hygroscopicity, flow properties and compatibility.
A food production facility deep fries chicken products coated with a milk, wheat and soy batter and then uses the same oil to cook other products containing no allergens. My understanding is that the hot oil renders the allergens into non proteins and therefore nonallergenic. Has there been anyone known to have an allergic response to food declared to be nonallergenic after being cooked in oil previously used to cook allergen containing food? Can anyone point to a scientific research document?
I've listed a couple relevant papers below. In general, the consensus seems to be that thermal denaturation can reduce/ eliminate the activity of some allergens, and the degree of this effect seems to be related to the structural properties of the given allergen and how they interact with antibodies in the human body. In the specific example you give, I'd be particularly concerned about the wheat and the soya, as both contain storage proteins which tend to be quite thermostable due to their numerous disulphide bridges.
Davis, P. J. and Williams, S. C. (1998), Protein modification by thermal processing. Allergy, 53: 102–105. doi: 10.1111/j.1398-9995.1998.tb04975.x
Mills, E. N. C., Sancho, A. I., Rigby, N. M., Jenkins, J. A. and Mackie, A. R. (2009), Impact of food processing on the structural and allergenic properties of food allergens. Mol. Nutr. Food Res., 53: 963–969. doi: 10.1002/mnfr.200800236
Rumbo M, Chirdo FG, Fossati CA & Añón MC. 2001. Analysis of the Effects of Heat Treatment on Gliadin Immunochemical Quantification Using a Panel of Anti-Prolamin Antibodies. J Agric Food Chem 49(12):5719-5726.
Plumb GW, Mills ENC, Tatton MJ, D'Ursel CCM, Lambert N & Morgan MRA. 1994. Effect of Thermal and Proteolytic Processing on Glycinin, the 11s Globulin of Soy (Glycine Max): A Study Utilizing Monoclonal and Polyclonal Antibodies. J Agric Food Chem 42(3):834-840.
Sabouraud Dextrose Agar (SDA) has been suggested as a medium that can grow yeast cultures. I don't know if it can be as simple as using SDA prepared petri dishes, adding samples of honey, and then incubating and watching for culture growth.
If you want to count only saccharomyces cerivisae counts, than SDA is not a good choice since other yeasts will grow as well. A good indication could be to use the difference between CFU counts of SDA and SDA with cycloheximide. Saccaromyces normally doesn't grow in the presence of cycloheximide whereas wild yeast will. other media could be differential schwart'z medium
For my manuscript, I would like to produce a stable product from ginger. Salabat is a common beverage in the Philippines and I am conducting an experiment on how to make a product that is readily drinkable after the addition of hot water.
I am currently researching on dry noodles from non-wheat ingredients, from sweet potato. I'm having a problem that the noodles turn to brown color. I've added CMC and eggs to improve their texture. What materials should I order additionally, so that the dried noodles product still has a color that is interesting?
Any information whether any starch like potato or tapioca, which is usually added to processed fish can hinder the detection of fish allergen? Is there any specific reaction between allergen with the starch?
The coating of feed ingredients with either starch of fat helps minimize nutrient losses during processing of the product. Therefore, if you are unable to detect any substance in an analysis, then it could possibly be a factor.
It is very hard to separate oil from surimi wash water. However, since the property of this liquid is kind of similar to Milk, you can use the same method which is being used in dairy industry. I know some researchers and privet sectors used this method to separate the oil from protein hydrolysates solution and surimi wash water. They could separate 95% of the oil in the liquid.
Minimally processed fruits and vegetables are Ready-to-cook and Ready-to-eat materials which undergoes minimal primary operations like, cleaning, cutting, trimming, de-seeding , packaging etc. which are to be stored in cool environment.
The prospect of commercializing minimally processed fruits and vegetables in developing differ with the ease it is being adopted in developed countries as most of the develop countries are located in low temperature zone have good quality power supply. In contrast as developing countries located in higher temperature zone (tropical ) this higher temperature will encourage microbial growth, that such products are required to be stored at lower temperature in absence of it the produce may spoil soon. Hence we can use the technology in metro in a limited manner.
Food samples are preserved for microbiological analysis by operators for public health to understand an outbreak. There should be a standard operating procedure around this process of collecting, preserving, and maintaining the library for public health inspection, audits for system verification, and finally removal in the event of an outbreak.
there may not be the problem of rancidity. the problem can be protein denaturation and immunoglobulins absorption due to irradiation treatment. please refer to this article www.ncbi.nlm.nih.gov/pubmed/18024765
I would like to inoculate some bacteria in marinated fish and then I will treat it with high pressure. During my storage period I also would like to do sensory assessment. But I'm confused how to perform a sensory analysis. It is impossible in inoculated samples. Should I do sensory evaluation in control or it will not be a correct comparison?
May 31, 2014
Why is it impossible to carry out sensory analysis on inoculated fish? What is the nature of the marinade?
One simple method is to first gelatinize the starch and then freeze dry the samples. It will take a lot of time (since the freeze drying is slow and only a small amount can be dryed at the same time), but it works.
Well, hysteresis loop is the area under the curve or it represents the upward and downward movement od shear stress vs shear rate rheolograms and can predict texture degradation. You can consult my one paper on egg rheology where I showed hysteresis. Viscoelasticity is on the other hand material behavior and show how much solid-like or liquid-like property in terms of elastic and viscous modulus. For a perfect viscoelastic fluid both could be the same and if G' exceeds G'' then the solid-like property dominates. I have many papers you can find in research gate.
It is my pleasure to guide you if you do need more info.
For foamed batter density, just fill a cup of even volume and level off the top with a knife before weighing. Check the cup volume by filling to the top with water at 20 C and weighing, subtracting the weight of the empty cup. Weigh to at least 1 decimal place.
To measure unaerated batter density, centrifuge idli batters in a low speed swing-out centrifuge in paired tubes, marking the containers on the side with a line showing the height of foamed batter after filling, and weighing the tube+batter before spinning.
After spinning for 30 min between 3000-5000 g draw a line carefully on the side of the tube for the level of the batter after foam is broken. Tip out the liquid and measure its weight. Draw another line for the level of the pellet. Weigh the tube + pellet. Remove pellet, wash and dry the tube, weighing the tube. Using water at 20 C, fill the tube to each line carefully, noting the weight at each line. They represent the volume of the pellet, the liquid fraction, and the gas volume in idli batter. Replicate tubes give you replicate measures.
From the weights and the volumes at each step you can calculate the gas volume fraction, liquid volume fraction and density , and solids volume and density in the batter.
I have measured idli cooked volume by seed displacement method. Method reference Griswold, R. (1962). Evaluating food by objective methods Experimental study of foods (pp. 540-541). Boston, U.S.: Houghton MiZin Co.
Weigh idlis individually on a sensitive balance (at least 1 decimal place).
Take a large container with an even lip at the top, enough to fill around 0.4 kg seed. Weight the empty container. Fill with water at 20 C to determine container volume.
Dry container, then overfill with small seeds (poppy or mustard). Tap gently to settle, level off the top evenly with a ruler and weigh. Repeat several time to get a reproducible baseline to calculate the relationship between seed weight and seed volume.
Take out a third of the seeds, place in an idli, and refill with seeds to the top, tap and level. The idli must be completely covered. Then carefully remove idli, brushing all seeds back into container, and reweigh container. Repeat to get an idea of idli volume reproducibility.
The idli density can be calculated from idli weight divided by the seed volume displaced by the idli.
You can weigh more than one idli each time, but for scientific publication ans tatistical analysis, each should be weighed separately, with replication, to determine between-idli variability. My microwave idli have about 6-8% standard deviation in volume for a 12 idli batch. Steamed idlis may be less variable.
In comparison with other modern and new processes, food irradiation seems to be relatively well studied. However, application in Germany and other EU countries seems to be very limited. The EU positive list has not been enlarged since many years (just herbs and spices) as different stakeholders didn't agree if there is a “technological need” for this treatment. If there is interest in understanding the reasons, I plan data collection and publication.
Most probably the fear of irradiation. Still people are cautious about the aftermath of IR treatment. As a Food Technologist, I also do not have clear understanding about the fate of IR into a food system. Although there is no report on health issue but it needs further confirmation or more study on health issue. The process is suitable for spices, potato and onion.
One of the leading US instant pudding manufacturers is Kraft Foods, which makes the Jello brand. Writing to such manufacturers may direct you to the standards and legislation you want.
Additionally, write to or check the websites of the US Food and Drug Administration and the European equivalents.
Also, the book "Salt, Sugar, Fat" by Michael Moss gives some good insight into how natural products have been radically changed by using chemicals to aid in faster or cheaper processing, and included an example about emulsifiers being used to change the time to make products from hours to just minutes! In the book, he speaks of other leading US manufacturers as well as additive suppliers - many of whom may have information that can help you.
Finally, I wonder if you would find it useful to research lobbying or consumer advocate efforts related to your area of interest. I believe many calls for change from "tinkering" with product chemistry back to natural food chemistry come from nutritionists, dieticians, and even home economics advocates. This last group was also mentioned in Michael Moss' book, which I pointed out above.
There are plenty of literature on the issue. Well it depends upon how you are treating your data or the instrument you are using. For simplicity, if there is no suspended particles (filtered juice) Power law is the best. If there is pulp, try HB model. If you are using oscillatory rheology then try to match Cox-Merz rule.
Or provide the properties of apple in the book : Choi Y, Okos MR. Thermal properties of liquid foods review. In: Okos MR, editor. Physical and Chemical Properties of Food, St Joseph, MI: American Society of Agricultural Engineers, 1986
You may check these and the related cross references:
Diffusivity of CO2 and Water Vapors in `Gala' and `Granny Smith' Apples
Theophanes Solomos and
John C. Bouwkamp
+ Author Affiliations
Dept. of Horticulture and Landscape Architecture, Univ. of Maryland, College Park, MD 20742-5611
[HortScience August 1996 vol. 31 no. 4 590 ]
Previous observations have shown that the diffusivity of water vapors is much larger than the value that is predicted theoretically from the magnitude of the diffusion coefficient of CO2, C2H4, or both. This has been ascribed to the ability of water to diffuse through the cuticle and to the transport of water via the capillaries of cellulase micorfibrels to the surface of the lenticels, where it evaporates. We measured the diffusivity of CO2 in `Gala' and `Granny Smith' apples. The former are more permeable to CO2 than the latter cultivar, in particular after prolonged storage at 2°C. The diffusivity of H2O was 10- to 20-fold larger than that of CO2. Furthermore, the ratio of D(H2O)/D(CO2) was similar for both cultivars. Infiltration of dyes and gas flow through apples submerged in water show that in `Gala' apples, the number of open lenticels is larger than in `Granny Smith'. Thus, the data indicate that lenticels are the main avenue of gas exchange in apples.
POJ 3(3):97-102 (2010)
Drying of apple slices (var. Golab) and effect on moisture diffusivity and activation energy
*E. Meisami-asl, S. Rafiee, A. Keyhani and A. Tabatabaeefar
Department of Agricultural Machinery, Faculty of Bio-Systems Engineering, College of Agricultural and Natural Resource, University of Tehran, Karaj, Iran
Drying is one of the primary methods of food preservation. Determining coefficients used in drying models is essential to predict the drying behaviour. The present study was conducted to compute effective moisture diffusivity and activation energy of samples of apple slices. The thin-layer drying experiments were carried out under five air temperatures of 40, 50, 60, 70 and 80ºC, three air velocities of 0.5, 1.0 and 2.0 m/s and three apple slice thicknesses of 2, 4 and 6 mm and constant air humidity of 21%. Results indicated that drying took place in the falling rate period. Moisture transfer from apple slices was described by applying the Fick’s diffusion model. The
effective diffusivity values for all conditions changed from 1.50×10-8
to 1.71×10-7 m²/s. An Arrhenius relation with an activation energy value of 22664.1 to 30919.0 J/mol and the diffusivity constant value of 1.16×10-4 to 6.34×10-3 m²/s were obtained which shows the effect of drying air temperature, air velocity and slice thickness on the diffusivity.
Apple, activation energy, moisture diffusivity, thin layer, Page model
I am calculating evaporation by the formula used by Datta et al; which depends on the difference of equilibrium vapor pressure and vapor pressure. I have done the model but not sure the range of values of equilibium vapor press or vapour pressure. If anybody done it, can you share what should be the value range ?
Dear Chandan, what you have to do highly depends on the system you are working on. Maybe you could clarify a bit. What is precisely your fluid mixture? If you fluids hardly mix, the equilibrium vapor pressures of your liquids will be close to the value of the pure components. In case that the fluids mix, your equilibrium vapor pressure will be lowered. How precisely depends on the liquids. There is a lot of data in the literature on mixtures, so you might find the answers there.
Another factor to take into account is the nature of your porous material. If the pores become below the 50 nm capillary effects might start to influence the equilibrium vapor pressures (look in the literature for the Kelvin equation for capillary condensation). How precisely depends on your fluids and porous material.
I am going to do research about the use of medical and aromatic plant in food stuffs and am looking for a research partner. Is there anyone who's interested in this field and who would like to join me?
You can just read some good quality papers of mine in association with my Sir (Dr. Kuldeep Dhama) on medicinal plants. That will help you to extend your knowledge and will help you to apply it in relevant research activities which you are planning to do.
Sep 13, 2013
Is there any fellowship for Ph.D students studying in india from central govt or any other agency
In fruit juices with pH < 3.7, spores will not germinate, so a pasteurization to destruct the vegetative micro-organisms will be sufficient. A very rough guideline for foods with pH < 3.7, to be stored at ambient temperatures, is a P value of 10 minutes with a z = 10 oC.
Tucker and Featherstone (2011): Essentials of thermal processing; Wiley/Blackwell, Chichester, table 4.6 on page 68 suggests more exact pasteurization values for fruits, depending on their pH. His table lists P values at reference temperature of 93.3 oC and z = 8.9 oC.
Unfortunately, Tucker does not list pommegranate juice, but if you have measured the pH of your juice, you can find an indication of the P value in Tucker’s table 4.6.
Sometimes in fruit juices the pH is deliberately lowered by adding small quantities of lemon juice; lowering the pH thus may be helpful to reduce the thermal treatment of the juice, and therefore to improve the nutrient quality of the juice.
The P value (sometimes referred to as F value) is the time-temperature combination, required in the coldest point of the product. Example: a P value of 0.5 min. at 93.3 oC with z = 8.9 min. means: The coldest point of the juice should be raised to at 93.3 oC and kept at that temperature for 0.5 min. The z value helps to recalculate the P value to other temperatures. If the coldest point is z = 8,9 oC lower, so at 93.3 - 8.9 = 84.4 oC, the heating time has to be 10x as high, so 10 * 0.5 = 5 minutes at 84.4 oC.
Recalculation formula of a Pknown at temperature Tknown to a new Pnew at new temperature Tnew:
Pnew = Pknown * 10^((Tknown - Tnew)/z)
So if Pknown = 0.5 min. at Tknown = 93.3 oC and z = 8.9 oC
and you want to find the Pnew at temperature Tnew = 90 oC
I am working in glucosinolate analysis and composition of different Eruca species.
As probably you know rocket leaf contains glucoraphanin, a glucosinolate with antioxidant and anticancer properties. I suppose glucosinolate content will be modified during processing. I wonder if you are also interested in the fate of rocket leaf glucosinolates. If so, we could collaborate in this research.
A.S. Mujumdar (Ed.) (2006): Handbook of Industrial Drying; Taylor & Francis, Boca Raton, gives limited information about foaming agents and foaming stabilizers in general :
"Vegetable gum and soluble protein have successfully been used in the food industry as foam-stabilizing agents." See section 21.7.10; FOAM MAT DRYERS (Autors: Shahab Sokhansanj and Digvir S. Jayas)
Also: "Film-forming components used in the drying of fruits and vegetables are glyceryl monostearate, solubilized soya protein, and propylene glycol monostearate. See section 25.4.6 FOAM DRYING (Autors: K.S. Jayaraman and D.K. Das Gupta)
Currently work with pumpkin (extruded and dried). In our thermograms pumpkin flour (Cucurbita moschata) dont show melting points at the temperature that you said 158 C..Also in another work we demonstrate that influence of lipids and starch (Amylose - lipids complex increase thermal stability up 95 C). the event of protein denaturation ocurrs at lower temperature than 158 C. At this temperature I agree with prof Islam carbohydrates are contributing to the melting point instead proteins and lipids.
if you have to estimate the real fruit content (depending on the fruit cultivar) you can measure malic and isocitric acid, formol number, sorbitol, phosphate, potassium and use the AIJN Code of Practice or the RSK medium values
Carrageenan has more than 600-year history of safe and healthy use. This is a naturally-occurring product and non-synthetic in any way. Obtained from non-GMO seaweed (marine vegetable) is widely used in food because of its great versatility. The levels of use are very low and so the level of consumption are really minimal, far below many other food ingredients. Moreover carrageenan is not absorbed by the human body acting as fiber and being eliminated undigested (this is because we don't have the enzymes to break down the long chained carrageenan molecules). Most of the controversy came after Dr. Tobacman request to FDA a review about carrageenan safety. Her request was replied recently (see link below).
Check my paper "High pressure processing of meat, meat products and seafood", You can download it from my personal page. A paragraph is dedicated to oxidative stability of meat products following high pressure treatments.
Microencapsulation of onion oleoresin by using spray drying research paper related
I have to make some product of buckwheat, preferably chips or flakes, for my Ph. D program. Is it possible? If not, please suggest what other products could be made from the mentioned object.
Feb 27, 2013
Technically you can make buckwheat flakes. The process is simillar to the one used in making oat flakes. The grains are soaked in water followed by pressing between hot roller drums. The degree of starch gelatinization depends on flakes thickness, water uptake during soaking, and thermal treatment conditions. Due to the high fibre content in buckwheat, you may need to modify sensory attributes of the finished product.
I'll explain what the experiment is meant for more deeply: i'll pick up samples of olive pastes from the malaxer at regular intervals in order to create a kynetic model of the evolution of volatile compounds during the malaxation. To stop the lipoxygenase cascade, that lead to the production of volatiles, i need a chemical agent inside the vial that will be filled with some grams of olive paste. That will stop the reactions and freeze the volatile composition at the time the sample was picked up. The vials with sample and inhibitor will be stored in freezer until analyses. I've found some indications in the literature about Calcium cloride saturated solution as an inhibitor, if you know of more and/or better inhibitors i'll be grateful if you could share. Thank you in advance.
I'm afraid the question is not that simple. It depends on the target materials and the quality of end products that you want. Define purity that you would like to achieve. Ask yourself if it is necessary to "separate" them? Because anthocyanins are not "one" compound, they are a group of natural compounds and one may have distinct properties compared to the other. I suggest you provide specific details for whatever you're interested in, then you may likely to get what you want to know here.
If none of any quality issue is your concern, press and spray-dry would be the most simple solution.
The study was to provide the theoretical basis for development and utilization of pigment from purple sweet potato.[Method] With purple sweet potato variety Chuanshanzi as the material,the basic physicochemical property of its pigment and the effects of pH value,temperature,light,oxidant and reductant and metal ions on the stability of pigment were studied.[Result] The pigment from purple sweet potato was easily soluble in water,methanol and ethanol,but insoluble in acetone,ethyl acetate,ether,and petroleum ether.When the pH value of aqueous solution of pigment from purple sweet potato was 1.0-3.0,the properties of the pigment was stable,bright red,and with the increase of pH value,the pigment colour became shallower,and its degradation index increased.When the temperature was 20-60 ℃,the properties of the pigment was stable,and when the temperature was over 60 ℃,the stability of the pigment was decreased rapidly.The effects of light on stability of pigment was little,after 8 d continuous irradiation,the preservation rate of pigment was 87%.The oxidative resistance and resistance of ascorbic acid reducing power was poor.Al3+ and Zn2+had an effect of protecting the color of pigment,and could improve the stability of the pigment,but Fe3+ had a destructive effect.[Conclusion] The pigment from purple sweet potato was a kind of water-soluble natural pigment,and its main composition was anthocyanin substances.
As per book reference, 60 brix. is prepared by 60g sugar in 40g or ml of water, giving a solution of 60 brix. but I am not getting the correct brix value. How do I prepare 100 ml solution of 60 brix. representing sugar concentration in brix or just percentage of sugar for 100 ml solution - which looks better for research work?
Degrees brix is the % w/w of soluble solids in a solution. If the only soluble solids in the solution is sucrose then it equal to the sucrose concentration. Can be determined by using a refractometer.
To answer your question, it depends on whether the final mass of solution (60 degrees brix) you want is important or not. If you want 1000 gm of 60 brix solution as your product then weigh 600gm sucrose and add water until you obtain a total mass of solution of 1000gm. If the final mass is not important start with 1 kg of water and add 1.5 kg sucrose and you will have the same concentration.
For long goods, the first stage of drying is carried out in the pre-dryer where
the moisture content is decreased from about 30 percent down to around 17 to 19
percent . In the case of short goods, the moisture content has already been
lowered and decreases from about 25–27 percent down to between 17 to 19
ercent. The pasta, long or short, then moves into the final drying phase where
the moisture content is further reduced to about 12.5 percent. The product is then
stabilized so that the moisture remaining within the product can redistribute
self evenly so that there are no stressful moisture gradients from the center to
the outside of the product. If the product is not provided with appropriate
stabilization, stress fractures or checking may develop. In the case of long goods
dampening step may follow stabilization to slightly increase moisture content
and further stabilize the product and thus protect it from cracking.
The product must then be cooled to a temperature (28–32ºC) close to that of the surrounding.
Low temperature drying processes are now considered the traditional means of
High temperature (HT) drying at temperatures of 60–85ºC was
introduced to the industry in the 1970s and early 1980s.
The initial driving force behind the development of HT drying was improved bacterial control for egg products. Another immediately recognized benefit was much shorter drying cycles (8 h) that permitted more compact drying lines for a given capacity
concomitant with a reduction in the high capital costs associated with plant
space. As HT drying cycles became operational, it was discovered that an
additional benefit was improved cooking quality and better color.
Once the benefits of HT drying to product quality became generally recognized, HT
quickly became the process of choice for most pasta manufacturers worldwide.
In the past few years, the application of ultra-high temperature (UHT) drying
(85–110ºC) has become common, with drying times as short as 4–5 h for long
goods and 2–3 h for short goods. UHT drying reportedly produces pasta
products with cooking quality and color equal to or better than that obtained
with HT drying.
For more detailed please tak e alook at to Gavin, cereal product manufacturing
Osmotic dehydration of fruits involves dipping fruit slices in concentrated sugar syrup for specific duration taking it out and hot air drying. Now the issue here is that there are 13-14 parameters which affects mass transfer important one are which fruit, variety, stage of maturity, size of slices, osmotic agent, concentration of syrup, ratio of fruit to syrup, duration of dipping, atmospheric pressure, stirring, temperature etc. Hence under this back ground asking detailed process of OD of fruits is not a proper question. The question should be specific in terms of fruits/variety etc.
I am eager to collaborate with researchers in the area of resistant starch as I am preparing a research proposal on the subject. The researcher/s should have good knowledge of starch chemistry and measurement of RS including X-ray diffraction. I can take care of the other part. A Post-Doc position will be considered for a candidate having experience in the field.
Salam Ida. It is nice to get a response from you. I am more interested on your research since I also worked on nanopackaging and currently I do have a antimicrobial nanopackaging project. We can collaborate.
I analyzed my liquid food sample for total polyphenols by chemical method and run the same sample with range of dilutions in FT-NIR and got the spectra. Now, there are various peaks in the spectra. How to select the wavelength which corresponds to polyphenols. I would be very grateful if anyone could suggest any book or step by step process of interpreting the spectra . Please help.
Can someone advise on pH loss in Food Products during storage?
Jul 6, 2013
Can anyone explain the possible reasons for pH decrease in fruit and vegetable processed products during storage.
Jul 21, 2013
Asides microbial reasons, since the pH of your sample is around 4.1-4.4, if stored at room temperature (25C) you cannot rule out completely the gradual or slow loss of moisture from the tomato puree which will subsequently increase the sample concentration and hence a decrease in pH.
I like to document the elements present in my fruit sample. Came to know about this EDX spectroscopy and hope it will serve my purpose. My question is whether a single run itself will give a spectrum with all elements which are present in the sample? And how estimation of each elements is done?
When used with 30kV electrons (within a SEM), EDX (or EDS) will give you information on all elements on the sample with confidence (Z>~5-6) in a single spectrum. The spectrum must have high statistics: major peaks with more than 10kcounts.
The quantification is done by considering the intensity of the peak of each element and some corrections (for fluorescence, absorption, etc). The quantification is usually reasonable directly from the EDS software but care must be taken on light elements (Z<10). Since light elements will be abundant on your sample, it may be difficult to evaluate properly the amount of the other elements. Usually, the sample must be flat and at the exact work-distance.
If you need to find trace elements (concentration below 1%) or need high accuracy (error below 1%), you may need standards and very careful acquisition.
Any body can send the soft copy of this paper: - Concentration of tomato juice and other fruit juices by reverse osmosis D. Pepper, et al
To my opinion, rheology could be used but in conjunction with other methods. You should keep in mind that emulsion destabilisation can result mainly from creaming (or sedimentation depending on the relative densities of the dispersed and continuous phases), flocculation and coalescence of the droplets. I would propose to keep the emulsions in standardized steady conditions (controlled-temperature), to look at creaming and/or oiling-off (naked-eye observation ; some instrumented systems also exist) and to make droplet size measurements (light scattering or light diffraction methods ; its depends on the size of the droplets ; you may also use microscopy + image analysis)
In the case of alkaline-conditioned type B (basic) gelatine, both asparagine and glutamine are almost completely converted to aspartic and glutamic acids respectively. The amino acid composition of collagen and an acid-conditioned type A (acid) gelatine hardly differ. This explains the different
iso-electric points (IEP) typical of types A and B gelatine. For gelatine of type A, this corresponds to collagen at about pH 8–9 and for type B at pH 4.8–5.5.
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How much amount of Nutritional composition ?
May 8, 2013
Tannin, Ferrous reducing power and Flavonoid content of amla fruit
It depend on the kind of gas you want to detect. For the detection of O2, CO2, CO and the amount of CH4 in a package you can use a flue gas analyser. For the detection of organic gases like alkenes or alkines it is better to use a special gaschromatograph or GC-MS.
I want to produce margarine through crystalization of oils at 500kg/day, which translates into about 80kg/hr. Anyone know where I can get such a small plant? All suppliers can only supply 500kg/hr and more.
I currently want to research into value addition of fish can anybody suggest research areas to me.