Carotenoid Deposition in Plant And Animal Foods and Its Impact on Bioavailability

Abstract

Over the past decades, an enormous body of literature dealing with the natural deposition of carotenoids in plant- and animal-based foods has accumulated. Prominent examples are the large solid-crystalline aggregates in carrots and tomatoes or the lipid-dissolved forms in dairy products and egg yolk. Latest research has identified lipid-dissolved forms in a rare number of plant foods, such as tangerine tomatoes and peach palm fruit (Bactris gasipaes Kunth). In addition, liquid-crystalline forms were assumed in so-called tubular chromoplasts of numerous fruits, e.g., in papaya, mango, and bell pepper. The bioavailability of carotenoids from fresh and processed foods strongly depends on their genuine deposition form, since their effective absorption to the human organism requires their liberation from the food matrix and subsequent solubilization into mixed micelles in the small intestine. Consequently, a broad overview about the natural array of carotenoid deposition forms should be helpful to better understand and modulate their bioavailability from foods. Furthermore, naturally highly bioavailable forms may provide biomimetic models for the improved formulation of carotenoids in food supplements. Therefore, this review paper presents scientific evidence from human intervention studies associating carotenoid deposition forms with their bioavailability, thus suggesting novel technological and dietary strategies for their enhanced absorption.

Unique chromoplast organisation and carotenoid gene expression in carotenoid-rich carrot callus

“…crystalloid, globular, tubular and membranous, depending on their ultrastructure and chemical composition (Egea et al 2010; Solymosi and Keresztes 2012; Schweiggert and Carle 2017). Usually one type of chromoplasts dominates in the tissue, but the coexistence of some other types, even in the same cell, is known.…”

Bioaccessibility of carotenoids from plant and animal foods

“…pepsin) efficiently break down proteins, particularly, those of thermally processed foods. Thus, pepsin is considered to be important for the release of carotenoids from protein complexes or protein‐rich matrices . The use of pepsin to allow proteolytic cleavage (200 U mL −1 final digestion mixture) and an incubation time of 2 h at 37 °C have also been specified.…”

“…Esterification is considered to be advantageous to the plant because it aids an increase in the accumulation of these highly lipophilic compounds and facilitates their incorporation into plastoglobules or so‐called tubules of chromoplasts. In the latter, carotenoid esters are considered to be accumulated in the form of nematic liquid crystals . Furthermore, carotenoid esters were shown to form so‐called J‐aggregates, exhibiting an additional bathochromically shifted absorption band compared to the monomer .…”

“…These findings confirm the importance of the matrix break‐down to allow an improved carotenoid release and subsequent absorption. Further information on this topic with regard to green‐leafy vegetables is provided elsewhere …”

Recent Insights Into Health Benefits of Carotenoids

“…Because humans are incapable of biosynthesizing carotenoids, any potential health benefit directly depends on the uptake of carotenoids from the diet. In addition, the physical deposition state of the carotenoids within the respective food, being either solid crystalline, liquid-crystalline, lipid-dissolved, or protein-bound, is proposed to exert a significant influence on bioavailability (Cooperstone et al, 2015;Schweiggert and Carle, 2016;Schweiggert et al, 2014). Although the absorption of these compounds generally follows the pathway of other dietary lipids, numerous factors are to be considered regarding their bioavailability.…”