Autoxidation interference assay to evaluate the protection against lipid oxidation of antioxidant administration: Comparison of the efficiency of progressive release or total administration

Lipid oxidation is a cause of food spoilage, and antioxidants are used to retard it, but the timing of administration is important for this effect. The research aims to evaluate the protective efficiency against oxidative deterioration through the prolonged or complete addition of antioxidants without retention in the matrix. For this purpose, three modes of administration of the synthetic antioxidant BHT and oregano essential oil were evaluated: 100, 50, and 25 in which 100 % was incorporated at the beginning, 50 % in two aliquots, and 25 % in 4 aliquots. After adding the aliquots, all treatments reached 0.02 w/w of antioxidant in oil. An accelerated oxidation study was performed at 60 °C for 12 days, and chemical indicators (Peroxide and Conjugated Dienes value) along with volatiles (2-Heptenal and 2,4-Decadienal EE) were assessed. The order of protection shows that the initial addition of antioxidants yielded the highest efficiency.

Use of mushrooms as antioxidants in a lipid oxidation model under indirect and direct oxidation tests: ethanolic extracts of Ganoderma resinaceum and Phlebopus bruchii

BACKGROUND

Foods contain lipids that are easily susceptible to oxidation, which can modify their sensory properties. Although these compounds provide characteristic flavours and odours, there are also unwanted compounds, such as volatile secondary oxidation products, representing a recurring problem for both the industry and consumers. Synthetic antioxidants are often employed to prevent this but their chronic consumption can be detrimental to human health. The present study evaluates the antioxidant potential of ethanolic extracts from Ganoderma resinaceum and Phlebopus bruchii using an accelerated oxidation test.

RESULTS

The composition profile of the extracts was investigated, identifying the presence of tryptophan, quinic acid, caffeic acid and 3,4-dihydroxyphenylglycol-phenolic acid. The antioxidant capacity of the extracts was compared with that of butylated hydroxytoluene (BHT) in sunflower oil that was oven-heated at 60 °C. Chemical (peroxide value, p-anisidine value and conjugated dienes) and volatile (2-octenal, 2-heptenal and 2,4-decadienal) indicators were measured over 28 days. The peroxide value decreased for both extracts at a similar level to that of BHT 0.02% w/w, and conjugate dienes decreased in the presence of G. resinaceum 0.1% w/w. Meanwhile, p-anisidine exhibited a slightly greater decrease for P. bruchii 0.1% w/w than for BHT. The sample with 0.1% w/w of extracts showed a reduction in volatile secondary oxidation compounds, indicating significant antioxidant activity.

CONCLUSION

Based on these results, both extracts could be proposed as potential antioxidants in foods with a high lipid content. © 2024 Society of Chemical Industry.

Comparative study of accelerated assays for determination of equivalent days in the shelf life of roasted high oleic peanuts: Chemical and volatile oxidation indicators in accelerated and room temperature conditions

Lipids present in peanuts are susceptible to oxidation, which affects food quality and safety, for this reason shelf-life studies are carried out. The objective was to determine the relation between accelerated oxidation conditions and room temperature storage for roasted peanuts. Lipid oxidation indicators and roasted flavour volatiles were measured. There was a negative correlation between roasted and oxidation volatiles. In this research, 2,5-dimethylpyrazine and 2-ethyl-3,6-dimethylpyrazine were good indicators of the storage conditions of roasted peanuts, and the peroxide value (PV) was the most important oxidation indicator. For the comparision of equivalent days, it was used the peroxide value which reached 7.90, 2.47 and 0.89 Meq.O₂/kg after 21 days at 25, 45 and 60 °C, respectively. The accelerated storage condition of 60 °C is optimal for estimation of the shelf life at 25 °C wherein 1 day at 60 °C is equal to 8.79 days at 25 °C.