Bioaccessibility of Biofortified Sweet Potato Carotenoids in Baby Food: Impact of Manufacturing Process

Abstract

Orange-fleshed sweet potato (OFSP), a biofortified crop rich in β-carotene, can be used as a component of baby food recipes in order to tackle vitamin A deficiency in children <6 years old. In this work, the impact of formulation (addition of pumpkin, oil, and egg yolk) and industrial heat processing (pasteurization, sterilization) on carotenoid content and bioaccessibility was evaluated in an OFSP-based baby puree. A commercial OFSP baby food product from Brazil and a homemade OFSP puree were used as references. The losses of all-trans-β-carotene ranged from 16 to 21% (pasteurization, homemade) to 32% (sterilization). Because of higher particle sizes and despite a higher content in carotenoids, the homemade puree had a lower bioaccessibility (i.e., micellar transfer using in vitro digestion: 0.50%) compared with the sterilized and commercial purees (5.3-6.2%). Taking into account bioaccessibility and applying a 50% conversion to retinol, a 115 g baby portion of the sterilized OFSP-puree formulated with 2% oil provided 31.4% of the daily vitamin A requirement (RDA) for children under 6 years. In comparison, 115 g of homemade OFSP-puree provided only 3.5% of the RDA. Addition of pumpkin to OFSP did not improve the percentage of RDA. Interestingly, the incorporation of an emulsifier (egg yolk powder) before cooking could improve the percentage of provision by a factor of 2.7. These results showed that reaching a balance between formulation and processing is determinant to maximize carotenoid bioaccessibility of carotenoids from OFSP-based baby food.

Keywords: baby food; in vitro digestion; industrial processes; orange sweet potato; pro-vitamin A.

Figure 1

Schematic overview of the experimental process. HM, Home-made Process; BP, Blanching and Pasteurized or BS, Blanching and Sterilized; P, pasteurized, or S, Sterilized.

Figure 2

Evolution of temperature during pasteurization (P), sterilization (S) and home-made (HP) processes.

Figure 3

Light Microscopy image showing the microstrucutre of starch granules in OFSP puree (Lugol's test): (A) without blanching sterilized and (B) blanching sterilized.

Figure 4

Particle size distribution of the different processed OFSP purees.

Figure 5

Differences between estimates of vitamin A (% RDA child <6 years) in 115 g portion OFSP processed purees using classical estimate RAE from food (Retinol Activity Equivalent-μg trans-β-carotene/12 and 13-cis-β-carotene/24) and estimate taking into account bioaccessibility (calculated with RE: Retinol Equivalent μg trans-β-carotene/6 and 13-cis-β-carotene/12).