A chemometric approach to compare Portuguese native hops with worldwide commercial varieties

Abstract

A diversity of native hops can be found in Portugal, but little is known concerning their volatile and sensory profiles. Nowadays, the exponential growth of the craft beer sector and the preference for more flavoured beers promote the research of unexplored wild hops that have the advantage of being well adapted to the Portuguese edaphoclimatic conditions. Therefore, the goal of this study was to characterize the volatile profile of 75 native Portuguese hops and compare with 34 commercial varieties by means of headspace solid‐phase microextraction gas chromatography/mass spectrometry (HS‐SPME‐GC/MS), in order to select those that present similarities with commercialized hops and confirm by check‐all‐that‐apply (CATA) analysis if they present similar organoleptic characteristics. Due to the complexity of hop volatile profile and the great number of samples analysed, robust chemometric treatment of chromatographic and sensorial data was required to make reliable conclusions. Twelve Portuguese hops present a volatile profile and sensory characteristics quite similar to some commercial varieties, because 11 Portuguese hops were grouped with the European varieties Challenger, Hallertauer Magnum and Perle, both in volatile profile and sensory analysis and one clustered with American registered varieties.

Characterization of Wild Corsican Hops and Assessment of the Performances of German Hops in Corsican Environmental Conditions through a Multidisciplinary Approach

“…These data, according to a previous study on wild hops [24], demonstrated the discrimination power of the aromatic profile of hops. At the same time, these results are in partial disagreement with another study [13] where, among 75 Portuguese native hops studied, similarities were found between the aromatic profiles of 11 wild hops and 4 cultivars. As our results suggest, the essential oils of the accessions located in coastal areas of the island (Patrimonio, Ajaccio, Oletta) are similar (13% dissimilarity), unlike the one located in Corte far from the coast (40% dissimilarity).…”

“…These botanical varieties differ in their chemical composition, genetics, and morphology. For plants, and specifically for hop genotypes differentiation, it is possible to use morphological, chemical and or genetic markers [8][9][10][11][12][13]. The use of morphological or chemical markers alone make the differentiation among the studied genotypes not simple because of the small differences often present within the species, and because morphological and chemical characters are often dependent on biotic and abiotic factors and on plant age [14][15][16][17][18][19].…”

Optimized Supercritical CO2 Extraction Enhances the Recovery of Valuable Lipophilic Antioxidants and Other Constituents from Dual-Purpose Hop (Humulus lupulus L.) Variety Ella

“…Working conditions were: desorption time 5 min; oven temperature started at 40 • C (hold 1 min) and ramped to 250 • C at 7 • C/min rate (hold 1 min); modulator offset temperature 15 • C; transfer line to MSD 250 • C; the GC injector port temperature set at 150 • C then ramped to 250 • C at 720 • C/min; carrier gas (He) 1 mL/min; split ratio 1:20; TOF-MS acquisition rate 10 spectra/s, mass range 30-550 m/z units; detector voltage 1550 V; ion source temperature 250 • C. Data from the GC×GC-TOFMS system were collected by ChromaTOF software v.4.22 (LECO) after a solvent peak delay of 360 s. Volatile compounds were identified by comparing their mass spectra with the Adams, NIST, MainLib and Replib mass spectral libraries (acceptable matches: signal-to-noise ratio >50 and similarity >750). The linear retention indexes (LRI) were calculated using the retention times of C 7 -C 30 n-alkanes series and further compared with previously published data in literature [24][25][26][27][28][29][30], when available. The results were expressed as GC peak area arbitrary units × 10 7 (further abbreviated as AU) and percentage (%) of the total GC peak area.…”

Sensory and Olfactometry Chemometrics as Valuable Tools for Assessing Hops’ Aroma Impact on Dry-Hopped Beers: A Study with Wild Portuguese Genotypes

“…Hops were presented in original stored vacuum bags. The Check-All-That-Apply test (CATA) with a semi-trained panel of 25 individuals was performed to evaluate the hops’ odour [ 6 ]. In the training sessions, standard references and known commercial varieties of hops ( Table 1 ) were presented to panellists to define hop attributes.…”

“…Special attention is given to wild, unexplored plants and to their potential application in breeding programs, which means diverse genetic and environmental effects on hops composition and, consequently, a great number of hops to be analysed for their brewing properties. In Portugal, several wild hop populations were identified, revealing a large variability in morphologic [ 5 ], volatile profile and sensory characterization [ 6 ]. However, no published studies were found concerning the impact of Portuguese wild hops on the aromatic characteristics of beer.…”