Changes in lipid oxidation and related flesh qualities of white shrimp (Litopenaeus vannamei) during iced storage: Effects on the use of increasing ozone exposures
Authors: Okpala Charles Odilichukwu R. , Bono Gioacchino , Cannizzaro Leonardo , Jereb Patrizia 
Published: March 2016

For the first time, changes in lipid oxidation (peroxide value [PV], para‐anisidine value [p‐AnV], and total oxidation [Totox]) and related flesh qualities (titratable acidity [TA], water retention index [WRI] as well as volatile amines of total volatile basic nitrogen [TVB‐N], and trimethylamine nitrogen [TMA‐N]) of farm‐raised white shrimp (Litopenaeus vannamei) during iced storage of up to 11 days as affected by increasing ozone exposures were performed. Both fresh and ice‐stored sample situations were submitted to ozone exposures. Domestic facility commercially available that discharged ozone safely specifically was employed. Results indicated that PV, p‐AnV, Totox, and temporal PV/p‐AnV parameters at both ozone treatment situations would persist during the investigated storage. Increasing ozone exposures brought about some decreases in p‐AnV, Totox, and TVB‐N but less reliably in PV and TMA‐N. Most affected lipid oxidation and related flesh quality parameters would probably be p‐AnV and TVB‐N, respectively. Besides, the trends of TA and WRI over time seemed unclear. In this study, the domestic ozone facility appears promising to improve the quality of shrimp during iced storage. To help establish the ozone treatment approach that would improve the overall quality shelf of processed shrimp, further studies that involve other analyses such as browning development and sensorial acceptance are warranted and applicable to other economically important crustacea species.

Practical applications: Domestic facilities that safely discharge ozone for home use are increasingly marketed in many parts of the globe. On the other hand, lipid oxidation although responsible for rancidification and a process that significantly deters the overall fish product quality, remains among the many cold/iced storage concerns. Herein via domestic facility, increasing ozone exposures safely discharged onto farm‐raised shrimp has allowed for the study of lipid oxidation and related flesh qualities of processed samples during iced storage. This is the first report to demonstrate that increasing ozone exposures applied either on fresh and or ice‐stored shrimp situation(s) would result in different changes in PV, p‐AnV, Totox, TA, WRI, TVB‐N as well as TMA‐N. The data provided herein reveals the use of domestic ozone facility as promising candidate towards food safety, and increases both knowledge and understanding concerning changes in lipid oxidation and related flesh attributes of ozone‐treated crustacea.

During iced storage of up to 11 days, the evolution of tested parameters of ozone‐treated shrimp as it was affected by increasing ozone exposures showed that for lipid oxidation, the p‐anisidine value (p‐AnV) would appear the most affected probably because it would increase at a much faster rate to generate many secondary oxidation products fairly before the peroxide value (PV) attained the propagation reactions/periods. With respect to related flesh qualities, total volatile basic‐nitrogen (TVB‐N) would appear the most affected over the others namely, trimethylamine nitrogen (TMA‐N), titratable acidity (TA) as well as water retention index (WRI). Moreover, the TA might show a rather decreasing tendency. Amid the wave‐like pattern of TA and WRI that reflect the anticipated fluctuations/trends, the different measurement units of all these parameters put together can be apparently gauged by some proportional estimate.