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The Mighty Sweet Potato

Presented by:

Melissa Hsu Laura Prevo Reiko Sudduth Kali Tupper

Introduction

Sweet potatoes are a tuberous morning glory

Also known as batatas, el boniato, camote, and erroneously, yams

A species distinct from both yams and potatoes

Introduction

Sweet potatoes are cultivated in tropical and subtropical regions

North Carolina is the leading producer in the U.S.

Harvested September – December

Can be found fresh, canned or frozen year-round at any grocery store

Best to choose unblemished, wrinkle-free skin

Store in a cool, dark place

Do not refrigerate

Health Benefits

Sweet potatoes are a source of dietary carotenoids, especially β-carotene 8

Our bodies can use β-carotene to make vitamin A, helping prevent a vitamin A deficiency 10

Consuming carotenoids, including β-carotene, from whole foods regularly may: Decrease the risk of cancers such as breast, esophageal,

pancreatic, stomach, and lung cancer 8, 3

Promote heart health 8

Improve blood sugar regulation 9,11

Enhance the function of the immune system 8

Health Benefits cont.

In young adults aged 18–30 years old, carotenoids may promote lung16 and heart health,6 and lower the risk for hypertension5 and inflammation.6 The CARDIA and YALTA studies

Serum carotenoids measured: α-carotene, β-carotene, lutein/zeaxanthin,

β-cryptoxanthin, and lycopene

Sweet potatoes may have antibacterial and antifungal properties, as revealed in lab studies.18,12

Health concerns Unlike whole food sources of carotenoids,

supplemental forms of β-carotene are associated with an increased risk of cancer

Sweet potatoes contain approximately 26–99 mg of oxalates per half cup serving 13

Oxalates occur naturally in plants and can crystallize in body fluids if they become concentrated in large amounts in the body, causing health problems 4

Individuals with the following health conditions are advised to avoid sweet potatoes: 13

Calcium oxalate kidney stones High urine oxalate levels (hyperoxaluria)

Bioactives: Carotenoids in Sweet Potato

Carotenoids in 100 g of Sweet PotatoAlpha

Carotene (μg)

Beta Carotene (μg)

Lutein + Zeaxanthin

(μg)

Sweet potato, raw, unprepared 7 8,509 0

Sweet potato, cooked, baked in skin, without salt 43 11,509 0

Sweet potato, cooked, boiled, without skin 0 9,444 0

Sweet potato chips, unsalted 0 14,205 0

Sweet potato, canned, mashed 0 5,219 0

Sweet potato leaves, cooked, steamed, without salt 0 550 2,633

Source: http://ndb.nal.usda.gov/ndb/foods/list

Sweet Potatoes vs. Carrots: Side-by-Side Comparison of Beta-Carotene Content

Beta-Carotene (μg)

Preparation MethodSweet Potato (100 g)

Carrot (100 g)

Raw, unprepared 8,509 8,285 Cooked, baked in skin, without salt 11,509 Cooked, boiled, without skin 9,444 8,332 Chips, unsalted 14,205 Canned, mashed 5,219 Cooked, steamed, without salt 550 Source: http://ndb.nal.usda.gov/ndb/foods/list

Getting the most from your tatoe

Carotenoid content can vary with: Age of root when harvested Amount of moisture while

growing Mineral content of the soil Virus infestation

Burri B. Evaluating sweet potato as an intervention

food to prevent vitamin A deficiency. Compr Rev

Food Sci Food Saf. 2011;10:118-130.

Getting the most from your tatoe

Choose those with the deepest orange-colored flesh.

white < cream < yellow = purple < orange

orange up to 1000 times the beta carotene of white

Getting the most from your tatoe

Beta-carotene well retained during cookingTypical losses 0-12% (boiling, steaming, canning)Up to 41% lost (dehydration)

Cooking process breaks down food matrix and

makes carotenoids more bioavailable

Eat with some fatBeta-carotene absorbed via micelles3-5 grams of fat increases absorption from <1% to >25%

Recipe

Ingredients:• 1 pound sweet potatoes• 4 ounces goat cheese, crumbled• 3 tablespoons butter, softened• 1/2 teaspoon salt• 1/4 teaspoon ground white pepper

Method: Peel sweet potatoes and slice into one inch rings.

Steam 10 minutes, or until soft and fully cooked.

Place cooked sweet potatoes along with remaining ingredients in a stand mixer fitted with a whip attachment. Mix on low speed until smooth and creamy.

Adapted by Laura Prevo from PCC Natural Markets at http://www.pccnaturalmarkets.com/pcc/recipes/pcc-mashed-yams-and-goat-cheese, author PCC Deli.

Mashed Sweet Potatoes and Goat CheeseThis creamy, versatile dish can be served warm or cold and is sure to be a crowd pleaser. Choose organic, dark orange sweet potatoes for maximum flavor and carotenoids.

Preparation time: 20 minutesMakes 6 1/2-cup servings

Did you know…

NASA selected sweet potatoes for long-term space travel due to their amazing nutritional content

The Center for Science in the Public Interest (CSPI) named sweet potatoes as their #1 “Best Food”

Did you know…

Orange sweet potatoes may be part of the solution to vitamin A deficiency in Africa

Questions to ponder….

Sweet potatoes have been proposed as a solution to prevent vitamin A deficiency in developing countries.

What do you think are the benefits of providing sweet potatoes instead of vitamin A or carotenoid supplementation to these populations?

What ways of preparation are the best for optimal carotenoid release from the food matrix?

References1. Bengtsson A, Namutebi A, Larson Alminger M, Svanberg U. Effects of various traditional processing methods on the all-trans-beta-carotene content of

orange sweet potato. J Food Comp Anal. 2008:21;134-143.

2. Burri B. Evaluating sweet potato as an intervention food to prevent vitamin A deficiency. Comprehensive Reviews in Food Science and Food Safety. 2011:10;118-130.

3. Fraser PD, Bramley PM. The biosynthesis and nutritional uses of carotenoids. Prog Lipid Res. 2004;43(3):228-65.

4. Holmes RP, Kennedy M. Estimation of the oxalate content of foods and daily oxalate intake. Kidney Int. 2000;57(4):1662-7.

5. Hozawa A, Jacobs DR Jr, Steffes MW, Gross MD, Steffen LM, Lee DH. Relationships of circulating carotenoid concentrations with several markers of inflammation, oxidative stress, and endothelial dysfunction: the Coronary Artery Risk Development in Young Adults (CARDIA)/Young Adult Longitudinal Trends in Antioxidants (YALTA) study. Clin Chem. 2007;53(3):447-55.

6. Hozawa A, Jacobs DR Jr, Steffes MW, Gross MD, Steffen LM, Lee DH. Circulating carotenoid concentrations and incident hypertension: the Coronary Artery Risk Development in Young Adults (CARDIA) study. J Hypertens. 2009;27(2):237-42.

7. K’osambo LM, Carey EE, Misra AK, Wilkes J, Hagenlmana V. Influence of age, farming site, and boiling on pro-vitamin A content in sweet potato (Ipomoea batas (L.) Lam.) storage roots. J Food Technol Afr. 1999;4(3):77-84.

8. Krinsky NI, Johnson EJ. Carotenoid actions and their relation to health and disease. Mol Aspects Med. 2005;26(6):459-51.

9. Kusano S, Abe H. Antidiabetic activity of white skinned sweet potato (Ipomoea batatas L.) in obese Zucker fatty rats. Biol Pharm Bull . 2000;23(1):23-6.

10. Low JW, Arimond M, Osman N, Cunguara B, Zano F, Tschirley D. A food-based approach introducing orange-fleshed sweet potatoes increased vitamin A intake and serum retinol concentrations in young children in rural Mozambique. J Nutr. 2007;137(5):1320-7.

11. Oki N, Nonaka S, Ozaki S. The effects of an arabinogalactan-protein from the white-skinned sweet potato (Ipomoea batatas L.) on blood glucose in spontaneous diabetic mice. Biosci Biotechnol Biochem. 2011;75(3):596-8.

12. Noda N, Horiuchi Y. The resin glycosides from the sweet potato (Ipomoea batatas L. LAM. Chem Pharm Bull (Tokyo). 2008 Nov;56(11):1607-10.

13. Oxalosis & Hyperoxaluria Foundation. The oxalate content of foods. 2008. Retrieved from www.ohf.org/docs/Oxalate2008.pdf

14. Peggy Trowbridge Filippone. “Sweet Potato Facts, Selection, and Storage.” About.com Guide. The New York Times Company, n.d. Web. 10 May 2012. <http://homecooking.about.com/cs/productreviews/p/sweetpotato_pro.htm>.

15. “Sweet Potato.” Wikipedia, The Free Encyclopedia. 9 May 2012. Wikimedia Foundation, Inc. Web. 10 May 2012. <http://en.wikipedia.org/wiki/Sweet_potato>.

1. Thyagarajan B, A Meyer K, Smith LJ, Beckett WS, Williams OD, Gross MD, Jacobs DR Jr. Serum carotenoid concentrations predict lung function evolution in young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) study. Am J Clin Nutr. 2011;94(5):1211-8.

2. Wilson CD, Pace RD, Bromfield E, Jones G, Lu JY. 1998. Sweet potato in a vegetarian menu plan for NASA’s Advanced Life Support Program. Life Support Biosph Sci. 5:347–51.

3. Yin YQ, Huang XF, Kong LY, Niwa M. Three new pentasaccharide resin glycosides from the roots of sweet potato (Ipomoea batatas). Chem Pharm Bull (Tokyo). 2008 ;56(12):1670-4.