Food Biotechnology Dr Kamal E M Elkahlout Food
Food Biotechnology Dr. Kamal E. M. Elkahlout Food Biochemistry 5 Vitamins and minerals
Vitamins Micronutrients Minor components but essential constituents in foods absence in diet affect the health of people absorption levels affects its bioavailability which also affects cell function and thus health
Categories Fat-soluble Dissolve in fat Can be stored Water-soluble Dissolve in water Carried in bloodstream, not stored A, D, E, K C and B-complex vitamins A and D excess can be harmful E and K usually not Excess amounts may cause extra work on kidneys
Thiamin (B 1) Functions: Helps produce energy from carbs Sources: Whole-grain and enriched grain products Beef Liver
Thiamine (B 1) Deficiency � Decrease in activity of enzymes. � Beriberi (neurological and cardiac symptoms (severe) sources: legumes seeds, pericarp and germ of cereals, yeast, vegemite, milk and whole grain bread Loss � in cooking water, due to heat, change in p. H, metal ions and ionic strength. � Also destroyed by sulfites. (added to fruits & veg to prevent browning)
Riboflavin (B 2) Functions: Produce energy Changes tryptophan (amino acid) into niacin Sources: Liver Yogurt and milk Enriched grains Eggs Green, leafy veggies
Riboflavin Deficiency lead to accumulation of amino acids so there is decrease of glutathione reductase activity in red cells Stability Unstable when exposed to uv light
Niacin Functions: Helps body use sugars/fatty acids Helps enzymes function normally Produces energy Sources: Foods high in protein typically (poultry, fish, beef, peanut butter, legumes) Enriched and fortified grains
Nicotinamide (Niacin) Deficiency � Serious is pellagra (affects skin, digestion and nervous system – dermatitis, diarrhea and dementia) Stability �quite stable in heat and process Availability �increases slightly during baking due to alkaline conditions (baking powder) Loss �occurs in cooking water due to leaching.
Pyridoxine (B 6) Functions: Helps body make nonessential amino acids Helps turn tryptophan into niacin and serotonin Help produce body chemicals (insulin, hemoglobin, etc) Sources: Chicken Fish Pork Liver Whole grains Nuts Legumes
Pyridoxine (B 6) Deficiency Results in protein metabolic disorders eg haemoglobin synthesis Loss during cooking in cooking water extensive loss in dried milk due to interaction with sulfhydryl groups of proteins
Vitamin B 12 (cobalamin) Functions: Works with folate to make RBC’s In many body chemicals and cells Helps body use fatty acids/amino acids Sources: Animal products Meat Fish Poultry Eggs Milk, other dairy
Cobalamin, B 12 Stability Quite stable to food processing and cooking at p. H 4 -6 However, destroyed in alkaline media or in the presence of reducing agents E. g. Ascorbic acid and SO 2
Folate (folic acid) Functions: Produces DNA and RNA, making new body cells Works with vitamin B 12 to form hemoglobin May protect against heart disease Lowers risk of neural tube defects in babies Controls plasma homocystine levels (related to heart disease) Sources: Fortified and enriched grains and breakfast cereals Orange juice Legumes Green, leafy veggies Peanuts Avacados
Folic acid (Folacin, B 9 ) Deficiency leads to anaemia Loss vitamin C helps preserve folic acid in food, loss in milk due to oxidative process. However, no destruction during blanching of vegetables.
Biotin Functions: Produces energy Helps body use proteins, carbs, and fats from foods Helps maintain steady blood sugar level, helps strengthen hair and nails Sources: Wide variety of foods Eggs Liver Wheat germ Peanuts Cottage cheese Whole grain bread
Biotin Deficiency rare except in people who eat large amounts of raw egg (cooking releases biotin from protein) Stable vitamin-loss occurs during processing and storage.
Pantothenic Acid Helps produce energy Helps the body use proteins, fat, and carbs from food Sources: Found in almost all foods Meat, poultry, fish Whole grain cereals Legumes Milk Fruits, veggies
Pantothenic acid, B 5 Deficiency is rare Loss 10% during milk processing also during cooking of vegetables due to leaching
Vitamin C Functions: Helps produce collagen (connective tissue in bones, muscles, etc) Keeps capillary walls, blood vessels firm Helps body absorb iron and folate Healthy gums Heals cuts and wounds Protects from infection, boosts immunity Antioxidant Sources Citrus fruits Other fruits, veggies
Ascorbic acid (C) Deficiency leads to scurvy-failure of wounds to heal Stability Very unstable-readily oxidised to dehydroascorbic acid and then oxidized to 2, 3 diketogulonic acid which has no biological function. Alkaline p. H increases loss, high temperatures increases loss.
Fat Soluble Vitamins Stored in the fatty tissues-eg liver Accumulated Soluble in fat-need fat to be absorbed in body and can lead to toxicity Not required daily
Vitamin A (and carotenoids) � Functions: � Normal vision � Protects from infections � Regulates immune system � Antioxidant (carotenoids) � Carrotinoids Used in food industry as a colorant (orange) (label friendly) Food sources: Liver Fish oil Eggs Fortified milk or other foods Red, yellow, orange, and dark green veggies (carotenoids)
Vitamin A Loss High temperatures and oxygen affect stability. quite stable in food processing and storage
Vitamin D (the sunshine vitamin) Functions: Sources: Promotes absorption of calcium and phosphorus Responsible for calcium deposition in bone matrix Regulates cell growth Plays role in immunity Sunlight (10 – 15 mins 2 x a week) Salmon with bones Milk Orange juice (fortified) Fortified cereals
Calciferol, cholecalciferol (vitamin D) Deficiency impaired bone formation-increased secretion of Ca and P leading to osteomalacia (weakening and softening) Excessive intake hypercalcaemia-calcium deposition in various organs. Loss Sensitive to oxygen and light
Vitamin E Functions: Antioxidant, may lower risk for heart disease and stroke, some types of cancers Protects fatty acids and vitamin A Sources: Vegetable oils Foods made from oil (salad dressing, margarine) Nuts Seeds Wheat germ Green, leafy veggies
α –tocopherol, (vitamin E) Stablity Quite stable except for autoxidation. loss in activity in commercial deep fried frozen foods
Vitamin K Functions: Helps blood clot Helps body make some other proteins Sources: Body can produce on its own (from bacteria in intestines) Green, leafy veggies Some fruits, other veggies, and nuts
Vitamin K Deficiency reduced acitivity of prothrombin-leads to hemorrhage Loss Destroyed by light and alkali Stable to atmospheric oxygen and heat
What Are Minerals? Regulate body processes Give structure to things in the body No calories (energy) Cannot be destroyed by heat constituents which remain as ash after incineration of plant and animal tissues
Categories of minerals Major minerals Calcium Phosphorus Magnesium Electrolytes (sodium, chloride, potassium) Trace minerals Chromium Copper Flouride Iodine Iron Manganese Selenium Zinc
Sodium Maintains osmotic pressure of extracellular fluid Present mostly as an extracellular constituents Activates enzymes such as amalyse Excess intake-hypertension Food sources-salt, meat, milk Deficiency-various disorders Requirement-300 -350 mg
Potassium, K Regulates osmotic pressure within cells, involved in cell membrane transport Sources-major sources are potatoes and molasses, white bread is potassium deficient
Magnesium (mg) Roles: Constituents and activator of many enzymes including Conversion of energy-rich phosphate compounds Stabilizer of plasma, intracellular membranes and nucleic acids Life-supporting element Requirement-300 -350 mg Deficiency-various disorders
Calcium Ca essential nutrient: abundant in skeleton and other tissues building and maintenance of bones blood clotting and muscle contraction Requirement is 0. 8 -1. 0 g Major sources are milk and other dairy products, however low in fruits and vegetables, cereals, meat, fish and eggs
Chloride, Cl Role It serves as a counter ion for Na in extracellular fluid and for hydrogen ions in gastric juice Its absorption is rapid as its excretion in urine Food sources-salt-Na. Cl
Phosphate, P Has a role in metabolism Calcium in food : phosphate ratio should be 1
Trace elements Iron, Fe Present in haemoglobin and myoglobin pigments Present in other enzymes as peroxidase, catalase, hydroxylases and flavine Deficiency causes anemia Iron from vegetable sources –poorly absorbed-called non haem iron Iron from animal sources-haem iron well absorbed Vitamin C increases absorption Phytates in bran impairs absorption.
Problems on fortification of food with iron Higher chance of oxidation in wheat flour and decreased baking ability Catalyses oxidation of fat or oil, increased turbidity of wine and supports growth of iron –requiring bacteria
Copper, Cu Component of a no. of oxidoreductase (SOD, tyrosinase, urinase, amine oxidase Bound to ceruloplasmin in plasma (catalyses oxidn of Fe 2+ to Fe 3+- form transported by transferrin protein to Fe pool in liver Catalyses oxidative destruction of ascorbic acid
Zinc, Zn Component of certain enzymes such as alcohol dehydrogenase, lactate dehydrogenase, malate dehydrogenase, etc Zn poisoning due to food kept in Zn-plated metal containers
Manganese (Mn) Metal activator for pyruvate carboxylase Activates enzymes as arginase, amino peptidase, alkaline phosphatase, etc Relatively non-toxic
Cobalt, Co Component of vitamin B 12
Chromium, Cr Helps in the utilisation of glucose Activates phosphoglucomutase Increase activity of insulin deficiency cause decrease glucose tolerance Increase risk of CVD
Selenium, Se Is an antioxidant Enhance tocopherol activity Component of glutathione peroxidase Protect membranes from oxidative destruction
Fluorine Required for growth and reproduction Inhibits tooth decay by retarding solubilization of tooth enamel and inhibiting enzyme involved in dental caries
Iodine, I Utilised in thyroid gland in biosynthesis of hormone thyroxine Deficiency results in goiter (enlargement of thyroid gland) Good sources are seafoods Fortification-Iodization of common salt (100μg to 1 -10 g Na. Cl – combat the deficiency Higher amounts are toxic – affect reproduction and lactation in animals
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