role of enzymes in food, their uses and applications

Enzymes in food

1. Enzymes and Hormones in Foods Dr. Vinod Kumar Patil Assistant Professor Department of Food and Nutrition Faculty of Sciences Khaja Bandanawaz University Kalaburagi, Karnataka

2. Enzymes are substances present in the cell in small amounts that function to speed up or catalyze chemical reactions. On the surface of the enzyme is usually a small crevice that functions as an active site or catalytic site to which one or two specific substrates are able to bind. 

3. Many enzymes require a nonprotein cofactor to assist them in their reaction. In this case, the protein portion of the enzyme, called an apoenzyme, combines with the cofactor to form the whole enzyme or haloenzyme . ome cofactors are ions such as Ca++, Mg++, and K+; other cofactors are organic molecules called coenzymes which serve as carriers for chemical groups or electrons. NAD+, NADP+, FAD, and coenzyme A (CoA) are examples of coenzymes.

4. Enzyme activity is affected by a number of factors including: The concentration of enzyme : Assuming a sufficient concentration of substrate is available, increasing enzyme concentration will increase the enzyme reaction rate. The concentration of substrate : At a constant enzyme concentration and at lower concentrations of substrates, the substrate concentration is the limiting factor. As the substrate concentration increases, the enzyme reaction rate increases. However, at very high substrate concentrations, the enzymes become saturated with substrate and a higher concentration of substrate does not increase the reaction rate. The temperature : Each enzyme has an optimum temperature at which it works best. A higher temperature generally results in an increase in enzyme activity. As the temperature increases, molecular motion increases resulting in more molecular collisions. If, however, the temperature rises above a certain point, the heat will denature the enzyme, causing it to lose its three-dimensional functional shape by denaturing its hydrogen bonds. Cold temperature, on the other hand, slows down enzyme activity by decreasing molecular motion.

5. The pH : Each enzyme has an optimal pH that helps maintain its three-dimensional shape. Changes in pH may denature enzymes by altering the enzyme's charge. This alters the ionic bonds of the enzyme that contribute to its functional shape. Effect of Product Concentration:  The accumulation of reaction products can influence enzyme activity. In some cases, high product concentrations can inhibit enzyme activity through  negative feedback  mechanisms, ensuring that excessive product formation is controlled. This phenomenon helps maintain cellular  homeostasis . Effect of Activators:  Activators are molecules that enhance enzyme activity. These substances can bind to enzymes and induce conformational changes that increase the enzyme’s affinity for its substrate or stabilize the enzyme-substrate complex. As a result, the rate of the enzymatic reaction is boosted.

6. Name Description/habitat Optimal pH Optimal temperature Thermococcus hydrothermalis Prokaryotic  archaea  found in the East Pacific hydrothermal vent 5.5 85°C Sulfolobus solfataricus Prokaryotic archaea found in sulfur-rich volcanic fields 3.0 80°C Halomonas meridiana Gram-negative bacteria found in Antarctica salt lake 7.0 37°C Pseudoalteromonas haloplanktis Fast-growing bacteria found in Antarctic seawater 7.6 4°C

7. Enzyme Function pH range Optimal pH 1. ɑ-Amylase In saliva, amylase breaks down most polysaccharides in human diets. 6.4 – 7.0 6.6 2. Pepsin Pepsin is one of the many proteases found in the stomach’s gastric juice. It hydrolyzes peptide bonds in the protein’s amino acid chains. 1.5 – 4.5 2 3. Trypsin Found in the small intestine, trypsin is another protease that digests proteins. 7.5 – 8.5 7.8 4. Alkaline Phosphatase (ALP) ALP catalyzes the removal of phosphate groups from its substrate. It is found in all human tissue and is most abundant in the intestine and placenta. 8 – 10 10

8. Lipases:  This group of enzymes help digest fats in the gut. Amylase:  In the saliva, amylase helps change starches into sugars. Maltase:  This also occurs in the saliva, and breaks the sugar maltose into glucose. Trypsin:  These enzymes break proteins down into amino acids in the small intestine. Lactase:  Lactase breaks lactose, the sugar in milk, into glucose and galactose. Acetylcholinesterase:  These enzymes break down the neurotransmitter acetylcholine in nerves and muscles. Helicase:  Helicase enzymes unravel DNA. DNA polymerase:  These enzymes synthesize DNA from deoxyribonucleotides.

9. Active enzyme Zymogen Site of production Chymotrypsin Chymotrypsinogen Pancreas Trypsin Trypsinogen Pancreas Carboxypeptidase Procarboxypeptidase Pancreas Elastase Proelastase Pancreas Pepsin Pepsinogen Stomach

10. Proteases Proteases are a class of enzymes involved in a host of  fundamental physiological processes . Protease enzymes play a crucial part in the digestion of proteins. These enzymes catalyze the process of  breaking down complex protein molecules  into simple and more bio-available amino acids. Proteases are also involved in  regulating and modulating protein activation  in the body. Proteolytic enzymes are in many  fresh fruits and fermented foods , including: Pineapples (Contains A Protease Called Bromelain), Ginger (Has A Protease Named Zingibain ), Papaya (Contains The Protease Called Papain), Honey Miso Kimchi Kefir

11. Other vital functions of protease enzymes are involved in inflammatory responses and contribute to  ovulation and fertilization .  In addition, proteases are responsible for  cellular activities  like: Cell Signaling Differentiation Apoptosis Due to the critical functions proteases are involved in,  deficiencies of endogenous proteolytic enzymes  are associated with many health issues: Gastrointestinal Conditions Cancer Heart Disease Hypertension Inflammatory Disorders

12. Amylases Amylase enzymes initiate and participate in the body’s  metabolism of starches and carbohydrates . This category of  digestive enzymes  occurs naturally in foods such as: Mango Honey Kimchi Miso Amylase enzymes catalyze the  biochemical transformation  of carbohydrates, starches, and polysaccharides into simple sugars like glucose and maltose. By doing so, these enzymes support the functions of the following: Pancreas Kidneys Gastrointestinal System

13. Lipases Lipases are an enzyme group responsible for the  digestion of fat in the body . Lipase enzymes are synthesized by  bacteria ,  yeasts , and  fungi  rather than plants and animals we consume. These micro-organisms are used in the  fermentation of many traditional foods , so we can access lipase enzymes by eating: Miso Kimchi Kefir Lipases are critical for  breaking down triglyceride  fats into glycerol and fatty acids, which help the intestines to absorb fats. These enzymes also contribute to the healthy production of low-density lipoprotein.

14. Lactase The digestive enzyme that  breaks down the lactose sugar in dairy-based foods . Our bodies synthesize endogenous lactase, but these bacteria produce this crucial enzyme too: Lactobacillus acidophilus Lactobacillus bulgaricus Streptococcus thermophilus We can obtain lactase by eating  foods that are fermented  by these lactase-synthesizing micro-organisms, for example: Yogurt Miso Kefir These sources of lactase are particularly effective for  improving the digestion of lactose  because the enzyme is protected from stomach acids by bacterial cells. This protection gives the lactase enzyme more time to digest the lactose in the stomach.

15. In vertases Invertase Enzymes Act As Catalysts In The  Hydrolysis Of Sucrose . In This Critical Process, Invertases Enable  Water Molecules To Break Sucrose Into Fructose And Glucose . Dietary Sources Of Invertases Include: Honey Fresh Asparagus Heads Invertase Enzymes Are Also Involved In The Healthy Functioning Of The Gastrointestinal And Respiratory Systems. Another Health-promoting Role Of Invertases Is Their  Antioxidant Properties . Invertases  Prevent The Development Of Stomach Ulcers  Because These Enzymes Prevent The Toxic Accumulation Of Undigested Sugars In The Gut. Consequently, A Deficiency Of Invertase Enzymes May Be Linked With Stomach Ulcers. Given Their Involvement In Sucrose Metabolism, Invertases Play A  Significant Anti-glycemic Role . For This Reason, Invertase Enzyme Deficiencies Are Closely-associated With Insulin-related Conditions Like Diabetes.

16. Hormones are molecules synthesized by specific tissue. Classically these tissue were called glands. Hormones are secreted directly into the blood which carries them to their sites of action. Hormones are present at very low levels in the circulatory system. Hormones specifically affect or alter the activities of the responsive tissue (target tissue). Hormones act specifically via receptors located on, or in, target tissue

17. ACTH, calcitonin, glucagon, vasopressin, oxytocin, hormones of hypothalamus (releasing factors). • Amino acid derivatives : Examples: Adrenaline, Catecholamines, Thyroid Hormones; • Fatty acid derivatives : Examples: Eicosanoids (Prostaglandins); • Steroid hormones : These are derivatives of Cholesterol; Example: Estradiol , Progesterone, Testosterone, Cortisol, Aldosterone;

18. Hydrophilic Hormones (Lipophobic Hormones) • Hormones that are soluble in aqueous medium; • They cannot cross the cell membrane, • Thus, they bind to receptor molecules on the outer surface of target cells, initiating reactions within the cell that ultimately modifies the functions of the cells; Examples: Insulin, Glucagon, Epinephrine, GH. Lipophilic Hormones (Hydrophobic Hormones) • Hormones that are not soluble in aqueous medium, but soluble in lipid; • They can easily cross the cell membrane, • Thus, they can enter target cells and bind to intracellular receptors to carryout their action; Examples: Thyroid hormones, Steroid hormones.

19. Effects of Hormone actions: Change the permeability of cell membrane, accelerate the penetration of substrates, enzymes, coenzymes into the cell and out of cell. Acting on the allosteric centers affect the activity of enzymes (Hormones penetrating membranes). Affect the activity of enzymes through the messengers (cAMP). (Hormones that can not penetrate the membrane). Act on the genetic apparatus of the cell (nucleus, DNA) and promote the synthesis of enzymes (Steroid and thyroid hormones).

20. Steroid Hormone is a group of  hormones  that belongs to a class of chemical compounds called Steroids.  It is secreted by three steroid glands namely the adrenal cortex,  testes , and ovaries. During pregnancy, the  placenta  also secretes steroid hormones in smaller amounts. Cholesterol  is the source of all steroid hormones. They are then carried via the bloodstream to the cells of various target organs. Steroid hormones carry out and control a wide range of physiological processes.

21. Steroids are categorized according to the functions performed by them. They are primarily divided into two classes: Sex Hormones  or Sex Steroids (Progesterone, Androgens and Estrogens) Corticosteroids (Glucocorticoids and Mineralocorticoids) Corticosteroids: Corticosteroids are a group of steroid hormones that are produced in the adrenal cortex of  vertebrates . The two main groups of corticosteroids are glucocorticoids and mineralocorticoids.

22. Glucocorticoids: Glucocorticoids works for the regulation of glucose  metabolism , and are synthesized in the adrenal cortex. The immune system uses feedback to reduce  inflammation  and other elements of immunological function, and glucocorticoids are a component of this process.

23. Mineralocorticoids Mineralocorticoids are hormones made in the adrenal cortex that keep the body's balance of salt and water (electrolyte balance and fluid balance). The most important mineralocorticoid is aldosterone.

24. Steroid hormones called 'sex hormones' bind to steroid hormone receptors in vertebrates. They can also be referred to as gonadocorticoids , sex steroids, and gonadal steroids. Sex hormones include  androgens ,  estrogens , and progestogens.  Progestogens: They are commonly known as gestagens or progestogens. These steroid hormones belong to a group that binds to and stimulates the progesterone receptor (PR). Progestogens are so named because of the role they play in maintaining pregnancy. Androgen: A type of steroid hormone, natural or artificial, that binds to receptors in vertebrates and controls the development and maintenance of male characteristics is known as an androgen. Androgens are produced in the ovaries, adrenal glands, and testes.  Estrogen: It is usually referred to as  oestrogen , and is a sex hormone that affects secondary sex traits as well as the development and management of the  female reproductive system . The three primary endogenous estrogens essential for estrogenic hormonal activity are Estrone (E1), Estradiol (E2), and Estriol (E3). Estestrol (E4) is another oestrogen released during pregnancy. 

25. Some important functions of Steroid Hormones are as follows:  Carbohydrate  Regulation Help Modulate Sexual Development Help Modulate Metabolism and Immunological Responses, Help Modulate Salt and Water Balance Resistance to  Disease  and Injury. Mineral Balance Reproductive Functions Inflammatory Response Stress Response Bone Metabolism Cardiovascular Fitness Activates  DNA  for Protein Synthesis