Ch 13 vitamins and minerals

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Transcript Ch 13 vitamins and minerals

Food Micronutrients
Ch 13 vitamins and minerals
14 phytochemicals
& 16
Jigsaw assignments:
• 1. Fat soluble vitamins pg369-374
• 2. Water soluble vitamins pg 374-376
• 3. Non vitamins pg 376/ phytochemicals ch 14
• 4. Macro minerals pg 377-381
• 5. Micro minerals pg 381-384
• 6. phytochemicals pg 401-421
• 7.enrich/ fortify pg 385-389
Ch 13 vitamins and minerals
• Vitamins- organic compounds needed in small amounts to regulate
processes.
– No calories
– Work w enzymes to maintain health
– Fat soluble
– A: night vision, bones and teeth, hormone synthesis, cancer protection
–
Organic Acids
• Impart flavor
• Some used as antimicrobial agents
• Adjust pH or acidity of food (acidulants)
• Acidulant is a food additive that lowers the pH to give a tart or
bitter taste
Organic Acids• Examples
• Malic acid ( apples)
• Citric Acid ( citrus fruits, tomatoes, strawberries)
• Tartaric Acid ( grapes)
• Lactic Acid ( yogurt , cheese, olives and sauerkraut)
Organic acids- Determining Acidity
• 1. One simple method of determining if a food is acidic is to taste it
• A sour or acidic taste is a positive indicator
Organic acids- Determining Acidity
• 2. Use a pH meter
– Measure the H+ concentration (from acids in food) then converted to a pH
value
Organic acids- pH
• pH ranges from 0 (very acidic) to 7 ( neutral) to 14 ( very alkaline/ basic)
• Importance of acidity in foods
– Determines rate of chemical and enzymatic reactions
– Microbial growth / survival in foods
– pH value of 4.6 – critical to Food Industry
– Borderline between: “acid and low acid foods”
ORGANIC ACIDS- pH
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------------------------------------------------------------------------------------------------------***********************4.6********************8
ACIDIC
LOW ACID
Acidic or acid foods ( pH < 4.6)
citric juices, apple juices, strawberries, apples
will not support growth of most* disease-causing micro organisms
Low acid foods ( pH > 4.6)
meat
fish
vegetables
* Except Ecoli 0157:H
Colors and Pigments
• Extracted from natural and / or synthetic sources- added to foods
– Carotenoids:
– red in tomatoes (lycopene)
– Carrots ( beta carotene)
– Chlorophylis ( in celery, lettuce, and broccoli)
– Anthocyanins ( in blueberries, grapes, and cranberries
– Myoglobin ( in meat)
Aroma & Taste compounds…
• Aroma and Taste profiles in food= flavor
– Complex- 100s or 1000s of compounds
– Eg) aldehydes, ketones, acids, alcohols, fatty acids
– Aroma- volatile compounds
– Taste: non-volatile
• Present as part of the food matrix (eg strawberries) or
• Modified (eg cooked strawberries)
Vitamins and minerals
Water soluble
– Found in water-phase of foods
– Vit C , B complex, folic acid
Fat soluble
– Found within fat/oil portion of foods
– Vit A,D,E,K
– Some used as food additives: preservatives (antioxidants)
– E, C = antioxidants
Minerals:
Ca,Mg,Na,K,Fe,Zn