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Alcoholic fermentation induces melatonin synthesis in orange juice

Melatonin (N‐acetyl‐5‐methoxytryptamine) is a molecule implicated in multiple biological functions. Its level decreases with age, and the intake of foods rich in melatonin has been considered an exogenous source of this important agent. Orange is a natural source of melatonin. Melatonin synthesis occurs during alcoholic fermentation of grapes, malt and pomegranate. The amino acid tryptophan is the precursor of all 5‐methoxytryptamines. Indeed, melatonin appears in a shorter time in wines when tryptophan is added before fermentation. The aim of the study was to measure melatonin content during alcoholic fermentation of orange juice and to evaluate the role of the precursor tryptophan. Identification and quantification of melatonin during the alcoholic fermentation of orange juice was carried out by UHPLC‐QqQ‐MS/MS. Melatonin significantly increased throughout fermentation from day 0 (3.15 ng/mL) until day 15 (21.80 ng/mL) reaching larger amounts with respect to other foods. Melatonin isomer was also analysed, but its content remained stable ranging from 11.59 to 14.18 ng/mL. The enhancement of melatonin occurred mainly in the soluble fraction. Tryptophan levels significantly dropped from 13.80 mg/L (day 0) up to 3.19 mg/L (day 15) during fermentation. Melatonin was inversely and significantly correlated with tryptophan (r = 0.907). Therefore, the enhancement in melatonin could be due to both the occurrence of tryptophan and the new synthesis by yeast. In summary, the enhancement of melatonin in novel fermented orange beverage would improve the health benefits of orange juice by increasing this bioactive compound.

Fermented Orange Juice: Source of Higher Carotenoid and Flavanone Contents

The intake of bioactive compounds and moderate alcohol decreases the risk of cardiovascular diseases. These effects could be joined in a beverage created by a controlled alcoholic fermentation of orange juice. The influence of controlled alcoholic fermentation on the bioactive compound profile of orange juice has not been previously evaluated, and this is the purpose of the present study. Total and individual flavanones and carotenoids significantly increased throughout the fermentation. The reason for this was an enhanced extraction of these compounds from the pulp. Besides, the potential bioavailability of flavanones increased due to a higher content of hesperetin-7-O-glucoside (2-fold higher at the end of the fermentation process). Ascorbic acid did not undergo a significant change, and only total phenolics decreased. Antioxidant capacity was also evaluated. TEAC and FRAP values remained constant throughout the process. However, ORAC and DPPH values significantly increased. Correlation analysis concluded that the increase in ORAC and DPPH values could be due to enhancement of flavanones.

Effect of thermal processing on the profile of bioactive compounds and antioxidant capacity of fermented orange juice

Abstract Previously, we reported that alcoholic fermentation enhanced flavanones and carotenoids content of orange juice. The aim of this work was to evaluate the influence of pasteurization on the qualitative and quantitative profile of bioactive compounds and the antioxidant capacity of fermented orange juice. Ascorbic acid (203 mg/L), total flavanones (647 mg/L), total carotenoids (7.07 mg/L) and provitamin A (90.06 RAEs/L) values of pasteurized orange beverage were lower than those of fermented juice. Total phenolic remained unchanged (585 mg/L) and was similar to that of original juice. The flavanones naringenin-7-O-glucoside, naringenin-7-O-rutinoside, hesperetin-7-O-rutinoside, hesperetin-7-O-glucoside and isosakuranetin-7-O-rutinoside, and the carotenoids karpoxanthin and isomer, neochrome, lutein, ζ-carotene, zeaxanthin, mutatoxanthin epimers, β-cryptoxanthin and auroxanthin epimers were the major compounds. Pasteurization produced a decrease in antioxidant capacity of fermented juice. However, TEAC (5.45 mM) and ORAC (6353 μM) values of orange beverage were similar to those of original orange juice. The novel orange beverage could be a valuable source of bioactive compounds with antioxidant capacity and exert potential beneficial effects.

Consumption of orange fermented beverage reduces cardiovascular risk factors in healthy mice.

The consumption of fruits prevents the risk of cardiovascular diseases. Alcoholic fermentation has been carried out in fruits resulting in products which provide high concentration of bioactive compounds and variable alcohol content. The aim of this study was to assess the potential beneficial effect of an orange beverage obtained by alcoholic fermentation and pasteurization of orange juice on cardiovascular risk biomarkers. For this purpose, four mice groups (n = 8) ingested orange beverage (equivalent volume to 250 mL/day in human), orange juice, alcoholic solution (at the proportional amount of orange beverage) or water during 12 weeks. The equivalent amount to double serving of orange beverage (500 mL/day) was administered to mice in a subsequent intervention, and a control group was also evaluated. Orange beverage consumption increased levels of glutathione and uric acid, improved lipid profile, decreased oxidized LDL and maintained levels of IL-6 and C-reactive protein. Synergistic effects between the bioactive compounds and the alcohol content of orange beverage may occur. The intake of double serving also increased antioxidant enzyme activities, bilirubin content and plasma antioxidant capacity. These results suggest that orange beverage may produce greater protection against cardiovascular risk factors than orange juice in healthy mice.

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.

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.

β-Cryptoxanthin is more bioavailable in humans from fermented orange juice than from orange juice

Carotenoids, especially β-cryptoxanthin, exert multiple biological activities in the organism. Various processing techniques can improve carotenoid bioavailability in relation to the food matrix. The study objective was to compare the bioavailability of carotenoids from orange juice (OJ) with that from a beverage obtained by alcoholic fermentation of orange juice (FOB). Seven volunteers were recruited for a randomized, controlled, and crossover study. Post-intake plasma carotenoid concentrations were measured by HPLC in the subjects at 0-8 h after their consumption of OJ or FOB. β-Cryptoxanthin and lutein absorption was significantly higher from FOB than from OJ, but no significant difference in zeaxanthin absorption was found. The mean baseline-corrected area under the concentration curve (AUC0-8 h) for β-cryptoxanthin, lutein and zeaxanthin was 24.6-, 1.3- and 4.65-fold larger, respectively, after FOB versus OJ consumption. This fermented orange beverage could be an abundant source of bioavailable carotenoids, and its regular consumption may exert healthy effects.

Effect of daily intake of a low-alcohol orange beverage on cardiovascular risk factors in hypercholesterolemic humans

Oxidative stress, inflammation status, endothelial dysfunction, and imbalanced lipid metabolism play a major role in cardiovascular disease. Bioactive compounds and moderate alcohol consumption have been associated with decreased cardiovascular risk. This study aimed to evaluate the effect on cardiovascular risk factors of a low-alcohol beverage derived from the alcoholic fermentation of orange juice. Eighteen individuals with moderately high cholesterol levels were randomly assigned to an experimental group (n = 9) who drank 500 mL/day of the orange beverage for 2 weeks or a control group (n = 9) who drank no orange beverage. Blood samples were drawn at the beginning and end of the study period. Consumption of the beverage significantly decreased plasma levels of total cholesterol (-15.6%), LDL-cholesterol (-17.8%), LDL-cholesterol/HDL-cholesterol ratio (-21.4%), catalase (-25.5%), TBARS (-42.6%), and sVCAM-1 (-5.8%). This orange beverage would have a potential capacity to improve cardiovascular risk in hypercholesterolemic humans, supporting its future consideration as a functional beverage.

Changes in orange juice (poly)phenol composition induced by controlled alcoholic fermentation

Orange juice is a rich source of bioactive compounds. Fermentation processes have been carried out in fruits, resulting in products with higher bioactive compound contents than the substrates. The aim of this study was to evaluate changes in phenolic acids, flavones and flavanone derivatives during the alcoholic fermentation process (15 days) in orange juice and to optimize the fermentation time. A total of 45 (poly)phenolic compounds were detected by UHPLC coupled with a linear trap quadrupole (LTQ) and Orbitrap Elite series mass analyser (UHPLC-Orbitrap-MS/MS). We tentatively identified 21 hydroxycinnamic acids, including ferulic acid, caffeic acid, and sinapic acid, in addition to 18 hydroxycinnamic acid derivatives (7 ferulic acid derivatives, 8 caffeic acid derivatives, 2 sinapic acid derivatives, a p-coumaric acid derivative) as well as 2 hydroxybenzoic acid derivatives, a hydroxypropionic acid derivative and other compounds (citric acid, quinic acid, 3 quinic acid derivatives) for the first time in fermented orange juice. In addition, 16 flavonoids, 7 flavanones (didymin, hesperidin, narirutin and 4 narirutin derivatives), 7 flavonols (kaempferol derivatives) and 2 flavones (diosmetin, vicenin-2) were putatively identified in fermented orange juice for the first time. Total hydroxycinnamic acid, benzoic acid, flavones and flavonol derivative contents showed significant increases (7.9, 4.7, 18.3 and 24.5%, respectively) on day 11 of fermentation relative to the original juice. The optimum time for the procedure was 11 days, after which the highest content of (poly)phenolic compounds was reached. The potential beverage produced by alcoholic fermentation of orange juice would exert greater health effects in humans than the substrate, derived from both the (poly)phenolic content and the low level of alcoholic content.