Chemical and microbial stability of lumpfish (Cyclopterus lumpus) roe during refrigerated storage in acid-salt brines with or without antioxidants. Chemical and microbial stability of lumpfish (Cyclopterus lumpus) roe during refrigerated storage in acid-salt brines with or without antioxidants

When producing lightly preserved lumpfish (Cyclopterus lumpus) roe products an intermediate roe product is stored refrigerated for up to a year prior to final processing. This lengthy storage makes it susceptible to microbial growth and lipid oxidation potentially decreasing the sensory and nutritional quality, as lipid oxidation and the microbiota can produce rancid off-flavours and off-odours during storage. The aim of this study was to evaluate the effect of salt, organic acids, and antioxidants on preventing oxidative and microbial changes of an intermediate roe product during refrigerated (1.94±0.56°C) storage for one year. Freshly harvested roe was mixed with 8-12% (w/w) NaCl, and combinations of organic acids (benzoic acid, acetic acid, and lactic acid) with or without addition of one of two antioxidants i.e., Viv Ox 7.5 (IFF Inc.) or Herbalox D-450 (Kalsec Inc.). The high salt content and addition of organic acids ensure the microbial food safety of this intermediate product. Sampling was performed after 50, 80, 120, 210, 288 and 353 days of storage. The total aerobic counts increased to ~7 log CFU/g after 120 days of storage and the microbiota of all samples were dominated by yeast, specifically Debaromyces hansenii, identified through MALDI-TOF and metagenome sequencing. The addition of antioxidants reduced formation of lipid hydroperoxides (PV) and thiobarbituric acid reactive substances (TBARS). The results for the formation of volatile compounds showed that both Herbalox D-450 and VivOx 7.5 were able to reduce the formation of 1-penten-3-ol, whereas VivOx 7.5 was not able to inhibit the formation of pentanal. The formation of 2-methyl-butanal and 3-methyl-butanal appeared related to the metabolism of the microbiota present in samples without benzoic acid. The use of Herbalox D-450 was shown to be the overall most efficient in reducing oxidative changes and the effect of organic acids on oxidative alterations remained inconclusive.