Oxidative Stability and Sensory Attributes of Fermented Milk Product Fortified with Fish Oil and Marine Phospholipids

Abstract

Marine phospholipids (PL) are potential ingredients for food fortification due to its numerous advantages. The main objective of this study was to investigate whether a fermented milk product fortified with a mixture of marine PL and fish oil had better oxidative stability than a fermented milk product fortified with fish oil alone. Fortification of a fermented milk product with marine PL was performed by incorporating 1 % w/w lipids, either in the form of neat oil or in the form of a preemulsion. Lipid oxidation was investigated in the neat emulsions and fortified products by the measurements of primary, secondary volatile oxidation products and tocopherol content upon 32 days storage at 2°C and 28 days storage at 5°C, respectively. Analyses of particle size distribution, viscosity and microbial growth were also performed. In addition, sensory attributes such as sour, fishy and rancid flavor/odor were evaluated in fortified products by a trained panel. The results obtained showed that incorporation of a mixture of marine PL and fish oil into fermented milk products decreased the oxidative stability and sensory quality of fortified products. The pHdependent behavior of iron seemed to be the main factor that influenced the lipid oxidation in the marine PL emulsion and fermented milk system. In addition, both oxidative stability and sensory acceptability of fortified products varied depending on the quality of the marine PL used for fortification.

Marine phospholipids: The current understanding of their oxidation mechanisms and potential uses for food fortification

“…Under certain conditions such as high temperature and the presence of transition metal ions, unstable lipid hydroperoxides may decompose through the formation of peroxyl and alkoxyl radicals, and cleavage of the alkoxyl radicals by homolytic β-scission to form a wide variety of shorter-chain secondary oxidation volatiles. To the best of our knowledge, study on the characterizations of marine PL derived volatiles is scarcely available in the literature except several studies from our laboratory (Lu et al, 2012b(Lu et al, , 2012c(Lu et al, , 2013a(Lu et al, , 2013b. Due to the high content of n-3 LC PUFA in marine PL, we obtained an almost similar lipid derived volatile profile as fish oil for marine PL emulsions.…”

“…Their results again showed that the fortified products were acceptable to consumers. However, our recent studies showed that fortification of fermented milk product with a mixture of fish oil and marine PL did not provide a better oxidative stability than fortification with only fish oil (Lu et al, 2013b). Incorporation of neat/pre-emulsified marine PL into fermented milk system increased lipid oxidation in fortified products.…”

“…To date, many studies on n-3 TAG fortified functional foods are available in literature, whereas food fortification with marine PL is a new area in food industry. Only several studies have been carried out to investigate the potential use of marine PL (Lu et al, 2013b) and krill oil (which comprises approximately 30-40% PL) for food fortification (Pietrowski et al, 2011;Kassis et al, 2010Kassis et al, , 2011Sedoski et al, 2012). Nevertheless, these studies reported that both marine PL and krill oil fortified foods are still susceptible to oxidation due to the high content of n-3 LC PUFA in marine PL and krill oil.…”

“…Therefore, the oxidative stability of marine PL and krill oil in real food systems need to be further investigated. Information on the oxidative stability of marine PL are scarcely available except a few studies on marine PL based liposomes (Mozuraityte et al, 2006a(Mozuraityte et al, , 2006b(Mozuraityte et al, , 2008, marine PL liposomes under gastrointestinal condition (Cansell et al, 2001;Nacka et al, 2001aNacka et al, , 2001b and several studies on marine PL emulsions and krill oil from our laboratory (Lu et al, 2012a(Lu et al, , 2012b(Lu et al, , 2012c(Lu et al, , 2013a(Lu et al, , 2013b(Lu et al, , 2014Thomsen et al, 2013).…”

The oxidative stability of omega-3 oil-in-water nanoemulsion systems suitable for functional food enrichment: A systematic review of the literature

“…A further issue with krill oil is its unpleasant off-odour and flavour, which cannot usually be removed by refining and deodorisation during processing. This makes it unacceptable in terms of quality to consumers when used for food enrichment purposes unless it is encapsulated and incorporated into novel nanocarriers to create a sensory barrier (Henna Lu et al 2011, Lu et al 2013, Zhu, et al 2015.…”