Review: Analysis of carotenoids in orange juice

Assessing the impact of isochoric freezing as a preservation method on the quality attributes of orange juice

Isochoric (constant volume) freezing is a novel food preservation technology that has demonstrated the ability to preserve food products at subfreezing temperatures in an unfrozen state, thereby avoiding the detrimental effects of ice formation. It minimizes the quality loss of fresh fruits and juices, increases their nutrient content, and reduces microbial counts. Orange juice (OJ) samples were subjected to conventional freezing (CF) and isochoric freezing (IF) for 7 days and then stored at 4°C for an additional 7 days. We evaluated the microbiological and physicochemical quality of CF and IF OJ before and after storage. The IF was performed at three different conditions: -5°C/73 MPa, -10°C/93 MPa, and -15°C/143 MPa. The results indicate that the total aerobic count of OJ remained below the detection limit after heat treatment, 7 days of CF and 7 days of IF. Yeast and mold counts increased in fresh and CF OJ after 7 days of storage at 4°C, whereas IF OJ remained below the detection limit. Less color difference was observed in IF (-15°C/143 MPa) OJ compared to heat-treated and CF OJ. Heat treatment inactivated 42% of pectin methylesterase (PME), whereas 7-day long IF increased PME activity up to 150%. Additionally, IF (-15°C/143 MPa) OJ showed reduced pulp sedimentation, which can be advantageous, as sedimentation in juices has been a recognized technological issue in the juice industry. Ascorbic acid level was significantly higher in IF (-15°C/143 MPa) OJ compared to fresh and CF OJ after storage.

Juices and By-Products of Red-Fleshed Sweet Oranges: Assessment of Bioactive and Nutritional Compounds

The content of nutrients and bioactive compounds, and antioxidant capacity were assessed in the juices from two red-fleshed oranges, Cara Cara and Kirkwood, and compared with that of a standard Navel orange. Two juice extraction procedures, hand-squeezing and industrial, and two treatments, pasteurization (85 °C/30 s) and high-pressure homogenization (HPH, 150 MPa/55 °C/1 min), were evaluated. For most of the nutrients and bioactive compounds, the hand and industrial juice squeezing rendered similar extraction efficiency. Individual composition of carotenoids in the juices were differentially affected by the extraction procedure and the treatments, but the red-fleshed orange juices contained between 3- to 6-times higher total carotenoids than the standard Navel juices, being phytoene and phytofluene the main carotenoids. The industrial and treated juices of both red-fleshed oranges contained 20-30% higher amounts of tocopherols but about 20% lower levels of vitamin C than Navel juices. Navel juices exhibited higher hydrophilic antioxidant capacity, while the red-fleshed orange juices showed an improved lipophilic antioxidant capacity. The main distinctive characteristic of the industrial juice by-product of the red-fleshed oranges was a higher content of carotenoids (×10) and singlet oxygen antioxidant capacity (×1.5-2) than the Navel by-product.

Comparative Evaluation on the Bioaccessibility of Citrus Fruit Carotenoids In Vitro Based on Different Intake Patterns

The intake pattern has a great impact on the bioaccessibility of carotenoids from citrus fruit. Here, we compared the bioaccessibility of carotenoids from fresh citrus fruit (FC), fresh citrus juice (FCJ), and not-from-concentrate citrus juice (NCJ) and analyzed the influencing factors. The results demonstrated that particle size, viscosity, and some active components of the samples during digestion are potential factors affecting the bioaccessibility of carotenoids. The total carotenoid bioaccessibility of NCJ (31.45 ± 2.58%) was significantly higher than that of FC (8.11 ± 0.43%) and FCJ (12.43 ± 0.49%). This work demonstrates that NCJ is an appropriate intake pattern to improve the bioaccessibility of carotenoids from citrus fruit. The findings also suggest that adjustment of food intake patterns is an effective way to improve the digestion and absorption of nutrients.

Greater bioavailability of xanthophylls compared to carotenes from orange juice (high-pressure processed, pulsed electric field treated, low-temperature pasteurised, and freshly squeezed) in a crossover study in healthy individuals

This study examined the effect of the intake of orange juice provided freshly squeezed (FS) or processed using low-temperature pasteurisation (LP), high-pressure processing (HPP), or pulsed electric field (PEF) treatment on the serum carotenoid concentrations of 12 healthy individuals, aged 20-32 years, enrolled in a crossover study. Participants were instructed to consume 500 ml of orange juice/day for 14 days. Carotenoid concentrations in the orange juice as well as serum samples retrieved on days 7 and 14 were analysed via HPLC. A significant increase in serum xanthophyll concentrations, but not serum carotenes, was observed, with the highest increase in α- and β-cryptoxanthin. The processing technologies applied appeared to affect serum carotenoid concentrations, with concentrations being similar in the HPP and FS orange juice types. As high variability in serum carotenoid concentrations was observed, the effect of different technologies on serum carotenoid concentration warrants further studies with larger sample sizes.

Impact of freeze-drying conditions on the sensory perception of a freeze-dried orange snack

BACKGROUND

The health benefits provided by fruit mean that there is continuous interest in offering consumers new products to stimulate its consumption. To this end, dehydrated fruit snacks may be an interesting option. In this study, we evaluated the impact of freezing rate (slow and high), shelf temperature (40 and 50 °C), and working pressure (5 and 100 Pa) on the perception and acceptability of a freeze-dried orange snack obtained from an orange puree.

RESULTS

Of the different freeze-drying conditions studied, working pressure was the variable with the greatest effect. The lowest working pressure (5 Pa) led to samples being obtained with a slightly lower water content, which was perceived with higher citrus flavor and crispiest. The highest pressure (100 Pa) led to samples with a greater water content, perceived with a more yellow intense color. Nevertheless, there is no significant consumer preference for any of the different processed samples. The number of force peaks, which is positively correlated with the crispness, shows a significant and negative correlation (r = -0.91) with the water content of the sample.

CONCLUSION

The study revealed that considerations other than the sensory can determine the best conditions of the freeze-drying process with which to obtain an orange snack. The number of force peaks obtained from a penetration test may be proposed as a tool for instrumental analysis of the snack's crispness that supplies information closely resembling customer perception of this attribute. © 2021 Society of Chemical Industry.

Effect of Adding Resistant Maltodextrin to Pasteurized Orange Juice on Bioactive Compounds and Their Bioaccessibility

Resistant maltodextrin (RMD) is a water-soluble and fermentable functional fiber. RMD is a satiating prebiotic, reducer of glucose and triglycerides in the blood, and promoter of good gut health, and its addition to food is increasingly frequent. Therefore, it is necessary to study its potential effects on intrinsic bioactive compounds of food and their bioaccessibility. The aim of this study was to evaluate the effect of adding RMD on the bioactive compounds of pasteurized orange juice with and without pulp, and the bioaccessibility of such compounds. RMD was added at different concentrations: 0 (control sample), 2.5%, 5%, and 7.5%. Ascorbic acid (AA) and vitamin C were analyzed using HPLC, whereas total phenols, total carotenoids (TC), and antioxidant capacity were measured using spectrophotometry. After that, sample in vitro digestibility was assessed using the standardized static in vitro digestion method. The control orange juice with pulp presented significantly higher values of bioactive compounds and antioxidant capacity than the control orange juice without pulp (p < 0.05). RMD addition before the juice pasteurization process significantly protected all bioactive compounds, namely total phenols, TC, AA, and vitamin C, as well as the antioxidant capacity (AC) (p < 0.05). Moreover, this bioactive compound protective effect was higher when higher RMD concentrations were added. However, RMD addition improved phenols and vitamin C bioaccessibility but decreased TC and AA bioaccessibility. Therefore, the AC value of samples after gastrointestinal digestion was slightly decreased by RMD addition. Moreover, orange pulp presence decreased total phenols and TC bioaccessibility but increased AA and vitamin C bioaccessibility.

Potential of pumpkin to combat vitamin A deficiency during complementary feeding in low and middle income countries: variety, provitamin A carotenoid content and retention, and dietary reference intakes

The risk of child vitamin A deficiency (VAD) in low and middle income countries (LMICs) begins during the age range of complementary feeding (6-24 months), when children are fed complementary foods (CFs) deficient in vitamin A. However, pumpkin, a source of provitamin A carotenoids (PVACs) is widely cultivated in LMICs, but underutilized as a complementary food. Moreover, when consumed by humans, PVACs are bioconverted to retinol, the active form of vitamin A used by the body. This study evaluated the potential of pumpkin toward combating VAD by reviewing varieties of pumpkin cultivated in LMICs and their provitamin A carotenoid (PVAC) content; retention of PVACs in pumpkin during processing it as a CF; and the extent to which a CF prepared from pumpkin may meet the dietary reference intakes (DRIs) for vitamin A for children aged 6-24 months old. Pumpkin may combat VAD because the varieties cultivated have high β-carotene content, it is a provitamin A biofortifiable food crop, and 100% retention of PVACs was observed when processed using home cooking methods. Feeding less than 50 g of cooked pumpkin per day meets 100% of the recommended dietary allowance (RDA) and adequate intake (AI) of vitamin A for children 6 to 24 months old. Consumption of pumpkin may be used to complement vitamin A supplementation, fortification, and diversification of CFs with animal source foods. For better yield of pumpkin in LMICs, nutrition sensitive agricultural programmes such as biofortification and agronomic management of pumpkin need to be promoted and supported.

Influence of high pressure homogenization and pasteurization on the in vitro bioaccessibility of carotenoids and flavonoids in orange juice

Production of high-quality healthy foods through sustainable methodologies is an urgent necessity. High pressure homogenization (HPH) is an interesting alternative to obtain premium citrus juices, but its effects on bioactive compounds are unclear. There was studied the influence of HPH (150 MPa) and pasteurization (92 °C for 30 s and 85 °C for 15 s) processing on physicochemical properties and in vitro bioaccessibility of carotenoids and flavonoids in orange juices. Regarding fresh juice, physicochemical properties of samples remained unchanged although cloudiness was improved by homogenization. Pasteurization did not affect total carotenoids content and retinol activity equivalents (RAE) of juices whereas homogenization yielded a significant reduction (1.37 and 1.35-fold, respectively). Interestingly, particle size reduction from homogenization drastically enhanced (about 5-fold) bioaccessibility of carotenoids including hardly bioaccessible epoxycarotenoids, finding unaltered rates in pasteurized samples. Bioaccessibility of flavonoids was constant in all cases. Results can promote HPH as an efficient option to obtain health-enhanced foods.

The Influence of the Agglomeration Process on Stability of Microencapsulated β-Carotene

Effects of agglomeration of β-carotene microencapsulated by spray drying on its stability were analysed. Mixtures of Arabic gum (GA), maltodextrin (MD), modified starch (OSA), and whey protein (WP) were used as carriers. GA + MD and OSA + MD microcapsules were subjected to agglomeration. All the samples were stored for 60 days with access to daylight. Stability of the emulsions had a significant effect on efficiency of microencapsulation but had no effect on β-carotene retention during sample storage. Among the tested samples, the highest retention of colorant characterized the samples containing GA + MD. The agglomeration process reduced the content of β-carotene in the microcapsules almost by half. However, retention of the colorant during storage of the microcapsules was increased most of all and half-life of β-carotene was significantly prolonged. Changes in L* and a* colour parameters during storage were more limited in the case of agglomerated samples.

Evaluation of California-Grown Blood and Cara Cara Oranges Through Consumer Testing, Descriptive Analysis, and Targeted Chemical Profiling

The acceptability of Moro, Tarocco, Cara Cara, Shahani, Bream Tarocco, Boukhobza, and Sanguinelli oranges from both commercial and research orchards was tested with adult (n = 152) and child (n = 72) consumers. Qualitative focus groups were also conducted to understand consumer familiarity and thoughts about the fruit. Sensory descriptive and chemical analyses were carried out to identify drivers of liking. Overall, consumers preferred the lighter colored varieties consisting of Tarocco, Cara Cara, and Boukhobza. One cluster of adults (n = 80) showed preferences towards sweet and fruity flavors and away from sourness and citric acid. The second adult cluster (n = 72) was tolerant of the sour fruit but did not like fruit high in bitterness and flavonoid content. The largest child cluster (n = 42) showed preferences for samples higher in orange and tropical flavors (Cara Cara, Tarocco, and Boukhobza varieties). The appearance of the Cara Cara was strongly liked by the consumer population in both quantitative and qualitative settings. Hunter scale a color values strongly correlated to the higher berry/dried fruit flavors, and concentrations of naringenin. Focus group participants noted that they were relatively unfamiliar with blood oranges. Growers and producers may want to invest in the lighter colored varieties, such as Cara Cara, Tarocco, Boukhobza and Shahani, as these were liked by a majority of consumers and were low in less desirable sensory characteristics, such as bitterness and sourness. PRACTICAL APPLICATION: Through consumer tests, sensory evaluation, and chemical analyses, this research uncovered which sensory properties may drive consumer acceptance of blood and Cara Cara oranges, and informed potential production and marketing strategies for increasing their consumption. This information should benefit the citrus industry as a whole and may enhance the use of specialty oranges by the food, beverage, and food service industries.

An Overview of Carotenoids, Apocarotenoids, and Vitamin A in Agro-Food, Nutrition, Health, and Disease

Carotenoids are fascinating compounds that can be converted into many others, including retinoids that also play key roles in many processes. Although carotenoids are largely known in the context of food science, nutrition, and health as natural colorants and precursors of vitamin A (VA), evidence has accumulated that even those that cannot be converted to VA may be involved in health-promoting biological actions. It is not surprising that carotenoids (most notably lutein) are among the bioactives for which the need to establish recommended dietary intakes have been recently discussed. In this review, the importance of carotenoids (including apocarotenoids) and key derivatives (retinoids with VA activity) in agro-food with relevance to health is summarized. Furthermore, the European Network to Advance Carotenoid Research and Applications in Agro-Food and Health (EUROCAROTEN) is introduced. EUROCAROTEN originated from the Ibero-American Network for the Study of Carotenoids as Functional Food Ingredients (IBERCAROT).

Fruit-based juices: Focus on antioxidant properties-Study approach and update

This paper proposes a perspective literature review of the antioxidant properties in fruit-based juices. The total antioxidant properties due to compounds such as carotenoids, polyphenolic compounds, flavonoids, and tannins as well as the assessment of interactions between natural active compounds and other food matrix components can be seen as the first step in the study of potential health benefits of fruit-based juices. A brief summary is given on the significance of antioxidant properties of fruit juices, the conventional methods for antioxidant activity evaluation, and on the newly emerged sample analysis and data interpretation strategies, that is, chemometric analysis based on spectroscopic data. The effect of fruit processing techniques and the addition of ingredients on the antioxidant properties of fruit-based juices are also discussed.

Long-Term Effect on Bioactive Components and Antioxidant Activity of Thermal and High-Pressure Pasteurization of Orange Juice

The long-term effect of thermal pasteurization (TP) and high-pressure processing (HPP) of orange juices stored under refrigeration, on the bioactive components and antioxidant activity, was compared. Total phenolic content (TPC), flavonoid, anthocyanin, and carotenoid contents, the individual content of major phenolic components, and the antioxidant activity, were evaluated in TP- and HPP-treated juices over a 36-day period. At day 0, no significant differences in TPC, and a decrease in carotenoid content after both treatments, were observed. TP caused a decrease of flavonoid and anthocyanin contents, while HPP increased flavonoid content. Three major phenolic components were identified: apigenin-6,8-di-C-glucoside, naringenin-7-O-rutinoside, and hesperetin-7-O-rutinoside, the latter increasing ca. 45% immediately after HPP. During storage, a decrease in TPC, and in the anthocyanin and carotenoid contents of both treated juices was observed, with higher anthocyanin and phenolic contents in HPP juices. A significant increase of hesperetin-7-O-rutinoside content was observed in HPP juice. Both treatments caused a decrease (26% and 13%, respectively) of antioxidant activity. Most of the kinetic profiles followed zero-order patterns, with HPP juices showing a considerably higher half-life than TP ones. These results clearly demonstrate the advantages of HPP for orange juice preservation allowing, also, their nutritional benefits to be enhanced by increasing the content of some bioactive components.

Bulk industrial fruit fibres. Characterization and prevalence of the original fruit metabolites

Here we analysed the content of primary and secondary metabolites in nine types of industrially processed fibres derived from the juice industry. Specifically, we examined fibre from: apple, peach, and pear, as non-citrus fruits; the peel and flesh of orange and tangerine, and lemon flesh, as citrus fruits; and carrot, as vegetable. Regarding primary metabolites, the sugar content ranged from 21.6 mg/g in lemon to 290 mg/g in orange peel and lower mass organic acid content ranged from 25.0 mg/g in pear to 250 mg/g in lemon. The content of fatty acids were constant during fibre processing, ranging from 0.5 to 1.46%. Furthermore, the fatty acid profile was not affect for the processing. Concerning secondary metabolites, industrial processing did not decrease the sterols content, which ranged from 0.51 to 1.66 μg/g. Regarding carotenoids, of note was the presence of epoxycarotenoids, which may reflect the quality of the industrial process, thus giving added value to the by-product.

Comprehensive Database of Carotenoid Contents in Ibero-American Foods. A Valuable Tool in the Context of Functional Foods and the Establishment of Recommended Intakes of Bioactives

Foods that are commonly consumed in the diet are considered to provide more than 40 different carotenoids. However, the content in carotenoids varies considerably in both qualitative and quantitative terms as a consequence of different genotypes, climatic conditions of the production area, and agronomic factors, among others. In this paper, analytical data, obtained by HPLC or UHPLC, of carotenoids in fruits and vegetables produced in Ibero-America have been compiled from peer-reviewed journals, organized in food categories, and documented in relation to the sampling and analytical quality system used. In addition to common products of the diet of the Ibero-American countries, other wild or little used fruit and vegetables have been included with the aim of contributing to promote and to value species and local varieties. The importance of the commodities containing carotenoids in food, health, agriculture, and biodiversity, and the need of their preservation, was evidenced in this work namely by the large differences in carotenoid content related to the locals of production and varieties, and the high levels of carotenoids in native fruits and vegetables. The contribution of these compounds to meet the needs of vitamin A as well as the necessity of establishing recommendation for the daily intakes of theses bioactive compounds were also discussed.

Consumption of orange fermented beverage improves antioxidant status and reduces peroxidation lipid and inflammatory markers in healthy humans

BACKGROUND

Alcoholic fermentation of fruits has generated novel products with high concentrations of bioactive compounds and moderate alcohol content. The aim of this study was to evaluate the potential effect on cardiovascular risk factors of the regular consumption by healthy humans of a beverage obtained by alcoholic fermentation and pasteurization of orange juice.

RESULTS

Thirty healthy volunteers were enrolled in a randomized controlled study. The experimental group (n = 15) drank 500 mL orange beverage (OB) per day for 2 weeks (intervention phase), followed by a 3-week washout phase. Blood samples were collected at baseline (E-T0) and at the end of the intervention (E-T1) and washout (E-T2) phases. Controls (n = 15) did not consume OB during a 2-week period. OB intake significantly increased oxygen radical absorbance capacity (43.9%) and reduced uric acid (-8.9%), catalase (CAT) (-23.2%), thiobarbituric acid reactive substances (TBARS) (-30.2%) and C-reactive protein (-2.1%) (E-T1 vs. E-T0). These effects may represent longer-term benefits, given the decreased uric acid (-8.9%), CAT (-34.6%), TBARS (-48.4%) and oxidized low-density lipoprotein (-23.9%) values recorded after the washout phase (E-T2 vs. E-T0).

CONCLUSION

The regular consumption of OB improved antioxidant status and decreased inflammation state, lipid peroxidation and uric acid levels. Thus OB may protect the cardiovascular system in healthy humans and be considered a novel functional beverage. © 2017 Society of Chemical Industry.

Quality characteristics and thermal behavior of buriti (

This work reports a complete characterization of buriti oil. Physicochemical properties were determined according to AOCS methodologies and thermophysical properties were measured using a controlled stress rheometer and a digital electronic density meter. β-carotene and tocopherol contents were obtained using HPLC systems. Fatty acids and acylglycerol classes were determined using GC and HPSEC systems, respectively, while triacylglycerol composition was estimated using the software PrOleos. Thermal behavior (crystallization and melting) was analyzed using a DSC. The results attested high levels of total carotenoids with β-carotene as the major one; total tocopherols contained α- and β-tocopherols which accounted for 91% of the total; and monounsaturated fatty acids were mainly represented by oleic acid. The results showed close agreement between density and viscosity of buriti and olive oils. The crystallization and melting peaks occurred at -43.06 °C and -2.73 °C, respectively. These properties enable Buriti oil to be recommended as an excellent alternative for enriching foods with bioactive compounds.

Development and Application of a Multiplex Real-Time PCR Assay as an Indicator of Potential Allergenicity in Citrus Fruits

The effects of tissue type, harvest maturity, and genetic factors on the expression of genes that related to citrus fruit allergies remain poorly understood. In the present study, a multiplex real-time PCR assay was developed to monitor the expression of citrus allergen genes individually with the advantages of much fewer sample requirements and simultaneously multiple target genes detection. Gene specific primer pairs and Taqman probes of three citrus allergen genes Cit s 1.01, Cit s 2.01, and Cit s 3.01 and the house-keeping gene β-actin were designed based on gene sequence differences. The PCR results showed that differential expression patterns were found during the ripening process. The expression levels of Cit s 3.01 were much higher than those of Cit s 1.01 and Cit s 2.01 in both peel and pulp tissues among 10 citrus cultivars. Data suggested that Kao Phuang Pummelo could be safely consumed with a potential low risk in allergenicity. Considering that assessing allergenicity is one of the tests in food safety, this assay might also facilitate the breeding and production of "allergy-friendly" citrus fruits.

Multivariate analyses of a wide selection of orange varieties based on carotenoid contents, color and in vitro antioxidant capacity

Carotenoids, color and in vitro antioxidant capacity were analyzed in twenty-two genotypes of oranges produced in Spain in two consecutive seasons. The colorless carotenoids phytoene and phytofluene were also analyzed. An important influence of the genotype on the carotenoid profile was observed. In most genotypes, such profile was characterized by the predominance of xanthophylls (82.7-93.0%), except in Cara Cara, with a higher proportion of carotenes (around 70.0%). β-cryptoxanthin was the predominant carotenoid in Rohde late and Ambersweet. The samples with the lowest carotenoid contents were the ones exhibiting the lowest Trolox Equivalent Antioxidant Capacity (TEAC) and vice versa. A formula obtained by multiple regression is proposed to estimate the TEAC value from the carotenoid content. No significant correlation between TEAC values and color coordinates were obtained, suggesting that color parameters are not good predictors of TEAC values. Lastly, the samples could be classify with a high rate of success (>90%) by Linear Discriminant Analysis based on color and carotenoids.

Guide for Carotenoid Identification in Biological Samples

In recent years there has been considerable interest in carotenoids with respect to their biological roles in animals, microorganisms, and plants, in addition to their use in the chemical, cosmetics, food, pharmaceutical, poultry, and other industries. However, the structural diversity, the different range of concentration, and the presence of cis/trans-isomers complicate the identification of carotenoids. This review provides updated information on their physical and chemical properties as well as spectroscopic and chromatographic data for the unambiguous determination of carotenoids in biological samples.

In vitro bioaccessibility of carotenoids, flavonoids, and vitamin C from differently processed oranges and orange juices [Citrus sinensis (L.) Osbeck]

Carotenoid, flavonoid, and vitamin C concentrations were determined in fresh orange segments and a puree-like homogenate derived thereof, as well as freshly squeezed, flash-pasteurized, and pasteurized juices. Lutein and β-cryptoxanthin were slightly degraded during dejuicing, whereas β-carotene levels were retained. Vitamin C levels remained unaffected, whereas flavonoid levels decreased 8-fold upon juice extraction, most likely due to the removal of flavonoid-rich albedo and juice vesicles. Likewise, the presence of such fibrous matrix compounds during in vitro digestion was assumed to significantly lower the total bioaccessibility (BA) of all carotenoids from fresh fruit segments (12%) as compared to juices (29-30%). Mechanical disruption of orange segments prior to digestion did not alter carotenoid BA, whereas pasteurization of the freshly squeezed juice slightly increased BA by 9-11%. In addition to carotenoid BA, the stabilities of hesperidin, narirutin, and vitamin C including dehydroascorbic acid during in vitro digestion were monitored, and applied analytical methods were briefly validated.

Carotenoid bioaccessibility in pulp and fresh juice from carotenoid-rich sweet oranges and mandarins

In this work the concentration and bioaccessibility of carotenoids in sweet oranges and mandarins rich in bioactive carotenoids were evaluated in pulp and fresh juice.

Analysis of carotenoids and tocopherols in plant matrices and assessment of their in vitro antioxidant capacity

Carotenoids and tocopherols are lipid secondary metabolites that play essential roles in plants. They are also relevant compounds from a nutritional standpoint and attract much attention due to their proposed antioxidant properties. In this chapter, methodologies for the extraction and HPLC analysis of these compounds are described as well as a widely used protocol to assess their antioxidant capacity.

Identification of carotenoids using mass spectrometry

The present review compiles positive MS fragmentation data of selected carotenoids obtained using various ionization techniques and matrices. In addition, new experimental data from the analysis of carotenoids in transgenic maize and rice callus are provided. Several carotenes and oxygen-functionalized carotenoids containing epoxy, hydroxyl, and ketone groups were ionized by atmospheric pressure chemical ionization (APCI)-tandem mass spectrometry (MS/MS) in positive ion mode. Thus, on the basis of the information obtained from the literature and our own experiments, we identified characteristic carotenoid ions that can be associated to functional groups in the structures of these compounds. In addition, pigments with a very similar structure were differentiated through comparison of the intensities of their fragments. The data provide a basis for the structural elucidation of carotenoids by mass spectrometry (MS).

Effect of alcoholic fermentation on the carotenoid composition and provitamin A content of orange juice

Orange juice is considered a rich source of carotenoids, which are thought to have diverse biological functions. In recent years, a fermentation process has been carried out in fruits resulting in products that provide higher concentrations of bioactive compounds than their original substrates. The aim of this study was to evaluate the effect of a controlled alcoholic fermentation process (15 days) on the carotenoid composition of orange juice. Twenty-two carotenoids were identified in samples. The carotenoid profile was not modified as result of the fermentation. Total carotenoid content and provitamin A value significantly increased from day 0 (5.37 mg/L and 75.32 RAEs/L, respectively) until day 15 (6.65 mg/L and 90.57 RAEs/L, respectively), probably due to a better extractability of the carotenoids from the food matrix as a result of processing. Therefore, the novel beverage produced could provide a rich source of carotenoids and exert healthy effects similar to those of orange juice.