Refined liquid smoke: a potential antilisterial supplement to cold-smoked sockeye salmon (Oncorhynchus nerka)

Montazeri Djouybari, Naim

Name:

Djouybari_N_2011.pdf

Size:

113.8Mb

Format:

PDF

Download

Author

Montazeri Djouybari, Naim

Chair

Oliveira, Alexandra
Himelbloom, Brian

Committee

Crapo, Charles
Leigh, Mary Beth

Abstract

Listeria monocytogenes, the causative agent of listeriosis can contaminate cold smoked salmon (CSS) and make it a high-risk ready-to-eat food product. Due to the lack of a critical control point in the cold-smoking process, a post-process elimination is essential to ensure product safety. The goal of this project was to improve safety of vacuum-packaged CSS supplemented with commercially refined liquid smoke (LS). Gas chromatography-mass spectrometric analysis showed the LS were high in carbonyl containing compounds and low in phenol derivatives. The LS (AM-10 and AM-3) producing the greatest inhibition against L. innocua in a paper disk diffusion assay were applied to the CSS strips at 1% (v/w). The CSS were inoculated with L. innocua, vacuum packaged, and stored at 4°C. Addition of LS imparted a listericidal effect with a 2-log reduction by day 14, and no growth up to 35 days of storage. For the sensory evaluation, AM-3 was selected for its slightly stronger listericidal activity. A simple difference sensory test including 180 untrained assessors showed the overall sensorial quality of CSS was not influenced by the addition of the LS. The present study recommends refined LS as a suitable antilisterial supplement to CSS.

Description

Thesis (M.S.) University of Alaska Fairbanks, 2011

1. General introduction -- 1.1. Justification and need -- 1.2. Smoking of seafood -- 1.3. Basic quality aspects of smoked seafood -- 1.4. Liquid smoke -- 1.4.1. Quality and safety of liquid seafood -- 1.4.1.1. Nonmicrobial aspects -- 1.4.1.2. Microbial aspects -- 1.4.3. Regulations -- 1.5. Listeria monocytogenes in smoked seafood -- 1.5. Listeria monocytogenes in smoked seafood -- 1.5.1. Characteristics of Listeria and listeriosis as related to smoked seafood -- 1.5.2. Regulations -- 1.5.3. Preventing Listeria monocytogenes contamination of cold-smoked salmon -- 1.5.4. Controlling the growth of Listeria monocytogenes in cold-smoked salmon -- 1.6. Antilisterial activity of liquid smoke -- 1.7. Commercial applications of liquid smokes to cold-smoked salmon -- 1.8. Research goal and objectives -- 1.9. References -- 2. Chemical characterization of commercially refined liquid smokes -- 2.1. Abstract -- 2.2. Introduction -- 2.3. Material and methods -- 2.3.1. Liquid smokes -- 2.3.2. Color -- 2.3.3. pH and titratable acidity (TA) -- 2.3.4. Total phenol content (TPC) -- 2.3.5. Extraction of volatile and semi-volatile compounds in LS -- 2.3.6. Separation, identification and qualification of volatile and semi-volatile compounds in LS -- 2.4. Results and discussion -- 2.4.1. Color -- 2.4.2. pH and titratable acidity (TA) -- 2.4.3. Total phenol content (TPC) -- 2.4.4. Volatile and semi-volatile compounds in LS -- 2.4.4.1. Phenolic compounds -- 2.4.4.2. Aldehydes and ketones -- 2.4.4.3. Furans and pyrans -- 2.4.4.4. Organic acids -- 2.4.4.5. Other compounds -- 2.5. Abbreviations used -- 2.6. Acknowledgements -- 2.7. Literature cited -- 3. Refined liquid smoke: a potential antilisterial supplement to cold-smoked sockeye salmon (Oncorhynchus nerka) -- 3.1. Abstract -- 3.2. Material and methods -- 3.2.1. Liquid smokes -- 3.2.2. Inoculum preparation -- 3.2.3. In vitro testing of LS -- 3.2.4. Salmon -- 3.2.5. Cold-smoked salmon (CSS) -- 3.2.6. Inoculated CSS -- 3.2.7. Microbiological analyses -- 3.2.8. Chemical and color analysis -- 3.2.9. CSS preparation for sensory evaluation -- 3.2.10. Statistical analyses -- 3.3. Results and discussion -- 3.3.1. In vitro LS analysis -- 3.3.2. Nonmicrobial analyses -- 3.3.3. Microbial analyses -- 3.3.4. Sensory evaluation -- 3.4. Acknowledgements -- 3.5. References -- 4. General conclusion -- Appendices.

Date

2011-12

Type

Thesis

Collections

Fisheries