Food processing and preservation techniques and factors

Food processing and preservation techniques:

Techniques for food processing and preservation are essential for increasing food shelf life, assuring food safety, and retaining nutritional content. Here are some typical techniques for food preparation and storage:

Vacuum Packaging:

Vacuum packaging includes taking the air out of the container and tightly closing it. The growth of aerobic bacteria, which depend on oxygen to survive, is inhibited by this process. Vacuum packaging slows down spoilage and preserves the food's quality by removing the air. It is frequently used to package perishable goods including meats, cheeses, and other foods. Vacuum packaging is not a sterilization technique; hence it must be used in conjunction with other preservation methods for best results.

Fermentation:

A natural process called fermentation involves the action of bacteria or yeast on sugars or carbohydrates in food to produce alcohol, organic acids, or fumes. Food can benefit from this technique in terms of flavor, texture, and preservation. Yoghurt, cheese, sauerkraut, kimchi, pickles, tempeh, and sourdough bread are examples of fermented foods. By creating an acidic or alcoholic environment, fermentation protects food by preventing the growth of hazardous germs.

Drying/Dehydration:

Food is dried or dehydrated by removing moisture from it, which prevents the growth of bacteria that cause deterioration. This method of preservation has been practiced for generations. Foods that have been dehydrated last longer, are lighter, and take up less space in storage. The drying process can be carried out using a variety of techniques, including air drying, sun drying, and the use of specialized machinery like freeze-dryers or food dehydrators. Fruits, vegetables, herbs, spices, jerky, and dried veggies are some examples of dried foods.

Pasteurization:

Pasteurization is a heat treatment process that eliminates or reduces the number of pathogenic microorganisms in food and beverages, making them safe for consumption. The most common application of pasteurization is in milk and dairy products, where the liquid is heated to a specific temperature (usually around 72°C or 161°F) for a brief period. This process helps to kill harmful bacteria while maintaining the nutritional quality and taste of the product.

Freezing:

Freezing is a widely used preservation method that involves lowering the temperature of food below its freezing point (-18°C or 0°F). Freezing slows down the growth of microorganisms and the chemical reactions that cause food spoilage. It helps to maintain the nutritional value, flavor, and texture of many foods. However, freezing can affect the texture of certain fruits and vegetables with high water content, such as lettuce or cucumbers.

Canning:

Canning involves placing food in cans or jars and sealing them tightly. The food is then heated to kill bacteria, yeasts, and molds that may be present. This high heat destroys enzymes that could cause spoilage and prevents the growth of microorganisms. The sealed containers prevent the entry of air and microorganisms, helping to preserve the food for an extended period. Canned foods can include fruits, vegetables, soups, sauces, and meats.

Salting:

Adding salt to food is a classic preservation technique called salting. Bacteria, yeasts, and molds cannot survive in the environment that salt creates by removing moisture from the food. By stopping the growth of germs, this method avoids spoiling. Salted goods, like salted fish or cured meats, have a longer shelf life, although they may need to be soaked or rinsed to lessen the salt level before eating.

Irradiation:

Food irradiation is a preservation method that uses ionizing radiation, such as gamma rays, X-rays, or electron beams, to kill bacteria, insects, parasites, and molds that may be present in food. The radiation disrupts the DNA and cellular structure of microorganisms, rendering them unable to grow or reproduce. Irradiation can extend the shelf life of various foods, reduce the risk of foodborne illnesses, and control insect infestations. The irradiated food itself does not become radioactive and is considered safe for consumption, but its use is regulated and requires proper labeling.

Smoking:

Smoking is a preservation technique where food is exposed to smoke from burning wood or other materials. The smoke contains antimicrobial compounds that help inhibit the growth of bacteria, yeasts, and molds. Smoking also imparts a distinct flavor to the food, making it desirable for many consumers. Common smoked foods include meats (such as ham, bacon, or smoked salmon), cheese, and certain vegetables.

These methods of food processing and preservation are used all year long to preserve food quality, safety, and availability. The choice of technique depends on the type of food, target shelf life, nutritional requirements, and consumer preferences. Each method has advantages and considerations of its own.

Factors that affect food processing and preservation:

Several factors can influence food processing and preservation. Here are some key factors:

Storage Conditions:

The shelf life of preserved foods is significantly impacted by the storage conditions after preparation. Microorganism development, chemical interactions, and nutritional degradation can all be impacted by variables like temperature, humidity, light exposure, and air movement. To maintain the quality of food, it is crucial to use proper storage techniques, such as maintaining the right temperature and humidity levels, shielding from light exposure, and avoiding cross-contamination.

Type of Food:

Different foods have varying characteristics, including moisture content, pH level, nutrient composition, and susceptibility to enzymatic or microbial activity. These factors influence the choice of processing and preservation methods. For example, high-acid foods like citrus fruits are well-suited for canning, while low-acid foods like vegetables require pressure canning. Foods with high moisture content may be more prone to spoilage and may require dehydration or freezing.

Hygiene and Sanitation:

To ensure food safety, it is essential to use good hygiene practices throughout the entire food processing and preservation process. Microbial contamination is less likely when tools, surfaces, and hands are cleaned properly. The quality and safety of the finished product may be compromised by contamination by microorganisms, allergies, or chemicals.

Packaging:

The kind of packaging used for food processing and preservation has a significant impact on the product's quality and shelf life. The materials used for packaging should be impermeable to moisture, air, and light in order to shield the food from outside influences that could hasten deterioration. Maintaining the food's flavor, texture, and nutritional content can all be aided by proper packing. Cans, glass jars, plastic containers, vacuum-sealed bags, and flexible pouches are a few examples of different packaging materials.

Moisture Content: Moisture content influences the stability and shelf life of food. High moisture levels can promote microbial growth, enzymatic activity, and chemical reactions that lead to spoilage. Dehydration or drying methods are commonly used to remove moisture from food, inhibiting microbial growth and extending shelf life. In contrast, freezing is effective for preserving foods with higher moisture content.

Temperature Control:

Temperature plays a crucial role in food preservation. Most microorganisms have specific temperature ranges in which they thrive or become inactive. The control of temperature during processing and storage is essential to prevent or slow down microbial growth, enzyme activity, and chemical reactions that can lead to spoilage. Processes like pasteurization, canning, freezing, and refrigeration rely on appropriate temperature control to ensure food safety and quality.

pH Level:

The acidity or alkalinity of a food product, as indicated by its pH level, affects its susceptibility to spoilage and microbial growth. Some preservation methods, such as canning or fermenting, are more effective in low-acid or acidic environments. Acidic conditions inhibit the growth of many bacteria, while alkaline conditions can inhibit the growth of certain types of spoilage organisms.

Microbial Load:

The selection and efficacy of preservation techniques are influenced by the initial microbial load present in food. To ensure safety and a longer shelf life, foods with high microbiological contamination might need more stringent processing procedures or a mix of preservation strategies. The microbial load can be affected by elements like handling procedures, storage conditions, and the presence of harmful microorganisms.

Processing Time and Intensity:

Food quality can be affected by processing processes' duration and intensity. Nutrient loss, unpleasant textural changes, and flavor degradation can result from over processing or excessive heat exposure. Achieving the required preservation effect while preserving the food's nutritional value and sensory qualities depends on striking the proper balance between processing time and intensity.

These criteria enable food processors and preservation experts to choose the best methods, packaging materials, and storage settings to maximize the shelf life, safety, and sensory qualities of preserved foods.

Improvement of oil quality through oil processing

Introduction:

Refining is done to improve oil quality and make it suitable for consumption. Crude oil has many impurities. i.e., fatty acids, gummy substances, sterols, hydrocarbon, tocopherols, and phosphatides This is the traditional method of refining used for a long. Its main objective is to saponify Free Fatty Acids by using an alkali which results in soap formation. Chemical refining can be applied to refine almost all crude oils. FFA and other undesirable materials like non-glycerides are also removed through this process thus enhancing the shelf stability of oils and improving their quality.

Free fatty acids are eliminated in a physical refining deodorizer without being neutralized in a preceding processing step, according to a concise explanation of physical refining. It also emphasizes the superior quality of physically refined vegetable oils. (Speight, 2020). Physical refining eliminates just a few contaminants from the oil (mainly phosphatides, also known as phospholipids or gums).

Chemical Refining is used for removing free fatty acid. This can be done by neutralizing with caustic soda. Further Settling and centrifugal separators are used to remove sodium soap resulting in soap stock formation. Further, these neutral oils are bleached and deodorized according to the requirements. Frying depends upon the quality of the oil. Selection of good and stable quality. In refining heating temperature of the oil is 107 to 188 Fahrenheit. Count on us to guarantee that your edible oils have the best flavor, fragrance, stability, appearance, and nutritional value while also increasing product quality, safety, and yield.

Chemical Refining:

Introduction:

This is the traditional method of refining used for a long. Its main objective is to saponify Free Fatty Acids by using an alkali which results in soap formation. Chemical refining can be applied to refine almost all crude oils. FFA and other undesirable materials like non-glycerides are also removed through this process thus enhancing the shelf stability of oils and improving their quality.

Refining is done to improve oil quality and make it suitable for consumption. Crude oil has many impurities. i.e., fatty acids, gummy substances, sterols, hydrocarbon, tocopherols, and phosphatides. Chemical Refining is used for removing free fatty acid. This can be done by neutralizing with caustic soda. Further Settling and centrifugal separators are used to remove sodium soap resulting in soap stock formation. Further, these neutral oils are bleached and deodorized according to the requirements. Frying depends upon the quality of the oil. Selection of good and stable quality. In refining heating temperature of the oil is 107 to 188 Fahrenheit.

·       These impurities mainly consist of:

• ·       Oxidized products
• ·       Phospholipids (gums)
• ·       Color pigments (gossypol) in cottonseed
• ·       Metal ions (iron, copper)

Chemical Refining Steps:

• ·       Degumming
• ·       Neutralization
• ·       Bleaching
• ·       Winterization
• ·       Deodorization

Degumming (Optional):

This step can be done both in physical and chemical degumming. But optional in chemical refining as other chemicals are already used that can effectively refine the oil thus this step is optional. But degumming is necessary for physical degumming.  

Neutralization:

Neutralization can reduce many impurities and thus improve final oil quality. i.e. Free Fatty acids, phosphatides, carbohydrates, traces of metals, residual proteins, oxidation products, and other pigments. In this process, oil is treated with an alkali usually a caustic soda that converts FFAs into Soap stock and neutralizes them. More soap stock means less oil yield. Impurities separate and come on the surface then are removed. Then washing of oil to remove the soap contents. The sludge that is obtained in the bottom consists of solid material mixed with water. This stock is sold to soap manufacturers for soap formation.

This can be further used for both food and feed purpose. Hydrated gums for food and food. Soap Stock in inedible industries. This refining is compulsory in oils having more pigments and high acidity contents. Further, this will improve the oil color by reacting with the other polar compounds present in the oil. i.e., Gossypol, sesamol etc. Gossypol in cottonseed and sesamol in sesame seeds respectively. Free Fatty Acids' contents depend on the concentration of caustic soda. The more FFAs the more the soda is used to neutralize it and purify the oil.

Miscella refining:

This method is used to neutralize the cottonseed oil. This technique will effectively remove the gossypol contents in oil. Using a solvent and oil refining process in miscella refining. Miscella is pre-concentrated will adding press oil or in hexane evaporation step. This temperature is set below the boiling point of n-hexane and a solvent like caustic soda is added to it. Mixing is done in a reaction mixture. Soap Stock is further separated from it. Because of the explosion risks of hexane, this is performed in explosion-proof centrifuges.

Overall By-products of chemical refining:

These are two major by-products that are produced from chemical refining i.e. soap stock and hydrated gums.

Soap stock:

This is a source of fatty acid. Traditionally this by-product was discarded but now many soap manufacturing and other inedible industries are utilizing it. Acid oil is produced from soap stock consisting of a fatty portion of soap stock and with 1 to 2% of the moisture contents. The impurities that are removed in the neutralization process are further used in acid oil making for acidulation. This is used in feed as a high-energy nutrient. Proving 9 calories per gram than the protein of 4 calories per grams. The process should be performed as soon as possible otherwise will separate the oil and water phases and have corrosive nature.

Lecithin:

This is called hydrated gums or lecithin obtained from water degumming.  Commercially it is widely used in industries for emulsifiers and other purposes. This is made from a mixture of phospholipids.  It's a good extraction souse in soybean oil. Because it has phospholipids in high amounts. Stream and 2% water is added and centrifuged it in order to make the lecithin in hydrated form. The hydrated gums are dried to moisture below 1%. This is done to reduce damage of the oil color. Cooling is done. Then further ingredients are added according to requirements.  It is usually treated with a chemical called H2O before and after drying to remove the color pigments. Further, it has different uses.

 

Gamma irradiation and its effect on the quality of Meat

Gamma irradiation for food

The process of gamma irradiating food involves subjecting it to ionizing radiation. The shelf life of food products is increased, microbes are eliminated or inhibited from growing, and insect infestation is managed. Gamma rays are a powerful type of electromagnetic radiation that may pass through objects and kill insects and bacteria.

Here are some key points about gamma irradiation for food:

How it works:

Food products are exposed to gamma rays emitted by a radioactive source, typically cobalt-60 or cesium-137. These rays pass through the food, interacting with the cells of microorganisms, insects, and other pests. The high-energy radiation damages the DNA or RNA of these organisms, preventing their ability to reproduce and causing their death.

Safety:

Gamma irradiation has been extensively studied and approved by various international organizations, including the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the International Atomic Energy Agency (IAEA). It is considered safe when applied within recommended dosage levels and proper control measures. The process does not make the food radioactive and does not significantly affect its nutritional value.

Microbial control:

Gamma irradiation is effective in reducing or eliminating a wide range of microorganisms, including bacteria, molds, yeasts, and parasites. It can significantly reduce the risk of foodborne illnesses caused by pathogens such as Salmonella, E. coli, and Listeria. The exact dosage required depends on the specific food product and the target microorganism.

Insect control:

Gamma irradiation is also used to control insect infestation in stored grains, dried fruits, and other food commodities. It disrupts the insects' reproductive cycle, sterilizing them and preventing population growth. This helps in preventing post-harvest losses and reducing the need for chemical insecticides.

Shelf-life extension:

By controlling microbial growth and insect infestation, gamma irradiation can extend the shelf life of food products. It inhibits the spoilage caused by microorganisms, molds, and insects, helping to maintain the quality and freshness of the food for longer periods.

Approved applications:

Gamma irradiation is approved for use in several countries for various food products, including fruits, vegetables, spices, grains, meat, poultry, seafood, and certain food ingredients. The specific regulations and dosage requirements vary depending on the country and food item.

Gamma irradiation is a useful tool for food preservation, but there are a variety of other options as well. Depending on the particular food product and the intended result, other techniques can also be utilized, such as heat treatment, freezing, canning, and high-pressure processing.

Effect on the quality of Meat

Gamma Radiations is the best method to control pathogens in meat. It greatly affects the quality changes such as color, odor, and flavor in raw and cooked meat. These factors affect the consumer’s acceptance criteria.

Color:

Color is important quality parameter which influence customer acceptance. The color variations depend upon irradiation dose, animal species, muscle type, and packaging type. Usually, light meat produces pink color whereas dark meat become brown or gray after irradiation treatments. After applying irradiation redness increases in the observed lion of the beef meat. It depends on the dose and Lab values that was measured trough colorimeter. A bright pink color appeared on surfaces if meat thus increase in a value. Moreover, hue and saturation were also increased upon gamma treatment. These radiations give meat the same color as sodium nitrate in curing of meat. This color variation is observed in both cooked and raw meat.

When irradiations are applied on the meat activated oxygen atom react with iron-porphyrin (heme group) and imparts a bright pink color to the meat. The L value was increased but b value hasn’t any influence on meat color. Thus, both gamma treatment and sodium nitrite give the same color. Moreover, globin portion is denatured and addition of another nitric oxide molecule in the iron-porphyrin ring. When gamma radiations apply on vacuum packaged meat it develops purple color which indicates absence of oxygen and bright red color in presence of oxygen. Thus, to conclude the effect on meat color shows that irradiations increased the color of meat significantly but color decreases as well on storage of meat.  These color changes occur mainly due to alterations in the iron ion of myoglobin.

Texture:

Radiations treatments affects the structure of intracellular skin and muscles. Further it activates some enzymes that accelerates the rate of glycolysis. Thus, gamma rays effect the post mortem inspection and morphological properties of meat. Shorting of sarcomere does not occurs however irradiated muscles swells on gamma treatment. This shows that irradiations disrupt the actin and myosin bonds. Thus, sarcomere length shortening does not occur due to denaturation on the fibrous proteins. i.e., A research shows that this happens more at 4 °C during storage. Rapid decline in pH was observed in the irradiated muscle of meat. After gamma radiations the ageing period shortens and anaerobic metabolism of meat accelerates. Thus, irradiated meat sample preserved a good quality and texture during 21 days of chilled storage, however the control sample showed putrefaction means slimy textured meat because Histamine content was reduced after irradiation treatment, such decrease strongly it correlates with the applied dose level of gamma rays.

Flavor:

Flavor is produced by combining the basic tastes (sweet, sour, bitter, salt, and umami) obtained from water-soluble molecules and odor produced from volatile compounds present in the product from the beginning or produced via numerous actions.  The precursor compounds of fresh meat are responsible for the production of favorable and unfavorable odors. Acids, alcohols, aldehydes, aromatic compounds, esters, ethers, furans, hydrocarbons, ketones, lactones, pyrazines, pyridines, pyrroles, sulphides, thiazoles, thiophenes, pyrroles, and oxazoles are some of the flavor and different odor volatile compounds found in meat. 

The flavor of the normal meat is different from irradiated meat because of the impact of the radio lytic byproducts. The main challenge with the irradiated meat and poultry has been the formation of an unpleasant flavor. The purpose of irradiation research in the 1950s and 1960s was to sterilize the product, which required the use of high-level doses. The high dosages, along with a variety of processing factors, resulted in a flavor known as "irradiation flavor." Irradiation flavor has been defined as a "scorched flavor," but it has been described as a "goaty" or "wet dog" flavor. The production of irradiation flavor is dose dependent, according to evidence, and the threshold dose for noticeable flavor differs per species. 1.50 kGy, 1.75 kGy, 2.5 kGy, and 2.5 kGy, respectively, are required for a detectable flavor in turkey, hog, beef, and chicken.

The irradiation odor of meat is caused by volatile Sulphur compounds produced by irradiation. It also speeds up the oxidation of lipids in meat. Unsaturated fatty acids are the most important component of the lipid fraction. Irradiation may result in the generation of free radicals at the carbonyl groups and carbon double bonds because they are electron-deficient. Hydroxyl radicals (OH) are thought to be the initiators of lipid oxidation in muscle tissue because they react with conjugated systems. After that, traditional mechanisms for autoxidation is start. These changes will cause off flavors in meat. There is less change in flavor of poultry because of low concentration of unsaturated fatty acids.

Tenderness

Tenderness is a desirable characteristic since tender meat is softer, easier to chew, and more appealing than tough meat. The meat tenderness was considerably enhanced by irradiation (1 to 6kGy). Similarly, irradiation breaks down myofibrils proteins, which are regulated by the presence of calcium-dependent proteases or calpains, which are known to affect meat tenderness. Similarly, it is claimed that the meat tenderness is caused by physical rupture of myofibrils. The radiation also enhances the collagen and protein solubility which increase the tenderness of meat. The radiations also breakdown the myofibril and sarcoplasmic protein of the meat. Radiations break the S-S bridges and split the hydrogen in the meat which help to increase the tenderness of meat.

Market trends of composite flour

                                         Market trends of composite flour

Now a days with increasing population there is a rapid increase in the demand of food, living and dwelling styles of people. Moreover, more development and advancement in the field of science and technology has introduced a crave towards nutritious food. Thus, with the increased income and enhanced buying capacity of people have shifted towards processed and baked foods. More ready to eat and convenience products are available. To more the nutritional profile of flour people is shifting towards other alternatives to improve their diets. Use of mixed flours for one type of preparation of different baked products is increasing all over the world. This flour is called composite flour. However, this concept of composite technology was initiated by FAO (1964) which aimed to encourage the use of different crops such as yam, maize, and others in partial substitution of wheat flour which reduces or even eliminates the import of wheat that in turn helps to feed more people.

However, composite flour is considered advantageous in developing countries as it reduces the importation of wheat flour and encourages the use of locally grown crops as flour. Local raw materials substitution for wheat flour is increasing due to the growing market for confectioneries and baking. Thus, several developing countries have encouraged the initiation of different ways to evaluate the feasibility of alternative locally available flours as a substitute for wheat flour.

Market Importance of Composite Flour:

Composite flour has a great market importance. This flour at the same time has an advantage to save foreign swap, thus raising local agriculture and agribusiness. Composite flours are beneficial for developing countries.

Scientific research aims to boost composite flour use and increase wheat flour and bread consumption. Different countries' quality and food safety requirements should produce a new standard for composite flour. After that composite flour will be in high demand as a premium, affordable, healthy product. It can evolve market items, thus helps in boosting the agricultural economy of the country.

Composite flour has different advantages that’s why market trend is shifting towards it:

v Advantages of composite flours:

Incorporation of other cereal/ pulse flour in the base flour i.e., wheat has received many appreciations in respect of quality, acceptability and economically from the more health-conscious generations:     

• Blending traditional wheat flour with other cereal flours which is inexpensive supports the baker economically as well as it becomes nutritionally rich
• · Wheat is nutritionally deficient in essential amino acids i.e., lysine and threonine and pulse flours are good source of these amino acids
• ·     Using of composite flour as advantageous to the developing countries, if they have adequate technologies using these blends could lead to improved utilization of different cereal crops
• ·      It will improve the nutritional status of the people
• ·      Helping those suffering from degenerative diseases, especially those associated with changing lifestyles and environment
  

Trend in Global Market:

Bakery products from composite flour is famous and increase in the market because of economic and nutritional benefits. The world of bakery products market showed a growth rate of about 3.9% between 2001 and 2010. The sales volume of bread in the global market in 2006 was approximately 122m tons and in 2011, it increased to 125m tons. It is remarkable difference that bread proceeded to grow in the market despite ongoing economic uncertainty during these years.

Bakery products and derivatives have an important place in the food consumption all over the world i.e., Mostly in Kazakhstan and Turkey. Bread, pasta, bulgur, biscuits, cakes, and breakfast cereals are the most consumed composite flour industrial cereal products. Bakery products constitute 65% of the food industry in Turkey and about 80% in Kazakhstan.

This graph shows difference of using bread made from organic or composite flour. Organic and composite flour/bread is consumed mostly by students, scientific workers, others and businessmen/businesswomen. Organic flour and bread are consumed more in Kazakhstan than in Turkey, and composite flour is consumed more in Turkey than in Kazakhstan.

Conclusion:

In the present, past and future, flour and bread have been an important part of our lives. The consumption of composite flour and bread had diminished, but again their consumption has restarted in the twenty-first century as healthy food option. In the time of globalization, a lot of consumers consume a composite flour product without knowing because all dietetic, healthy baked products, pasta and other baked products are prepared from mixed flours. But now people are more aware of its nutritional profile. These is difference in consumption, preferences, and judgments of different types of flour and bread. This difference is seen because of different income, age, and education levels. i.e., High low and Middle incomes countries. Researchers search new ways of nutrients that could be healthiest food in the future. The social communities should develop new social and economic arrangements for fulfilling this. i.e., The development of Composite technology. Composite flours show a good potential for use as a functional agent in bakery products. Utilization of such flours not only improves the nutritional status but also helps those suffering from degenerative diseases associated with today’s modern lifestyle. Still there is a need to find out the optimum levels of incorporation, functionality of ingredients and other related characteristics for better economic and nutritional benefits.

Food science and technology and its factors

Food science and technology

Food science and technology is a field that encompasses various scientific disciplines to understand the production, processing, preservation, packaging, and distribution of food products. It applies principles from chemistry, microbiology, biochemistry, nutrition, engineering, and other related fields to ensure the safety, quality, and sustainability of food.

Here are some key areas within food science and technology:

Food Microbiology:

Microorganisms that can affect food safety and quality, such as bacteria, yeasts, molds, and viruses, are studied by food microbiologists. They concentrate on locating and eliminating pathogens that cause foodborne illnesses as well as germs that deteriorate food and compromise its flavor, texture, and shelf life. Microbiologists create procedures for cleansing, preservation, and microbiological testing.

Food Processing:

Food processing involves converting raw agricultural materials into edible products. It includes various techniques such as heat treatment (e.g., pasteurization, sterilization), dehydration, extraction, fermentation, and extrusion. Processing methods can affect nutritional content, texture, flavor, and safety of the final products.

Food Engineering:

Food engineers apply engineering principles to design and optimize food production processes and equipment. They develop efficient systems for food processing, packaging, and distribution, ensuring food safety and quality. Food engineers also work on improving energy and resource utilization, waste reduction, and automation in the food industry.

Food Chemistry:

Food chemists study the chemical composition of food components and how they change during processing, storage, and cooking. They analyze flavors, colors, and nutritional content, and develop techniques to enhance or preserve them. They also investigate chemical reactions that affect food quality, such as oxidation and Maillard reactions.

Food Packaging:

Packaging is crucial for protecting food products from physical, chemical, and biological damage. Packaging materials should be safe, hygienic, and able to maintain product quality and freshness. Packaging technologists develop innovative materials, designs, and technologies, taking into account factors like shelf-life extension, convenience, sustainability, and consumer appeal.

Sensory Evaluation:

Sensory evaluation is used to assess the sensory attributes of food, including taste, texture, aroma, appearance, and even sound. Trained sensory panels or consumer panels provide feedback on product acceptability and preferences. This information helps in product development, quality control, and market research.

Food Quality and Safety:

Ensuring food quality and safety is a paramount concern. Quality assurance professionals monitor and enforce quality standards throughout the production process. They conduct inspections, implement quality control systems, and analyze samples for microbiological, chemical, and physical attributes. Regulatory agencies set and enforce food safety regulations to protect consumers.

Food Product Development:

Food product developers create new food products or improve existing ones to meet consumer demands and trends. They consider factors like taste, nutrition, convenience, cost, and sustainability. Product development involves recipe formulation, prototyping, scale-up, and sensory testing to ensure the final product meets expectations.

Food Preservation:

Food preservation techniques are employed to extend the shelf life of food while maintaining safety and quality. Preservation methods include thermal processing (e.g., canning, pasteurization), refrigeration, freezing, dehydration, fermentation, and the use of preservatives or natural antimicrobial agents. These methods inhibit microbial growth, enzymatic activity, and oxidation.

Food Sustainability:

Food sustainability focuses on minimizing the environmental impact of food production, reducing waste, and promoting ethical practices. It involves sustainable agriculture, including organic farming, conservation of natural resources, minimizing food losses and waste, and considering the social and economic aspects of food production and consumption.

To assure the manufacture of safe, wholesome, and enticing food items, the multidisciplinary discipline of food science and technology integrates scientific knowledge with practical applications. It is essential for tackling issues like food security, sustainability, and public health while fulfilling the rising demands of an expanding global population.

Factors that affect food science and technology

Food Quality:

Food science and technology focus on maintaining and improving the quality of food. This includes factors like taste, texture, appearance, nutritional content, and shelf life. Methods such as sensory evaluation, quality control, and quality assurance are employed to assess and enhance the overall quality of food products.

Food Processing and Preservation:

Food technology plays a crucial role in developing efficient methods for processing and preserving food. Techniques such as pasteurization, canning, freezing, dehydration, and irradiation are utilized to extend the shelf life, reduce spoilage, and maintain nutritional value.

Nutritional Science:

Food science and technology incorporate knowledge from nutritional science to understand the impact of food on human health. Scientists analyze the nutritional composition of food, study bioactive compounds, and develop strategies to fortify or enhance the nutritional value of food products.

Food Safety:

Ensuring the safety of food products is of paramount importance. Factors such as microbial contamination, chemical hazards, and physical hazards are studied and addressed to prevent foodborne illnesses. Techniques like hazard analysis and critical control points (HACCP) and Good Manufacturing Practices (GMP) are used to minimize risks.

Food Engineering:

Engineering principles are applied to design and optimize food processing equipment, packaging systems, and manufacturing processes. This involves areas such as heat transfer, mass transfer, fluid dynamics, and automation to ensure efficient and safe production of food.

Food Product Development:

Scientists and technicians in the food industry work to create new food products or enhance already existing ones. To develop novel and enticing food products that satisfy consumer expectations, tastes, and dietary restrictions, they perform research on ingredients, formulations, and processing techniques.

Food Regulations and Standards:

Food science and technology are influenced by regulations and standards set by regulatory bodies at national and international levels. These regulations govern food labeling, safety standards, quality requirements, and manufacturing practices, aiming to protect consumer health and ensure fair trade.

Sustainability and Environmental Impact:

As the global population grows, there is increasing focus on sustainable food production and minimizing the environmental impact of the food industry. Food scientists and technologists work on developing environmentally friendly processes, reducing food waste, and exploring alternative food sources.

Consumer Trends and Preferences:

Consumer demands and preferences shape the direction of food science and technology. Factors such as convenience, health and wellness, ethnic diversity, and sustainability influence product development and innovation in the food industry.

Research and Collaboration:

Continuous research, innovation, and collaboration among scientists, researchers, industry professionals, and academia are essential for the advancement of food science and technology. Sharing knowledge, conducting experiments, and exploring emerging technologies contribute to the growth of the field.

These variables interact and build upon one another to spur innovations and improvements in the area of food science and technology, which eventually benefit both the food business and consumers.

Composition and botanical properties of watermelon rind

Botanical properties:

The composition of Citrallus lanatus (water melon) is 93% water, hence giving the name “water” melon.  The “melon” aspect is the product of the fruit being big, round and a soft, pulpy texture. The scientific name of water melon comes from both the Greek and Latin sources. The Citrullus part is derived from a Greek word “citrus” which refers to the fruit. The lanatus part is from Latin language and means to be fuzzy, referring to the small hairs on the plant’s stems and leaves.

Watermelon is believed to have been originated in southern Africa as it grows in the wild region and reaches largest diversity of forms there. It has been grown for over 4,000 years in Africa. Spanish brought Citrullus lanatus to America and it quickly became the very popular one. Citrullus lanatus is a prostrate or annual climbing plant with many herbaceous, firm and sturdy stems up to 3m in length. The young parts are heavily woolly with yellow to brownish hair, meanwhile the older parts are colorless. The leaves are herbaceous but stiff, being dull on both sides; 60-200mm long and 40-150m thick, but usually 3-lobed or doubly lobed again’ the central lobe is much higher. The leaf stalks are very hairy and have a length of up to 150mm. The tendrils are very robust and normally split into the upper portion. On the same (monoecious) plant, male and female flowers occur with the flower stalk up to 400mm long up to 150mm. Subglobose is its wild form, indehiscent and having diameter of up to 200mm, while fruit stalk is up to 50mm in length.

Typically the fruit is globose to oblong or ellipsoid, often ovoid, 5–70 cm long and weighing 0.1–3.0 kg (0.1–2.5 kg in egusi melon, 1.5–3.0 kg in watermelon), the seeds are obovate to elliptical, rounded, 0.5–1.5 cm x 0.5–1 cm, smooth, yellow to brown or black, hardly white.

Nutrient composition:

The weight by weight composition of Citrullus lanatus consists of around 6% sugar and 92% fat. As with a lot of other fruit, it is a source of vitamin C. The composition of dried egusi seed per 100 g, without shell is; Water 5.1 g, energy 2340 kJ (557 kcal), protein 28.3 g, fat 47.4 g, carbohydrate 15.3 g, calcium 54 mg, phosphorus 755 mg, iron 7.3 mg, thiamin 0.19 mg, riboflavin 0.15 mg, niacin 3.55 mg and folate 58 μg. The seed is an excellent source of nutrition, and does not contain any hydrocyanic acid, which makes it suitable for animal feed. Linoleic, oleic, palmitic and stearic acid glycosides are present in seed oil. The flesh of fruits produces bitter cucurbitacins.

Watermelon composition per 100 g edible portion (50–70 percent of ripe fruit) includes: water  0.4g, carbohydrate 7.2 g, calcium 8 mg, phosphorous 9 mg, iron 0.17 mg, thiamine 0.08 mg, riboflavin 0.02 mg, niacin 0.2 mg, folate 2 mg and ascorbic acid 9.6 mg.

Watermelon is a rich natural source of lycopene, a highly important carotenoid due to its antioxidant ability and associated health benefits. Plants of cucurbitaceae contain bioactive compounds, such as cucurbitacin, triterpenes, sterols and alkaloids.

Every part of watermelon fruit has nutritional value, including the rind and the seeds. The most common way to consume watermelon is pink or yellow flesh consumption, eaten raw, the way it was grown. Other common types, however, include pickles of watermelon rind, deep fried watermelon, watermelon cake and watermelon lemonade.

Dietary fibers (soluble, insoluble, total):

The key form of fiber present in watermelon rind is insoluble fiber (50.32 g/100 g), which has been associated with many health benefits including a decreased risk of cardiovascular disease and weight gain, diabetes and other cancers. Among fruits, watermelon has been traditionally considered as good source of fibers (>0.5g/100g edible portion) with remarkable contents in both soluble and insoluble fibers.

Flavonoids:

Flavonoids have antifungal, antioxidant and antibacterial properties, therefore the availability of flavonoid in the samples recommends that their use offer protection against the diseases which is related to free radicals, fungal and bacterial activities. Phytonutrients analysis exposed the presence of flavonoids. Phytonutrients is a natural bioactive compound from plants which have many generals benefits to human health.

The total flavonoids content of saccharomyces cerevisiae was significantly increase in fermented watermelon as compared to unfermented watermelon rind. the best described property of almost every group of flavonoids is that it acts as antioxidants. The most powerful flavonoids are flavones which protect the body against ROS. Consumption of flavonoids can be used in the managing of coronary heart disease. Watermelon rind was chosen as the chief ingredient for production of natural food preservation. We choose watermelon rind because it contained flavonoids and anthocyanins. Flavonoids have high antioxidant. Antioxidant activities have been widely studied in different foodstuffs. Antioxidant activities of foodstuff increases with the presence of high concentration of total flavonoids.

Phytate:

Phytate are anti nutrient which are naturally occurring compound found in all plants that reduce the ability of body to absorb essential nutrients. Phytate is an anti-nutritional, On the bioavailability of essential dietary minerals negative phytate have many. negative effects. Phytate is mostly considered antinutritional factor, because it is implicated with the impaired absorption of minerals. Phytates is a natural antioxidant and the presence of phytate in the samples is indicative of antioxidant benefit following their consumption.

Phytic acid is the storage form of phosphate and inositol generally in seeds and grains to minerals such as iron, zinc, copper, calcium, and magnesium, and inhibit their absorption by the small intestine. In the body Phytates bind to calcium and iron. Phytate cannot digest by human body, hence it is not a nutritional source of inositol or phosphate. In the body Phytates bind to iron and calcium and could prevent their absorption into the body causing deficiencies.  Phytic acid is harmful for those who have deficiencies of zinc, iron. as an antioxidants phytic acid have positive dietetic impact which prevent carcinogenesis for this purpose determining the phytic acid content of foods is essential. The phytate levels had a range of 0.3g/100 g dry matter. The alkaloid, saponin, phytates and oxalate content in each sample were determined by the colorimetric method for phytate and alkaloid the absorbance of each sample was measured at 420 nm.in watermelon rind phytate is present in very lowest amount.

Cyanide:

The cyanide content in the food samples was determined by the alkaline picrate method. There was no cyanide is present in the watermelon rind while the amount in the seed (0.79±0.01 mg/100 g) was comparably much lower than the value (30.24±0.02 mg/100 g) in sweet potatoes leaves. The absence of cyanide in the rind is nutritionally significant in interpretation of the general cyanide toxicity which is formed when acids react on metal cyanides.

The levels of hydrogen cyanides ranged from 26.96 ± 0.01 to 121.02 ± 0.02mg/ 100g. The lowest level was obtained in pomegranate rinds and the highest in watermelon rind. Within a few minutes High dose of hydrogen cyanide can cause death, while lesser dosages may result to stiffness of the throat, chest, palpitation and muscle weakness. The result obtained falls within the threshold value (below 350 mg/ 100g) reported as safety limit. Severe cyanide toxicity at low doses between 0.5 and 3.5 mgkg-1 body can cause headache, tightness in throat, and muscle weakness. Symptoms of acute cyanide poisoning include; rapid respiration, drop in blood pressure, rapid pulse, headache, dizziness, vomiting, diarrhea, mental confusion, stupor, cyanosis, twitching and convulsions. In order to prevent cyanide toxicity, processing procedures such as peeling, grating, crushing, grinding, soaking, fermenting and drying have been used for centuries to reduce potential toxicity of cyanogenic plants before consumption.