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STABILITY AND BIOACCESSIBILITY OF DIFFERENT FORMS OF CAROTENOIDS AND VITAMIN A DURING IN VITRO DIGESTION

Authors: Julie COURRAUD1, Jacques BERGER1, Jean-Paul CRISTOL1,2, Sylvie AVALLONE1,3

Workplace: 1 IRD; UMR Nutripass (204), IRD/Montpellier2/Montpellier1, F-34394 Montpellier, Cedex 5, France2 Lapeyronie Hospital, Biochemistry Laboratory, CHRU Montpellier, France 3 Montpellier SupAgro, France

INTRODUCTION• Vitamin A deficiency

→ defined as plasma retinol concentration < 0.70µmol/L→ affects an estimated 190 million preschool-age children and 19.1 million pregnant women

around the world→ mostly in African and South-East Asian developing countries (WHO, 2009)

• Vitamin A is essential fora normal vision, gene expression, a performing immune system, growth , embryonic development, and reproduction (Combs, 2008).

Poster Reference Number : 27/847

• Fig. 4 In carrot juice and cooked spinach, the bioaccessibility of xanthophylls (lutein) > hydrocarbon carotenes (α-, β-carotene) (**) → in agreement with the literature (Tyssandier et al., 2003)• Hydrothermal cooking ↑ lutein and β-carotene bioaccessibility• Lutein and β-carotene from carrot juice > from raw and cooked spinach• Bioaccessible provitamin A carrot juice > cooked > raw spinach

Data not shown• Pure β-carotene and retinyl palmitate → bioaccessibilities ≈ 0.4%• Pure lutein and retinyl acetate → bioaccessibilities ≈ 8.2%

→ consistent with their respective stabilities

Area of Nutrition and Healthy Lifestyle

• Food carotenoids → some can be converted to vitamin A : called as provitamin A (Fig.

1)→ depending on their structure

• They are particularly important in developing countries where access to animal products is limited.

• Mainly β-carotene, α-carotene and β-cryptoxanthin → common dietary sources are carrots, sweet potatoes, green leafy

vegetables and numerous other fruits and vegetables characterised by their orange to red colour

Fig. 2 In vitro digestion protocol (IVD)(Hedren et al., 2002)

samples

+ lipids (oil)

extraction +

HPLC

centrifugation + filtration

Bioaccessiblecarotenoids

Total carotenoids:

stability

oral solution: 10 min

+

gastric solution: 60 minpepsin, pH 2

+

intestinal solution: 30 minpancreatin, biliary salts,

pH 7,5

37°C under stirring

METHODS• Spinach cooking:

→ individual sealed amber tubes → boiling mineral water for 20 min at 98 °C→ spinach/water ratio of 0.14

• Miniaturized in vitro digestion protocol (Fig. 2)

• Simultaneous HPLC dosage of retinoids, tocopherols and carotenoids (Fig. 3)

• Extraction: → ethanol/hexane (4:3, v/v) → NaCl 10% or 25% (p/v)→ organic extract dried under N2

→ acetone + 0.2 µm filtration

• Reverse phase HPLC: → polymeric C30 column, 5 μm particle size→ flow rate of 1 mL.min1

→ methanol, methyl tert-butyl-ether and milli-Q water

OBJECTIVES Evaluation of the stability and bioaccessibility of carotenoids and retinoids from standards without food matrix, carrot juice, raw and cooked spinach and a fortified infant flour during in vitro digestion.

KEYWORDS: Carotenoids, Retinoids, Fortification, Food matrix, Heat Treatments.

292 and 298 nm

tocopherols

325 nm retinoids

carotenoids 450 nm

Fig. 3 Example of chromatogram obtained with our method

CH3H3C

CH3

H3C CH3

H3C

CHCH3H3C

CH3

O

HCH3C CH3

H3C

O

β-dioxygenaseβ-carotene

2 x retinal

Fig. 1 Cleavage of β-carotene in retinal

BIOACCESSIBILITY RESULTS

Fig. 4 Bioaccessible carotenoids (mg/100g DM) and their relative bioaccessibility (%) in carrot juice and raw and cooked spinach (n = 4)

Fig. 6 Stability of retinoids during in vitro digestion of (a) pure molecules, (b) the fortified flour (n = 3 or 4)

Fig. 5 Stability of carotenoids during in vitro digestion of (a) pure molecules, (b) dietary carotenoids from carrot juice, (c) dietary carotenoids from raw spinach (d) dietary carotenoids from cooked spinach. Comparisons were made between each digestion phase remaining contents and the corresponding initial contents. (n = 3 or 4).

References E. Hedren, V. Diaz, et U. Svanberg, « Estimation of carotenoid accessibility from carrots determined by an in vitro digestion method », European Journal of Clinical Nutrition 56 (2002): 425-30.V. Tyssandier et al., « Processing of vegetable-borne carotenoids in the human stomach and duodenum », American Journal of Physiology-Gastrointestinal and Liver Physiology 284 (2003): G913-G923. G. F. Combs, The Vitamins: fundamental aspects in nutrition and health (Ithaca: Elsevier Academic Press, 2008)WHO, Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO global database on vitamin A deficiency (Geneva (Switzerland): World Health Organization, 2009)

* significant difference (p < 0.05), ** significant difference (p < 0.001).

b (FORTIFIED FLOUR)

a (STANDARD)

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a (STANDARD)

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a (STANDARD)

a (STANDARD) b (CARROT JUICE)

b (CARROT JUICE)

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c (RAW SPINACH)

c (RAW SPINACH)c (RAW SPINACH)

d (COOKED SPINACH)

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author contactjulie.courraud@gmail.comWith the support of the French Nutrition Society