Blood Orange Juice Research Articles

Pulsed Electric Field as a Mild Treatment for Extended Shelf-Life and Preservation of Bioactive Compounds in Blood Orange Juice

The agri-food processing industry predominantly relies on fossil fuels, contributing significantly to greenhouse gas emissions and extensive water use. Climate change requires a conversion of food processing technologies towards sustainability. Our research focuses on testing and validating pulsed electric field (PEF) technology as a mild processing method for stabilizing freshly squeezed, not from concentrate, blood orange juice. Experiments were carried out on a continuous pilot plant endowed with a patented treatment chamber that ensures a constant flow of product without “hot spots” for a homogeneous treatment. Once the operative conditions of the process in terms of energy density were optimized, PEF-treated blood orange juice was tested in order to evaluate the effects on physico-chemical parameters (total soluble solids, total acidity, pH, CIE L*, a*, b*, C*, h color indices, cloud, bioactive compounds (ascorbic acid, total anthocyanins, total and individual flavanones), antioxidant activity (ORAC units, total phenolic content), microbial communities (aerobic mesophilic viable count, yeasts and molds, acid-tolerant microorganisms), residual enzymatic pectinmethylesterase activity, and sensory attributes (flavor, off-flavor, off-odor, color, intensity of odor, acidity, sweetness, bitter, freshness, cooked flavor). Then, in order to simulate the commercial refrigerated distribution of PEF-treated blood orange juice and define its refrigerated shelf-life, the PEF-treated freshly squeezed, not from concentrate, blood orange juice was subjected to physico-chemical, antioxidant, microbiological, and sensory evaluations over twenty days of refrigerated storage at 4 ± 1 °C. The PEF treatment effectively ensured excellent microbial inactivation and enhanced the nutritional and health characteristics of the juice, thereby extending its shelf-life. This study demonstrates the significant potential of the PEF treatment to produce blood orange juice suitable for a new retail segment—freshly squeezed juices with superior health quality, fresh-like characteristics, and extended refrigerated shelf-life.

Olive mill wastewater as booster to produce a blood orange juice with high healthy value

Olive mill wastewater as booster to produce a blood orange juice with high healthy value

Pre- and Post-harvest Elicitation with Methyl Jasmonate and Salicylic Acid Followed by Cold Storage Synergistically Improves Red Colour Development and Health-Promoting Compounds in Blood Oranges

Red blush is one of the key quality markers of blood orange fruit (Citrus sinensis L. Osbeck). Therefore, the influence of pre- (1, 2, and 3 mM) and postharvest (0.5, 1, and 1.5 mM) methyl jasmonate (MeJA) and salicylic acid (SA) (1, 2, and 3 mM) treatments on redness, colouring pigments, and health-promoting compounds in cold stored ‘Tarocco Ippolito’ blood oranges was investigated. Preharvest application of 3 mM MeJA significantly increased rind citrus colour index (CCI) by 43.3% and colorimetric coordinate a* (redness) by 3.1% and decreased h° (hue angle, 0 = red), L* (lightness), and b* (yellowness) by 13.7%, 12.6%, and 23.4%, respectively. This treatment also enhanced CCI (57.4%), reduced h° (16.5%) and L* (36.4%), and increased total anthocyanins (88%), monomeric anthocyanins (117%), and flavonoids (77%) in the juice. Postharvest dip of 1.5 mM MeJA (5 min) improved CCI of juice (53.6%) and a* (5.5%), reduced h° (15.9%), L* (19.8%), and b* (19.4%), and increased total anthocyanins (66.7%), monomeric anthocyanins (74%), and flavonoids (23.4%) in the juice. Preharvest application of 1 mM SA increased rind CCI (50.8%) and reduced L* (13.6%), b* (16.4%), and h° (29.5%). All preharvest SA treatments significantly increased total phenolics in the juice. Lycopene was increased (61.7%) by 5 min postharvest dip of 3 mM SA. In conclusion, 3 mM preharvest spray application of MeJA four weeks before harvest and postharvest dip of 1.5 mM MeJA (5 min) are effective in improving red colour of rind and juice and health-promoting compounds in blood orange juice.

Comparison of anthocyanin and volatile organic compounds in juices and fruit wines made from blood oranges (Citrus sinensis L. Osbeck) at different maturity stages

The variation in profiles of anthocyanins and volatile organic compounds (VOCs) in juices and in the corresponding fruit wines made from blood oranges ripened at different maturity stages were investigated. The compositions of sugars and organic acids were monitored, as well. Original findings have been reported for the maturity effect on blood orange juices, while the impact of fruit ripening on wine is explored for the first time. Using UPLC-DAD-ESI-Q-TOF-MS, based on elution order, UV–vis spectra, fragmentation pattern, and authentic standards, thirteen individual anthocyanins were identified, nine common to unfermented and fermented blood orange samples, while four (identified as hydroxyphenyl-pyranoanthocyanins) generated from fermentation. The total anthocyanin content in unfermented blood orange juice showed dramatic increases during maturation, especially in the late maturity stage, while fermentation resulted in significant reductions. The monitoring of VOCs in blood orange and wines was provided via a combination approach of HS-GC-IMS and HS-SPME-GC-MS for the first time. Forty-five and ninety-one VOCs were identified by GC-IMS and GC-MS, respectively. The concentrations of alcohols, ketones, and terpenes decreased with maturity, while that of esters increased significantly during this period. Fermentation enhanced the complexity and intensity of VOCs, with all VOC categories except ketones showing 2.1−94.3 times increase after fermentation. This work improves the knowledge on the processing management of blood orange juice and wine in order to obtain superior quality products.

Blood orange juice intake changes specific bacteria of gut microbiota associated with cardiometabolic biomarkers.

Blood orange juice is an important source of flavanones and anthocyanins, mainly hesperidin, narirutin, and cyanidin-3-O-glucoside. The benefits of these bioactive compounds have been reported, but the mechanistic details behind their biological effects are not well established. This study investigated the effects of Moro orange (Citrus sinensis L. Osbeck) juice (MOJ) on gut microbiota composition and cardiometabolic biomarkers in overweight women. In this study, 12 overweight women (BMI from 25.0 to 29.9 kg/m2), aged 18-37 years, consumed 500 mL of MOJ every day for 4 weeks. We assessed the gut microbiota composition, levels of short-chain fatty acids (SCFAs), cardiometabolic biomarkers, and insulin resistance (HOMA-IR) at baseline and after 2 weeks and 4 weeks of MOJ intake. The results suggested that MOJ intake affected the abundance of specific operational taxonomic units (OTUs) of the gut microbiota but did not significantly alter the diversity and general composition of the gut microbiota. However, MOJ intake increased the production of SCFAs, especially propionic and isobutyric acids, and significantly improved cardiometabolic biomarkers such as blood pressure and plasma VCAM-1 levels in the overweight women. Additionally, we observed significant associations between gut microbiota OTUs belonging to the Bacteroidetes phyla and Prevotella 9 genera and the cardiometabolic biomarkers. Furthermore, MOJ reduced fasting glucose and insulin levels and HOMA-IR values, thereby enhancing insulin sensitivity in the insulin-resistant overweight women. Finally, we highlighted the importance of orange juice intake duration because some beneficial changes such as blood pressure improvements were evident at the 2-week time interval of the intervention, but other changes became significant only at the 4-week interval of MOJ intake. In conclusion, our study demonstrated that changes in specific OTUs of the gut microbiota in response to MOJ intake were associated with significant improvements in some cardiometabolic biomarkers and SCFA levels in overweight women with insulin resistance.

Red Fruit Juice Concentration by Osmotic Distillation: Optimization of Operating Conditions by Response Surface Methodology.

Osmotic distillation (OD) was implemented at laboratory scale to concentrate a red fruit juice produced from a blend of blood orange, prickly pear, and pomegranate juice. The raw juice was clarified by microfiltration and then concentrated by using an OD plant equipped with a hollow fiber membrane contactor. The clarified juice was recirculated on the shell side of the membrane module, while calcium chloride dehydrate solutions, used as extraction brine, were recirculated on the lumen side in a counter-current mode. The influence of different process parameters, such as brine concentration (20, 40, and 60% w/w), juice flow rate (0.3, 2.0, and 3.7 L min-1), and brine flow rate (0.3, 2.0, and 3.7 L min-1) on the performance of the OD process in terms of evaporation flux and increase in juice concentration, was investigated according to the response surface methodology (RSM). From the regression analysis, the evaporation flux and juice concentration rate were expressed with quadratic equations of juice and brine flow rates, as well as the brine concentration. The desirability function approach was applied to analyse the regression model equations in order to maximize the evaporation flux and juice concentration rate. The optimal operating conditions were found to be 3.32 L min-1 brine flow rate, 3.32 L min-1 juice flow rate, and an initial brine concentration of 60% w/w. Under these conditions, the average evaporation flux and the increase in the soluble solid content of the juice resulted in 0.41 kg m-2 h-1 and 12.0 °Brix, respectively. Experimental data on evaporation flux and juice concentration, obtained in optimized operating conditions, resulted in good agreement with the predicted values of the regression model.

‘Pera’ Orange and ‘Moro’ Blood Orange Juice Improves Oxidative Stress and Inflammatory Response Biomarkers and Modulates the Gut Microbiota of Individuals with Insulin Resistance and Different Obesity Classes

Orange juice contains flavanones, which are associated with reducing the risk of obesity-associated diseases. We evaluated the effects of two varieties of orange juices on the oxidative stress, inflammatory response, and gut microbiota of individuals with insulin resistance and different obesity classes. In a randomized crossover study, obese patients consumed ‘Pera’ (POJ—source of flavanones) and ‘Moro’ (MOJ—source of flavanones and anthocyanins) orange juices for 15 days. Blood, urine, and fecal samples were collected before and after the intervention. Daily orange juice intake significantly reduced HDL and total cholesterol, in addition to urinary 8-OHdG and plasmatic MCP-1 levels. Multivariate analyses highlighted the beneficial effects of orange juice intake, mainly the modulation of inflammatory and oxidative stress biomarkers. Patients in different obesity classes presented a gut microbiota with obesity-associated alterations (dysbiosis), and the consumption of Pera and Moro orange juices improved this profile by modulating their gut microbiota in different ways. Although the Firmicutes/Bacteroidetes ratio changed after both interventions, MOJ provided more accentuated changes than POJ. Blautia, Bifidobacterium, and other genera had their relative abundance altered by juice consumption, which correlated with patient parameters (such as HDL-cholesterol and diastolic blood pressure) and biomarkers (such as TNF-α and 8-OHdG). In conclusion, regular orange juice intake can be associated with a reduction in oxidative stress and inflammatory response, in addition to modulating gut microbiota.

Blood orange juice intake modulates plasma and PBMC microRNA expression in overweight and insulin-resistant women: impact on MAPK and NFκB signaling pathways

Blood orange consumption presents potential health benefits and may modulate epigenetic mechanisms such as microRNAs (miRNAs) expression. MiRNAs are non-coding RNAs responsible for post-transcriptional gene regulation, and these molecules can also be used as biomarkers in body fluids. This study was designed to investigate the effect of chronic blood orange juice (BOJ) intake on the inflammatory response and miRNA expression profile in plasma and blood cells in overweight women. The study cohort was comprised of twenty women aged 18–40 years old, diagnosed as overweight, who consumed 500 mL/d of BOJ for four weeks. Clinical data were collected at baseline and after 4 weeks of juice consumption, e.g., anthropometric and hemodynamic parameters, food intake, blood cell count, and metabolic and inflammatory biomarkers. BOJ samples were analyzed and characterized. Additionally, plasma and blood cells were also collected for miRNA expression profiling and evaluation of the expression of genes and proteins in the MAPK and NFκB signaling pathways. BOJ intake increased the expression of miR-144-3p in plasma and the expression of miR-424-5p, miR-144-3p, and miR-130b-3p in peripheral blood mononuclear cells (PBMC). Conversely, the beverage intake decreased the expression of let-7f-5p and miR-126-3p in PBMC. Computational analyses identified different targets of the dysregulated miRNA on inflammatory pathways. Furthermore, BOJ intake increased vitamin C consumption and the pJNK/JNK ratio and decreased the expression of IL6 mRNA and NFκB protein. These results demonstrate that BOJ regulates the expression of genes involved in the inflammatory process and decreases NFкB-protein expression in PBMC.

Phenols recovered from olive mill wastewater as natural booster to fortify blood orange juice

In the present study, a tangential membrane filtration system was applied to recover phenols from olive mill wastewater. The obtained concentrates were characterised for physico-chemical traits, antioxidant activity and antimicrobial effects. Results indicated that the highest concentration of hydroxytyrosol (7203.7 mg/L) was detected in the concentrate obtained by reverse osmosis, which also showed the highest antioxidant and antimicrobial activity. Moreover, the same concentrate was added, at different ratio, up to 4:250 v/v, into a commercial blood orange juice. The fortified juice with the addition of the concentrate, up to 2:250 v/v ratio, did not show off-flavour and off-odour compared to the control. Furthermore, after 60 days of refrigerated storage, the fortified juice exhibited a hydroxytyrosol content still complying with the daily intake recommended by EFSA health claim. The obtained results can be industrially useful in producing orange juice added with a natural antioxidant concentrate as a ‘clean label’ ingredient.

Blood Orange Juice Intake Modulates the Expression of miR-126–3p and let-7f-5p in PBMC of Overweight and Insulin Resistance Women

ObjectivesTo investigate the effect of chronic blood orange juice intake on the microRNA profile in peripheral blood mononuclear cells (PBMC) of overweight and insulin resistance women. MethodsInterventional and chronic study with women (n = 8) aged 18 to 40 years, diagnosed with overweight [body mass index (BMI) 25–29.9 kg/m2] and insulin resistance [homeostatic model assessment insulin resistance (HOMA-IR) index >2,71]. For four weeks, the volunteers ingested 500 mL/day of blood orange juice (Moro variety), with blood samples collected at baseline and four weeks after the beginning of drink ingestion. Evaluation of the expression of 137 microRNAs in PBMC was performed by real-time polymerase chain reaction (PCR). ResultsBlood orange juice intake decreased the expression of miR-126-3p (p = 0.004) and let-7f-5p (p = 0.005) in PBMC. These microRNAs are involved in suppressing the synthesis of several proteins of the insulin signaling pathway. Insulin receptor substrates (IRS) 1 and 2 were identified as target genes of mir-126. Insulin-like growth factor 1 receptor (IGF1R), insulin receptor (INSR), IRS2, phosphatidylinositol-3-kinase interacting protein 1 (PIK3IP1), and protein kinase B/Akt 2 (AKT2) were identified as target genes of let-7f. ConclusionsBlood orange juice, rich in vitamin C, flavonoids, and anthocyanins, downregulates the expression of microRNA involved in impairing the insulin signaling pathway. Funding SourcesFood Research Center (FoRC), São Paulo Research Foundation (FAPESP)

Comparison Study of Synthesized Red (or Blood) Orange Peels and Juice Extract-Nanoflowers and Their Antimicrobial Properties on Fish Pathogen (Yersinia ruckeri).

In this work, we synthesized blood orange peel extract-copper (II) (Cu2+) ions nanoflower (NFs) and blood orange juice extract-copper (II) (Cu2+) ions nanoflower examine their antimicrobial properties on the fish pathogen (Yersinia ruckeri). The main compounds of the blood orange peel extract and the blood orange juice extract were organic components, and the copper (II) (Cu2 +) ions were inorganic components. BOPE-Cu2 + nanoflowers are quite compact, porous, and uniform as compared to BOJE-Cu2+ nanoflowers. Scanning Electron Microscopy, Fourier Transform Infrared spectrometry, and Energy-Dispersive X-ray spectroscopy were used to observe the structures of the NFs. The findings of FT-IR show Cu-O and Cu-N bonds in NF, which may be an indicator of the development of NFs. Although the antimicrobial actions of BOPE-hNFs and BOJE-hNFs against Yersinia ruckeri (NCTC 12,268) have been confirmed.

Efficacy of dietary supplements containing isolated organic compounds for weight loss: a systematic review and meta-analysis of randomised placebo-controlled trials.

A systematic review with meta-analysis was conducted to synthesise evidence on the efficacy of dietary supplements containing isolated organic compounds for weight loss. Four electronic databases (Medline, Embase, Web of Science, Cinahl) were searched until December 2019. Sixty-seven randomised placebo-controlled trials of dietary supplements containing isolated organic compounds for weight loss were included. Meta-analyses were conducted for chitosan, glucomannan, conjugated linoleic acid and fructans, comparing mean weight difference post-intervention between participants receiving the dietary supplement or placebo. Statistically significant weight differences compared to placebo were observed for chitosan (-1.84 kg; 95% confidence interval [CI] -2.79, -0.88; p < 0.01), glucomannan (-1.27 kg; 95%CI -2.45, -0.09; p = 0.04), and conjugated linoleic acid (-1.08 kg; 95%CI -1.61, -0.55; p < 0.01). None met our threshold for clinical significance (≥2.5 kg). There was no statistically significant effect on weight for fructans compared to placebo (p = 0.24). For dietary supplements with an inadequate number of trials for meta-analysis, a statistically and borderline clinically significant weight difference compared to placebo was found for modified cellulose, manno-oligosaccharides (in males), blood orange juice extract, and three multiple-ingredient dietary supplements. These were only reported in one trial of each. Thus, more evidence is needed before recommending them for weight loss. While some dietary supplements containing isolated organic compounds warrant further investigation to determine efficacy and safety, there is currently insufficient evidence to recommend any of these dietary supplements for weight loss.

Stratification of Volunteers According to Flavanone Metabolite Excretion and Phase II Metabolism Profile after Single Doses of 'Pera' Orange and 'Moro' Blood Orange Juices.

Large interindividual variations in the biological response to citrus flavanones have been observed, and this could be associated with high variations in their bioavailability. The aim of this study was to identify the main determinants underlying interindividual differences in citrus flavanone metabolism and excretion. In a randomized cross-over study, non-obese and obese volunteers, aged 19–40 years, ingested single doses of Pera and Moro orange juices, and urine was collected for 24 h. A large difference in the recovery of the urinary flavanone phase II metabolites was observed, with hesperetin-sulfate and hesperetin-sulfo-O-glucuronide being the major metabolites. Subjects were stratified according to their total excretion of flavanone metabolites as high, medium, and low excretors, but the expected correlation with the microbiome was not observed at the genus level. A second stratification was proposed according to phase II flavanone metabolism, whereby participants were divided into two excretion groups: Profiles A and B. Profile B individuals showed greater biotransformation of hesperetin-sulfate to hesperetin-sulfo-O-glucuronide, as well as transformation of flavanone-monoglucuronide to the respective diglucuronides, suggestive of an influence of polymorphisms on UDP-glucuronosyltransferase. In conclusion, this study proposes a new stratification of volunteers based on their metabolic profiles. Gut microbiota composition and polymorphisms of phase II enzymes may be related to the interindividual variability of metabolism.

Chemometric analysis of amino acid profiles for detection of fruit juice adulterations – Application to verify authenticity of blood orange juice

In this work, fruit juices have been analyzed by high-performance liquid chromatography (HPLC) to measure whole amino acid profiles for various fruit types. The fruit juice authentication capabilities of whole amino acid profiles employed in various multivariate analysis methods including principal component analysis (PCA) and partial least squares (PLS) analysis have been investigated. PCA of the profiles exhibited a good separation of most fruit types and were validated using quality control samples. Furthermore, these profiles were considered in a blood orange juice versus blond orange juice adulteration study. Applying PLS regression allowed for the detection of ~20 percent blond orange juice adulterant added in blood orange juice. The highest regression coefficients were found for glutamic acid and valine, with regards to blood orange juice, and for phenylalanine and glycine, with regards to orange juice. These results suggest that chemometric approaches have great potential for the implementation in food testing.

Blood Orange Juice Consumption Increases Flow-Mediated Dilation in Adults with Overweight and Obesity: A Randomized Controlled Trial

Epidemiological studies have indicated an inverse association between citrus fruit consumption and cardiovascular disease (CVD) risk. There is, however, a paucity of data concerning effects of blood orange juice (BOJ) intake on endothelial function and cardiovascular risk biomarkers. We examined short-term effects of BOJ on endothelial function, blood pressure, lipid profile, and inflammatory markers in healthy participants of European origin who were overweight or obese. In a randomized, controlled, single-blind, crossover trial, 15 men and women (age: 28.7±6.5 y; BMI: 28.3±3.1 kg/m2) consumed BOJ or a sugar-matched control drink (CD) (200 mL twice daily) for 2 wk with a washout period of 1 wk. Endothelial function, measured as flow-mediated dilation (FMD) (primary outcome), and the secondary outcomes blood pressure, anthropometric measures, lipid profile, inflammatory markers, markers of vasodilation and vasoconstriction, and urinary flavanone metabolites were evaluated prior to and at the end of each treatment period following an overnight fast. Changes between treatments over time were assessed using repeated-measures ANOVA. The results demonstrate a significant increase in FMD following BOJ consumption (pre: 8.15%±2.92%; post: 10.2%±3.31%; P=0.002) compared with CD (pre: 8.11%±2.52%; post: 7.77%±2.43%; time × treatment interaction: P=0.001). Concurrent significant increases in urinary hesperetin-3'-glucuronide and hesperetin-7-glucuronide were observed following BOJ supplementation only (time × treatment interaction: P≤0.01). Baseline blood pressure, lipid profile, high-sensitivity C-reactive protein, and endothelin-1 were generally within healthy ranges and unaffected by the intervention. A 2-wk consumption of BOJ exerted favorable effects on endothelial function in healthy women and men who were overweight or obese, which is likely mediated by the combined actions of anthocyanin and flavanone metabolites on mechanisms that contribute to enhancing NO bioavailability. This trial was registered at clinicaltrials.gov as NCT03611114.

252 - Evaluation of antiurolithiatic activity of blood orange and grapefruit juices against calcium oxalate-induced urolithiasis in rats

252 - Evaluation of antiurolithiatic activity of blood orange and grapefruit juices against calcium oxalate-induced urolithiasis in rats

Blond and blood juice supplementation in high fat diet fed mice: effect on antioxidant status and DDAH/ADMA pathway.

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease spread throughout the world. The most frequent causes of death in NAFLD patients are due both to liver and cardiovascular damage. Several pathways, including the dimethylarginine dimethylaminohydrolase (DDAH)/asymmetric dimethylarginine (ADMA) pathway, are involved in the pathogenesis of NAFLD. It has been reported that ADMA plasmatic levels are increased in patients with hepatic dysfunction such as NAFLD. Although many studies demonstrated that some foods are effective in the treatment of NAFLD, few studies have evaluated their effects with respect to the prevention of the disease. It has been reported that sweet orange juice (OJ) consumption may be associated with potential health benefits. However, some varieties of sweet orange are more effective than others. The aim of the present paper was to investigate the effect of blond and blood sweet orange juice in prevention of NAFLD by evaluating its ability to improve liver steatosis in mice with diet-induced obesity, reducing oxidative stress and affecting the DDAH/ADMA pathway. Results obtained in our experimental conditions evidenced that blood orange juice rather than blond orange juice was more effective. Blood orange juice or blond orange juice enriched in anthocyanins may represent a promising dietary option for the prevention of fatty liver disease.

Effect of low temperature-storage on the proteome of ‘Moro’ blood orange flesh

Anthocyanins are a subclass of flavonoid pigments with important therapeutic properties beneficial to human health. Blood oranges are rich in these pigments, which present synergistic effects (i.e., anti-inflammatory and anti-obesity) with other orange juice phytonutrients. Anthocyanin biosynthesis is cold induced in blood citrus cultivars, requiring a broad day/night thermal range to get purple pigmentation in fruit. This cold-dependency limits geographically a reliable quality for commercial production to only a few regions worldwide. For example, cultivation of blood oranges under tropical/subtropical climates, as those of Brazil, yields fruit with very low level or lack of anthocyanins. A feasible alternative in tropical countries to enhance anthocyanin content is cold postharvest storage, as it has been shown that anthocyanin synthesis is induced when fruits are kept below 10°C for a few weeks after harvesting. Blood oranges kept at 9°C showed higher expression levels of anthocyanin biosynthetic genes, increased anthocyanin content and reached a darker purple coloration than those stored at 4°C. In order to gain insight on the effect of storage temperature on activation of anthocyanin biosynthesis and accumulation as well as on purple orange coloration, we have investigated the proteome of 'Moro' sweet orange [Citrus sinensis (L.) Osbeck] fruit stored either at 4°C (low temperature) or at 9°C (moderate temperature). Results on increased or reduced accumulation of specific proteins in the 'Moro' orange pulp upon storage at different temperatures reinforces that postharvest storage at 9°C could be better to enhance anthocyanin biosynthesis and accumulation on blood orange juices.

Effect of low temperature-storage on the proteome of ‘Moro’ blood orange flesh

Anthocyanins are a subclass of flavonoid pigments with important therapeutic properties beneficial to human health. Blood oranges are rich in these pigments, which present synergistic effects (i.e., anti-inflammatory and anti-obesity) with other orange juice phytonutrients. Anthocyanin biosynthesis is cold induced in blood citrus cultivars, requiring a broad day/night thermal range to get purple pigmentation in fruit. This cold-dependency limits geographically a reliable quality for commercial production to only a few regions worldwide. For example, cultivation of blood oranges under tropical/subtropical climates, as those of Brazil, yields fruit with very low level or lack of anthocyanins. A feasible alternative in tropical countries to enhance anthocyanin content is cold postharvest storage, as it has been shown that anthocyanin synthesis is induced when fruits are kept below 10°C for a few weeks after harvesting. Blood oranges kept at 9°C showed higher expression levels of anthocyanin biosynthetic genes, increased anthocyanin content and reached a darker purple coloration than those stored at 4°C. In order to gain insight on the effect of storage temperature on activation of anthocyanin biosynthesis and accumulation as well as on purple orange coloration, we have investigated the proteome of 'Moro' sweet orange [Citrus sinensis (L.) Osbeck] fruit stored either at 4°C (low temperature) or at 9°C (moderate temperature). Results on increased or reduced accumulation of specific proteins in the 'Moro' orange pulp upon storage at different temperatures reinforces that postharvest storage at 9°C could be better to enhance anthocyanin biosynthesis and accumulation on blood orange juices.

Contribution of Blood Orange-Based Beverages to Bioactive Compounds Intake

The study aimed at screening the levels of ascorbic acid, hydroxycinnamic acids (HCAs) and total anthocyanins in commercial beverages containing blood orange juice (BOJ), estimating the contribution of these products to the intake of health-promoting compounds and at discussing the actual value of the products on a price/bioactive level basis. Results demonstrate that the reference to BOJ in many beverages is misleading, as inferred from the very low bioactive levels observed. These beverages, in label should refer as “water-based” instead of “fruit-based beverage.” Accordingly, the intake of bioactives from BOJ-based beverages, with the exception of ascorbic acid used in the most cases as preservative, is often very low. The intake of bioactive components from blood orange consumption is much higher compared to the consumption of BOJ-based beverages, hence the consumption of blood oranges and 100% BOJs should be preferred in order to guarantee the intake of a rich pool of bioactive compounds. Finally, the market value of BOJ-based beverages is not correlated with their real nutritional value: the relative unitary cost of the three classes of bioactive compounds considered increased in the order: fresh blood oranges < 100% BOJ < BOJ-based beverages. Hence, the consumption of fresh blood oranges represents the cheapest way to ensure the intake of health-promoting bioactive compounds such as anthocyanins and HCAs.