Pascalization, alternative way of postharvest hops processing
Pascalization is an innovative technology used in the food industry. It comprises a high pressure treatment of foods. This technology is also known under the acronym HPP (high pressure processing) since the 19th century. Even with careful drying of hop cones, a part of labile compounds, with demonstrated or potential health effects, is lost. Therefore, a patented process for the preservation of fresh hop under high pressure was developed and 3-year tests on three cultivars of hops, including storage, were made. The homogenate of non-dried hop cones treated with high pressure has in comparison with dried hops higher content of beta acids, essential oils, total polyphenols, xanthohumol and shows a higher antiradical activity. Shelf life of homogenate packaged in barrier packaging is comparable to identically packaged dried hops. High pressure treatment ensures microbiological purity and stability of the homogenate. In the pilot brewing trials (200 L) of pale lager, the homogenate was applied in whirlpool or as the last kettle dose. Compared with dried hops, beer had a higher content of alpha acids, iso-alpha acids and prenylflavonoids, presumably due to the faster release of undried matrix and a different composition of essential oils. Beers had slightly higher astringency and slower bitterness decay. The homogenate was applied in the development of a low-alcoholic beer and unfermented hopped wort beverage. Relatively high content of prenylflavonoids with acceptable sensorial quality of beverages was achieved. The homogenate was tested for antimicrobial activity against the causative agent of gastric ulcer disease, Helicobacter pylori. Laboratory tests demonstrated reliable inhibitory effect considerably higher than the effect of the beta or alpha acids. Homogenates of fresh hops may find application in manufacturing of special, e.g., dry hopped beers and food supplements. Based on a license, chocolate and jelly confectionery containing hop homogenates are being produced by two companies.
Mikyška, A., Krofta, K., Houška, M. and Čermák, P. (2019). Pascalization, alternative way of postharvest hops processing. Acta Hortic. 1236, 23-30
hop secondary metabolites, drying, hop oils, alpha acids, food supplements