Georgios Koutsidis

The effect of Maillard reaction products and yeast strain on the synthesis of key higher alcohols and esters in beer fermentations

The effect of Maillard reaction products (MRPs), formed during the production of dark malts, on the synthesis of higher alcohols and esters in beer fermentations was investigated by headspace solid-phase microextraction GC-MS. Higher alcohol levels were significantly (p<0.05) higher in dark malt fermentations, while the synthesis of esters was inhibited, due to possible suppression of enzyme activity and/or gene expression linked to ester synthesis. Yeast strain also affected flavour synthesis with Saccharomyces cerevisiae strain A01 producing considerably lower levels of higher alcohols and esters than S288c and L04. S288c produced approximately double the higher alcohol levels and around twenty times more esters compared to L04. Further investigations into malt type-yeast strain interactions in relation to flavour development are required to gain better understanding of flavour synthesis that could assist in the development of new products and reduce R&D costs for the industry.

Lycopene and Tomato and risk of cardiovascular diseases: A systematic review and meta-analysis of epidemiological evidence

ABSTRACT Background and aims: Worldwide, cardiovascular diseases (CVDs) remains as the main cause of mortality. Observational studies supports an association between intake of tomato products or lycopene with a reduced CVDs risk. Our aim was to undertake a systematic review and meta-analysis of the evidence on the topic. Methods: Medline, Web of Science, and Scopus were searched from inception until July 2017. We included longitudinal and cross-sectional studies reporting associations between lycopene and tomato consumption and cardiovascular morbidity and mortality among adult subjects. Random-effects models were used to determine the pooled effect sizes. Results: Twenty-eight publications met our inclusion criteria and 25 studies provided quantitative data for meta-analysis. Results showed that individuals in the highest consumption category of, or with the highest serum concentration of, lycopene had significantly lower risk of stroke (hazard ratio (HR) 0.74, 0.62–0.89, p = 0.02; I2 = 32) and CVDs (HR 0.86, 0.77–0.95, p = 0.003; I2 = 0). In addition, individuals categorised in the highest serum concentration of lycopene also had significantly lower risk of mortality (HR 0.63, 0.49–0.81, p<0.001; I2 = 46). Lycopene was not significantly associated with myocardial infarction, while scarce evidence on the association of lycopene with atherosclerosis, congestive heart failure, or atrial fibrillation was evident. Evidence from three studies suggested that higher intakes of tomato were associated with non-significantly lower stroke, CVDs and CHD. Conclusions: This comprehensive meta-analysis suggests that high-intakes or high-serum concentration of lycopene are associated with significant reductions in the risk of stroke (26%), mortality (37%) and CVDs (14%).

Odour characteristics of seafood flavour formulations produced with fish by-products incorporating EPA, DHA and fish oil.

Thermal degradation of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids was investigated. As a novelty, EPA, DHA or fish oil (FO) were incorporated as ω-fatty acid sources into model systems containing fish powder produced via Maillard reactions. Aroma composition of the resulting products was determined and complemented with sensory evaluation. Heating of the oils led to a fast decrease of both, EPA and DHA, and to the development of characteristic volatile compounds including hexanal, 2,4-heptadienal and 4-heptenal, the most abundant being (E,E)-2,4-heptadienal (132±44-329±122μmol/g). EPA and DHA addition to the model systems increased the concentration of these characteristic volatile compounds. However, it did not have a considerable impact on the development of characteristic Maillard reaction products, such as pyrazines and some aldehydes. Finally, the results of the sensory evaluation illustrated that panellists would chose samples fortified with FO as the ones with a more pleasant aroma.

Sensory analysis and aroma compounds of buckwheat containing products—a review

ABSTRACT Buckwheat is a rich source of starch, proteins, minerals and antioxidants, and as such has become a popular functional ingredient incorporated in diverse recipes/products with particular use in the gluten free market. Due to the absence of gluten, application of buckwheat or buckwheat derived ingredients in this particular food sector has increased significantly over recent years with many buckwheat-based products appearing globally. Sensory analysis is an integral part of the development of products that fulfill consumer expectations. Therefore, investigations on the incorporation of health promoting functional ingredients such as buckwheat into traditional recipes are often complemented by the evaluation of appearance, aroma, taste and texture as well as overall quality through standardized procedures involving trained judges or consumer panels. Aroma is of particular importance in driving consumer preference and its sensory assessment is often complemented with analytical workflows aiming to isolate and determine the concentration of volatile compounds in food and understand the effect of food components on the overall aroma intensity and/or perception of the final product. The present manuscript provides a review of recent advances and knowledge on the sensory characteristics, consumer preference and volatile compound analysis of buckwheat and buckwheat based products.