Biomedical subjects

Jean-Xavier Guinard

Publications and source records attributed to Jean-Xavier Guinard.

3 recordsLinked to original sources

PubMed2004

Yield effects on 2-methoxy-3-isobutylpyrazine concentration in cabernet sauvignon using a solid phase microextraction gas chromatography/mass spectrometry method.

A rapid and automated solid phase microextraction (SPME) stable isotope dilution gas chromatography/mass spectrometry (GC-MS) method for 2-methoxy-3-isobutylpyrazine (MIBP) quantification in red wine was developed. Wines with 30% (w/v) NaCl and 2-methoxy-(2)H(3)-3-isobutylpyrazine internal standard were sampled with a 2 cm divinylbenzene/carboxen/poly(dimethylsiloxane) SPME fiber for 30 min at 40 degrees C and analyzed by GC-MS. The method was used to measure MIBP concentrations in Cabernet Sauvignon wines that were produced from six winter pruning treatments over two vintages. MIBP concentrations were significantly negatively correlated with buds per vine. In addition, the MIBP concentration was directly related to sensory vegetal intensity ratings obtained by descriptive analysis.

Gas Chromatography-Mass Spectrometry↗

PubMed2003

Novel approaches and application of contemporary sensory evaluation practices in iron fortification programs.

Iron deficiency is the leading nutritional deficiency in the U.S. and the rest of the world, with its highest prevalences in the developing world. Iron fortification of food has been proposed as a strategy to reduce the high prevalence of iron deficiency. Poor consumer acceptance, unacceptable taste, and discoloration of the iron-fortified foods have been frequently listed as causes of unsuccessful iron fortification programs. An excellent prospect for improving consumer acceptance of iron-fortified foods is the incorporation of a thorough, organized, and unified approach to sensory evaluation practices into iron fortification programs for product optimization. The information gained from systematic sensory evaluation allows for the manipulation of the sensory attributes, and thus improvement of the sensory properties of the fortified food. However, iron fortification programs have not systematically measured the effect of fortification on the sensory quality of the food. Because sensory evaluation is an important criterion in successful iron fortification, an integrated approach is necessary. Therefore, nutritionists and sensory scientists should work closely with each other to select the most suitable sensory tests and methods. The objectives of this article are to: (1) critically review and discuss some traditional and contemporary approaches and applications of sensory evaluation practices in iron fortification programs, and (2) demonstrate the importance of incorporating a multidisciplinary, systematic sensory evaluation approach in iron fortification programs.

Adult↗

PubMed2002

Relation between PROP (6-n-propylthiouracil) taster status, taste anatomy and dietary intake measures for young men and women.

Previous studies have related 6-n-propylthiouracil (PROP) taster status to preference for, and consumption of various (bitter-tasting) foods recognized for their cancer-preventive properties. The aim of this study was to examine PROP taster status in relation to general measures of dietary intake as well as the consumption of specific food groups. College students (n=183) were classified as non-tasters (n=49), medium tasters (n=89) and supertasters (n=45) of PROP based on intensity ratings of NaCl and PROP solutions. Dietary intake measures were derived from a food frequency questionnaire and body mass indices (BMI) were derived from self-reported height and weight. Supertasters had higher fungiform papillae counts on the anterior tongue than tasters and non-tasters, yet the distributions of papillae counts overlapped across PROP taster groups. No significant differences were found for BMI values and energy intake among taster groups. PROP-tasting women derived a greater percentage of their dietary energy from fat, and consumed less fruit than non-tasters. PROP supertasters did not differ from tasters and non-tasters in intake of bitter fruits, vegetables or beverages except for a lesser intake of green salad. The hypothesis that PROP supertasters, through heightened sensitivity to, and avoidance of, bitter-tasting fruits, vegetables and other foods with antioxidant properties, may therefore be at increased risk for diet-linked diseases such as cancer, is not supported by these findings.

Adolescent↗