Abstract:Carotenoid cleavage enzymes have been investigated for more than 50 years. Nevertheless, progress in this area has been slow and a complete understanding of the reaction mechanisms of carotenoid biodegradation has not been achieved at the present time. In this study, the enzymatic cleavage of carotenoids in several insect species (Calliphora, Ornithoptera, and Locusta) is examined. The enzymatic degradation of carotenoids in plants is also elucidated. Quince (Cydonia oblonga) and star fruit (Averrhoa carambola… Show more
“…In addition, several studies have discovered the presence of carotenoid cleavage enzymes in plants 28–30 and animals. 29 The increased interaction of one or a combination of these enzymes with their respective substrates due to decrease in activation volume (under pressure), coupled with changes in their conformation and activity, might explain some of the lycopene degradation observed at lower pressure and temperatures.…”
This study highlights the changes in lycopene and β-carotene retention in tomato juice subjected to combined pressure–temperature (P-T) treatments ((high-pressure processing (HPP; 500–700 MPa, 30 °C), pressure-assisted thermal processing (PATP; 500–700 MPa, 100 °C), and thermal processing (TP; 0.1 MPa, 100 °C)) for up to 10 min. Processing treatments utilized raw (untreated) and hot break (~93 °C, 60 s) tomato juice as controls. Changes in bioaccessibility of these carotenoids as a result of processing were also studied. Microscopy was applied to better understand processing-induced microscopic changes. TP did not alter the lycopene content of the tomato juice. HPP and PATP treatments resulted in up to 12% increases in lycopene extractability. all-trans-β-Carotene showed significant degradation (p < 0.05) as a function of pressure, temperature, and time. Its retention in processed samples varied between 60 and 95% of levels originally present in the control. Regardless of the processing conditions used, <0.5% lycopene appeared in the form of micelles (<0.5% bioaccessibility). Electron microscopy images showed more prominent lycopene crystals in HPP and PATP processed juice than in thermally processed juice. However, lycopene crystals did appear to be enveloped regardless of the processing conditions used. The processed juice (HPP, PATP, TP) showed significantly higher (p < 0.05) all-trans-β-carotene micellarization as compared to the raw unprocessed juice (control). Interestingly, hot break juice subjected to combined P-T treatments showed 15–30% more all-trans-β-carotene micellarization than the raw juice subjected to combined P-T treatments. This study demonstrates that combined pressure–heat treatments increase lycopene extractability. However, the in vitro bioaccessibility of carotenoids was not significantly different among the treatments (TP, PATP, HPP) investigated.
“…In addition, several studies have discovered the presence of carotenoid cleavage enzymes in plants 28–30 and animals. 29 The increased interaction of one or a combination of these enzymes with their respective substrates due to decrease in activation volume (under pressure), coupled with changes in their conformation and activity, might explain some of the lycopene degradation observed at lower pressure and temperatures.…”
This study highlights the changes in lycopene and β-carotene retention in tomato juice subjected to combined pressure–temperature (P-T) treatments ((high-pressure processing (HPP; 500–700 MPa, 30 °C), pressure-assisted thermal processing (PATP; 500–700 MPa, 100 °C), and thermal processing (TP; 0.1 MPa, 100 °C)) for up to 10 min. Processing treatments utilized raw (untreated) and hot break (~93 °C, 60 s) tomato juice as controls. Changes in bioaccessibility of these carotenoids as a result of processing were also studied. Microscopy was applied to better understand processing-induced microscopic changes. TP did not alter the lycopene content of the tomato juice. HPP and PATP treatments resulted in up to 12% increases in lycopene extractability. all-trans-β-Carotene showed significant degradation (p < 0.05) as a function of pressure, temperature, and time. Its retention in processed samples varied between 60 and 95% of levels originally present in the control. Regardless of the processing conditions used, <0.5% lycopene appeared in the form of micelles (<0.5% bioaccessibility). Electron microscopy images showed more prominent lycopene crystals in HPP and PATP processed juice than in thermally processed juice. However, lycopene crystals did appear to be enveloped regardless of the processing conditions used. The processed juice (HPP, PATP, TP) showed significantly higher (p < 0.05) all-trans-β-carotene micellarization as compared to the raw unprocessed juice (control). Interestingly, hot break juice subjected to combined P-T treatments showed 15–30% more all-trans-β-carotene micellarization than the raw juice subjected to combined P-T treatments. This study demonstrates that combined pressure–heat treatments increase lycopene extractability. However, the in vitro bioaccessibility of carotenoids was not significantly different among the treatments (TP, PATP, HPP) investigated.
“…This cleavage can be caused by enzymatic activities or physicochemical conditions. This degradation has been and still is the subject of many studies (19,20) using enzymes (21)(22)(23) and physical (24) or chemical media (25).…”
Section: Introductionmentioning
confidence: 99%
“…This cleavage can be caused by enzymatic activities or physicochemical conditions. This degradation has been and still is the subject of many studies ( , ) using enzymes ( − ) and physical () or chemical media (). 1 Pathways for the synthesis of β-ionone 4 , 5,6-epoxy-β-ionone 5 , and DHA 6 from β-carotene 1 and through 5,6-epoxy- 2 and 5,8-epoxy-β-carotene 3 : (A) pathway proposed in the literature ( − ); (B) pathway observed by Bosser et al ().…”
beta-Carotene is, when cleaved, an important source of flavor and aroma compounds in fruits and flowers. Among these aroma compounds, the main degradation products are beta-ionone, 5,6-epoxy-beta-ionone, and dihydroactinidiolide (DHA), which are associated by flavorists and perfumers with fruity, floral, and woody notes. These three species can be produced by degradation of beta-carotene through an attack by enzyme-generated free radicals and a cleavage at the C9-C10 bond. This study investigated the influence of cis/trans isomerism at the C9-C10 bond on the production of beta-carotene degradation compounds, first with a predictive approach and then experimentally with different isomer mixtures. beta-Carotene solutions containing high ratios of 9-cis-isomers produced more DHA, suggesting a different pathway than for the transformation of all-trans-beta-carotene to ionone and DHA. These results are important in the search for financially viable processes to produce natural carotene-derived aroma compounds.
“…But, whereas the enzymatic cleavage of carotenoids in animal tissues is well-known (8)(9)(10)(11)(12), there is little evidence for similar reactions in plant tissues. With the exception of enzymes specifically degrading neoxanthin to abscisic acid in a one-step reaction (13), there is only information about carotenoid cleavage enzymes in Arabidopsis thaliana (14) and in starfruit (15), both with C13 and C15 compounds as most likely reaction products.…”
For the first time, a cytosolic carotenoid cleavage enzyme isolated from quince (Cydonia oblonga) fruit is described. The enzyme was partially purified by using centrifugation, acetone precipitation, ultrafiltration (300 kD, 50 kD), isoelectric focusing (pH 3-10), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (7.5%). In this way, an enzymatically active protein fraction was obtained that contained three similar proteins, all exhibiting molecular weights in the range of 20 kD. Using beta-carotene as substrate, the enzyme activity was detected spectrophotometrically at a wavelength of 505 nm. The time constant of the reaction was 8.2 min, the Michaelis constant (K(m)) was 11.0 micromol x L(-1), and the maximum velocity (v(max)) was 0.083 micromol x L(-1) x min(-1) x mg(protein)(-1). The optimum temperature was above 50 degrees C.
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