Combined effect of brine salting and high-hydrostatic-pressure processing to improve the microbial quality and physicochemical properties of milkfish fillet

Authors: TSAI, Y-H - National Kaohsiung University Of Science And Technology; KUNG, H-F - Tajen University; LIN, C-S - Yuan-Pei University Of Medical Technology; HWANG, C-C - Yu-Da University Of Science And Technology; LIU, S-S - National Kaohsiung University Of Science And Technology; HUANG, C-Y - National Kaohsiung University Of Science And Technology; CHANG, SAM - Mississippi State University; LEE, Y-C - National Kaohsiung University Of Science And Technology

Submitted to: International Journal of Food Properties
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2022
Publication Date: 4/13/2022
Citation: Tsai, Y., Kung, H., Lin, C., Hwang, C., Liu, S., Huang, C., Chang, S.K., Lee, Y. 2022. Combined effect of brine salting and high-hydrostatic-pressure processing to improve the microbial quality and physicochemical properties of milkfish fillet. International Journal of Food Properties. 25:872-884. https://doi.org/10.1080/10942912.2022.2066120.
DOI: https://doi.org/10.1080/10942912.2022.2066120

Interpretive Summary: Fresh fish fillet has a limited shelf-life due to bacteria growth and enzymatic-chemical reactions. In order to extend shelf-life of fish, innovative technologies must be developed to control bacteria growth and reduce enzymatic and chemical reactions. The specific objective of this project was to develop a combined treatment of brine salting (3 and 9% salt) and high-hydrostatic pressure processing to improve the microbiological quality and physicochemical properties, including fishy odor-related nitrogen, color and texture. The results showed that the combined treatments at 3% salt and moderate high-pressures could effectively reduce total bacterial count and total cold-tolerant bacteria and total volatile nitrogen content, which contribute to fishy smell. The combined salt brine and high pressure treatments also can maintain color and texture of fresh milkfish fillet. The technologies developed may be applied to other fish species such as catfish and other seafood products.

Technical Abstract: The e'ects of soaking milk'sh 'llet in 3% or 9% NaCl brines for 90 min at 4°C, and followed by processing with varying hydrostatic pressures (300, 400, 500, and 600 MPa) for 5 min on microbial quality and physicochemical properties were evaluated. After brine salting, the color of the 'llet, the L* (lightness), W (whiteness), and 'E (color di'erence) values increased with the increases in pressure, whereas the a* (redness) and b* (yellowness) values decreased, indicating that the 'llet became brighter and whiter. Among them, 3% brine salting combined with pressures of 300 and 400 MPa groups had higher redness (a* value) and lower 'E value compared to the higher pressure groups. Regarding the texture of the 'llet, the hardness and chewiness of unsalted 'sh were signi'cantly higher than that of brine salted 'sh under the same pressure, whereas the cohesiveness of the unsalted 'llet was signi'-cantly lower than that of brine salted 'llet. The results indicates that brine salting could make the instrumental texture of 'sh softer, which can com-pensate for the disadvantages of increased hardness and chewiness of the 'llet caused by high-pressure processing. Brine salting combined with high pressure produced a signi'cantly reducing e'ect on aerobic plate count (APC), psychrotrophic bacteria count (PBC), and total volatile basic nitrogen (TVBN) values of the 'sh as compared with that by brine salting or high pressure alone. Therefore, brine salting at a proper brine concentration (3%) and followed by high-pressure processing at 300 or 400 MPa for 5 min can improve or maintain a relatively good color and texture, as well as result in a synergistic bactericidal e'ect.