Engineering a fermenting yeast able to produce the fragrant ß-ionone apocarotenoid for enhanced aroma properties in wine.

Wine is composed of multitudinous flavour components and volatile organic compounds that provide this beverage with its attractive properties of taste and aroma. The perceived quality of a wine can be attributed to the absolute and relative concentrations of favourable aroma compounds; hence, increasing the detectable levels of an attractive aroma, such as ß-ionone with its violet and berry notes, can improve the organoleptic qualities of given wine styles. We here describe the generation of a new grape-must fermenting strain of Saccharomyces cerevisiae that is capable of releasing ß-ionone through the heterologous expression of both the enzyme carotenoid cleavage dioxygenase 1 (CCD1) and its substrate, ß-carotene. Haploid laboratory strains of S. cerevisiae were constructed with and without integrated carotenogenic genes and transformed with a plasmid containing the genes of CCD1. These strains were then mated with a sporulated diploid wine industry yeast, VIN13, and four resultant crosses-designated MQ01-MQ04-which were capable of fermenting the must to dryness were compared for their ability to release ß-ionone. Analyses of their fermentation products showed that the MQ01 strain produced a high level of ß-ionone and offers a fermenting hybrid yeast with the potential to enhance the organoleptic qualities of wine.

The Sensory Significance of Apocarotenoids in Wine: Importance of Carotenoid Cleavage Dioxygenase 1 (CCD1) in the Production of ß-Ionone.

Olfactory cues are key drivers of our multisensory experiences of food and drink. For example, our perception and enjoyment of the flavour and taste of a wine is primarily steered by its aroma. Making sense of the underlying smells that drive consumer preferences is integral to product innovation as a vital source of competitive advantage in the marketplace, which explains the intense interest in the olfactory component of flavour and the sensory significance of individual compounds, such as one of the most important apocarotenoids for the bouquet of wine, ß-ionone (violet and woody notes). ß-Ionone is formed directly from ß-carotene as a by-product of the actions of carotenoid cleavage dioxygenases (CCDs). The biological production of CCDs in microbial cell factories is one way that important aroma compounds can be generated on a large scale and with reduced costs, while retaining the 'natural' moniker. The CCD family includes the CCD1, CCD2, CCD4, CCD7 and CCD8; however, the functions, co-dependency and interactions of these CCDs remain to be fully elucidated. Here, we review the classification, actions and biotechnology of CCDs, particularly CCD1 and its action on ß-carotene to produce the aromatic apocarotenoid ß-ionone.

Effect of supervised, periodized exercise training vs. self-directed training on lean body mass and other fitness variables in health club members.

Conventional wisdom suggests that exercise training with a personal trainer (PTr) is more beneficial for improving health-related fitness than training alone. However, there are no published data that confirm whether fitness club members who exercise with a PTr in the fitness club setting obtain superior results compared with self-directed training. We hypothesized that club members randomized to receive an evidence-based training program would accrue greater improvements in lean body mass (LBM) and other fitness measures than members randomized to self-training. Men, aged 30-44 years, who were members of a single Southern California fitness club were randomized to exercise with a PTr administering a nonlinear periodized training program (TRAINED, N = 17) or to self-directed training (SELF, N = 17); both groups trained 3 days per week for 12 weeks. Lean body mass was determined by dual-energy x-ray absorptiometry. Secondary outcomes included muscle strength 1 repetition maximum (1RM), leg power (vertical jump), and aerobic capacity (V[Combining Dot Above]O2max). TRAINED individuals increased LBM by 1.3 (0.4) kg, mean (SEM) vs. no change in SELF, p = 0.029. Similarly, significantly greater improvements were seen for TRAINED vs. SELF in chest press strength (42 vs. 19%; p = 0.003), peak leg power (6 vs. 0.6%; p < 0.0001), and V[Combining Dot Above]O2max (7 vs. -0.3%; p = 0.01). Leg press strength improved 38 and 25% in TRAINED and SELF, respectively (p = 0.14). We have demonstrated for the first time in a fitness club setting that members whose training is directed by well-qualified PTrs administering evidence-based training regimens achieve significantly greater improvements in LBM and other dimensions of fitness than members who direct their own training.