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Reaction Kinetics in Food Systems
Published in Dennis R. Heldman, Daryl B. Lund, Cristina M. Sabliov, Handbook of Food Engineering, 2018
Ricardo Villota, James G. Hawkes
Vitamin A is generally classified into two ma in groups possessing biological activity: (a) C20 unsaturated hydrocarbons including retinol and its derivatives from animal origin and (b) C40 unsaturated hydrocarbons including carotene and a number of other provitamin A carotenoids of plant origin. Vitamin A is a generic descriptor for all β-ionone derivatives with the biological activity of all-trans-retinol (also referred to as vitamin A alcohol or vitamin A1). Provitamin A carotenoid is a generic descriptor for all carotenoids with the qualitative activity of β-carotene. Natural forms of vitamin A predominantly occur in the more stable form of all-trans-retinyl esters, along with small levels of 13-cis-retinol as found in fish livers. Other natural retinyl derivatives present include esters of 3-dehydroretinol (vitamin A2, with ~40% retinol activity) and retinal (vitamin A aldehyde with ~90% retinol activity). Commercially available forms of synthetic vitamin A may be found as either retinol acetate or palmitate and can be supplied in crystalline form or as concentrates in oil, emulsions, or in encapsulated forms. Similarly, different forms of provitamin A carotenoids are available. Some of the carotenoids with significant provitamin A activity include β-carotene (100%); 3,4-dehydro-β-carotene (75%); β-apo-8′-carotenal (72%); β-apo-12′-carotenal (120%); 3-hydroxy-β-carotene (50%–60%); α-carotene (50%–54%); and γ-carotene (42%–50%) (Bauernfeind, 1972). Because of the wide variety of forms of vitamin A and provitamin A carotenoids, labeling requirements report total vitamin A activity in terms of “retinol equivalents” (RE), where one RE is equivalent to 1 µg retinol, 6 µg β-carotene, and 12 µg other provitamin carotenoids. In terms of international units (IU), one RE = 3.33 IU retinol or 10 IU β-carotene (NRC, 1980).
Marine Natural Products
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Humans’ consumption of foodborne carotenoids in their diet is mainly represented by β-carotene, besides lycopene, lutein, zeaxanthin, β-cryptoxanthin, and α-carotene, which roughly account for 90% of circulating carotenoids. During circulation, carotenoids are absorbed and bound to lipoproteins and then targeted to different tissues (liver, lung, macula, prostate, skin, adipose, brain, skin) playing functional and bioactive performance. Carotenoids can be divided into vitamin A precursor compounds and nonvitamin A precursor compounds according to whether carotenoids can be broken to form vitamin A (Liu et al. 2021). For instance, less than 10% of the carotenoids have been reported as metabolized to retinol and act as vitamin A precursors. In blood plasma, the predominant carotenoids represent about 90%, namely, β-carotene, lycopene, lutein, β-cryptoxanthin, and α-carotene. Carotenoids can be further classified into provitamin A carotenoids and exist in four forms: beta-carotene, alpha-carotene, gamma-carotene, and beta-cryptoxanthin that can each be converted to retinol (vitamin A). The other group or non-provitamin A carotenoids (e.g., lycopene, lutein, zeaxanthin, astaxanthin) cannot be converted to retinal or retinol because they lack the nonsubstituted β-ionone ring structure. The provitamin A activity of carotenoids confers them the ability to prevent and resist serious human health disorders, as well as other nutritional value (Liu et al. 2021). Provitamin A carotenoids mean that they can be converted in the body to vitamin A. Among provitamin A carotenoids, β-carotene may be used to provide all or part of the vitamin A in multivitamin supplements, which vitamin A activity from supplements may be much higher than that of β-carotene from foods. This vitamin is recognized as essential for normal growth and development, immune system function, and vision. Currently, the only essential function of carotenoids recognized in humans is that of provitamin A carotenoids (α-carotene, β-carotene, β-cryptoxanthin) to serve as a source of vitamin A.
Synthesis Plan Analysis
Published in John Andraos, Synthesis Green Metrics, 2018
β-Carotene, or provitamin A, is produced from β-ionone according to the synthesis plan shown. Balance all equations, draw a synthesis tree diagram, and determine the overall atom economy for the plan.
Study on the wall-breaking method of carotenoids producing yeast Sporidiobolus pararoseus and the antioxidant effect of four carotenoids on SK-HEP-1 cells
Published in Preparative Biochemistry and Biotechnology, 2019
Chang Liu, Yuliang Cheng, Chao Du, Tianqi Lv, Yahui Guo, Mei Han, Fuwei Pi, Weiguo Zhang, He Qian
Several studies have attributed observed beneficial health effects to the consumption of carotenoids, such as the prevention of cancer, diabetes and inflammatory diseases.[29–31]S. pararoseus. can biosynthesize intracellular carotenoids in abundance, containing β-carotene, γ-carotene, torulene, and torularhodin. All of these carotenoids can be classified into provitamin A carotenoids, which means all of them can be converted to vitamin A in human body.[32,33] Many in vitro studies, especially those that include cellular models, have aided in establishing a link between carotenoids and oxidative stress.[34,35] Thus, the roles of the four carotenoids (β-carotene, γ-carotene, torulene and torularhodin) in S. pararoseus. intracellular products on oxidative damage of H2O2-exposed SK-HEP-1 cells were investigated in this study. The results indicated that all carotenoids exerted protective effect on oxidative damage from hydrogen peroxide in dose- dependent manner, and the protective effect was torulene > torularhodin ≈ β-carotene > γ-carotene. These results implied that all carotenoids in S. pararoseus. extract are promising carotenoids in preventing diseases caused by oxidative damage.