Effect of fermentation and subsequent pasteurization processes on amino acids composition of orange juice

The fermentation of fruit produces significant changes in their nutritional composition. An orange beverage has been obtained from the controlled alcoholic fermentation and thermal pasteurization of orange juice. A study was performed to determine the influence of both processes on its amino acid profile. UHPLC-QqQ-MS/MS was used for the first time for analysis of orange juice samples. Out of 29 amino acids and derivatives identified, eight (ethanolamine, ornithine, phosphoethanolamine, α-amino-n-butyric acid, hydroxyproline, methylhistidine, citrulline, and cystathionine) have not previously been detected in orange juice. The amino acid profile of the orange juice was not modified by its processing, but total amino acid content of the juice (8194 mg/L) was significantly increased at 9 days of fermentation (13,324 mg/L). Although the pasteurization process produced partial amino acid degradation, the total amino acid content was higher in the final product (9265 mg/L) than in the original juice, enhancing its nutritional value.

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.

Two methods to determine the prevalence of overweight and obesity in 8-9 year-old-children in Seville, Spain

OBJECTIVE

The prevalence of overweight and obesity in Spanish children has increased considerably in the last decades. Obesity has been recognized as a public health problem in developed countries because its association with increased risk for several pathologies. Obesity in children and, specifically, in adolescents, is a major concern. Actually, in Spain, the prevalence rates of childhood overweight and obesity are among the highest in European countries. The objective of this study was to measure the prevalence of overweight and obesity in children from Seville.

METHOD

A cross-sectional study was performed on 990 children, aged 8-9 years old (51.5% 8-year old and 48.5% 9-year old). Overweight and obesity were defined according to two methods: Spanish standards, applying the criterion of BMI-specific percentiles for age and sex, and the international standards established by Cole et al. (IOTF).

RESULTS

A high prevalence of overweight (11%) and obesity (22%) was observed. The prevalence of obesity as well as the prevalence of overall excess weight was significantly higher in 9-year old children (28% and 41%, respectively) than in 8-year old children (17% and 27%, respectively).

CONCLUSION

The prevalence of overweight and obesity among Sevillian school children is high, and increases in the studied range of age.

Repeated red wine consumption and changes on plasma antioxidant capacity and endogenous antioxidants (uric acid and protein thiol groups)

This study aims to ascertain the in vivo antioxidant properties of red wine by determining how it affects antioxidant biomarkers (plasma antioxidant capacity (PAC) and endogenous antioxidants such as uric acid or protein thiol groups). Antioxidant biomarkers have been assessed in eight healthy human volunteers after repeated intakes of 300 mL of red wine every day for a week. During this intervention period, volunteers followed a low phenolic diet designed to prevent the phenolic compounds in wine from interfering with the phenolics from other foods or beverages. This diet was followed throughout the week that the volunteers drank wine and for another control week when they drank water. Biomarkers were determined before the subjects taking part in the study started the intervention period with red wine (Monastrell variety) and 1, 3, and 7 days after. PAC was evaluated by the Ferric Reducing Ability of Plasma assay (FRAP), and the Oxygen Radical Absorbance Capacity assay using fluorescein (ORAC-FL). In addition, the concentrations of endogenous antioxidants such as uric acid, albumin, bilirubin, and protein thiol groups were analyzed. The FRAP method shows that PAC increased after the week of wine consumption but decreased after the week without wine consumption. The uric acid concentration did not show any changes that were significantly different from our results in acute wine intake studies. Protein thiol groups decreased significantly (p < 0.05) with the low phenolic diet, but this decrease was not statistically significant if the diet was taken with red wine (p < 0.05).

Acute Intake of Red Wine does not Affect Antioxidant Enzymes Activities in Human Subjects

The purpose of this work was to test if the acute intake of red wine has an effect on the activity of antioxidant enzymes. Eight healthy, non-alcoholic, non-smoking human volunteers took part in the study. Ethical approval for the study was obtained from the Ethical Research Committee of the University Hospital Virgen Macarena from Seville. Each subject fasted 12–14 hours before the experiment started. Volunteers were asked to consume 300 mL of red wine in 5 minutes. Venous blood sample was obtained by antecubital venipuncture, with heparin vacutainer. Blood extraction was performed before wine ingestion (baseline value) and 30, 55, and 120 minutes after wine intake. Blood samples were immediately centrifuged at 12,000 × g for 3 minutes, avoiding unnecessary exposure to light. Antioxidant enzymes under study were: superoxide dismutase in erythrocytes, glutathione peroxidase in whole blood, and glutathione reductase in plasma. Determinations were performed spectrophotometrically with commercial available enzymatic kits. No statistically significant changes were observed on the activities of the enzymes superoxide dismutase, glutathione peroxidase, and glutathione reductase assayed at any of the times after wine intake. The intake of red wine did not modify the short-term activity of antioxidant enzymes.

Antioxidant capacity of plasma after red wine intake in human volunteers

Plasma antioxidant capacity (AC) has been assessed in eight healthy human volunteers after wine intake. Analytical methods used for evaluating AC included the ferric reducing ability of plasma (FRAP) and oxygen radical absorbance capacity using two different fluorescent probes, beta-phycoerythrin (ORAC-PE) and fluorescein (ORAC-FL). In addition, the concentrations of endogenous antioxidants such as uric acid, albumin, and bilirubin were determined. The suitability of analytical methods was evaluated with two different biological matrixes: plasma and serum. Plasma AC was determined before ingestion of 300 mL of red wine (baseline value) and 30, 55, and 120 min afterward. Maximum average increase in AC values was reached at 55 min. Plasma AC determined by ORAC-PE at time zero was significantly correlated with albumin concentration. Plasma AC determined with FRAP at time zero is well correlated with uric acid. Moreover, a good linear correlation was found between uric acid concentration and AC determined by FRAP in each volunteer. The maximum concentration of uric acid occurred after 55 min. Uric acid increase accounts for a nonnegligible part in FRAP values and must be evaluated when using this method for assessing AC in plasma.