Photosynthesis and Fiber Module 3.3

Photosynthesis Glucose, the basic carbohydrate building block. Glucose is made of water and carbon dioxide in the presence of chlorophyll and sunlight = process: photosynthesis Photosynthesis– converts light energy to chemical energy Raw materials (carbon dioxide and water) Photosynthesis requires chlorophyll. Energy source-sun End products (oxygen and carbohydrates: sugars, starch and fiber) 6H2O + 6CO2 ---> C6H12O6+ 6O2

Photosynthesis Converts light energy into the chemical energy of sugars and other organic compounds. The process consists of a series of chemical reactions that require carbon dioxide (CO2) and water (H2O) and sunlight. Occurs in organelles called chloroplasts. The chloroplast is enclosed by a membrane. Within the membrane is an aqueous fluid called the stroma. Inside the stroma are flattened disks (stacks of thylakoids - grana). The chlorophyll pigment molecules sit on the surface of each thylakoid and capture light energy from the Sun. Using this light energy (photons) electrons are transfered from water to the carbon dioxide molecules, forming energy-rich sugar molecules (glucose) then stored in the plant. In the process, oxygen (O2) is released into the atmosphere.

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Complex Carbohydrates Fiber -- the indigestible residues of food Comes from the supporting structures of plants: leaves, stems and seeds. Fiber cannot be broken down by human digestive enzymes Fiber has few calories because it is not digested. Conveys a sense of fullness Delays stomach emptying Offers multiple health benefits There are two types of fiber in the plant varieties: Soluble fiber in fruits, oats and legumes Insoluble fiber mostly in grains and vegetables

Fiber Categories Insoluble Solubility Fiber Sources Food Sources -Softens & gels in water. - Attract water Pectins Gums Mucilages - Fruits (like apple pectin), vegetable, legumes, and oats Fiber Categories Solubility Fiber Sources Food Sources -Does NOT soften or gel in water. - Attract water Cellulose Hemi-cellulose Lignins -Whole grains -Celery strings -Apple peels Soluble Insoluble

Fiber Recommendations The DRI for total fiber intake: Adult male is 38 grams. Adult ♀ is 25 grams. Personalized DRI is 1.4 grams total fiber per 100 Calories consumed. Example: A person eating 4200 Calories in 1 day should consume 59 grams of fiber. High fiber intake is well over 2 grams/100 Calories consumed. High fiber foods provide > 2 gm fiber/serving. High fiber foods are easy to assess on the food package label by comparing the grams of fiber with reference to the Calories provided/serving. Fiber Sources: Grains, cereals, legumes, fruits, vegetables

Fiber in Foods

Food Group Very High >4gm High 2-4gm Good 1-2gm Low ≤1gm Grains ½ C Bran Flakes 1 C Shredded whole wheat or whole multigrain cereal 1 C Oatmeal or puffed brown rice cereal 1 Slice Whole Wheat Bread 1 Slice Rye Bread ½ C Brown or Wild Rice 1 Corn Tortilla 1 C Cornflakes ½ C White Rice ½ C Pasta Food Group Very High >4gm High 2-4gm Good 1-2gm Low <1gm Vegetable ½ C Legumes (dried beans) ½ C Broccoli, Cauliflower, Corn, Beans, Cabbage 1oz Nuts & Seeds ½ C Carrots, Green pepper, Celery, Onion, Lettuce 1 C Some Vegetable Juices

Food Sources & Amounts of Fiber Group Very High >4gm High 2-4gm Good 1-2gm Low <1gm Fruit N/A 1 Apple, Banana Orange, Peach, 1 C Berries 2 Prunes ½ C Watermelon,Honeydew melon, Cantaloupe 1 C Fruit Juice

Insoluble fiber Does not dissolve in water Provides bulk, aids intestinal motility Speeds removal of waste-less time in colon decreases possibility of colon cancer Prevents: constipation, hemorrhoids, and diverticulosis and diverticulitis. Types: Cellulose-provides strength; acts like a broom in the gut Hemicellulose- in the outer bran layer Lignin - woody parts of vegetables wheat bran, brown rice, nuts, seeds, skins, whole grains 11

Diverticulosis and Diverticulitis

Soluble fiber Dissolves or swells in water Helps delay glucose absorption Lowers blood cholesterol Types -- beans, oats, lentils, peas, barley, carrots, corn, rye Pectin gel-forming acts like cement giving body and shape to fruits. Gums- thick gel forming fibers that help plants hold together Example: Psyllium husks nearly 5X higher than that of oat bran. Pectin 13

Fiber Content in Foods Dietary fiber: found naturally in the fruits, vegetables, nuts, and grains. Functional Fiber: Indigestible carbohydrate isolated from natural sources or synthetic indigestible carbohydrate. Added to foods to boost their fiber content. An example of indigestible carbohydrate isolated from a natural source is cellulose gel added to a processed food Has beneficial physiological effects in humans. Total Fiber: Is the combination of dietary & functional fiber in food. Is reflected as the fiber content value on food package labels in the Nutrition Facts panel.

Beneficial Actions of Fiber Bulk Increases volume of food in the diet without adding calories decreases the caloric density of the food. Bulks the stool volume. Both soluble & insoluble fiber provide these benefits. Stool softener Complex carbohydrate chemical structures binds water or attracts water creating a softer stool; easier to move through G.I. tract. Relieves CONSTIPATION, HEMORRHOIDS, & DIVERTICULOSIS. Decreases transit time Food, bolus, chyme, and feces move through the GI tract faster, reducing transit time for nutrient absorption and elimination of waste Decreases time in the colon. Reduces exposure time to potential carcinogens thus reduces COLON CANCER.

Beneficial Actions of Fiber Increases gastric emptying time. It takes a longer time for the chyme to leave the stomach. The rate of glucose absorption is slowed. This is beneficial with DIABETES & reactive hypoglycemia. Sense of fullness – less likely to overeat; decrease risk of OBESITY Soluble fiber provides this benefit. Improves GI tract muscle tone The larger volume of bulk and the softer mass moving through the “tube” allows the GI tract muscles to exercise efficiently. Both soluble & insoluble fiber provide this benefit. Improves Heart Health and Diabetes Reduces HEART DISEASE risk by binding cholesterol-rich bile in the GI tract. Normally, bile is reabsorbed. Bile binds tightly to soluble fiber & cannot be reabsorb. Thus, a large source of cholesterol can be excreted in the feces. Helps control Diabetes: Fiber rich food is less likely to cause a spike in high blood sugar. Does not require insulin.

Cholesterol and Soluble Fiber

Benefits-Actions of Fiber: Heart-Health Liver Makes Bile from Cholesterol Gallbladder stores Bile Released Bile emulsifies fat in G.I. tract In absence of soluble fiber Bile is reabsorbed, little is excreted Bile is reabsorbed In presence of soluble fiber is excreted

Negative Effects of too Much Fiber Causes gas & bloating (due to decomposition of fiber by gastrointestinal microbes) Too large & frequent bowel movements Binds positively charged minerals (Ca2+, Na+, P+,) Binds beta-carotene (inactive form of Vitamin A Decreases caloric value Can cause GI tract blockages without adequate water intake

The Wheat Kernel A Whole Grain Wheat kernels are refined by removing the husk, bran, & germ. The endosperm (containing mostly starch & protein) remains. Iron, thiamin, riboflavin, niacin, folate, vitamin B6, magnesium, zinc, & fiber are lost. Husk- outer chaff Bran- 14% - most of the fiber and some vitamins Germ- 2.5% -protein, oil and vitamins Endosperm- 83% - starch, protein, vitamins, and minerals

Complex Carbohydrates Whole food: a food that is altered as little as possible from the plant or animal tissue from which it was taken—such as milk, oats, potatoes, or apples. Grain milled in its entirety (all but the husk) The more a food resembles the original, farm-grown product, the more nutritious it is likely to be. Refined Foods: food that has had parts removed, leaving it with less nutrients than when it was whole. i.e. white rice Processed Foods: a food that's been changed through some form of processing (grinding, pureeing, cooking, etc.), but hasn't had any nutritional components removed. i.e. brown rice flour

Enriched and Fortified Foods Enriched – Some nutrients, lost during food processing, are added back into refined grain products as a result of the Enrichment act of 1942. Added: iron, thiamin, riboflavin, niacin, folate Not Added: vitamin B6, magnesium, zinc, fiber Fortified foods - adding nutrients to food that weren’t originally present. (Approximately 10%)

% Nutrients in whole grain, enriched white & unenriched white breads Which is best?