NUTR201-Ch12

Pigments/Phytochemicals in Produce:Carotenoids

Color: Orange, yellow, red Purpose: Antioxidant, vitamin A Foods: Carrots, butternut squash, cantaloupe, apricots

Pigments/Phytochemicals in Produce: Anthocyanins; anthoxanthins

Color: Red, blue, purple; pale yellow Purpose: Antioxidants Foods: Radish, potatoes, tomatoes, apples, red cabbage; cauliflower, onions, potatoes

Pigments/Phytochemicals in Produce: Betalains, indoles (a lot in supplements)

Color: Red, yellow Purpose: Antioxidants Foods: Beets, chard, cactus pear

Fruit

The ripened ovary of a flowering plant that contains the seeds.

Simplest and most effective way to reduce pesticide exposure

WASH/PEEL YOUR PRODUCE Most nutrients are stored close to skin, so excessive trimming may result in huge reduction in a vegetable's nutritional value. The benefit of pesticide removal becomes minimal after rinsing in running water for 5 minutes.

Plant cell walls are lined by

a lipid-protein membrane permeable to H2O (in+out)

Cancer, Fruit and Vegetable Consumption

~20,000 cases of cancer/year could be prevented by increasing V+F consumption of half the US population by 1 serving/day, while 10 cancer cases/year could be caused by increased pesticide consumption

Blanching

Boiling the vegetable for 1-2 minutes and then plunging it into cold water to stop the cooking will destroy the active enzymes that can affect produce color and flavor by reacting (and causing a buildup) when frozen.

Hemicellulose

Branched form of plant structure material made of various monosaccharides

Lycopene (type of carotenoid)

Bright red compound found in tomatoes and some other red fruits and vegetables

Caloric contribution

Carbohydrates supply 4 calories of energy per gram -A typical piece or ½ cup of fruit provides about 50 calories -Vegetables provide about 25 calories per ½ cup, while the more starchy types provide 75 calories per cup.

Plant Ripening

Cell wall structure changes are also responsible for texture changes during ripening: -Pectin content is lost when plant enzymes alter cell walls, causing them to break down; ex: mushy overripe apple -Glucose molecules that became starch in fruit once again return to sugar, making the fruit sweeter; ex: bananas, grapes, pears ripen this way. -Other fruits and vegetables stop ripening when picked, and their sugars combine to make more complex starches; ex: if broccoli/asparagus are permitted to grow for too long, their stalks will become more woody as more complex cellulose strands (lignin) form.

Boiling

Cellulose strands are intact, other cell parts soften and dissolve in water. Long cooking times leach plant enzymes from the cell, H ions replace Mg in the chlorophyll, so green veggies lose color.

Pigments/Phytochemicals in Produce:Chlorophylls

Color: Green, blue Purpose: Photosynthesis Foods: Leaves, stems

Disaccharides

Glucose+glucose=maltose Glucose+fructose=sucrose (invert table sugar) Glucose+galactose=lactose (milk sugar)

Plant cells have strong walls made of

Insoluble cellulose! Long glucose chains, similar structurally to amylose but bound together by stronger bonds

Pectin

"Glue" binding cell wall fibers together

Phenolic compounds

*could be present in a vacuole; substances that affect the taste, aroma, mouthfeel, and nutrient content of the fruits and vegetables; defend the plant against predators (ex: flavonoids) by damaging their enzymes and cell membranes

Meal Planning and Nutritional Content

-A 2000-calorie diet should include about 2 cups of fruit and 2.5 cups of vegetables each day. -The Dietary Guidelines recommend choosing a variety of fruits and vegetables each day. -Several times a week, choices should include dark greens, orange-colored produce, legumes, and starchy vegetables.

EB

-A quick way to stop enzymatic browning is to plunge the produce into water to avoid contact with oxygen. -Another way to avoid oxidation is to coat the surfaces with an antioxidant, like vitamin C (lemon, lime, orange juice) -Chilling the food to below 40 degrees F (4 C) will also slow down the browning process.

Fiber in produce

-Fiber is classified as either soluble or insoluble -Unlike whole grains, most fruit and vegetable fiber is of the soluble form, which binds with cholesterol that is eliminated in the stool. -Pectin is a type of soluble fiber found in fruit that is used in making jams and jellies -Cellulose and lignin fibers are insoluble fibers.

Food Safety: Special topic

-Most whole, raw fruits and vegetables can be stored at 41°F (5°C) or lower to prevent them from drying out. -Your refrigerator should be kept at a humidity of 85-95%. Most produce should not be washed before storage as this could promote the growth of mold.

Chloroplasts

The plant cell organelles in which photosynthesis takes place; contain the green pigment, *chlorophyll*

Arctic apple

-non browning apples -have reduced PPO content -PPO naturally initiates a chemical reaction that results in the apple's flesh turning brown

Edible Parts of Plants

-roots: beets, carrot, radish, sweet potato -stems, stalks, tubers, rhizomes: asparagus, broccoli, celery -leaves: spinach, lettuce -flowers: broccoli, artichoke -seeds: beans, corn -bulbs: garlic, onion -fruits: pepper, olives, avocado, cucumber -bark: cinnamon

NOP

-set by USDA in 2002 -National Organic Program -sets standards for organically produced agricultural items -use of sustainable practices and minimal use of pesticides and herbicides are the main hallmarks of organic farming

Plant Cell Structure

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Plant structure

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Oligosaccharides

3-10 monosaccharides; form simple carbs that are easier to digest as their short, single chains between sugar molecules are easier to cleave than those of polysaccharides, complex carbs (have long, branches chains)

Pome

A fleshy fruit (apple or pear or related fruits) with a middle core and seeds

Cellulose

A homo-polysaccharide of glucose indigestible by human enzymes; the predominant component of plant cell walls and has no caloric contribution

Resveratrol

A strong antioxidant and anti-inflammatory compound found in red wine, grape juice, and peanuts

Amylopectin

A water soluble polysaccharide composed of highly branched chains of glucose found in plants. With amylose, it makes up starch.

Amyloplast

An organelle in some plant cells that stores starch. usually found in starchy plants like tubers and fruits.

4 Cs of Food Safety

Cross-contamination avoidance Clean Chill Cook This is most important when produce is mixed with meats, fish, eggs, or poultry. Using a special colored cutting board just for produce will help prevent cross-contamination.

Cytoplasm

Fluid inside the cell that contains the organelles

Climacteric fruits

Fruits that continue to ripen once picked

Nonclimacteric fruits

Fruits that ripen only when left on the plant, begin to deteriorate immediately after picking

Organic more healthy?

Literature lacks strong evidence suggesting that OF are significantly more nutritious than CF. Their consumption may reduce the exposure to pesticide residues and antibiotic-resistant bacteria, but the fatality rate due to that reason is similar to annual mortality risk from motor vehicle accidents.

Plant Aging

Microscopic examination of plant cell walls shows rigid, fibrous strands of compact glucose molecules, cellulose, intertwined with other less rigid forms of fiber, like pectin/hemicellulose, and a bath of minerals and proteins. As the cell wall loses its moisture to evaporation, it begins to collapse. A mushy, soft texture allows the intercellular fluid to easily escape.

Special Section: Farm to Plate

National Farm-to-Plate programs encourage people to get to know their local farmers, support their local economy, and eat foods in season.

Phytochemical Content

Non-nutrient constituents of food plants with anticipating health promoting/beneficial effect: -Carotenoids (pigment, antioxidants) -Glucosinolates (defense against pests and disease) -Polyphenols (antioxidants) Should I cook my veggies and fruits? IT DEPENDS. Vitamin C usually is the most susceptible to heat. Can affect the phytochemical content of the food

Organic Pesticides/Herbicides/Insecticides

ORGANIC VS CONVENTIONAL: It's not use of pesticides, is ORIGIN of pesticides

Freezer burn

Occurs when the natural moisture is pulled from food cells in the dry environment of the freezer (produce left uncovered in cold air)

Amylose

One of the polymers in starch; a linear chain composed of hundreds/thousands of glucose molecules; H2O-soluble and makes up 20-25% of starch.

Chromoplasts

Organelles that store plant pigment, responsible for fruits and flowers color (carotenoids, flavonoids, betalains). Many of pigment phytochemicals may have bio-significance with regards to human health.

Vegetable

Part of a plant that is grown primarily for food; the leaf of spinach, the root of a carrot, the flower of broccoli, and the stalk of celery are all vegetables.

Heirloom

Plants from seed of older times. Existed before industrial times, and are GMOs.

H2O Insoluble plant fiber has been marketed as

Prebiotic-non-digestible fiber that induces the growth/activity of beneficial microorganisms in the GI tract.

Gelatinization

Process that involves heating starch granules in a moist environment; the granules swell (amylose chains easily absorb water) and disrupt the organization of the starch granules. Amylopectin contributes to plant cells' rigid structure and thickening when its cooked.

Photosynthesis

Process whereby plants use sunlight, H2O and carbon dioxide to create O2 and glucose: 6water+6carbon dioxide-> glucose+6oxygen

Vitamins and minerals

Produce usually high in vitamin A, C, folate and potassium. 80-90% water. Some veggies (spinach, okra) are good sources of calcium. Sources of Vitamin A (Carotenoids): bright orange vegetables (carrots, sweet potatoes, pumpkin); tomatoes and tomato products, red sweet pepper; leafy greens; orange fruits Sources of Vitamin C: Citrus, berries, guava, papaya, cantaloupe; broccoli, peppers, tomatoes, cabbage; leafy greens Sources of Folate: Cooked dry beans and peas; oranges; deep green leaves (spinach and mustard greens) Sources of Potassium: cooked greens, bananas, many dried fruits, soybeans, tomato products

Monosaccharides

Single sugar molecules

Enzymatic Browning

Some produce turns brown after being cut and inner plant cells are exposed to oxygen; ex: apples, bananas, pears, potatoes, avocados. Enzymatic browning is the result of mixing three reactants: plant enzymes in the cytoplasm, phenolics in the vacuole, and oxygen. These inadvertently mix together when certain produce is cut and cell parts get broken, spilling their contents.

Steaming

Steaming cooks the vegetable without allowing the enzyme components to exchange ions in the water. The food's green color is thus preserved as well as its nutrient content.

Food Regulations and Food Quality

The FDA has jurisdiction over fruit and vegetable regulations. Former President Obama signed a new Food Safety Prevention law. The FDA will now have the authority to order a recall instead of waiting for manufacturers to do it voluntarily.

Effects of Freezing

The cold temperature turns the cellular fluid contents to ice crystals, which then puncture the cell walls when thawed. Thawing produce is frequently seen with a puddle of liquid collecting around it. This is fluid escaping through the broken cell walls of the food.

Vacuole

The largest structure in the plant cell; holds a mix of sugars, enzymes, pigments, other compounds contributing to the food's flavor

Stone

The pit of a fruit, found in fruits like cherries, plums and peaches

Acid-Base Chemistry

There are effects of cooking acid/base balance on produce colors that are flavonoids or chlorophyll. -Acids (citrus juice, vinegar, or wine) will turn chlorophyll pigments olive-brown, but have no effect on flavonoid pigments. -Alkalis (baking soda) cause flavonoids like anthocyanins, to lose their color, and green plants to retain their color.

The storage form of glucose in animals is...in plants, it is...

glycogen (liver+muscle); starch (chloroplasts+amyloplasts)

Better for the Environment

organic systems require more land, cause more eutrophication, use less energy, but emit similar greenhouse gas emissions (GHGs) as conventional systems; grass-fed beef requires more land and emits similar GHG emissions as grain-feed beef; low-input aquaculture and non-trawling fisheries have much lower GHG emissions than trawling fisheries. Increasing agricultural input efficiency (the amount of food produced per input of fertilizer or feed) would have environmental benefits for both crop and livestock systems. Further, for all environmental indicators and nutritional units examined, plant-based foods have the lowest environmental impacts.