Light-induced protein and lipid oxidation in low-fat cheeses: whey proteins as antioxidants

Abstract

International audiencePhoto-oxidation of cheese products has become an issue due to the fact that packaging of cheeses in transparent materials is very frequently used. The present study aimed to give new aspects of the possible antioxidative activity of whey proteins in photo-oxidation of cheese and the whey proteins were expected to act as scavenger and thereby reduce lipid oxidation. Oxidation was investigated in low-fat model cheese with whey protein isolate (WPI) added and compared to a low-fat control cheese. The cheeses were packed in air or in vacuum, respectively, and stored under light. Accumulations of lipid hydroperoxides, pentanal, hexanal, heptanal, 1-hexanol, dimethyl disulfide and dityrosine were all found to be dependent on the availability of oxygen. The presence of WPI reduced the accumulation of both lipid and protein oxidation products. The consumption of the naturally occurring antioxidant alpha-tocopherol was not affected by the added WPI. After the seventh day of light-exposed storage during which all riboflavin was decomposed and the concentration of alpha-tocopherol had found a stable level, the presence of WPI resulted in an extension of the observed lag phase in the accumulation of secondary lipid oxidation products. As WPI reduced the accumulation of protein oxidation products as well, it is suggested that WPI is not a typical radical scavenger

Volatile organic compounds generated by cultures of bacteria and viruses associated with respiratory infections

“…Indeed, 1-hexanol has been documented in previous studies as a product of lipid peroxidation (Dalsgaard et al, 2011), that is, peroxidation of host cells' membrane in the viral growth media. The data used in this analysis contained peak identity ( given by the retention time) and VOC concentration (proportional to area under the peak).…”

Relationship between lipid and protein oxidation in fish

“…His residues and carnosine can postpone oxidation by removing metal ions from the surface of other macromolecules (Guiotto, Calderan, Ruzza, & Borin, ). Furthermore, some peptides, which contain Trp or Tyr at the C‐terminus have shown to possess a high radical scavenging ability (Saito et al, ) and as mentioned above, for example, dityrosine formation as a consequence of two tyrosine radicals reacting with each other will terminate the radical (Dalsgaard, Sorensen et al, ). The amount of riboflavin, which is responsible for photo‐oxidation is variable in different fish species (Brjekkan, ), may play an important role as well.…”

A review of analytical methods measuring lipid oxidation status in foods: a challenging task

“…They range from 250nm to 500 nm for excitation, and from 280nm to 600nm for emission [53,[102][103][104]. Many authors have used the ability of these Schiff bases to emit fluorescence to monitor thermal oxidative processes, especially in dairy products [105,106], meat [107,108], fish [109,110] and oils [111], but fluorescence methodologies are still poorly documented in food lipid oxidation analysis. Both Gatellier et al [104] and Nguyen et al [110] found a high correlation between fluorescent pigments and TBARS of meat and fish products, which demonstrated that the interaction between proteins and aldehyde products of lipid oxidation is mainly involved in the production of fluorescent pigments and these are good markers of lipid oxidation.…”