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The objective of this review was to collect, contrast and analyse the conventional and non-conventional extraction techniques to obtain ß-carotene from carrot (Daucus carota L.), by conducting a bibliometric analysis of different recent studies and investigations where different approaches, techniques, and findings converge. Similarly, the contribution of green solvents to the extraction process is established to determine its applicability at an industrial scale. Carrots are rich in carotenoids, and especially in ß-carotene, a source of provitamin A used as a natural coloring in the food and pharmaceutical industry. Microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), and Supercritical fluid extraction (SFE) have been evaluated using the carrot and have been compared to conventional solvent extraction techniques (CSE), showing similar and even higher extraction yields and efficiencies. However, ultrasound-assisted extraction (UAE) shows successful and considerably higher results (157.0 mg b-carotene/100 g DB) compared to other non-conventional techniques. Further investigations are required to optimize the extraction conditions and parameters, as well as the evaluation of suitable preservation conditions for both the raw material and the final extract that ensure a higher stability of the end-product, and thus providing a higher extraction yield. Green alternatives should be considered to reduce environmental impact in future extraction processes. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the kinetic parameters of the thermal degradation of the pigments extracted from teak leaves at different temperatures (45, 60, 75 and 90 °C) using the kinetic models of order zero, one and two. As a result, the thermal degradation follows first-order kinetics. The rate constants (k) and the halflife times (t½) were determined for each temperature. The activation energy, calculated according to the Arrhenius equation, has a value of 67.6 ± 2,3 kJ/mol. Finally, it was found that the betalains present in the extract of teak leaves are more thermostables than those from beet. [ABSTRACT FROM AUTHOR]

The teak leaves (Tectona grandis L.), byproduct of the wood industry, can be used as a source of red dye, so this research was aimed at knowing the optimal conditions for the extraction of the red pigments of the dried leaves using the incomplete factorial design (three factors in three levels) type Box-Behnken. The independent variables were: extraction temperature (30-60 °C), alcohol concentration (30-90 % v/v) and solid-liquid ratio (1:10-1:20 g×mL-1) and as response variable mass of extracted pigments. The results showed that all the independent variables contribute significantly to the quadratic model with good adjustment of the experimental data. The optimal conditions for the extraction of the pigments were: temperature 54 °C, alcohol concentration 64 % v/v and solid-liquid ratio 1:16 m/v. Under these optimal conditions, the experimental values agreed with those predicted by the quadratic model, verifying its validity. [ABSTRACT FROM AUTHOR]

The optimal extraction conditions of anthocyanins from the calyxes of Hibiscus sabdariffa L. were determined using the D-optimal design, and the chromatic characterization was performed on the obtained extract. The independent variables selected were: temperature (40-60 °C), alcohol concentration (0-80 % v/v) and solidsolvent ratio (1:5-1:15 m/v) and extraction yield as response variable. The results showed that only the alcohol concentration and solid-solvent ratio contribute significantly to the extraction yield. The optimal conditions for the extraction of the pigments were: temperature 40 °C, water as solvent and solid-solvent ratio 1:5 m/v. The color of the extract expressed in the CIELAB chromatic coordinates was: L* = 69,09; a* = 43,01 and b* = 23,83. [ABSTRACT FROM AUTHOR]

Introduction. The waste of palm pear fruit are byproducts generated after its consumption and/or industrial transformation. In Valle del Cauca, Colombia, the palm pear fruit's mesocarp is traditionally cooked and consumed with salt or sugar. Nevertheless, the waste generated (peel) is usually thrown away. Objective. Determine the composition of the carotenoid pigments that give the characteristic color to the flour obtained from this fruit, in order to consider its use as a natural colorant. Materials and methods. The identification and quantification of the carotenoids was achieved by the use of a YMC column, reversed-phase column of carotenoids S-5 C30 (4.60 mm × 150 mm: particle size, 5 μm), in a HPLC equipment using a DAD detector with 450nm wavelength. Results. The results obtained in the flour demonstrated that there are: violaxanthin (1.35 ± 0.10 μg/g), lutein (4.87 ± 0.20 μg/g), zeaxanthin (4.37 ± 0.20 μg/g), 15-cis β carotene (3.86 ± 1.40 μg/g), 13-cis α carotene (25.12 ± 0.23 μg/g), All-trans β carotene (125.43 ± 3.20 μg/g), 9-cis β carotene (17.10 ± 0.38 μg/g) and a-carotene (12.59 ± 2.80 μg/g). Conclusion. Palm pear fruit's flour is an important source of carotenoids, especially All-trans β carotene, a carotenoid pigment that can be an important source of provitamin A and also be a natural colorant for food industries. On the other hand, this is one of the first studies on carotenoids quantification in palm pear fruit's epicarp flour. [ABSTRACT FROM AUTHOR]