Applications of sand roasting and baking in the preparation of snacks

In India, the sand roasting technique is widely used by street food vendors, villagers and cottage industries for making various value-added food products from different cereals, millets and legumes. The traditionally produced sand-roasted products are commonly utilized as ready to eat snacks or for the preparation of various other snacks.

The techniques of sand roasting and baking are gaining importance as cheap, effective, oil-free, healthier ways of cooking. However, further studies are needed on micronutrient availability and functional food development for community nutritional disorders. Also, the residual silica levels and difficult working environment mandates the development of energy-efficient and high-output-orientated technologies such as continuous, microwave, and fluidized bed roasters.

In terms of health benefits, minimally processed foods are better than the processed foods. Among the minimal processes, sand roasting is a traditional, rapid food processing method which utilizes dry heat for a shorter span of time. In this high-temperature short-time treatment, the heat energy is transferred via conduction. The sand roasting causes faster dehydration, characteristic thermal and chemical reactions, and reduction in water activity of the grains. During roasting, the far infrared rays produced from the sand penetrate the grains and aid in breaking down of the starch, protein, and fats in the grains.

The cereals belong to the family Graminaceae and include rice, wheat, maize, barley, oat, and rye. They are the important carbohydrate resources, in addition to minerals, dietary fiber, and bioactive compounds. The different methods such as conventional dry heating, sand roasting, hot-air popping, gun puffing, microwave heating are used for producing value-added cereals with distinctive aroma and taste.

Sand Roasting of Rice

Among the cereal crops, rice occupies a key position as a major cereal crop and staple food in human nutrition due to its texture, taste, and nutritional qualities. There are vast number of paddy varieties grown in different states of India which are suited for raw milling, parboiling, and value-added rice products. In India, around 10% of the production is used for making value-added rice products such as popped, puffed, and flaked rice.

Popped Rice

It is known as pelalu, khoi, etc. in various Indian languages. It is a traditional value-added product with high cold water swelling capacity originated from raw paddy; arising from high starch gelatinization and low retro gradation. It is prepared directly by high-temperature short-time treatment from the moisture-adjusted raw paddy by sand roasting in a pan at a temperature of 150–250 °C for 25–45 s.

Puffed Rice

It is known as maramaralu, murmura, murra, muri, puri, borugulu, mandakki, kallepuri, etc. in various Indian languages. It is one of the popular, common, oldest minimally processed food items especially used as snack, ready to eat breakfast cereal, infant food, etc. in India. It is also distributed as prasadam to devotees in temples and gurudwaras. It is mostly produced in home or cottage industries by skilled artisans using the cheaply available local material, sand as a heat transfer medium for the uniform distribution of temperature among the grains.

Flaked Rice

It is also known as rice flakes, parched rice, flattened rice, and beaten rice in English and atukuluavalakki, aval, pohachura, chira, chiwada, etc. in various Indian languages. It is one of the oldest traditional rice product which is consumed as a cereal breakfast and sweet or salty snack either by toasting, roasting, frying, spicing, or soaking in water, milk, and seasoning with vegetables and spices in India. It is a flattened, carbohydrate rich, edible, precooked, rice product produced by soaking the paddy, sand roasting, and flattening.

Sand Roasting of Maize

Popcorn is the most important, popular commercial snack produced worldwide from corn. It is available in small packs, coated with various ingredients such as hydrogenated oil, sugar syrup, salt, β-carotene, favors, etc. for improving the sensory quality. There are various corn-popping methods are available including conventional sand roasting, gun popping, hot-air popping, and microwave popping. Among which, the microwave and pressure cooker popping are the most popular methods at households due to energy-efficiency and short time. The popping of maize depends on corn variety; kernel size, shape, and density; pericarp thickness; moisture content (11-16%); popping temperature; and popping method.

There are many more products and different types of sand roasting techniques:

  • Sand roasting of barley
  • Sand roasting of oats and wheat
  • Sand roasting of millets
  • Sand roasting of groundnut fruits and seed kernels
  • Sand roasting of chickpea, cowpea, pea, black gram, and kidney beans
  • Sand roasting of other food items
  • Sand baking of vegetables, eggs, meat, and cake

The limitations of the sand roasting technique are lack of temperature control, uneven temperature distribution and sand contamination in the final products. The sand roasting method is energy inefficient, tedious, manual in operation involving continuous hand stirring, sometimes unhygienic, and limited by low output. The workers are prone to direct influence of heat, flame, and smoke originated from the commonly used fuels such as crop and agro-industrial residues, wood, charcoal, kerosene, and gas. Thus, the current traditional and industrial sand roasting method necessitates the development an alternate technology for production of value-added cereal and legume food products which is low-cost, energy-efficient, effective, high-output-orientated with no exposure of the food products to impurities. For example, continuous, microwave, and fluidized bed roasters save cost, reduces the manual labor, enhances productivity, and maintains uniformity in roasted products. In addition to consumer satisfaction, it also provides temperature range optimization, even heat distribution within the heating chamber and food grains and applicability to wide range of materials.

We at KERONE have a team of experts to help you with your need for roasting & baking in various products range from our wide experience.

A Model-Based Methodology for Spray-Drying Process Development

Solid amorphous dispersions are frequently used to improve the solubility and, thus, the bioavailability of poorly soluble active pharmaceutical ingredients (APIs). Spray-drying, a well-characterized pharmaceutical unit operation is ideally suited to producing solid amorphous dispersions due to its rapid drying kinetics. This paper describes a novel flowchart methodology based on fundamental engineering models and state-of-the-art process characterization techniques that ensure that spray-drying process development and scale-up are efficient and require minimal time and API. This methodology offers substantive advantages over traditional process-development methods, which are often empirical and require large quantities of API and long development times. The methodology is used from early formulation-screening activities (involving milligrams of API) through process development and scale-up for early clinical supplies (involving kilograms of API) to commercial manufacturing (involving metric tons of API). It has been used to progress numerous spray-dried dispersion formulations, increasing bioavailability of formulations at preclinical through commercial scales.

Spray-drying is a widely used unit operation for pharmaceutical applications. In addition to its use in preparing solid amorphous spray-dried dispersions (SDDs), spray-drying is used in excipient manufacture, pulmonary and bio therapeutic particle engineering, the drying of crystalline active pharmaceutical ingredients (APIs), and encapsulation.

In common practice, spray-drying process development is often empirical and is experimentally driven. Traditional methods often use an iterative design of experiments (DOE) or statistical treatment of the process parameters and resulting product attributes. This is often a time-intensive exercise, requiring large quantities of API, and the resulting process is often not well understood or sufficiently robust.

The spray-drying process is a well-established unit operation in the pharmaceutical industry. To manufacture an SDD, a spray solution—which consists of API and polymer dissolved in a common solvent—is delivered to an atomizer inside a spray-drying chamber concurrently with a hot drying gas. Organic solvents are typically used to produce SDDs because the API tends to be poorly water-soluble. Nitrogen drying gas is employed to provide an inert processing atmosphere when processing organic solvents. The spray solution is atomized into droplets using a spray nozzle. Many different types of spray nozzles can be used including two-fluid, ultrasonic, rotary, and pressure (or hydraulic) nozzles. Pressure nozzles are often preferred due to their simplicity, scalability, and ease of droplet-size tuning. When the spray-solution droplets contact the hot drying gas, the solvent in the droplets evaporates, leaving dried SDD particles entrained in the drying gas that exits the drying chamber. These particles are collected and then separated from the gas stream, usually by a cyclone separator.

Based upon an evaluation of the physicochemical properties of the API, several initial formulations (generally, two to four) are selected and screened in this step. A screening-scale spray dryer designed for maximizing yields from SDD batches of <100 mg is used. This dryer is not designed to replicate optimized bulk powder properties (e.g., particle size, density) of larger-scale spray dryers, but rather is used to match physicochemical properties for fast, efficient formulation-screening studies. Analogous to the process-development flowchart methodology, a formulation selection flowchart, comprising predictive physical-stability models, rapid chemical-stability screens, and bio relevant in vitro performance tests is key to selecting a lead SDD polymer and drug-to-polymer ratio. For the sake of brevity, these will not be addressed in this paper.

After a robust formulation has been identified, equipment-related and formulation-related process constraints are identified, resulting in definition of the drying-gas flow rate (M gas) and drying-gas inlet temperature (T in).

The thermodynamic operating space described above defines the process based upon near-equilibrium assumptions and does not account for kinetic limitations such as the drying of large droplets or increased drying resistance due to film formation at the droplet surface. Drying kinetics of single droplets can be studied experimentally, but the information provided—while useful—does not account for the actual conditions in the spray dryer such as droplet velocity and momentum exchange between the droplets and the drying gas.

Many aspects of this approach can be directly translated to other atomization/evaporative processes, such tablet-coating and fluid-bed processes. A similar strategy can also be applied to many other pharmaceutical-processing unit operations.

We at KERONE have a team of experts to help you with your need for spray drying in various products range from our wide experience.

Rice and Paddy Processing Plant & Equipment

Kerone has been familiar with the development of rice mills/plants from last 47 years. We are the right partner from a mill with an hourly capability of 2,000 kilogram to the totally automated giant mill. Our clients can avail from us an excellent range of Rice Processing Plant, which is made using latest technology. Widely used for making finest quality rice, these plants are easily installable and thus deliver best results. These plans are highly appreciated for their features like reliable operations and less maintenance. We at Kerone Design and Manufacture Customized Rice Mills/Plants in many specifications.

Rice is the world’s largest food crop and in many countries of the world rice is the most important staple food. Due to the constantly growing world population the demand for rice continues to increase. It has become necessary to meet the demand of the world’s current population growth rate, and the least costly means for achieving this aim is to increase rice productivity, wherever possible.

Features of complete rice mill production plant

  • Fully automatic complete rice mill production plant, less power consumption.
  • Simple operation, the whole operation can be operated by only one person.
  • Paddy rice mill processing plant starts with innovative design and highly efficient transmission technology that provide unbeatable milling performance with a minimum of complexity.
  • Matched a polishing machine; users can flexibly polish white rice for different rice, reduce the broken rice rate of finished rice and satisfy different rice polishing process requirements.
  • The processed rice can be bagged directly to reduce labor intensity.
  • We are complete rice mill processing plant manufacturer which have rich experiences of building the rice processing plant at abroad successfully, and received high reputation from our customers for good quality, best price as well as professional technical support.

Our technology covers the complete range of rice and paddy handling – from pre-cleaning, paddy storage, dryers, hullers, polishers, rice whiteners, optical sorters to bagging.

But we provide far more than machines. We’ve got groups of food scientists, who will facilitate with consumer trends and recipes. Our digital services will help speed up your method, or use our consultancy to enhance efficiency, food safety or energy savings. We work with every type of rice plants

Guide to Understanding the Baghouse Filter Bags

Since the Clean Air Act in the 1970s, the utilization of fabric filter baghouses for both process and nuisance dust collection has experienced a 16% compound growth rate worldwide. Growth rates have leveled in the U.S., but maintained themselves in emerging countries. Government and social mandates have brought requirements for larger and more sophisticated baghouse cleaning designs, and more advanced fabric filter bag designs and filter media for use in baghouse filtration.

Common Names for Dry Fabric Filter Bags

Since there are so many different industries that utilize dust collection, filter bags adopt many different names. Sometimes what a filter is referred to can be dependent on the application it is used for or the material it is made out of. The following are a list of names; some you may have heard of and others you may not have. Getting to know this list can instantly help when trying to troubleshoot a dust collector with a co-worker or service provider.

  • Reverse Air Bags
  • Filter Bags
  • Filter Socks
  • Filter Media Bags
  • Tubular Bags
  • Dust Bags
  • Felted Bags
  • Woven Bags
  • Fiberglass Bags
  • Envelop Bags
  • Cartridges
  • Pleated Elements
  • Fabric Filter Bags
  • APC Filter Bags
  • Baghouse Filter Bags
  • Pulse-Jet Bags
  • Shaker Bags

Dry fabric filters, more commonly known as baghouse filters, are used to remove dust from the air by capturing air borne dust(s) suspended in the air. The air is directed using either vacuum suction or pressure into a series of ducts, which run horizontally and vertically from pick-up points at single and multiple plant process and nuisance dusting areas. The dust-laden air is sucked into a main gathering duct trunk line terminating at the air inlet of a baghouse fabric filter.

The baghouse itself is a large housing sometimes designed with multiple chambers. Dust collectors are designed to capture the dust and thus filter the air from particulate laden (dirty air) turning the dirty air into clean air; virtually particle free. Once the air is cleaned, it’s exhausted from the collector’s clean air side back into the atmosphere. Dirty solid particles are captured on the filter bags surface, while the gases being filtered pass through the filter bags media. This bag media is called “filter media” and will be discussed later.

Baghouses can automatically clean the filtered particles off of the filter media based on a periodic need to clean the filter bags media. This is called regenerating the filter bag medias permeability, which removes enough compacted dust cake to allow air to flow again at a low (<6” W.G. static loss) restriction (static loss) across the filter media. The system depends on a Fan or Blower to either pressure (push) or vacuum (suck) the air across the filter bags’ media. This means the filter bags media has a dirty side and a clean side. The dirty side intercepts, filters, and compacts the dirty air stream gases, while the clean side has contact with clean air stream gas as it passes through the media.

Characteristics of Filtration Fibers

  • Acrylic Fibers
  • Aromatic Polyamide (Nomex)
  • Polyester (PE)
  • Polypropylene (PP)
  • P84 (Polyimide)
  • Teflon
  • Glass
  • Ryton (Polyphenylene Sulfide)

As a baghouse OEM, one of the most important Baghouse Equipment design criteria considerations is the proper selection of both the bag’s filter media and the bag’s size / tailoring. To select a proper bag filter media as a baghouse OEM and as baghouse owner in the market to purchase bag replacements, you need to determine the following information:

  • Compare baghouse application / process to filter media application selection chart by temperature and chemical resistance.
  • Evaluate previous job dust handling experience to select suitable internal can and interstitial velocity ranges.
  • Once internal velocities ranges are agreed upon, then final air to cloth ratio and filter bag length can be calculated.
  • Filtration efficiency selection in terms of outlet dust emission requirements to meet air permit is revisited based on actual internal velocities, air to cloth ratio, and bag length. This final analysis and review is used to determine if special media surface treatments or PTFE membrane is required to insure success in meeting filtration efficiency and maintaining a DP range of between 2.5” WC to 4.5” WC.
  • Determine special application design requirements for ground wire, bottom wear guards, and special sewing / needle hole close-offs. At this point in your developing final filter bag selection and specifications you will have determined the following bag design criteria:
  • Next, here are some helpful tips to ensure you receive the filter bag you have specified and have placed on order

There you have it. You are now on your way to becoming a expert in baghouse filter bags. If you’d like to expand your knowledge even further we can send one of our engineers to your facility to conduct a workshop custom fit for your equipment and staff.

We at KERONE have a team of experts to help you with your need for baghouse filter bags in various products range from our wide experience.

Advantages and Importance of Grain Drying

The drying of cereals could be a method known since ancient times that, over the decades, has skilled evolutions and changes. The grain drying treatment, that tried indispensable, continues to be carried out nowadays, in several and alternative ways. If done effectively, this method will deliver necessary advantages to farmers and farms. But in what way? And what benefits are we talking about, exactly?

The grain drying treatment, whether it’s carried out naturally or unnaturally, plays a basic role within the marketing of the product. However, the best benefits occur once the method is dispensed with specific and advanced drying systems, like mobile grain dryers and tower dryers.

Grain dryers of first generation were unlikely to adapt to hostile atmospheric condition, with the result that drying was usually not effective. Today, however, the foremost technologically advanced grain dryers will optimally satisfy any drying requirement, even with high humidity levels (i.e. 35%) and in environments with very low temperatures and fewer favourable conditions.

The main advantages of grain drying with these systems are:

Safer storage – By reducing the moisture content in the grains, the possibility of degradation or germination of the cereal is eliminated: therefore, it can be stored even for long periods in a safe manner maintaining the quality of the product.

Less molds and/or aflatoxins – The reduced water content also makes it possible to eliminate the risk of the onset of harmful agents such as molds or aflatoxins, which can damage the cereal and also represent a danger to human and animal health.

Less waste – Grain drying, eliminating the risks associated with the possible deterioration of the product, allows to significantly reduce the losses associated with numerous movements of the product, exposure to theft, birds and rodents: the greatest part of the harvested product will then be marketed, without significant losses;

More productivity and quality – Grain drying through a dryer allows to speed up the process, allowing greater flexibility and an increase in productivity: in a few hours it is possible to dry many tons of products, a process that would require several days with the traditional method. Owning a dryer means being independent in the treatment, which can be performed at any time and keeping the parameters that affect drying under control. Also, by eliminating the risks associated with product degradation, even the quality remains at best.

More value and profits – The flexibility gained by the farmer, combined with the benefit of greater security regarding the conservation and quality of the harvested cereals, offer the opportunity to sell the product at a higher price, following the most favourable periods for putting it on the market. In this way, profits also increase and they are maximized.

The advantages of grain drying are necessary and decisive for the success of a farm, particularly if carried out with systems specifically designed for this purpose, like grain dryers. To mention the five main advantages that may be obtained, we have: larger safety for storage, elimination of the onset of molds and aflatoxins, reduction of waste, higher product quality and productivity, increase and maximization of profits.

Kerone has been a specialist within the production of grain dryers for many years and continually pursues innovation and constant improvement. If you wish to get the benefits of grain drying directly, contact us: our team of specialists is at your disposal to assist you discover the proper resolution for your wants.

We at KERONE have a team of experts to help you with your need for drying technologies for grains in various products range from our wide experience.

Manufacturing Methods for Production of Pharmaceutical Tablet

A tablet is a pharmaceutical dosage form. It contains of a combination of active substances and excipients, generally in powder form, passed are compacted into a solid dose.


  1. Diluents, binders or granulating agents, glidents and lubricants to ensure efficient tableting;
  2. Disintegrates: to promote tablet break up in the digestive tract;
  3. Sweeteners or flavours: to enhance the taste;
  4. Polymer coating: it is applied to make the tablet smoother and easier to swallow, to control the release rate of the active ingredient, to make it more resistant to the environment.

There are three methods by which tablets are manufactured;

  • Wet granulation
  • Dry granulation
  • Direct compression

Manufacturing process depends on many factors, including the compression properties of the therapeutic agents, the particle size of the therapeutic agent, excipients and the chemical stability of the therapeutic agent throughout the producing method.

Wet Granulation

  • It is most commonly used method for the manufacturing of tablets.
  • Water is frequently used as the granulation fluid (and heat is employed to dry the formed granules), it is important to ensure that the therapeutic agent is chemically stable during the granulation process.
  • The wet granulation exhibit sufficient mechanical properties to be subsequently exposed to other unit operations, Eg: film coating.
  • Tablet quality is directly affected by the choice and concentration of binder and the type and volume of granulation fluid. Due to the number of unit operations to the required, the manufacture of tablets by wet granulation is not as efficient as other methods. Eg: direct compression.

Dry Granulation

  • When tablet ingredients are sensitive to moisture and unable to withstand elevated temperature during drying and when the tablet ingredient have insufficient cohesive properties, slugging may be used to form granules.
  • This technique is used in preparation of aspirin, aspirin combination, and acetophenetidin.

Excipients used in this method:

  • Diluents/ filler: anhydrous lactose/ lactose monohydrate, starch, dibasic calcium phosphate, and MCC
  • Disintegrants: Starch, MCC, Sodium starch glycolate, Croscarmellose sodium, Crospovidone.
  • Lubricants: Stearates (Mg. stearate, steric acid), Glyceryl fatty acid esters, polyoxyethylene stearates, SLS.
  • Glidants: Talc, Colloidal silicon dioxide.
  • Miscellaneous Excipients: Colours, sweetening agents, etc.

Advantages & Disadvantages:

  • This technique popularity has decreased in recent years, having been superseded by direct compression.
  • However both slugging and roller compaction are still employed in tablet manufacture.

Direct Compression

  • Wet granulation and dry granulation methods having series of unit operations, both time consuming and potentially costly.
  • Potentially more attractive option for the manufacture of tablets involves powder mixing and subsequent compression of the powder mix, thereby obviating the need for granulation. This process is called direct compression.
  • The mechanism of particle-particle interactions in tablets produced by direct compression are similar to those operative in tablets produced by dry granulation and roller compaction.

Manufacture of Tablets Steps:

  • Mixing of the therapeutic agents with the excipients
  • Granulation of the mixed powders (this is not performed in direct compression)
  • Mixing of the powders or granules with other excipients (mostly lubricants)
  • Compression into tablets
  • The details of each of these steps will vary depending on the manufacturing method used.

The selection of a tableting method depends on variety of things, including the chemical properties of the API similarly because the desired mechanical options of the finished tablets. Whereas heat-based granulation techniques are unsuitable for APIs with temperature sensitivities, and liquid- or foam-based processes may be harmful to water-sensitive APIs, these methods can provide many of the advantages of dry granulation, without the fragility of a dry-compressed tablet product.

We at KERONE have a team of experts to help you with your need for different methods of tablet manufacturing in various products range from our wide experience

Importance of Drying During Production

At a certain point, each production method encounters the problem of moisture. The causes of moisture will vary widely and therefore the consequences of moisture are usually terribly completely different. However, the answer continually comes all the way down to an equivalent thing: remove the maximum amount moisture as possible. Drying or blow-off solution will prevent a lot of your time, energy and cash.

Possible causes of moisture?

The causes of moisture formation will vary widely. Our expertise shows that these causes are often divided into 3 broad classes:

  1. Cooling – several product are cooled. Typically because the last step during a sterilization or pasteurization method. Water is usually used for this purpose, leaving water droplets on the product. For example: prepared meals, cans, pet food, other examples are extrusion of plastics or rubbers.
  2. Cleaning – After production, the product are usually cleansed, washed or rinsed. Once again, water droplets remain behind. For example: beer, jam, sauces, and soft drinks.
  3. Steam – To sleeve products, they are often placed in a steam tunnel. The excess water must be removed. For example: fruit juices.

Possible problems due to moisture?

  1. Contaminated environment – First of all, moisture contaminates the space in which the production process takes place. Moisture is difficult to control. Especially in places where hygiene is of great importance, (polluted) water can make the whole environment dirty and dangerous (slippery).
  2. Ink spill – Printing on damp products is not possible. Many products require a production date or an expiry date. As long as the product is still damp, the inkjet codes will run out and become illegible.
  3. Non-adhesive labels – Even if you want to stick labels on the products, this will not work as long as they are damp. The glue from the labels can only stick on completely dry surfaces.
  4. Damaged machines – After all, many (packaging) machines are not resistant to water. Wet products can leave moisture in your machine and cause it to break down faster.
  5. Failing control equipment – Production processes are often checked at different times and on different parameters (such as speed, weight, etc.). The cameras, metering cells and different equipment used for this purpose sometimes don’t perform properly once the product remains coated with water droplets. Or the equipment could sustain water damage.
  6. Mould formation – Food is often packed in plastic. If the product is still wet, the moisture evaporates and mould can form.
  7. Cracking cardboard – Another ordinarily used method of packaging is cardboard. Cardboard, too, isn’t resistant to water and often tears when it gets wet.

We at KERONE have a team of experts to help you with your need for drying technologies in various products range from our wide experience.

Advantages and Common Applications of Vacuum Drying

Vacuum drying is that the mass transfer operation during which the moisture present in a substance, typically a wet solid, is removed by means of making a vacuum. In chemical process industries like food process, pharmacology, agriculture, and textiles, drying is an important unit operation to get rid of moisture. Vacuum drying is usually used for the drying of substances that are hygroscopic and heat sensitive, and relies on the principle of making a vacuum to decrease the chamber pressure below the pressure level of the water, causing it to boil. With the assistance of vacuum pumps, the pressure is reduced around the substance to be dried. This decreases the boiling point of water within that product and thereby will increase the speed of evaporation considerably. The vacuum drying method may be a batch operation performed at reduced pressures and lower relative humidity compared to close pressure, enabling quicker drying. The drying kinetics and drying efficiency of vacuum drying for fruits and vegetables is improved by combining microwave power to vacuum drying.

Vacuum Dryer:

Vacuum dryer is that the equipment with the assistance of which vacuum drying is carried out. in the pharmaceutical industry vacuum dryer is known by a standard name known as vacuum oven. Vacuum dryers are generally created from cast iron, however most currently are made from stainless steel, so they will bear the high vacuum pressure without any kind of deformation .The oven is split into hollow trays that will increase the extent for heat conductivity .The oven door is locked air tight and is connected to air pump to reduce the pressure.

The materials to be dried are kept on the trays within the vacuum dryer and pressure is reduced by means that of pump. The dryer door is tightly shut and steam is passed through the area between trays and jacket so the heat transfer happens by conductivity. Water vapours from the feed is distributed into the condenser and once drying pump is disconnected and therefore the dried product is collected from the trays.


Vacuum dryer may be wont to dry heat sensitive hygroscopic and toxic materials. If the feed for drying is a solution, it may be dried utilizing vacuum dryer because the solvent are often recovered by condensation. to enhance quality of products, like for fruit preservation, hybrid drying combining osmotic dehydration followed by heat pump drying and microwave-vacuum drying proven effective.

drying is one amongst the foremost industrial drying techniques for heat-sensitive, hygroscopic, and/or toxic powders and granules. Avoiding excessive heat whereas drying powder is also necessary for a variety of reasons, starting from product quality to safety:

Pharmaceutical powders – active ingredients may lose their medicinal effect when warmed.

drying – certain nutrients may break down if exposed to high temperatures. Taste, consistency, and appearance can also degrade under too much heat.

Plastics and chemical processing – synthetic materials can leach toxins with prolonged exposure to heat. This can even make convection drying methods hazardous, as the hot air stream must eventually be emitted.

Vacuum drying may be a safe and extremely methodical technique for drying giant volumes of heat-sensitive powders or granules at a far lower temperature than would be needed in a traditional industrial dryer. In a vacuum, wherever ambient pressure is reduced, the flashpoint of liquids lowers significantly.

Drying is among the foremost energy-intensive unit operations, because of the high latent heat of vaporization of water and therefore the inherent inefficiency of using hot air because the (most common) drying medium. Depending on the precise product attributes needed, completely different business sectors need different types of drying technology. Drying high-value products that are seemingly to be heat-sensitive, like food, pharmaceuticals and biological products, demands special attention. Once dried by convection at higher temperatures, these heat-sensitive products.

We at KERONE have a team of experts to help you with your need for vacuum drying in various products range from our wide experience.

Different Methods of Grain Drying

Grain drying is method of drying grain to stop spoilage throughout storage. The grain drying represented during this article is that which uses fuel- or electric-powered processes supplementary to natural ones, as well as swathing/windrowing for drying by close air and sunshine.

Hundreds of millions of tonnes of wheat, corn, soybean, rice and different grains as sorghum, sunflower seeds, rapeseed/canola, barley, oats, etc., are dried in grain dryers. Within the main agricultural countries, drying contains the reduction of moisture from about 17-30% w/w [clarification needed] to values between eight and 15%w/w, looking on the grain. The ultimate moisture content for drying should be adequate for storage. A lot of oil the grain has, the lower its storage moisture content is (though its initial moisture for drying will be lower). Drying is carried out as a requisite for safe storage, so as to inhibit microbic growth. However, low temperatures in storage are extremely suggested to avoid degradative reactions and, especially, the expansion of insects and mites. a decent maximum storage temperature is regarding eighteen °C.

The performance of a drier are often simulated with computer programs supported mathematical models that represent the phenomena concerned in drying: physics, physical chemistry, thermodynamics, and heat and mass transfer. Most recently computer models are used to predict product quality by achieving a compromise between drying rate, energy consumption, and grain quality. A typical quality parameter in wheat drying is bread creating quality and germination percentage whose reductions in drying are somewhat connected.

Drying starts at the bottom of the bin, that is the primary place air contacts. The dry air is referred to by the fan through a layer of wet grain. Drying happens in a layer of one to two feet thick that is termed the drying zone. The drying zone moves from the bottom of the bin to upper part, and once it reaches the very best layer, the grain is dry. The grain below drying zone is in equilibrium moisture content with drying air, which implies it’s safe for storage; whereas the grain on top still requires drying. The air is then forced out the bin through exhaust vent.

  • Allowable Storage Time
  • Proper moisture levels for safe storage
  • Equilibrium Moisture Content
  • Temperature
  • Aeration

The drying value is created from 2 parts: the cost of capital and also the operating expense. cost of capital is essentially rely upon the drying rate demand, and equipment value. operating expense refers to fuel, electricity and labor value. the number of energy needed to dry a bushel of grain is comparable for all the drying ways. Some ways rely mostly on natural air, whereas others might use lp heat or fossil fuel, that create energy price vary. Basically, fuel and electrical power are the foremost parts of the operating expense. Drying value is predicated on the B.T.U. consumption of temperature change from environment to desired one.

Classification of grain drying methods according to mode of heat transfer:

Storage drying methods

  • Low-temperature drying
  • Multiple-layer drying

Batch drying methods

  • Bin batch drying
  • Column batch drying

Continuous flow drying methods

  • Cross flow drying
  • Counter flow drying
  • Concurrent flow drying

Applications of grain drying

  • Sunflower drying
  • Bean drying
  • Corn drying

We at KERONE have a team of experts to help you with your need for drying of grains in various products range from our wide experience.

Drying Methods for Improving the Quality of Dried Herbs

Herbs are “any plant with leaves, seeds, or flowers used for seasoning, food, medicine, or perfume”. Herbs are considered to be extremely perishable foods thanks to their high moisture content and most herbs are chill-sensitive. They’re thus processed by drying to make shelf-stable product. Drying preserves the standard of herbs by reducing the moisture content that inhibits the expansion of microorganisms and chemical alterations throughout dried storage. Within the cooking sense, dried herbs are usually used as “flavouring” agents to feature their characteristic aromas to the foods. Aside from the cooking usages of herbs, their oil may be used as AN antimicrobial agent that’s effective against microorganism, yeast, and molds. Dried herbs even have several applications in alternative fields, like in medical and toiletry product and in fragrance producing. Herbs are identified to be a superb source of antioxidants. The standard characteristics thought of to be the most necessary for dried herbs could rely upon their usage. For example, the standard of medical dried herbs is defined by the content of bioactive compounds. Whereas the standard of culinary dried herbs is typically defined by their color and fresh-like characteristic aroma.

Dried culinary herbs are typically high in price, thus, the expectation of end user relating to the standard of the product are typically high. The quality specifications of dried herbs are listed largely to make sure the chemical and microbiological safety of the product, such as, moisture content, bulk density, foreign matter, and the content of excretory product, aflatoxins and heavy metals.

Essential oil is the main contribution of herb aroma though it’s present in little amounts. The international organization for Standardization (ISO) has defined the meaning of the term “essential oil” as a “product obtained from a natural material of plant origin, by steam distillation, by mechanical processes from the pericarp of citrus fruits, or by dry distillation, when separation of the liquid section — if any — by physical processes”. Essential oils are often utilized in many varieties of applications, like pharmaceutics, cosmetics, and therefore the medical and food industries. In fresh herbs, essential oils are keep on the surface of the leaves in specialised structures referred to as trichomes, that are uni- or multicellular appendages within the epidermal cells that develop outward from the surface of plant organs like leaves, roots or barks. Therefore, conserving trichome integrity or minimizing the harm to trichomes throughout drying may improve the yield of essential oils and therefore the aroma quality of dried herbs. Volatile compounds in herbs may be conjointly found in glycosidically-bound forms as they’re water soluble and may be accumulated within the plant tissues. 

Essential oils are composed of some or several chemical compounds, with some kinds of herbs containing over 100 chemical compounds. The chemical composition of the essential oils varies decided by the kind of herb, harvesting season, postharvest practices, age of the plant and storage conditions. Every compound contributes its specific flavor to the essential oil. This contribution depends on their specific odour threshold, which may be determined by the structure and volatility of the compound. The changes within the concentration of the essential oil chemical parts (either by chemical reactions or degradation), even with minor elements, could lead to drastic changes within the essential oil flavor.

The changes in volatile compounds throughout the drying method additionally rely on the biological factors of the herbs, as well as initial moisture content, the age of the plant, growth conditions and harvesting time. Storage conditions also have an effect on the content of volatiles of the dried product, particularly within the presence of light and oxygen. The reduction of some essential oil elements may be considered to be a profit, like the reduction of pulegone, a hepatotoxin in hedeoma pulegioides and mentha pulegium.

Pre-treatments before drying are process methods aimed toward achieving high-quality dried herbs; shorten the drying time, and reducing the energy consumption. Smart pre-treatments implementation should produce solely smallest modification to the drying method settings to reduce the follow-up prices from the modification. Many pre-treatments are reported to provide advantages for drying of herbs, like blanching, pulsed electric field, and ultrasonic treatment.

Drying technique is one among the main factors affecting the quality of dried herbs. Drying strategies applying extreme temperature would considerably decrease the number of aroma compounds, since aroma compounds are heat-sensitive substances and might be evaporated from plant tissues simply throughout drying.

Drying Methods used for herbs are classified below:

  • Sun drying
  • Shade drying
  • Solar-assisted drying
  • Hot-air drying
  • Freeze drying
  • Microwave drying
  • Microwave-vacuum drying
  • Heat-pump-assisted drying
  • Infrared drying
  • Fluidized bed drying
  • Supercritical CO2 drying (scCO2)
  • Radio-frequency drying
  • Hybrid drying methods

A number of pre-drying treatments and drying strategies, investigated in numerous herbs, are developed, showing an improvement in quality, better energy conservation, and higher method efficiency. Hybrid-drying techniques have shown promising results on the development of dried herbs quality as well as each color and aroma. In spite of those technological developments, obtaining high-quality dried herbs remains a difficulty as herbs are sensitive to completely different pre-drying and drying method conditions, primarily in regard to color and aroma. Moreover, the standard of dried herbs is incredibly sensitive to the kind of herb, harvesting season, postharvest practices, age of the plant and storage conditions.

We at KERONE have a team of experts to help you with your need for drying of herbs in various products range from our wide experience.