Pectin Influences the Absorption and Metabolism of Polyphenols from Blackcurrant and Green Tea in Rats.

Consumption of polyphenols and dietary fiber as part of a normal diet is beneficial to human health. In this study, we examined whether different amounts of dietary soluble fiber (pectin) affect the absorption and metabolism of polyphenols from blackcurrant and green tea in rats. After 28 days, the rats fed blackcurrant and green tea with pectin (4 or 8%) had significantly lower body weight gain and food intake compared to the rats fed a control diet. Rats fed a blackcurrant and green tea diet with 8% pectin had significantly higher fecal nitrogen output and lower protein digestibility. No polyphenols were observed in the urine, feces and plasma of rats fed the control diet. Parent catechins and flavonols were absent in urine obtained from all diet groups. Gallocatechin glucuronide was only observed in the plasma of rats fed the blackcurrant and green tea diet without pectin. Meanwhile, epicatechin and catechin gallate were present in the feces of rats fed a blackcurrant and green tea diet with and without 4% pectin. Pectin (4 or 8%) added to the blackcurrant and green tea diet increased the plasma antioxidant capacity in rats. Inclusion of pectin in the diet altered the host absorption and metabolism of polyphenols from blackcurrant and green tea.

Changes in markers of inflammation, antioxidant capacity and oxidative stress in smokers following consumption of milk, and milk supplemented with fruit and vegetable extracts and vitamin C.

Two milk-based beverages delivering twice the average daily antioxidant intake were formulated, based on synergistic combinations of fruit and vegetable extracts, and containing vitamin C (1.00 mg/ml) for shelf stability. Smokers (n = 42) consumed prototype milk A, B or non-supplemented milk (no extracts or vitamin C; 200 ml) twice daily for 6 weeks. Fasting and post-prandial (2 h after milk consumption) blood samples were collected at baseline and the end of each treatment. Non-supplemented milk significantly reduced fasting inflammatory cytokines (interleukin (IL) 6, IL-1ß, tumour necrosis factor-α) compared to baseline. Both supplemented milk-based beverages significantly increased fasting plasma vitamin C concentrations and antioxidant potential and decreased serum uric acid, compared to non-supplemented milk. The beverages did not induce post-prandial oxidative stress or inflammation. Therefore, regular consumption of the supplemented milks may confer health benefits because of increased antioxidant potential or through mechanisms resulting from increased vitamin C or decreased uric acid concentrations.

Inheritance and epistasis of loci influencing carotenoid content in petal and pollen color variants of california Poppy (Eschscholzia californica Cham.).

The model basal eudicot plant California poppy (Eschscholzia californica Cham.) typically has intense yellow to orange petals and orange pollen due to pigmentation by carotenoids. Flower color variants ranging from white to yellow and orange are common. We analyzed flower color inheritance in a diverse range of white and yellow color variants with reduced carotenoid content. The inheritance of the petal-pollen color of 24 variant flowers was investigated through complementation analysis by hybridization between different color variants and screening F(1), F(2), and BC(1) populations for segregation of petal-pollen color. All white and yellow flower color variants exhibited the pleiotropic effect with each mutation influencing both petal and pollen color, with both petal and pollen color phenotypes coinherited. A total of 5 complementation groups were identified with the color variants behaving as single recessive loci. Epistatic interactions among the loci were also identified. The white/yellow California poppy color variants described in this paper represent a unique genetic resource for analysis of carotenoid biosynthesis in this basal eudicot species.

Release of antioxidant components from tomatoes determined by an in vitro digestion method.

Tomatoes are an important source of antioxidant compounds, such as lycopene, phenolics and ascorbic acid. The main objective of this study was to determine the accessibility (availability for absorption) of the antioxidant compounds (total phenolics, total flavonoids, lycopene, ascorbic acid) and the antioxidant activity in fresh tomatoes of three cultivars (Excell, Tradiro and Flavourine) grown in New Zealand. The tomatoes were subjected to an in vitro digestion method, in which the pH, temperature, enzymes and chemical conditions were maintained according to human gastrointestinal conditions. The results showed that a high amount of the total phenolics and total flavonoids (71-77%) were released from tomatoes during digestion. However, only 3.2-4.5% of the total lycopene was released. No ascorbic acid could be detected after completion of in vitro digestion, probably due to degradation. After completion of digestion, the in vitro digestion extracts were found to have 45-50% antioxidant activity compared with the total antioxidant activity of fresh tomatoes (as measured by the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid diammonium salt radical decolourization assay). This study shows that the antioxidant components of tomatoes were affected by the in vitro digestion conditions depending on the type of compound. This in vitro digestion method gives an estimate of the release of antioxidant components in tomato, which may predict their in vivo behaviour.

An investigation of the antioxidant properties and colour of glasshouse grown tomatoes.

The colour and the antioxidant content of five different cultivars of tomatoes (Lycopersicon esculentum L.), grown in glasshouses using commercial hydroponic techniques, were measured in freshly harvested tomatoes and after 2 and 5 days of storage in the dark at 15 degrees C. The two cocktail cultivars of tomatoes, Aranca and Flavourine, were the smallest tomatoes but they contained higher dry matter contents compared with the three standard salad cultivars, Excell, Celero and Dutch Chaser. There were significant differences (P < 0.001) in lycopene (the major carotenoid), ascorbic acid and total antioxidant activity in the whole fruit of the five different cultivars evaluated at harvest, while the total phenolic contents were very similar. The lycopene levels of all the cultivars increased significantly (P < 0.001) after storage for 2 and 5 days at 15 degrees C. Overall, the total phenolic content of all the cultivars did not change appreciably after storage at 15 degrees C while the levels of ascorbic acid fell by 12.6% when stored for 5 days in the dark. There was a significant difference (P < 0.001) in the total antioxidant activity between the five different cultivars when freshly harvested; the highest levels of total antioxidant activity were observed in the two cocktail cultivars, Aranca and Flavourine. Antioxidant activity showed different patterns of change depending on cultivar. An increase in the total antioxidant values could be seen in cultivars Dutch chaser and Excell, after storage for 5 days at 15 degrees C. The total antioxidant activity values of Flavourine and Celero fell on storage while the values for stored Aranca were very similar to the values when freshly harvested. The skin colour, as shown by Commission Internationale l'Eclairage (CIE) L*a*b* values of each cultivar were markedly different at harvest even though each cultivar was harvested at the same maturity. The a* value of each cultivar increased significantly (P < 0.001) when they were stored in the dark, for either 2 or 5 days, at 15 degrees C. Regression analysis showed that overall there was no significant relationship (R(2) = 0.14) between the lycopene content and the a* value of all the tomatoes; however, when examined individually, the two cocktail tomatoes Aranca and Flavourine showed strong correlation-R(2) = 0.96 and R(2) = 0.97, respectively. Overall, the (a*/b*)(2) was the most reliable indicator of lycopene concentration (R(2) = 0.96) in the tomatoes examined in this study.