The nutrient contribution from various potato cultivars to add dietary diversity

Transcription

1 The nutrient contribution from various potato cultivars to add dietary diversity Van Niekerk, C., Schönfeldt, H.C., Hall, N. & Pretorius, B. Institute of Food, Nutrition and Well-being, University of Pretoria, Pretoria, South Africa

2 A global perspective on potatoes Numerous potato cultivars around the world Different in: colour & texture cooking and eating qualities (classification systems) Nutrient composition?

3 Potato production statistics tonnes

4 Banana Variety Edible Portion Cultivar differences Water g Bananas Energy kj (kcal) Calcium mg Phos mg Iron mg Cavendish (104) Botoan (101) Ternatensis (132) Ternatensis (134) Tuldoc (99) Uht en yap ß carotene mcg Philippine Food composition tables, 1997 and Englberger et al JFCA

5 South Africa More than 80 registered cultivars 16 Production regions Most significant: Sandveld Eastern Free State Limpopo Dry land vs. Irrigation

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7 Staple food expenditure patterns of socio-economic sub-groups (StatsSA IES 2010) Low inc: R140/hh /month 31% 23% 13% 9% 8% 7% 1% 93% Middle inc: R310/hh /month 24% 21% 14% 13% 8% 8% 1% 88% High inc: R300/hh /month 17% 16% 10% 7% 7% 5% 3% 65% Exp on particular staple food expressed as share of total exp by sub-group on staple foods Vermeulen, H. 2014

8 Nutrient data available 1998: BP1 cultivar With and without skin Raw and cooked (boiled) Convenience sample from market BP1 cultivars: Largest share of the market at the time Solanum tuberosum L.: cultivar BP1

9 Nutrient composition of potatoes in national composition tables 26 entries for potatoes in the National Food Composition Tables Most from BP1 analyzed locally Borrowed Calculated

10 South Africa Classification System In 2010 the Potato Industry of South Africa launched a potato cultivar classification system Groups cultivars together based on their cooking and eating qualities 11 cultivars

11 2011: Nutrient content of the 3 classes were performed Cultivars within each class were collected from two different production regions per class Analyses performed at SANAS Accredited Laboratory: With skin Cooked (boiled) Class Waxy Waxy/Floury Floury Cultivar Mondial Van der Plank Up to Date & Darius Northern Cape (Vryburg) Eastern Fee state Koue Bokkeveld Production & (Harrysmith) & Region Eastern Free State & Gauteng (Randfontein) (Lindley) Gauteng (Petit) Sample 1 bag 1 bag 1 bag 1 bag 1 bag 1 bag 6 Composite samples to be analysed 1 sample consist of six potatoes from each bag 1 sample consist of six potatoes from each bag 1 sample consist of six potatoes from each bag

12 Nutrient Data cooked with skin Nutrient Waxy Waxy/Floury Floury Average 2011 BP Proximate analysis Moisture g Protein (Nx6.25) g Fat g Ash g Dry matter g Energy (calc) kj Starch g Non-struc CHO g CHO (calc) g Dietary fibre g Minerals Calcium (Ca) mg Magnesium (Mg) mg Phosphorus (P) mg Potassium (K) mg Vitamins Vitamin C mg

13 Nutrient Data cooked with skin Nutrient Waxy Waxy/Floury Floury Average 2011 BP Proximate analysis Moisture g Protein (Nx6.25) g Fat g Ash g Dry matter g Energy (calc) kj Starch g Non-struc Probably CHO g no significant 14.5 difference in nutrient 16.2 delivery - CHO (calc) But, small g changes 16.1 might 16.3 influence 19.4 cooking 17.3 and eating 16.7 Dietary fibre g qualities between classes Minerals Calcium (Ca) mg Magnesium (Mg) mg Phosphorus (P) mg Potassium (K) mg Vitamins Vitamin C mg

14 Changing production system moving away from dryland to irrigation systems

15 Percentage of market Changes in market share of cultivars

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17 2013 Cultivar specific nutrient composition No cultivar specific nutritional composition data has been available before for raw South Africa cultivars Yet, there are significant differences in the nutritional value of root vegetables Possibly varieties can contribute better to nutrient requirements (Burlingame, Charrondiere & Mouille, 2009) Potatoes are a popular staple food in South Africa Maize meal porridge, bread, pasta, then potatoes Potatoes are cheaper than many cereals 85% of the plant is fit for human consumption Potatoes could be a strategy towards improving food and nutrition security, but variety/cultivar specific data is required in-line with biodiversity outcomes

18 Cultivars included in the analyses 2013: Nutrient content of specific potato cultivars Controlled growing and harvesting conditions With and without skin Raw 11 cultivars included in the classification system Solanum tuberosum L. cultivar Mondial Solanum tuberosum L. cultivar BP1 Solanum tuberosum L. cultivar Valor Solanum tuberosum L. cultivar Avalanche Solanum tuberosum L. cultivar BP13 Solanum tuberosum L. cultivar Darius Solanum tuberosum L. cultivar Fabula Solanum tuberosum L. cultivar Fianna Solanum tuberosum L. cultivar Sifra Solanum tuberosum L. cultivar Up to Date Solanum tuberosum L. cultivar Van Der Plank

19 Nutrient Unit p value Flesh only % of NRV* Flesh and skin % of NRV* Energy g (calculated) Protein g Fat g Available carbohydrates g Calcium mg a b Phosphorus mg Magnesium mg Copper mg Iron mg < a b 9 Manganese mg < b a 47.4 Zinc mg Potassium mg Sodium mg

20 Nutritional analysis of potato tubers, flesh and skin Nutrient flesh and Units p-value skin Starch g <0.001 Carbohydrates g <0.001 (calculated) Available % <0.001 carbohydrates Protein g <0.001 Fat g <0.001 Calcium mg <0.001 Phosphorus mg <0.001 Manganese mg <0.001 Magnesium mg <0.001 Iron mg <0.001 Zinc mg <0.001 Copper mg <0.001 Potassium mg <0.001 Sodium mg <0.001

21 Discussion & Conclusion Significant differences were seen in all nutrients over different cultivars Could influence structural, functional and nutritional properties of the different cultivars Certain cultivars can be promoted for their specific nutrient contribution to the diet

22 Thank you Potatoes South Africa University of Pretoria - NutriLab This study formed part of a MSc Nutrition vanniekerk.carmen@gmail.com