Nutritionally Rich Underutilized Vegetables by Ray-yu Yang, WorldVeg, Taiwan - Regional Expert Consultation on Underutilized Crops for Food and Nutritional Security in Asia and the Pacific November 13-15, 2017, Bangkok

1. Regional Expert Consultation on
Underutilized Crops for Food and
Nutritional Security in Asia and the Pacific
13-15 November, 2017, Bangkok
Ray-YuYang, Nutritionist,
WorldVegetable Center,Taiwan
ray-yu.yang@worldveg.org
Nutritionally Rich
Underutilized Vegetables

2. Outline
Are we fully capturing the nutritional
treasures in our diets?
• Distribution of phytonutrient contents in
– African and Asian traditional vegetables
– Taiwan traditional vegetables
– Taiwan commonly consumed vegetables
• Phytonutrient intakes
– Global and regions
– Top food sources
2

3. Nutritional Components in Plants
• Macronutrients (generally 90-98% dry wt)
– Carbohydrates, Lipids, Amino Acids (few
thousand compounds)
• Micronutrients (generally 1-10% dry wt)
– Minerals: 17 essential (Fe, Zn, Ca, Na, Cu, K...)
– Organics: 13 essential vitamins (A, B, C, D, E, K..)
• Secondary Metabolites (phytochemicals)
– Estimated >200,000 in plants!
– ~80,000 characterized

4. Classification of dietary phytochemicals
Rui Hai Liu Adv Nutr 2013;4:384S-392S

5. Classification of
phytochemicals
Catherine P. Bondonno et al.
Nutr Rev 2015;73:216-235
© The Author(s) 2015. Published by Oxford University Press on
behalf of the International Life Sciences Institute. All rights
reserved. For Permissions, please e-mail:
journals.permissions@oup.com.

6. Indigenous vegetable garden at WorldVeg, Taiwan
Southern Taiwan: hot-wet, cool-dry tropical climate

7. Laboratory analysis
• Macro-constituents
– Dry matter
– Protein
– Crude fiber
– Oil (total, n-3 & n-6)
• Micro-constituents
– Vitamins
• A (carotenoids)
• C (ascorbate)
• E (tocopherols)
– Minerals
• Ca, Fe, Zn
• Bioactives
– Flavonoids
– Carotenoids
– Glucosinolates
– Antioxidant activity
• Anti-nutrients
– Oxalate, phenolics
• LCMS profiles

8. No of vegetable species in the food composition tables
8
No.
genus
No. sp No of sp
in WVC
Note
WorldVeg 162 237 - Selected essential nutrients and
selected phytochemicals
USDA 99 57 Comprehensive essential nutrients
and selected phytochemicals
INFOOD (FAO)
• ASEAN 57 33 Selected essential nutrients
• West Africa 27 19 Selected essential nutrients
• Pan Africa 130 33 Macronutrient data only; 50% of
the species in the list have no
nutrient data; Many of plant species
are herbs or medicinal plants

9. In 100 g fw N Min Max Mean
Protein, g 323 0 11 3
b-Carotene, mg 324 0 22 3
Vit. C, mg 324 0 459 65
Vit. E, mg 297 0 71 3
Folates, mg 215 0 349 63
Ca, mg 323 2 1435 158
Fe, mg 323 0 26 2
Total phenol, mg 320 18 12070 516
Oxalate, mg 214 0 1277 129
Nutrient content range (based on 100 g fresh weight)
Specie no.: ~150

10. Iron
0
78
88
38
11 8 12
4 1
0
10
20
30
40
50
60
70
80
90
100
<0 <1 <2 <3 <4 <5 <10 <20 <30
Iron content (mg/100 g fw)
Frequency

11. High Iron Edible Plants
Chinese knotweed
Paederia scabdens
雞屎藤
25.6 mg/100g
Hydrolea zeylanica
探芹草
12.7 mg/100g
Jute mallow
Corchorus olitorius
長蒴黃麻
12.7 mg/100g

12. Micronutrient contents of commonly consumed and
indigenous vegetables
Ranges Tomato Cabbage Moringa Amaranth Aibika SP leaf
b-Carotene,
mg
0.0 - 22 0.40 0.00 15.28 9.23 5.11 6.82
Vit C, mg 1.1 - 459 19 22 459 113 82 81
Vit E, mg 0.0 - 71 1.16 0.05 25.25 3.44 4.51 4.69
Iron, mg 0.2 – 26 0.54 0.30 10.09 5.54 1.40 1.88
Folates, mg 2.8 – 349 5 ND 93 78 177 39
Antioxidant
activity, TE
0.6 -
82,000
323 496 2858 394 560 870
Data source: WorldVeg Nutrient Database
Ranges: including >100 vegetable species
100 g fresh weight

13. Content range of nutrient and anti-nutrient components of three
groups of vegetables consumed in Africa
Vegetable
groups
DM
%
A
mg
C
mg
E
mg
F
μg
Ca
mg
Fe
mg
Zn
mg
AOA
ugTE
TP
g
Oxa
mg
Exotic
total n=13
min 3.9 0.01 3 0.27 5 18 0.20 0.00 388 80 196
max 23.2 14.00 242 1.40 159 358 6.50 1.28 685 128 915
median 7.8 0.96 27 0.75 31 67 0.99 0.17 560 112 244
mean 10.4 2.52 50 0.73 47 123 1.63 0.37 544 107 452
stdev 6.5 4.70 67 0.46 45 122 1.83 0.39 149 24 402
n 13 8 13 5 11 12 13 11 3 3 3
Adapted
total n=33
min 4.2 0.00 3 0.00 3 9 0.21 0.00 276 26 21
max 41.4 8.29 221 4.52 140 589 8.90 1.48 3838 543 479
median 9.4 0.39 30 0.62 37 67 0.98 0.29 768 120 68
mean 11.0 1.88 46 1.03 47 135 1.63 0.46 1084 176 193
stdev 7.2 2.42 49 1.19 35 160 1.87 0.38 972 150 196
n 31 31 30 20 23 31 31 20 13 13 9
Indigenous
total n=73
min 4.3 0.02 3 0.05 3 3 0.20 0.00 164 24 8
max 25.5 12.59 400 17.72 198 711 29.20 3.10 13506 2140 353
median 13.0 2.14 40 1.40 70 172 1.81 0.46 847 204 33
mean 14.7 2.78 56 2.23 71 185 3.30 0.56 1683 345 67
stdev 11.9 2.99 68 3.72 56 165 4.96 0.72 2727 464 95
n 54 30 39 21 15 54 45 17 22 21 14
(1) DM: dry matter, A: β-carotene, C: vitamin C, E: α-tocopherols; AOA: antioxidant activity; TE: tolox equivalent; TP: total phenolics, Oxa:
oxalate (2)Vegetable grouping according to PROTA. Exotic: vegetables are recently introduced; Adapted: vegetables were introduced long
ago and widely adapted; Indigenous: Vegetables are native to Africa. (3) n: number of vegetables with available nutrient data
Yang et al., 2009

14. 14
Comparison of nutrient
values among three
vegetable groups
Yang, unpublished data

15. 15
Comparison of nutrient
values among three
vegetable groups
Yang, unpublished data

16. • Biodiversity provides rich phytonutrients
• Nutrient values of Taiwan-Ami traditional
vegetables comparable to traditional vegetables
from tropical Asia and Africa
• Commonly consumed vegetables in Taiwan, as the
example, have less dry matter and less nutrients
such as protein, beta-Carotene, vitamin C, minerals
and antioxidant activities, but not for sugars and n-3
fatty acids.
16

17. Comparison of phytonutrient intakes among Taiwan,
USA and Korea
17
Pan et al., J food Drug Analysis. 2017

18. Top fruit and vegetable sources
18
Region β-carotene (%) Lutein/zeaxanthin Lycopene
Americas &
Australia
Carrots and turnips(28%)
Lettuce and chicory(25%)
Lettuce, chicory(36%)
Cabbage, Brassicas(17%)
Tomatoes(73%)
Watermelons(21%)
Western
Europe
Carrots, turnips(42%)
Cabbage, Brassicas(16%)
Cabbage, Brassicas (35%)
Lettuce, chicory(14%)
Tomatoes(66%)
Watermelons(18%)
Asia
Cabbage and others
Brassicas(28%)
Spinach(20%)
Cabbage and others
Brassicas (41%)
Spinach (33%)
Watermelons (54%)
Tomatoes(32%)
Southern
Africa
Cabbage, Brassicas(38%)
Carrots and turnips(17%)
Plantains(11%)
Cabbage, Brassicas(66%)
Spinach(6%)
Tomatos(74%)
Mangoes, guavas(16%)
Watermelons(3%)
Taiwan
Sweet potato leaf (20
Carrot/products (14%)
Spinach (11%)
Sweet potato leaf (36%)
Spinach (17%)
Water spinach (14%)
Tomato/ products (63%)
Watermelon/products (31%)
Papaya/products (5%)
Murphy et al., British J Nutr 2014; Pan et al., J food Drug Analysis. 2017

19. Top fruit and vegetable sources
19
Region Anthocyanidins Quercetin
Americas &
Australia
Lettuce, chicory (24%)
Bananas(12%)
Onion, dry(46%)
Lettuce, chicory(16%)
Western
Europe
Grapes(17%)
Currants (16%)
Strawberries (62%)
Raspberries (28%)
Asia
Lettuce, chicory(26%)
Bananas(24%)
Bananas(27%)
Strawberries(22%)
Southern
Africa
Bananas(63%)
Cabbages, brassicas(14%)
Bananas(65%)
Pineapples(10%)
Taiwan
Radishes (41%)
Bananas (18%)
Grapes/products (12%)
Tea (55%)
Sweetpotato leaf (10%)
Spinach (6%)
Murphy et al., British J Nutr 2014; Pan et al., J food Drug Analysis. 2017

20. Classification of dietary phytochemicals
Rui Hai Liu Adv Nutr 2013;4:384S-392S

21. Recapture the vegetable diversity and
phytonutrients for healthier diets
• Phytonutrient intakes vary depending on the availability
of crops and varieties
• Limited evidence of health benefits of vegetables may be
due to limited high-nutrient varieties and diversity
• Monitor and/or piggyback phytonutrient enhancements
while breeding for high yield and diseases resistance
traits
• Introduce phytonutrient rich traditional vegetables back
to the diets
21

22. CN objectives
• to create much needed awareness on the role and value of
underutilized bioresources that have potential for diversification of
food basket to ensure better food and nutritional security in Asia
Pacific;
– Food system, dietary and phytonutrient pattern perspectives
• to share experiences and learn lessons to accelerate the use of
underutilized plants as crops for the future;
– Conservation, evaluation, selection (breeding), phenotyping,
homestead production and value chain approaches from
previous work
• to assess R&D status on priority crops and policies that are needed to
promote the use of these ‘Crops for Future’ in Asia and the Pacific
region
– Systematic decision support tools with big data to select
potential crops from diverse traditional vegetables to
address food and nutrition security
22

23. • Hypothesis:
– Modernization of food systems is leading to
consumption of diets containing a reduced range of
vegetables and to the loss of phytonutrients essential
for good health. Efforts to incorporate
indigenous/local vegetables with the desired
nutritional qualities into these modernizing food
systems would improve nutrition and health.
• Expected result:
– Evidence based recommendations on how the
consumption of high-micronutrient content foods
could be optimized in modernizing diets, and,
hypothetically, through more efficient production and
marketing of vegetables
– ….
23