Volatile compounds and odour characteristics during long-term storage of kombu seaweed (Laminaria ochroleuca) preserved by high pressure processing, freezing and salting

• Published in: Food science & technology Vol. 118; p. 108710
• Main Authors: López-Pérez, Olga, del Olmo, Ana, Picon, Antonia, Nuñez, Manuel
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2020
• Subjects: High pressure processing; Refrigerated kombu seaweed; Salting; Shelf-life; Volatile compounds; Shelf-life; Volatile compounds; Refrigerated kombu seaweed; High pressure processing; Salting
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2019.108710

Kombu seaweed (Laminaria ochroleuca) was preserved by refrigeration at 5 °C (control), by high pressure processing (HPP) at 400 or 600 MPa for 5 min followed by refrigeration at 5 °C, or by freezing at −24 °C. Those treatments were applied to both unsalted and salted kombu samples, which were stored for 180 days. One hundred three compounds belonging to 16 chemical groups were identified in the volatile fraction of kombu. Groups including the highest number of volatile compounds were alcohols (24), aldehydes (13), ketones (10), alkanes (9), haloalkanes (9), alkenes (8) and acids (7). HPP lowered the levels of acids, aldehydes, ketones, lactones + ionones, pyranones and terpenes + terpenoids, and increased alkenes and furans. Freezing lowered the levels of alkanes, aromatic hydrocarbons, pyranones and terpenes + terpenoids, and increased aldehydes, haloalkanes and thiazoles. Salting lowered the levels of pyranones, and increased acids, alcohols, aldehydes, alkanes, aromatic hydrocarbons, furans, haloalkanes, lactones + ionones and thiazoles. Control kombu odour acceptance fell below rejection level on day 60 while HPP-treated kombu showed the highest odour acceptance until day 180. Frozen kombu exhibited abnormal odours whereas salted kombu maintained acceptable odour characteristics. Principal component analysis associated the most relevant groups of volatile compounds with kombu microbiological and sensory characteristics.
•One hundred three compounds were identified in the volatile fraction of fresh kombu.•High pressure processing lowered the levels of six groups of volatile compounds.•Shelf life of control kombu at 5 °C was under 60 days due to low odour acceptance.•High pressure processing preserved kombu odour characteristics at 5 °C for 180 days.