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Three commercial Saccharomyces cerevisiae yeast strains: Viniferm Revelación, Viniferm SV and Viniferm PDM were evaluated for the production of pomegranate wine from a juice coupage of the two well-known varieties Mollar and Wonderfull. Further malolactic fermentation was carried out spontaneously. The same fermentation patterns were observed for pH, titratable acidity, density, sugar consumption, and ethanol and glycerol production. Glucose was exhausted while fructose residues remained at the end of alcoholic fermentation. A high ethanol concentration (10.91 ± 0.27% v/v) in combination with 1.49 g/L glycerol was achieved. Citric acid concentration increased rapidly a 31.7%, malic acid disappeared as result of malolactic fermentation and the lactic acid levels reached values between 0.40 and 0.96 g/L. The analysis of CIEa parameter and total anthocyanin content highlights a lower degradation of monomeric anthocyanins during winemaking with Viniferm PDM yeast. The resulting wine retains a 34.5% of total anthocyanin content of pomegranate juice blend., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

To contribute for setting reference guideline for commercial juice extracted from the Spanish lemon varieties, chemical composition of 92 direct and 92 reconstituted samples were investigated. In direct lemon juice, titratable acidity was 52.4 g/L, being the citric acid the main component. Glucose, fructose and sucrose concentrations were 7.9, 7.3 and 4.5 g/L, respectively. Predominant mineral was potassium (1264.2mg/L), followed by phosphorous (306 mg/L), calcium (112 mg/L) and magnesium (92.6 mg/L). Hesperidin ranged from 257 to 484.8 mg/L, while water soluble pectins varied between 164.8 and 550 mg/L. Similar values were obtained in reconstituted lemon juice. There are different parameters that did not reach or exceeded the limits proposed by the European Association of the Industry of Juices and Nectars. These levels should be taken into account to modify the present reference guideline and that Spanish lemon juices are not discarded for to have lower or bigger values., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Anthocyanins are unstable compounds prone to degradation during storage of pomegranates juices, leading to disadvantageous color changes. Blending varietal pomegranate juices could be useful not only to preserve the genuine characteristics of fresh juices but also to study different factors affecting anthocyanin stability while maintaining to the utmost the matrix studied. The effects of critical factors such as anthocyanin concentration, pH, and endogenous ascorbic acid on pigment integrity were assessed through the study of the degradation kinetics of pomegranate phytochemicals in blended juices made from two distinct cultivars ('Wonderful' and 'Mollar de Elche'). Pigment concentration and pH were the factors affecting anthocyanin stability, whereas ascorbic acid did not alter the degradation of anthocyanins. These results contributed to the definition of the so-called "cultivar effect" and to preserving to a great extent the anthocyanin load and color characteristics of fresh varietal juices, avoiding phytochemical degradation and browning development during storage.

To contribute for setting reference guideline for commercial juice from the pomegranate variety 'Mollar', chemical composition of eighteen samples directly obtained and commercialised in 2012 from three different fruit juice factories was investigated. According to the findings, the relative density of direct pomegranate juices varied between 1.061 and 1.064, which correspond to 15.15 and 15.71°Brix; titratable acidity changed between 2.6 and 2.8g/L, citric acid between 2.3 and 2.8 g/L, l-malic acid in a range of 1.3-1.4 g/L, and d-isocitric acid at levels less than 20mg/L. Glucose values ranged from 61.4 to 65.0 g/L, whereas fructose displayed values between 65.3 and 68.0 g/L. The predominant mineral was potassium (2,400-2,900 mg/L), followed by phosphorous, magnesium, calcium and sodium at levels of 81-89 mg/L, 17.6-28.5mg/L, 5.8-7.5mg/L and 4.3-5.3mg/L, respectively. Chemical determinations of anthocyanin and ellagitannin profiles and amino acids contents were also carry out. Concentrations of anthocyanins in commercialised samples were Cy3,5dG (19.30 ± 3.47 mg/L), followed by Dp3,5dG (17.87 ± 6.74 mg/L) and Cy3G (12.91 ± 6.32 mg/L). Punicalagin levels ranged between 503.70 and 762.85 mg/L, punicalins between 239.9 and 364.5mg/L, and free ellagic acid level was typically between 268.67 and 389.64 mg/L. The juice samples exhibited high amount of total phenolics (1,136-3,581 mg/L) as well as high ABTS radical scavenging activity (18-31 mmol Trolox/L)., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Influence of processing and storage conditions on anthocyanin stability and antioxidant activity of clarified and cloudy juices from arils of the 'Mollar' pomegranate variety was studied. Clarification process reduced the content of total monomeric and individual anthocyanins, and increased the antioxidant activity of pomegranate juice. Thermal treatments (65 and 90 °C for 30 or 5 s) decreased the percentage of polymeric anthocyanin form, increasing on the contrary the monomeric one. In any case, storage temperature was the main factor affecting all the parameters tested. Cyanidin 3-O-glucoside (Cy3G) was more instable than delphinidin 3,5-di (Dp3,5dG) and cyaniding 3,5-diglucosides (Cy3,5dG). A linear relationship was observed between oxygen radical absorbance capacity (ORAC) and total monomeric anthocyanins, suggesting that they contributed strongly to the antioxidant capacity. Results presented in this study show that hurdle technology (heating plus refrigeration) may help to reduce anthocyanin degradation in pasteurized pomegranate juice, avoiding a dramatic impact on its colour and preserving the beneficial effects of this specific bioactive compounds on human health., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Juices prepared from arils of 'Mollar' pomegranates were analysed for naturally occurring microorganisms, CIE Lab colour parameters, total phenols, anthocyanins and punicalagins, ellagic acid content and antioxidant capacity before and after low-, mild- and high-temperature pasteurisations (LTPs, MTPs and HTPs): 65, 80 and 90 °C for 30 or 60s. Mean aerobic plate count (APC), yeast and mold count (YMC), and lactic acid bacteria (LAB) for fresh juices were 5.7, 5.36 and 4.0 log CFU/mL, respectively. MTPs and HTPs were sufficiently effective to decrease APCs to nil or negligible levels. An increase in CIE a values and decrease in CIE b values were the characteristic colour changes in heat-treated juices. The effect of pasteurisations showed that total phenols, punicalagins and ellagic acid were not much affected by thermal processing. Total anthocyanin content and antioxidant capacity were substantially and significantly influenced by the heat treatment applied. A linear relationship was observed between Trolox equivalent antioxidant capacity (TEAC) values and total anthocyanins, suggesting that they contributed strongly to the antioxidant capacity of pomegranate juice., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: The study of 15 pomegranate cultivars was carried out in order to demonstrate the wide diversity among the quality of Spanish pomegranates, and compared to 'Wonderful' cultivars, which are used worldwide for industrial purposes. Juice yield, quality parameters, organic acids and sugars, colour, vitamin C, ellagic acid, punicalagins, anthocyanins, total phenolic content, antioxidant capacity, and sensory properties were measured., Results: A considerable variation was found between 'Wonderful' and pomegranates of Spanish origin, according to both cluster analysis and principal component analysis. 'Wonderful' juices displayed large antioxidant activity and a polyphenol content with very high acidity. In contrast, 'Mollar de Elche' showed fewer anthocyanins although it had very superior organoleptical properties. In addition to a high content in ellagitannins, 'Valenciana' juices had exclusive colour parameters., Conclusion: These useful results can be employed by the juice processing industry to select those properties more interesting for the development of pomegranate juices that are organoleptically attractive and rich in bioactive compounds., (Copyright © 2011 Society of Chemical Industry.)

The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Non-thermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined. Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H2O2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C. Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.