Comparison of inorganic and organic nitrogen supplementation of grape juice - Effect on volatile composition and aroma profile of a Chardonnay wine fermented with Saccharomyces cerevisiae yeast

Inorganic nitrogen salts, and to a growing extent organic nitrogen preparations, are widely used to ameliorate a nitrogen deficiency in wine fermentation, but the impact of nitrogen supplementation on perceived wine sensory profile is essentially unknown. Supplementation of a low nitrogen Chardonnay grape juice with either ammonium nitrogen or combined amino acid and ammonium nitrogen showed that the type of nitrogen and concentration in the range 160-480 mg N/l had a substantial impact on the formation of yeast volatile compounds and perceived wine aroma. Addition of amino acid and ammonium nitrogen increased both acetate and medium chain fatty acid esters to a greater extent and decreased higher alcohols to a lesser extent than ammonium nitrogen alone whereas ammonium nitrogen substantially increased ethyl acetate and acetic acid. Low nitrogen wines were rated relatively low in floral/fruity aroma descriptors, while moderate nitrogen wines showed a good balance between desirable and less desirable attributes, whereas high nitrogen produced either an acetic/solvent character or highest ratings for floral/fruity attributes, depending on nitrogen type. These results show that amount and type of nitrogen supplement can substantially modulate Chardonnay wine volatiles composition and perceived aroma. \ua9 2011 Elsevier Ltd. All rights reserved

Chemical composition of rosehips from different Rosa species: an alternative source of antioxidants for the food industry

It is important to explore new sources of natural additives because the demand for these compounds by consumers is increasing. These products also provide health benefits and help in food preservation. An unexplored source of nutrients and antioxidant compounds is rosehip, the fleshy fruit of roses. This work compares the antioxidant compound (vitamin C, neutral phenols and acidic phenols) content of four Rosa species rosehips: R. pouzinii, R. corymbifera, R. glauca and R. canina from different geographical zones. Results show quantitative variability in ascorbic acids and neutral phenols content, and quantitative and qualitative differences in acidic phenol content, depending on species. Vitamin C concentration was highly variable depending on species, R. canina being the one with the highest concentration and R. pouzinii the one with the lowest content. Variability was found in total neutral polyphenols concentration and a correlation between freshness of the rosehips and concentration of neutral polyphenols was also found. Significant differences were found in the acidic phenols content among the studied species. Generally antioxidant activity was higher in the vitamin C fraction.This study was supported by the Proyecto ELENA [grant number EFA 220/11 ELENA].Peer reviewe

<i>Rosa canina</i> Extracts Have Antiproliferative and Antioxidant Effects on Caco-2 Human Colon Cancer - Fig 5

<p><b>Cell-cycle analysis after treatment with two concentrations</b> (a: 125 and b: 1000 mg/L) of Fr 1: total extract (1), Fr 2: vit. C (2), Fr 3: neutral polyphenols (3) and Fr 4: acid polyphenols or flavonoids (4) from rosehip (<i>Rosa canina</i> L) after 72 h. In control (C), the cells are without treatment. Cell cycle and DNA fragmentation were determined by propidium iodide staining. Percentages of G₁, S and G₂-phase are shown when possible. Experiments were performed in triplicate.</p

Summary of PD7 and TC7 colon cancer cells treated with two concentrations (a: 125 and b: 1000 mg/L) of rosehip (<i>Rosa canina</i> L) fractions after 72 h.

<p>In control, the cells are without treatment.</p

Chemical formula, concentration and total antioxidant capacity of the different extract fractions.

<p>Chemical formula, concentration and total antioxidant capacity of the different extract fractions.</p