Basics of Fats

What are Fats?

According to nutrition facts, fats are an essential part of the diet and play an important role in maintaining a healthy life.

Fats and cholesterol tend to be the most focused terms of the public and health enthusiasts. There is a valid reason behind this. Fat happens to be the most concentrated source of energy in the diet that providing about 8 to 9 calories per gram, while on the other hand, carbohydrates and proteins have only four calories per gram. Fat is known to have three elements which include carbon, hydrogen, and oxygen. But, it has more carbon and hydrogen than oxygen, leading to nine calories per gram. Fats are the source of energy in food, belong to a group of elements called lipids, and they are all combinations of saturated and unsaturated fats.

The human body is well designed, which makes up two types of fats, essential for the proper functioning of the body and are obtained from the food consumed. These fats play a major role in controlling inflammation, blood coagulation, and brain development. It also serves as a storage unit for storing the body’s extra calories in fat cells or adipose tissue that helps to insulate the body. They tend to be an important source of energy. Fats also help the body absorb and transport the vitamins A, D, E, and K through the bloodstream.

Types of Fats

There are four different types of fats:

Saturated Fat

It is responsible for bad cholesterol. They are found in most animal products like cheese, milk, meat and so on and hence one must limit the quantity of intake. Unsaturated fat, on the other hand, is the substance that should be used in place of saturated fats to lower cholesterol levels. Trans fatty acids that one gets from vegetable oils also play a role in increasing cholesterol levels. Consuming saturated fat in large quantities is the most popular reason for heart disease as it causes cholesterol to block the arteries.

Monounsaturated fats

Monounsaturated fats are healthy fats found in Avocados, Macadamia nuts, Peanuts, Olives and Olive oil. It plays a vital role in protecting the heart and is also involved in supporting insulin sensitivity, fat storage, weight loss, and healthy energy levels.

Trans Fats

Trans fats are also called unsaturated fatty acids or trans fatty acids. These fats are naturally obtained in several foods such as beef, lamb, whole milk, cheese, cream, and butter from cattle. Conjugated linoleic acid is a natural trans fatty acid which is beneficial in strengthening the immune system and inhibiting the development of cancer. However, most trans fatty acids are made when manufacturers convert liquid oils into solid fats. In the application of hydrogenation, vegetable oils are hydrogenated to produce vegetable shortening, margarine, peanut butter, and other products used for salad dressing. Trans fats are present in many processed foods such as baked food items, cookies, crackers, snack foods, deep-fried foods and other food made or fried in partially hydrogenated oils.

Polyunsaturated Fats

Polyunsaturated fats are healthy fats, which are abundantly found in both plant and animal foods, such as vegetable oils, Walnuts, Flax seeds, salmon, etc. These fats include both Omega 3 and Omega 6 fats. Omega 3 helps reduce inflammation and supports healthy hormone levels and cell membranes. Omega 6 fatty acids play an important role in supporting healthy brain and muscle functioning.

We need a small amount of omega-6 fatty acids in our diet. Corn, soybean, safflower, cottonseed, grapeseed and sunflower oils are all high in omega 6’s. Apart from these, omega-6 fatty acids are also found in most baked goods like bread and bakery snacks and packaged foods like cookies, crackers, chips, and french fries, which are not stable.

Essential Fatty Acids

Our body is capable of synthesizing most fatty acids, apart from these three essential fatty acids: Linoleic acid, Linolenic acid, and Arachidonic Acid. These designated essential fatty acids must be supplied through the diet. The deficiency symptoms of these fatty acids include poor growth, and skin irritation and have been seen in infants fed with the formula lacking these essential nutrients.

Role of Fats

Fats play a wide range of roles in the functioning of organisms. Some of which are as follows:

• The fat in the body is stored in the form of fats. These include triglycerides, cholesterol and phospho fats.

• Fats need to be included in the dirt to facilitate the absorption of fat-soluble vitamins like A, D, E and K.

• Linoleic acid is a major component of most plant-based oils and fats. These are mostly omega-6 and omega-3 fatty acids. Studies have shown them to be beneficial for the development of infants, alleviating cancer related problems, treating cardiovascular and psychological ailments.

• Biological membranes are thought to be essential to the development of life itself. They separate the cells from their environments, cell organelles that perform specialised tasks and make metabolism and other functions possible. Consequently, the biological importance of fats is also very high since they make up these biological membranes.

Conclusion:

Fat is the concentrated form of energy. And that is why a small amount of lipid can produce high calories. Although unsaturated fats are considered good fats, excess amounts of Saturated, trans-fat, and cholesterol can be harmful to the human body.

Therefore, maintaining healthy fats in the body helps your body stay active and avoid risks of being overweight, heart problems etc.

Learn more about Fats:

References:

1. Siri-Tarino, P.W., et al., Saturated fatty acids and risk of coronary heart disease: modulation by replacement nutrients. Curr Atheroscler Rep, 2010. 12(6): p. 384-90.

2. Hu, F.B., Are refined carbohydrates worse than saturated fat? Am J Clin Nutr, 2010. 91(6): p. 1541-2.

3. Jakobsen, M.U., et al., Intake of carbohydrates compared with intake of saturated fatty acids and risk of myocardial infarction: importance of the glycemic index. Am J Clin Nutr, 2010. 91(6): p. 1764-8.

4. Hu, F.B., et al., Dietary fat intake and the risk of coronary heart disease in women. N Engl J Med, 1997. 337(21): p. 1491-9.

Web References:

1. https://nutritionsource.hsph.harvard.edu/what-should-you-eat/fats-and-cholesterol/types-of-fat/
2. https://unacademy.com/content/upsc/study-material/general-science/fat/
3. https://unacademy.com/content/neet-ug/study-material/biology/role-of-fats/
4. https://med.libretexts.org/Bookshelves/Nutrition/Book%3A_Nutrition_Science_and_Everyday_Application_(Callahan_Leonard_and_Powell)/05%3A_Lipids/5.02%3A_The_Functions_of_Fats
5. https://www.eufic.org/en/whats-in-food/article/facts-on-fats-dietary-fats-and-health

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Quiz of Basics of Fats

Notes on Fungi - Basics - Dr. J. Merrylin

Food Microbiology | Food Microbiology | Food Microbiology

Molds

• Molds  are  multicellular,  filamentous  fungi  whose  growth  on  food,  with  its  fuzzy  or  cottony  appearance,  sometimes  colored,  and  usually  moldy food is considered unfit to eat.

• Although molds are involved in the spoilage of many kinds of food, special molds are useful in the manufacture of certain foods or ingredients of foods.
• Thus some kids of cheese are mold-ripened. Eg., blue, Roquefort, camembert cheese,  etc.  and  molds  are  used  in  making  Oriental  foods.  Eg.,  soy  sauce, miso, sonti.

• Molds  have  been  grown  as  food  or  feed  and  are  employed  to  produce products used in foods, such as amylase for bread making or citric acid used in soft drinks.

 The body or vegetative structure of a fungus is called thallus. It varies in complexity  and  size,  ranging  from  the  single-cell  microscopic  yeasts  to multicellular molds, macroscopic puffballs, and mushrooms.

                

• The thallus is made of hyphae which are cyclindrical, tube like structure that elongates by growth at tip.
• A mass of hyphae known as mycelium (a tangled mass or tissue like aggregation) is responsible for filamentous nature of mold.
• The thallus of mold is made up of two part; mycelium and spore
• Molds have typical eukaryotic structures and have a cell wall usually composed of chitin, sometimes cellulose, and occasionally both. Furthermore, molds are obligate aerobes and grow by elongation at apical tips of their hyphae and thus are able to penetrate the surfaces on which they begin growing.

Types of hyphae

• The  hyphae  may  be  submerged,  or  growing  within  the  food,  or  aerial,  or growing into the air above the food
• Hyphae may be classified as vegetative and hence involved in the nutrition of the mold, or fertile, involved in the production of reproductive parts.
• In most molds the fertile hyphae are aerial, but in some molds they may be submerged.
• The hyphae of some molds are full and smooth, but the hyphae of others ar characteristically thin and ragged
• In some fungi hyphae is divided into cell or compartment by incomplete septum. Septum has a central pore which allows the movement of cytoplasm from one cell or compartment to another.
• There are three types of hyphae among fungi.

1. Coenocytic or non-septated hyphae
2. Septate hyphae with uninucleated cell
3. Septate hyphae with multinucleated cell

 

• Hyphae can be vegetative or reproductive
• Vegetative hyphae: It penetrates the soil or medium to absorb nutrition and moisture
• Reproductive hyphae: These are aerial hyphae and form spores for reproduction.
• Examples of some mold:
• Rhizopus
• Mucor

Reproduction of Molds

•       Molds reproduce primarily by means of asexual reproductive spores. Some molds also form  sexual spores
•        Asexual spore of molds are produced in large numbers and are small, light and resistant to drying. They are readily spread through the air.

           These include the following.

• A hypha can fragment (by the separation of hyphae through splitting of the cell wall or septum) to  form cells that behave as spores. These cells are called arthroconidia or arthrospores.

• If the cells  are  surrounded  by  a  thick  wall  before  separation,  they  are called chlamydospores.

 

• If the spores develop within a sac (sporangium) at a hyphal tip, they are called sporangiospores. 

• If the spores are not enclosed in a sac but produced at the tips or sides of the hypha, they are termed conidiospores.

• Spores produced from a vegetative mother cell by budding are called blastospores. 

Types of Mold

• Aspergillus: Common indoors, often found on food and dust.
• Penicillium: Found on decaying food and materials; some species are used to make antibiotics.
• Cladosporium: Grows on wood, carpets, and fabrics.
• Stachybotrys (Black Mold): Toxic mold that grows on wet materials like drywall.

Harmful Effects of Mold

• Causes allergies, skin rashes, and respiratory issues.
• Produces mycotoxins, which can be harmful if ingested or inhaled.

Uses of Mold

• Food Industry: Molds are used to make cheese (e.g., blue cheese) and ferment soy products.
• Medicine: Used to produce antibiotics like penicillin.

Learn About Molds in Microbiology

References

1. Martein Probisker,2018, Fundamentals of Microbiology, Jones & Bartlett Learning publication,11^th Ed
2. Frazier W.C. 1988, Food Microbiology - Tata Mc Graw Hill Book Company, 5^th Ed, Bombay.
3. Adams M.R. and Moss M.O.2000, Food microbiology - Royal society of Chemistry publication, 2^nd Ed.
4. Banwart G.T.2004, Basic Food Microbiology - CSS Publishers, 2^nd Ed 

Web Resources

1.  https://byjus.com/biology/kingdom-fungi/
2.  https://www.uou.ac.in/lecturenotes/science/MSCBOT-17/Unit%20%E2%80%9310%E2%80%93%20General%20Characters%20and%20Classification%20of%20Fungi%20by%20Dr.%20Kirtika%20Padalia-converted.pdf
3. https://www.bellarmine.edu/faculty/dobbins/Secret%20Readings/Lecture%20Notes%20113/FungusWO.pdf
   
4. https://www.rlsycollegebettiah.ac.in/wp-content/uploads/2023/02/file_63e39a790ec90.pdf
   
5. https://www.bdu.ac.in/cde/SLM/B.Sc.%20Botany/I%20Year/B.Sc.Botany_Alagi%2CFungi%20%26%20Plant%20Protection%20%28Practical%29_I-Year_SPS.pdf

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General Classification of Micro-organisms - Dr. Merrylin

Food Microbiology | Food Microbiology | Food Microbiology

Introduction to Microorganisms

Microorganisms, often referred to as microbes, are tiny living organisms that cannot be seen without the aid of a microscope. These organisms are diverse, occupying various ecological niches, and play significant roles in our lives. From being pathogens that cause diseases to beneficial organisms that drive ecosystems, microbes are indispensable in biology, medicine, industry, and environmental sciences.

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Importance of Classifying Microorganisms

Classification is essential to:

1. Identify and study microbes systematically.
2. Understand their roles—beneficial or harmful—in nature.
3. Develop effective disease treatments and industrial applications.
4. Advance biological sciences like genetics, immunology, and microbiology.

Criteria for Classification

Microorganisms are classified based on the following major characteristics:

1. Cell Type:
   • Prokaryotic (no well-defined nucleus) or Eukaryotic (having a well-defined nucleus).
2. Mode of Nutrition:
   • Autotrophic (prepare their own food through photosynthesis/chemosynthesis) or Heterotrophic (depend on other organisms for nutrition).
3. Genetic Material:
   • DNA or RNA as the primary genetic material.
4. Reproduction:
   • Asexual (binary fission, budding, etc.) or Sexual.
5. Habitat:
   • Microbes thrive in diverse environments: soil, water, host organisms, or extreme conditions (temperature, pH, salinity).

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Major Groups of Microorganisms

The six major groups of microorganisms are:

1. Bacteria

• Cell Type: Prokaryotic.
  
  

  

  
  

  
  

  
  
• Structure: Simple single-celled organisms.
• Shapes:
• Rod-shaped (Bacilli)
• Spherical (Cocci)
• Spiral (Spirilla)
• Comma-shaped (Vibrio)

• Examples:
• Lactobacillus – helpful, used in yogurt fermentation.
• Salmonella – harmful, causes food poisoning.

• Significance:
  • Useful in food production (fermentation).
  • Cause diseases (pathogenic bacteria).
  • Aid in nitrogen fixation in agriculture.

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2. Fungi

• Cell Type: Eukaryotic.
• Structure: Unicellular (Yeasts) or Multicellular (Molds and Mushrooms)    

    

           

• Reproduction: Asexual (spores, budding) or Sexual.

• Examples:
  • Yeast – used in bread and alcohol fermentation.
  • Candida – causes fungal infections.
• Significance:
  • Decomposers of organic matter.
  • Industrial applications: antibiotics, food production.
  • Some fungi are pathogenic.

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3. Protozoa

• Cell Type: Eukaryotic.

• Structure: Single-celled organisms with diverse movement mechanisms.
• Pseudopodia (false feet): Amoeba

• 
• Flagella (whip-like tail): Trypanosoma
• Cilia (hair-like structures): Paramecium

• Examples:
  • Plasmodium – causes malaria.
  • Amoeba – free-living protozoan.
• Significance:
  • Cause diseases like malaria and sleeping sickness.
  • Help in studying cellular functions.

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4. Algae

• Cell Type: Eukaryotic.

• Structure: Unicellular to multicellular.
• Nutrition: Autotrophic—photosynthetic organisms.
• Examples:
  • Chlorella – unicellular, produces oxygen.
  • Diatoms – important aquatic organisms.
• Significance:
  • Produce a significant amount of Earth’s oxygen.
  • Form the base of aquatic food chains.
  • Used in biofuel production and as dietary supplements.

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5. Viruses

• Cell Type: Acellular (not truly living outside a host).

• Structure:
  • Contain either DNA or RNA enclosed in a protein coat.
• Reproduction: Can replicate only inside living host cells.
• Examples:
  • Influenza virus – causes flu.
  • HIV – causes AIDS.
  • Coronavirus – causes COVID-19.
• Significance:
  • Cause a wide range of diseases in humans, animals, and plants.
  • Potential therapeutic applications (phage therapy).

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6. Archaea

• Cell Type: Prokaryotic.

• Unique Features: Different from bacteria due to distinct genetic and metabolic pathways.
• Habitat: Extremophiles—thrive in extreme conditions:
  • High temperature (Thermophiles).
  • High salt (Halophiles).
  • Methane-rich environments (Methanogens).
• Examples:
  • Methanobacterium – produces methane in anaerobic conditions.
• Significance:
  • Important in nutrient cycling.
  • Useful in biotechnology for biofuel production.

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Significance of Microorganisms

Microorganisms play a pivotal role in various fields:

1. Medicine:

   • Production of antibiotics (e.g., Penicillin from fungi).
   • Development of vaccines and genetic research.

2. Agriculture:

   • Nitrogen fixation by bacteria (e.g., Rhizobium in legume roots).
   • Decomposition of organic matter to enrich soil.

3. Industry:

   • Fermentation: Alcohol production (yeast) and dairy products (lactic acid bacteria).
   • Production of biofuels and enzymes.

4. Environment:

   • Biodegradation of pollutants (bioremediation).
   • Oxygen production by algae.

5. Research:

   • Studying microorganisms has led to advances in genetics, biotechnology, and immunology.

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Conclusion

Microorganisms, though invisible to the naked eye, have a profound impact on our world. Their classification helps us better understand their structure, role, and applications in science, medicine, and industry. By identifying and categorizing microbes, we can harness their potential for human welfare and mitigate their harmful effects.

General Classification of Micro-organisms

Reference

1. Martein Probisker,2018, Fundamentals of Microbiology, Jones & Bartlett Learning publication,11^th Ed.
2. Frazier W.C. 1988, Food Microbiology - Tata Mc Graw Hill Book Company,5^th Ed, Bombay.
3. Adams M.R. and Moss M.O.2000, Food microbiology - Royal society of Chemistry publication,2^nd Ed.
4. Banwart G.T.2004, Basic Food Microbiology - CSS Publishers, 2^nd Ed

Web Resources:

1. Food Microbiology - Frazier

2. Food Microbiology - EGyanKosh

3. Fundamentals of Microbiology - USDA

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