This document discusses using X-ray fluorescence (XRF) fast screening technology to support iron and zinc biofortification of potatoes. Calibrations for iron and zinc concentration in potato tubers using XRF were established, showing strong correlations. Training courses in Bangladesh and Rwanda built capacity for nutritional quality evaluation of potatoes, including sampling, sample preparation to avoid contamination, and basics of mineral analysis by XRF. XRF allows high-throughput, low-cost screening of minerals in potatoes to support biofortification programs addressing widespread micronutrient deficiencies.

1. Supporting Iron and Zinc Potato Biofortification through
XRF Fast Screening Technology
EAPR 2014, July 6th to 11th 2014
Thomas zum Felde, Gabriela Burgos, Walter Amoros, Paola Sosa, Merideth Bonierbale,
International Potato Center (CIP) and Georgia Guilt, Flinders University, Australia

3. Nutritional Quality Assurance and Enhancement Network (NQAEN)

4. CIP‘s Nutritional Quality Assurance and Enhancement
Network (NQAEN) in CRP-A4NH
1.
To build knowledge and capacity to enable researchers in target
countries to make accurate and cost-effective assessments of
micronutrient content of potato (and sweetpotato).
Responsible determination, reporting and labeling of micronutrient
concentrations is basic to assure the effectiveness of Biofortification as
an approach to improved nutrition.
2.
Research partnerships to contribute in building evidence that
micronutrients of RTCs and their products are bioavailable for the human
body with a view for improving human health and reducing poverty
through increased concentrations of bioavailable micronutrients in RTC
based diets.

5. Major micronutrient deficiencies (hidden hunger):
1.) Iron deficiency
• Estimated about 1.6 billion with iron deficiency
• Mostly young children and women of childbearing age
2.) Zinc deficiency
• Limited data on magnitude of deficiency, estimated to be similar
to iron
3.) Vitamin A deficiency:
• Circa 250 million children <5 years
• 20 million pregnant women with sub-clinical deficiency
Over three billion people worldwide are currently malnourished,
particularly in developing countries where insufficient intake of iron (Fe),
zinc (Zn) and Vitamin A constitute the most common micronutrient
deficiencies.

6. Zinc deficiency
• Growth failure
• Susceptibility to infections
• Diarrhea; skin lesions
• Neurological infections in infancy and childhood
Iron deficiency anemia
• Impairs mental development and learning capacity
• Limits capacity to perform physical labor
• Decrease immunity
Fe and Zn Deficiencies
(Implications for Human Health and Development)

7. Risk factors for micronutrient deficiencies
• Monotonous plant based diet, no vitamin A, poor Fe and Zn
bioavailability (phytate, polyphenols)
• Low intake of animal source foods; orange and yellow fruit / veg
• Low micronutrient density of complementary foods
• Increased demands during growth, pregnancy and lactation
• Increased demands due to infections and diseases
• Seasonal variation in food availability, food shortages

8. Category of public health significance
(anaemia prevalence)
Normal (<5.0%)
Mild (5.0-19.9%)
Moderate (20.0-39.9%)
Severe (≥40.0%)
No Data
1.) Iron deficiency as a public health problem
in preschool children (0-5 yrs)
(McLean et al. 2007)

9. 2.) National risk of zinc deficiency based on combined
information on childhood stunting in inadequate zinc intake
Hotz, Brown,
Food and
Nutrition
Bulletin 2004

10. GIS-based overlay of
•Potato production &
•Prevalence of Iron deficiency anemia (IDA) among
women and children
Potato biofortification Targets
(Populations at Risk of Malnutrition and with High Potato Consumption)

11. Iron µgg-1
P µgg-1
Rice polished
Maize
Wheat
Bean
Cassava
Potato
Lentil
Pearl Millet
Yams
P versus Iron
O SweetPotato

12. Zinc µgg-1
P µgg-1
Rice polished
Maize
Wheat
Bean
Cassava
Potato
Lentil
Pearl Millet
Yams
Wheat wild relatives
P versus Zinc
O SweetPotato

13. Mineral analysis
• established analysis with ICP:
sensitive
accurate
established methods
able to analyze multiple elements
requires trained technical staff
expensive equipment
high purity reagents
pre-analysis extraction

14. X-ray fluorescence
• x-rays excite atoms
• de-excitation results in x-ray
emission
• energy of emitted x-ray is
specific to element
• intensity of emitted x-ray is
dependent on abundance/
concentration

16. XRF for Harvest Plus
• screening for Fe and Zn
• analyze whole grain or flour
• does not require highly trained staff
• increases throughput and reduces
analysis cost

17. Grain calibrations

18. What about potato tubers???

21. y = 3.031x + 66.41
R² = 0.93
0
20
40
60
80
100
120
140
160
180
200
0 10 20 30 40
Iron
Reference ICP (mg/kg)
Intensity(cps)
y = 0.785x + 6.345
R² = 0.97
0
5
10
15
20
25
30
35
0 10 20 30 40
Zinc
Intensity(cps)
Reference ICP (mg/kg)
XRF Potato - Calibration
Calibrations for iron and zinc
concentration in potato tuber
samples coming from CIP’s
biofortified clones cycle II and III
and LBHT population.
Range (mg/kg)
Calibration
statistic
Trait N⁰ min max r² SEC
Iron 51 10 33 0.93 1.44
Zinc 51 9 29 0.97 0.99

22. Intensive Training and capacity building needed
2 Training courses in Bangladesh (2013) and in Rwanda (2014) with 20 participants, each.
• Tuber Crops Research Centre, Bangladesh Agricultural Research Institute,
Gazipur, March 18th to 21st, 2013
• RAB (Rwanda Agricultural Board), Ruhengeri Station, April, 1st to 4th, 2014
1.Increase participants’ awareness of current projects that include nutritional
quality evaluation of potato (and sweetpotato) for biofortification.
2.To train participants in sampling and sample preparation of potato (and
sweetpotato) for mineral (mainly iron and zinc) analysis avoiding
contamination with minerals from other sources like soil, dust and not
appropriate equipment.
1.Discuss and show basics of mineral analysis by X-ray Fluorescence
Spectrometry (XRF).

23. Present and discuss nutritional value of potato (and sweetpotato)

24. Field and sampling

25. Sample preparation of potato (and sweetpotato) for mineral analysis avoiding
contamination with minerals from other sources like soil and not appropriate
equipment

27. www.cipotato.org/qnlab
2005 - 2014