Determination of the botanical origin of hops (Humulus lupulusL.) using different analytical techniques in combination with statistical methods

Abstract

Beer flavour and aroma depend mostly on the hop variety used in the brewing process. For this reason it is of crucial importance for brewers to be certain about the botanical origin of the hop variety. Metabolic fingerprinting is one of the approaches that can be used for determination of the botanical origin of many agricultural and food products. The aim of the current work was to differentiate between the five most important hop varieties in Slovenia. Gas chromatography, high-performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy were carried out in combination with three different chemometric methodsprincipal component analysis, regularized discriminant analysis and hierarchical clusteringon 121 hop samples. The chemometric classification of the hop varieties was obtained with nearly 100% success. The best results were obtained with GC and HPLC data, within one year of harvesting.

Metabolomics as a marketing tool for geographical indication products: a literature review

“…Analytical, spectrometric, and computational techniques used in metabolomic studies enable the identification of particular characteristics and nuances of metabolites of plants belonging to the same species, revealing the consequences of region-specific natural resources and human processes involved in the cultivation system. A great variety of agricultural products and foodstuff have already been investigated using metabolomics, such as olive oils [ 46 ], wines [ 64 ], coffee [ 5 ], cheeses [ 91 ], hops [ 72 ], nuts [ 13 ], and vinegars [ 104 ]. Furthermore, globalization and smaller economic borders increase the importance of traceability for products with certification of origin as a way to fight fraud and adulteration of certain products [ 88 ].…”

Gas-phase volatilomic approaches for quality control of brewing hops based on simultaneous GC-MS-IMS and machine learning

“…Multivariate data analysis has already been applied in the quality control of hop, mostly for authenticity control [14,15]. Ocvirk et al used multivariate cluster analysis (CA) for the varietal classification of five different hop varieties concerning the bitter acid and essential oil composition [14] that are known to be characteristic for each hop cultivar [12,13,16]. Kovačevič et al also used GC-FID combined with principal component analysis (PCA) and CA for the verification of hop varieties [15].…”

Single Nucleotide Polymorphisms and Biochemical Markers As Complementary Tools To Characterize Hops (Humulus lupulus L.) in Brewing Practice

“…Hop is a labor-intensive crop for growers and a relatively expensive raw material for brewers. The specific taste and aroma profiles of beers depend on the hop variety or combination of varieties used and the character of the addition during the brewing process. − Therefore, quality control of a given hop batch supplied to the brewer is essential, especially on varietal origin. , Distinction between varieties can be based on plant morphological characteristics and the distinctive profile of biochemical components such as hop bitter acids, essential oils, or polyphenols. − However, the varietal origin of processed hop products used in brewing practice can hardly be determined unequivocally by observation of their external appearance, and in current brewing practice, determination of varietal origin of hop batches is mostly based on biochemical markers such as the content of hop bitter acids and essential oils. ,, This is, however, not straightforward because the biochemical profile of hop batches can vary by function of growth location and processing and storage conditions.…”