Essay: Food Processing - Thermal And Non-Thermal Methods For Understanding.

Types of Food Processing Techniques

Discuss about the Effect of the High-Pressure Processing on Colour.

Processing of food can be understood as the physical or chemical methods that are used to convert cooked ingredients into the final product. The process combines raw ingredients to product finished products that is marketable which can be prepared and consumed easily. The process involves several types of actions such as macerating, mincing, emulsification, pickling, pasteurization, liquefaction as well as cooking (like grilling, broiling, frying, or boiling) (Sun, 2014). It can also involve processes of packaging (by slicing, dicing or freezing and drying), preservation or canning of the finished product. Processing food helps in the better preservation, distribution and marketing of the products and also protects it from contamination by pathogens or toxic substances. It also helps to maintain year long availability of the products and makes the food easy to prepare and consume (Lelieveld et al., 2014; Maga, 2018).

Thermal processing utilises a combination of temperature and time in order to remove microbes or pathogens in the food. This type of food processing uses high temperatures for the preservation of food, and to ensure its safety from pathogens, and it is the most commonly used strategies of food processing used in the food industry (determined as a Critical Control Point, CCP) (Bauman, 2018). The two main categories of temperatures used in thermal processing include pasteurization and Sterilization (Bornhorst et al., 2017). These processes ensure the reduction or destruction of microbe activity in the food and also to reduce or destroy enzymatic activity and also produce desirable physical or chemical changes in the food, meeting a certain quality standard. The milder thermal processes include Blanching and Pasteurization, while more severe thermal processing involves sterilization, canning, baking, frying and roasting (Erdo?du & Boz, 2015; Sevenich & Mathys, 2018).

Blanching can be done at 100^oC with hot water or steam at or near atmospheric pressure, and can be used to destroy enzyme activity in vegetables or fruits. Pasteurization is used for milk, and uses mild heat (less than 100^oC) to destroy enzyme activity and certain microbes (such as non spore forming yeast, bacteria or moulds). In sterilization, high temperatures are used (110 to 121^oC) under high pressures to destroy or kill heat resistant microbes such as the spores of Clostridium or Baccilus (Orsat et al. 2017; Gao et al., 2016; Teixeira, 2015).

Non thermal processing of food involves strategies that do not require heat, in order to killing or inhibiting microbes in the food. This process helps to preserve the volatile compounds in the food and preserve the food at a better quality compared to thermal processing (Santhirasegaram et al., 2015). Different technologies can be used in the non thermal processing of food, such as using ultra high pressures, pulsed x ray, ionising radiations, high voltage arc discharges, ultrasound, magnetic fields, pulsed light or electric fields, cold plasma technology, hurdle technology and dense phase carbon dioxide (Buniowska et al., 2017; Trudeau, 2016).

Thermal Processing: Pasteurization and Sterilization

Important ingredients found is most foods include: Carbohydrates, fats, proteins, fibre and phenolics (Sahidi & Ambigaipalan, 2015; Zanini et al., 2015; Wang et al., 2016). Additionally, processed food can include several types of ingredients such as: preservatives, sweeteners, colour additives, flavours and spices, flavour enhancers, fat replacers, nutrients, emulsifiers, stabilizers, thickeners, binders, texturizers, pH control agents, acidulants, leavening agents, anti-caking agents, humectants, yeast nutrients, dough strengtheners and conditioners, firming agents, enzyme preparations and gases. These ingredients help to maintain and improve the safety and freshness, nutritional value, taste, texture as well as appearance of the food, and also to improve the shelf life of the food product (Fletcher, 2014; Elizabeth et al., 2017).

Nutritional quality of food as well as its safety is affected by the destruction of essential amino acids, interactions with various ions of metals, a reduced digestibility of the food, inhibition of proteolytic and glycolytic enzymes and the production of toxic or anti nutritional compounds in the food (Chiang & Quek, 2017). The Millard Reaction or Enzymatic Browning is a significant process that involves the interaction of amino acids, proteins and peptides with vitamin C and reducing sugars (Abdel-Razek et al., 2017).

The glycation of protein by sugars caused by Thermal Processing can negatively affect the nutritional value of proteins. The bioavailability of the proteins is reduced by the cross linkages formed and the destruction of reactive amino acids such as lysine. The loss in the nutritional quality can be associated with the reduction in nitrogen digestibility due to impaired absorption from the intestine for heat treated casein, casein-starch and casein-glucose, thus showing an overall reduction in digestibility of these proteins (Milkovska-Stamenova et al., 2017; Renzone et al., 2015). It has also been proposed that the reduction in the intestinal absorption of the lysine derivatives induced by the Millard Reaction is the basis of the reduction of the nutrient value of food after thermal processing. Also, apart from the physiological changes to the properties of the non enzymatic Millard’s Reaction Products, thermal treatment of food can also cause the formation of toxic products such as Lysinoalanine (LAL), Melanoids and Heterocyclic Amines (HA). LAL is a cross linking substance that is produced in proteins that is thermally treated under alkaline conditions which causes the amino group of the lysine in the protein chain to react with dehydroalanine (Jabbari et al., 2018). This cross linking reaction occurs mainly intramolecularly and causes a reduction in the digestibility of proteins (Sayers et al., 2016; Smith et al., 2015).

Non-Thermal Processing of Food

Carbohydrates are mostly found in foods containing grains, sugar and fibre, and are formed with molecules of sugar, oxygen, hydrogen and carbons fused together. Each carbohydrate molecules has a specific structure and composition in terms of the atoms that comprises it and its spatial position in the molecule (Smythe et al., 2018). When food rich in carbohydrate is cooked, it undergoes two possible types of changes such as Caramelization and Gelatinization (Hrynets et al., 2015; Kanmani et al., 2018). Caramelization occurs when the sugars present in the carbohydrates turns brown, while Gelatinization occurs when the starch in the carbohydrates starts to swell by absorbing water (Dalluge et al., 2014; Chen et al., 2014). Studies by Iyenagbe et al. (2017) shows that gelatinization of carbohydrates increases the water absorption capacity (WAC) values of food, which causes the typical swelling observed in food rich in carbohydrates. The volatile products produced during the heat processing of food (in techniques which requires temperatures above 200^oC such as baking, frying or roasting) results in the production of flavours in the food. Studies have shown that the volatile compounds produced due to the pyrolysis of starch, cellulose, glucose, sucrose and maltose were in effect identical, which shows that the same volatile agents are responsible for the flavours created in such food components (Wang er al., 2014). For carbohydrates such as monosaccrides and di-saccharides (low molecular weight carbohydrates), wet heat treatment (such as blanching, boiling or canning) loss of nutrients and micronutrients can occur, due to leaching into the processing water. For example, blanching carrots can cause a loss of 25% of the carbohydrate quantity, and an additional 20% loss can be caused by boiling (Stahl, 2014). This loss is however lesser in case of green beans, peas and sprouts. Boiling also causes a loss in fructose and glucose as well as sucrose (however it is lesser than glucose and fructose loss). The loss of carbohydrates is also affected by the period of storage of the food before processing as well as on its cultivation and harvesting, with more losses of carbohydrates occurring in food that is stored for a longer period of time before being processed (Deng et al., 2015).

The heat causes the weak bonds and glycosidic linkages in polysaccharide chains to be broken. This causes the depolymerisation of the carbohydrate molecules and improves the solubility of the compounds (Price et al., 2015). Extensive depolymerisation can cause the formation of alcohol soluble fragments and significantly reduced quantity of dietary fibres; while moderate depolymerisation can slightly affect the dietary fibre content, but can significant affect the physiological and functional properties of the food. The dietary fibre content is also affected by the leakage of nutrients into the processing water, production of the intermediates of Millard Reaction which causes an increase in the lignin content and the formation of resistant starch (Pold et al., 2016). Thermal processing also changes the architecture of the cell wall which also affects the nutritional and sensory characteristics of the food. The cell wall matrix changes as a result of heat treatment, that causes structural changes and affects the cross linkages between the phenolics and polysaccharides in the cell wall. For wheat flour, this can increase the solubility of the dietary fibre, which is also dependant on the net water content (lower water content allowing higher solubility of the fibre) (Ye et al., 2015; Fuller et al., 2016).

Important Ingredients Found in Most Foods

Studies have shown that after heat treatment, the free fraction in phenolics acids increased in the food product, while the amounts of glycoside, ester and ester bound compounds as well as the total flavanone glycosides decreased. It also resulted in the increased in the antioxidant activity and the total antioxidant capacity. Also, prolonged periods of heating at high temperatures can also destroy the flavinine glycosides (Juániz et al., 2016). However, other studies propose that for conventional and organically grown food, the phenolics content decreases as a result of thermal processing. This can be attributed to the minimal processing involved. Ion some vegetables, decreasing the temperature can help to preserve most of the phenolics content of the food, while steam cooking can significantly reduce the phenolics content of the food (Zoric et al., 2014). Processes like boiling, frying and microwave cooking have been found to reduce the phenolics content of food, with microwave processing causing the most significant changes compared to other thermal processes. These forms of processing not only reduces the total phenolics content of food, but also the effects the beneficial role of the phenolics. Thermal processing also results in the formation of antioxidants. This has a positive effect on the prevention of lipid oxidation, and also scavenges the active oxygen species. Chelation of metals is also another significant effect of thermal processing of food (Nayak et al., 2015; Turturic? et al., 2016).

Fats are present in poultry, meat, fish, milk products, whole grains and nuts, as well as in vegetables and fruits (to a lesser degree) and are important mediums for frying. They can be solid (fats) or liquid (oils) at room temperatures. When heated the fat molecules starts to break down and produce smoke. The process of heating or frying (at 180 to 220 ^oC changes edible oils causes chemical changes, resulting in the formation of trans-fatty acids and saturated fatty acids, increasing its quantity in the food, and also caused a decrease in cis-unsaturated fatty acids (Michas et al., 2014).

Roobab et al. (2018) studied that effect of non thermal technologies of food processing on the microbiological quality of food. The analysed the effects of ultrasonification, pulsed electric field PEF), irradiation and high pressure processing (HPP) as well as their combinations for the preservation of juice. These strategies allow the retention of the bioactive components as well as the nutritional values that are typically lost due to thermal processing. Technologies such as sonification HPP and PEF helps in the better retention of Vitamin C. For example, non thermal processing of watermelon juice can help in the better retention of ascorbic acid and lycopene. Similar outcomes were also seen in case of PEF processing of fruit juices, showing higher amounts of vitamin C after the processing. Similarly, irradiation also does not affect the level of Vitamin C in the food, thereby preserving its quantity. PEF also helps in the better retention of anthocyanins and polyphones in juice, compared to thermal treatment. For bioactive components, irradiation can have significant effects, for example, using gamma irradiation higher than 2 kGy for fruit juices can cause significant degradation of the antioxidants in various fruit juices (Lindgreen et al., 2016; Liu et al., 2016).

Effects of Thermal Processing on Nutritional Quality

High Pressure Processing of food uses high pressures (between 400 and 600 MPa) and mild processing temperatures, below 45^oC to induce the effect of pasteurization which can allow the preservation of most of the food, without effecting the nutrient value, texture or taste of the food, and can be used for both solid and liquid foods. With the increase in pressure by 100Mpa, the temperature of water can rise by 3^oC, and is even higher for compressible food ingredients such as fats. Thus during HPP, food with higher fat content experiences a higher rise in temperature. Molecules with low molecular weight are minimally affected by high pressures. Thus, molecules of vitamins, pigments and flavouring compounds are preserved in a better manner by HPP compared to thermal processing, thus ensuring better preservation of the nutrient values of the food. However, some other compounds (having higher molecular weights) are changed irreversibly due to HPP (Andres et al., 2016). For carbohydrates, the high pressure can cause gelatinization and for proteins, denaturation can occur due to the increase in temperature caused by the increase in pressure. The denaturation of the protein also impacts the function of the bacterial cells and its survivability. Due to the denaturation of proteins, the cell wall and cell membrane integrity can be disrupted, thereby killing the microbes. But for spore forming microbes, HPP can be ineffective (Paciulli et al., 2016; .

Ultrasonication is a technology that can be used to improve the quality of different types of food products such as fish, meat, vegetables, cheese, chocolates, fermented products, carbonated drinks, emulsions and fruit juices. The technology allows heat and mass transfer, cavitations or vibrations which can be used to process or preserve food and to inactivate microorganisms. The ultrasonic treatment helps in the destruction of the cell membranes of the microbes, produces free radicals and extrudes the intracellular matrix, thereby killing the microorganism instantaneously. The effects however depend on the intensity and profile of the ultrasound. Tiny gas bubbles are produced by the sonic waves creating pressure which helps to damage the cell wall and hence provides a bactericidal effect. For the processing of milk, ultrasound can be used for homogenisation of fat globules, removal of dissolved gases and improve the antioxidant activity of the product. Ultrasound does not affect the lactose or protein content of milk but can cause an increase in the concentration of fats. However, ultrasound does not cause the inactivation of lactoperoxidase and alkaline phosphatase activity. Studies have shown that processing of homogenised and pasteurised skimmed milk using ultrasound with 20kHz at 20 and 41W causes a reduction in the turbidity but no change in the viscosity of the milk. This is caused due to changes in the casein micelles, fat globules and soluble particles after an hour of sonification. Proteins also denature, forming aggregates of whey protein, which then interacts with casein micelles to form micellar aggregates (Leong et al., 2018).

Effects of Heat on Carbohydrates

Pulse electric field utilises pulse waves of electricity that can disrupt cell membranes, thus causing it to lose its viability, thus killing any microorganisms present in the food. The electric field causes the electroporation of the cell membrane, creating several poses on the cell surface, thereby destroying it. However this process does not destroy the organoleptic and nutrient quality of the food. The thinning of the cell membrane is caused due to the formation of transmembrane potential as the positive and negative electrical charges accumulate in the cell membrane, which attracts each other creating a compression pressure. With the increase in the electric field, pores are then formed on the cell membrane (Barba et al., 2015).

Pulsed X ray utilises radionuclide sources (like Cobalt 60 and Caesium 137) that generates high intensity x ray beams by bombarding it with Cobalt 39 and Caesium 136. This causes the production of gamma radiations. It can also be produced by electrically driven radiation sources, and the radiation can be used to irradiate the food for processing. This ionising radiation causes the inactivation of microorganisms. The inactivation occurs by 2 main processes, namely the direct interaction of the cellular components with radiation and the action of radiolytic products (like water radicals). The ionising radiation affects the chromosomal DNA and cytoplasmic membrane, causing chemical changes in the bonding, and causing the proteins to denature or lose its functionality. This inactivates the microbes or inhibits its growth. Similarly, pulsed visible light (produced by high voltage electric pulses up to 70KV/cm) also can allow decontamination or sterilisation of food, in a similar mechanism. Antimicrobial effect of pulsed lights or pulsed UV lights can be attributed to photochemical or photothermal mechanisms (Li & Farid, 2016). In the photochemical mechanisms, nucleic acids like DNA are affected. The energy is absorbed by the double bonds between carbon atoms thereby causing change in the structure and thus the function of the DNA or RNA. Ultraviolet C spectrum moreover affects the thymine dimer, which prevents the formation of new DNA, thus inhibiting the process of cell replication and proliferation of microbes. The advantage of pulsed lights is that it does not have any thermal effect on the food, and hence the quality and nutrient content are unaffected by the processing (Zeng et al., 2016).

Proteins, carbohydrates, fats, fibre and phenolics are important ingredients that decide the nutrient quality of a food. They affect the nutrient quality in different ways (Yang et al., 2015).

Effects of Heat on Polysaccharides and Dietary Fibres

Proteins are a vital component in each and every cell of the body. Protein is needed in order to build and repair tissues, produce enzymes, hormones and other important chemicals. It also forms the building blocks of blood, bones, muscle fibres, cartilage and skin. Like Carbohydrates, Proteins are macronutrients (that is it is required in large or macroscopic amounts), however, unlike carbohydrates or fats, the body cannot store proteins, and thus have no reservoir to store excess proteins. Due to this, intake of protein should be regular in order to function properly. Diet rich in protein is also very beneficial to health since it helps to maintain as well as lose weight, stabilise blood sugar levels, increase concentration and learning, increase energy levels, provide support to bones and muscles, and help in the absorption of several nutrients. Proteins are digested in the body to produce amino acids, which are the building blocks of all proteins. These amino acids are then used by the body to build and repair tissues and cells and maintain various metabolic processes. Thus protein is essential for the maintenance of good health and wellbeing (Solon-Beit et al., 2015).

Carbohydrates are a good source of energy and are found in vegetables, fruits, bread, pasta and dairy products. Carbohydrates are used to produce glucose, which is the primary source of energy for the body. The glucose can be utilised immediately or even stored for later use in the form of glycogen. Thus carbo0hydrates acts as vital sources of glucose in the body. Also, carbohydrates prevent the breakdown of proteins to produce energy. This phenomenon can be explained by the fact that the body can also utilise proteins as a source of energy, however, using them for energy also interrupts the important processes in which the proteins are an integral part of, such as growth and repair of cells and tissues. In the presence of carbohydrates, sufficient energy source is available and thus the body does not have to use the proteins as energy source. However, when there is a shortage of carbohydrates or during intense physical exercise (when the supply of energy from Carbohydrates and glucose cannot keep up with the energy demands), the body breaks down the proteins to compensate for the additional energy need.  Carbohydrates also play a key role in the metabolism of fats. When the body has sufficient amount of energy, the excess carbohydrates are stored in the form of fats, which are later broken down to provide energy (Hardy et al., 2015).

Effects of Heat on Phenolics

Fats are essentially energy reserves for the body. Excess carbohydrates which are not needed by the body are stored in the form of fat deposits in the adipose tissues. It provides the body energy when there is a lack of carbohydrates or glucose in the body. The fats actually are more energy dense compared to carbohydrates and proteins. It produces 9 calories of energy per gram, compared to 4v calories produced by carbohydrates or proteins. This shows that fats are a vital source of energy. Fats also help in the transportation of vitamins (such as vitamin A, D, E and K) in the bloodstream and also help their absorption in the body. These vitamins are fat soluble, which allows them to dissolve in the fats and thus be transported in the body. Fats are bad conductors of heat, and thus form a good layer of insulation, and help the keep the body warm. Essential amino acids such as linolenic and linolenic acids are also produced from fats, which play important roles in the process of inflammation, development of brain and the formation of blood clots. Moreover, unsaturated has additional health benefits, as it helps to lower the LDL (Low Density Lipid) cholesterol levels (Herron et al., 2017).

Dietary fibre is also known as bulk or roughage and involves parts of plant that cannot be digested or absorbed. The fibre is passed comparatively intact through our alimentary canal, and can be of two types (soluble and insoluble). Dietary fibre is mostly found in vegetables, fruits, whole grains and legumes. Soluble fibre dissolves in water, forming a gel like substance and can help to regulate the blood cholesterol and glucose levels. Insoluble fibre on the other hand helps in the movement of food through the digestive system and increases the bulk of stool produced. This can help to alleviate the effects of constipation, and improve bowel movement. Studies have shown that diet high on fibre can help to normalise the movement of bowel (increasing the weight and size of the stool and softening it), helps to maintain the bowel health (reducing the risks of haemorrhoids and diverticular diseases or diseases of the colon), reduces the levels of cholesterol in blood (by reducing the levels of LDL cholesterol), regulate blood glucose levels (helping in the absorption of glucose from blood, and reduce the risk of Type 2 Diabetes)), and helps to maintain healthy body weight (by controlling the appetite) (Divyashree et al., 2017).

Conclusion

Phenolic compounds such as simple phenols and phenolics acids and flavinoids are bioactive compounds found in plants. They affect the sensory and nutritional quality of the food. The phenolics are absorbed readily through the intestine and they have antioxidant properties which have a protective effect on the cells, preventing damage caused by free radicals produced during the oxidative reactions in the body. They can also help in anti-inflammatory processes in eaten regularly. Phenolics are plays an important role in the browning reaction, in which an undesirable brown colour and flavour develops in fruits, catalysed by polyphenoloxidase. This process is an essential part of fermentation helping in the development of characteristic smell and colour of certain fermented foods. This shows that phenolics are vital for the maintenance of not only the well being of the body, but also to preserve the nutrient quality and the flavour and sensory perception of the food (Anantharaju et al., 2016; Zhang & Tsao, 2016; Roleira et al., 2015).

Lack of these important nutrients in diet, or inadequate intake can cause several diseases or increase their risks. This effect can be understood in context of the important roles played by these nutrients in the body.

Lack of sufficient protein in diet can cause several physiological effects such as wasting of muscles (caused by the reduction in the mass of lean muscles, muscle strength and functions). Insufficient consumption of protein also can cause weakness, cramping and soreness of muscles, as the body tries to use the existing amounts of proteins as sources of energy. The overall effect is the atrophy of muscles. Lack of protein also slows the process of healing of wounds. This is because proteins and amino acids are important part of the growth and repair of tissues and cells, which is an integral part of the wound healing process. Inadequate dietary protein causes in a reduced production of collagen, which slows the wound healing process. Even the immune system function is also affected by the lack of adequate protein intake in diet. This increases the risks of various infections and diseases. Other physiological effects caused by protein deficit includes a slower metabolism, problems maintaining a healthy weight, problems building muscle mass, chronic lack of energy and fatigue, low levels of concentration and learning problems, mood swings, pain in bones and joints, fluctuations in blood glucose levels, impaired healing of wounds causing secondary infections and even gangrene, and immune deficiency (Solon-Beit et al., 2015).

Carbohydrates are important source of energy for the body, and thus its deficiency in diet causes a lack of adequate energy available for the body. Ketosis is a condition that occurs due to inadequate Carbohydrate intake, which causes the body to use fatty acids for generating energy, resulting in the formation of ketones. The side effects of carbohydrate deficiency include fatigue, intolerance to exercise or intense physical activities, nausea, headache, flu like symptoms and dehydration. The effects of low card diets can also cause starvation like symptoms, leading to the weakening of the body and losing weight rapidly, which can increase the risks of many other diseases like anaemia. Inadequate consumption of carbohydrate can also secondarily cause a reduction in the consumption of fibre (since most plant based food high on carbohydrates also has dietary fibres). The lack of fibre can lead to constipation and other effects caused by deficiency of dietary fibres. Nutritional deficiency is caused as the body’s ability to utilise important vitamins (such as vitamin A, B and C), which can lead to deficiency diseases for those nutrients. Thus a lack of adequate amounts of dietary carbon not only weakens the body by reducing the available sources of energy, but also increases the risks of several other diseases due to the weakening of the body, the immune system and the effects of vitamins in the metabolic pathways (Hardy et al., 2015).

Deficiency of adequate fat in diet can lead to inadequate utilisation of fat soluble vitamins such as vitamin A, D, E and K. This lack of vitamins can cause effects such as dry skin, night blindness, increased risks of infections, problems in the development of the bones and tooth (due to the inadequate utilization of Vitamin A), weakening of bones (due to inadequate utilisation of vitamin D), increase bleeding (due to inadequate utilisation of vitamin K). Fat deficiency can also cause skin problems, since fatty acids plays an important role in the maintenance of healthy skin), and its deficiency can increase the loss of water from the skin causing dry or scaly rashes and also slow wound healing. Cognitive deficits can also be caused by the deficiency of omega 3 fatty acids, docosahexaenoic acid (DHA) and eicosapenteinoic acid (EPA), which are required for the development of the brain. Inadequate levels of these compounds can cause learning difficulties and increases the risks of dementia and Alzheimer’s. Additionally, DHA and EPA are also components of the retina, and thus its deficiency can cause vision problems. DHA helps in the production of rhodopsin, the pigment found in the rod cells of the retina, and deficiency of DHA slows its production, thereby affecting the vision (especially during dimly lit conditions, such as during the night, thus called night blindness) (Herron et al., 2017).

Lack of fibre or inadequate amounts of fibre in diet can affect the bowel movement, causing the formation of hard and dry stool, which do not pass optimally through the alimentary canal, causing constipation. The improper movement of bowels can also increase the risks of diseases such as diverticulitis. Inadequate intake of fibre can also cause over eating, since the presence of fibre can give the feeling of ‘fullness’ after a meal. Due to the absence of such feeling after eating a low fibre food, overconsumption can occur, which secondarily can cause an unhealthy gain in weight, and additionally increase the risks of obesity, diabetes, cardiovascular diseases and even cancer. Lack of fibre in diet can lead to fluctuations in the blood glucose levels, as it impedes the ability of the body to effectively use glucose, which can increase the risks of type 2 diabetes. Replacing diet rich in fibre with high protein or low carb diet such as meats, eggs or cheese can cause an increase in the blood cholesterol and additionally cause nausea, tiredness and weakness (Divyashree et al., 2017).

Polyphenols have several beneficial roles for the body, and its deficiency can increase the risks of diseases such as cancers. Polyphenols contained in tea, cocoa, wine, fruit juices, and olive oil has anti carcinogenic properties and can inhibit the development of malignant tumours, by interacting with mutagens, activated carcinogens and reactive intermediates. It not only helps to remove the carcinogenic agents but also helps to control and modulate the cell signalling pathways of cancer cells and the progression through the cell cycle. Phenolics also help in the prevention of neurodegeneration, and thus the risks of several diseases such as Parkinson’s or Alzheimer’s or Dementia. The compounds in phenolics help to protect the neurons from degeneration and also improve the neuronal functions by stimulating the regeneration of the neurons. It also protects the neurons from oxidative stress and neuronal injury. Thus its deficiency can increase the risks of diseases related to neuronal degeneration, which can further cause cognitive and learning deficits as well as psychological problems (Anantharaju et al., 2016; Zhang & Tsao, 2016; Roleira et al., 2015).

Conclusion:

Food processing is a method, by which various ingredients are used to prepare the food in the form of a finished product which can be easily marketed, prepared and consumed or stored safety. Processing food involves several strategies (both physical and chemical processing) which improves the preservation or shelf life of the product and eliminates the risks of contamination of food by toxic substances or pathogens. Processing of food also allows the product to be available throughout the year, improving its availability in all seasons. Food can be processed primarily by two methods, thermal processing, in which heat is used to inactivate or kill the microbes and ensure safety of the food. This can involve methods such as blanching, pasteurization, sterilization, canning, frying or roasting. In non thermal processing, heat or temperature is not used instead using other strategies such as ultra high pressure, irradiation, pulsed X rays or pulsed lights, electric fields or ultrasound. While thermal processing leads to the loss of volatile components in the food such as the phenolics) which causes a deterioration in the nutrient quality of the food), the non thermal processes helps in the preservation of the nutrient quality, as the volatile compounds are preserved. Carbohydrates, fats, proteins and phenolics are important ingredients in the food, as each of these components serves a vital function in the maintenance of the health and well being. Other ingredients present in processed foods include additives and preservatives that can help to retain the quality, texture and nutrient in the food and also improve its shelf life. These ingredients are affects differently by thermal and non thermal processing of food. In thermal processing, the proteins undergo glycation which can reduce its bioavailability and digestibility. The carbohydrates undergo Caramelization and gelatinization, which increases the capacity of the food product to absorb more water. Volatile compounds and vitamins however are reduced due to thermal treatment. It also helps in the improvement of solubility of carbohydrates, breaking it into smaller components. For phenolics, heat treatment can reduce their amounts in the food, which thereby affects the nutritional and sensory perception of the food. For non thermal processing of food, the nutritional value of the food is less affected. It helps in the retention of the bioactive compounds that enhances the flavor of the food as well as keeping its nutrient value intact.

Ingredients such as proteins, carbohydrates, fats, fiber and phenolics are vital components of food, as they help in the maintenance of a healthy and balanced diet and thus the health and wellbeing. Proteins play important role in the cellular and tissue repair and regeneration as well as in growth and also serves as an additional source of energy (apart from carbohydrates and glucose), its deficiency in diet can inhibit healing processes, cause weakness, cramping, muscular atrophy and even cause mood swings. Carbohydrates are important sources of energy in the body, and its deficiency causes weakness, fatigue and inability to perform heavy physical activities. Fats are the energy deposits of the body, created when the body has excess carbohydrates. It helps in the transportation of fat soluble vitamins and also helps to insulate the body; its deficiency can cause improper utilization of vitamins and increases the risks of related deficiency diseases. Fiber though is not digested or absorbed by the body, plays a vital role in the movement of bowels and in the absorption of glucose and cholesterol from blood, thereby regulating their levels. Inadequate fiber in diet can increase the risks of obesity and diabetes. Phenolics are compounds that affect the sensory and nutritional characteristics of the food, and also have antioxidant effects. Its deficiency can increase the risks of cancer, as well as reduce the sensory and nutritional quality of the food.

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