A preliminary investigation into differences in hops’ aroma attributes

Climate-induced decline in the quality and quantity of European hops calls for immediate adaptation measures

A recent rise in the global brewery sector has increased the demand for high-quality, late summer hops. The effects of ongoing and predicted climate change on the yield and aroma of hops, however, remain largely unknown. Here, we combine meteorological measurements and model projections to assess the climate sensitivity of the yield, alpha content and cone development of European hops between 1970 and 2050 CE, when temperature increases by 1.4 °C and precipitation decreases by 24 mm. Accounting for almost 90% of all hop-growing regions, our results from Germany, the Czech Republic and Slovenia show that hop ripening started approximately 20 days earlier, production declined by almost 0.2 t/ha/year, and the alpha content decreased by circa 0.6% when comparing data before and after 1994 CE. A predicted decline in hop yield and alpha content of 4-18% and 20-31% by 2050 CE, respectively, calls for immediate adaptation measures to stabilize an ever-growing global sector.

Aroma characterization of regional Cascade and Chinook hops (Humulus lupulus L.)

Aroma compounds in Cascade and Chinook hops harvested from multiple Virginia locations were identified by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and aroma extract dilution analysis (AEDA). Selected aroma compounds were quantitated by combination of stable isotope dilution analysis (SIDA) and standard addition method (SAM). A total of 33 aroma-active compounds were detected in five samples with β-myrcene, methyl octanoate, geraniol and linalool being the predominant compounds based on their high flavor dilution (FD) factors and odor activity values (OAVs). L-Calamenene and germacrene B was the major characteristic component unique to Cascade and Chinook variety, respectively. Principal component analysis (PCA) showed distinctive aroma profiles for all samples except for Blacksburg and Petersburg Cascade. Hierarchical cluster analysis (HCA) reflected the higher contents of most aroma-active compounds in Meadowview Cascade and Chinook when compared to their counterparts. The significant variations suggested the potential influences of environmental factors and agronomic practices on hop aroma quality.

Investigating caloric values and consumers' perceptions of Nova Scotia rosé wines

In Nova Scotia, Canada, wine production has been increasing, yet little research has been done to identify and classify the sensory properties of Nova Scotia (NS) rosé wines. The first objective of this study was to identify the attributes consumers use to describe NS rosé wines. The second aim was to identify if presenting caloric labels on wine bottles would impact consumers' sensory perception. The first trial asked consumers (n = 85) to use projective mapping (PM) and ultra-flash profiling (UFP) to describe NS rosé wines (n = 8). In the second trial, consumers (n = 260) were asked to complete a check-all-that-apply (CATA) questionnaire, using the most frequently cited attributes from the PM and UFP trial, and to score their liking on 9-point hedonic scales (n = 4). Each wine was evaluated without a label and with each of the four fabricated caloric values, low (15 Calories), normal (100 Calories), high (180 Calories), and highest (240 Calories) per one serving. The projective mapping trial found that there were two main categories of rosé wines identified by consumers, those with fruit flavour and those lacking in fruit flavour. The penalty analysis from the consumer trial demonstrated that fruit attributes drove consumer liking of rosé wine. The consumer trial also displayed no significant difference between the caloric value and liking of rosé wines, even when the results were separated based on gender. Therefore, the findings support that the disclosure of caloric values on bottles will not influence consumers' sensory perceptions of wine. For future research, complete nutrition labels and not just calories alone should be used to determine their effect on consumers' perceptions.