Characterization of two Varieties of Patagonian Hops

C.M. VAN BAREN; P. DI LEO LIRA; D. RETTA; A. TROCHINE; J. BURINI; G. REINER; D. LIBKIND

Niza

Simposio; 47th International Symposium on Essential Oils (ISEO2016); 2016

p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; text-align: justify; }p.western { font-family: "Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "MS Mincho","MS Gothic",serif; font-size: 12pt; }p.ctl { font-family: "Times New Roman",serif; font-size: 12pt; }a:link { color: rgb(0, 0, 255); }Hops flowers are used as ingredients in brewing to contribute to thebitterness and flavour. The main chemical components responsible forthe aroma (and partly for the flavour) are part of the essential oilscontained in the lupulin glands and the content of α-acids. Theyield and chemical composition of essential oils may vary fordifferent varieties of cultivar and because of external influences onthe hop plant. Nowadays, new aromatic profiles in hops areprized as a way to produce novel types of beer. In Argentina,?Nugget? is a variety characterized among the bitter ones (highhumulones) and ?Cascade? is more aromatic than bitter. For thisreason, the volatile components of these varieties of hop cultivatedin ?El Bolsón? in the Patagonia, Argentina, were isolated byhydrodistillation and analyzed by GC-FID-MS. In addition,determination of α and β acids, as well as the α/β ratio and theHSI (Hops Storage Index) were donefollowing the ASBC Methods. Besides,performance data comparing "flowers" and "pellets"for each variety is presented.Essential oil yields were higher for thevariety ?Nugget? and always higherfor flowers than for pellets. The overall volatile composition of the?Cascade? and ?Nugget? varieties tested were similar to thosefound in other regions where it is cultivated, as USA and Spain.However, components as geranyl acetate, cis-α-bergamotene,neryl isobutanoate and E--farnesenewere detected in larger percentages or exclusively in the ?Cascade?variety; meanwhile, methyl nonanoate, 2-tridecanone and4,7(11)-amorphadiene were only present in the ?Nugget? variety.Values of α-acids in ?Cascade? were greater than for otherproducing regions, like USA or New Zealand, though the α/β ratioobtained is greater with a value of 1.5 for the Patagonian varietyregarding the 0.9-1.1 reported.Meanwhile, the α and β acids valuesfor the Patagonian ?Nugget?, as well as the α/β ratio, weresimilar to those reported for other producing regions (between 11-15%w/w). By comparing the hop flowers withpellets, values of α and β-acids were lower for pellets.A complete comparative discussion about thevalues obtained in these Patagonian hops referred to other producingregions, is given.