Treatment with the ethylene inhibitor 1-methylcyclopropene (1-MCP) considerably prolongs the storage and shelf life of apples, and diminishes the appearance of some physiological diseases, such as scald. Various fruit-quality parameters define fruit acceptance by consumers, while some also determine the storability of fruits, including firmness, acidity and internal ethylene concentration. The aroma of apples is regarded as one of the most important quality parameters. Many factors influence the aroma profile, with ethylene having a key role in the biosynthesis of flavour compounds. 1-MCP is an inhibitor of ethylene synthesis and is now widely used. We investigated apples of the three main varieties grown in Slovenia (‘Idared’, ‘Jonagold’ and ‘Golden Delicious’) following their treatment with 1 µL L-1 1-MCP at +2 °C, with 6 months of storage under standard ultra-low oxygen storage conditions (1.2% O2, 1.5% CO2). The fruit were analysed for firmness and ground colour, with headspace analyses of the aroma compounds, before and after storage. Compared to control fruits, 1-MCP-treated apples had significantly improved firmness and better colour parameters (L*, a* , b*), but showed strong inhibition of total aroma production. Among the aroma compounds, the esters were most severely suppressed by 1-MCP treatment, with the exception of 2-methylethyl acetate. In general, 1-MCP positively influenced most of the quality parameters (fruit firmness, ground colour, acidity), but profoundly suppressed the synthesis of the aroma volatiles.
COBISS.SI-ID: 3917432
The intake of foods containing trans fatty acids (TFAs) can have deleterious effects on human health, mainly on the cardiovascular system. Thus, it is important to consider the processes that form TFAs in foods, and the alternatives to minimise their formation. The influence of two added natural antioxidants on TFA formation during heat treatment (120 h at 180 degrees C) of sunflower vegetable oil were examined: rosemary extract (Rosmarinus officinalis L.) (1 g per kg oil) and lutein (0.1 g per kg oil). Changes in FA composition were determined using Ag-ion SPE and gas-liquid chromatography, with total polar compounds determined using dielectric constant measurements and the index of atherogenicity was calculated. Total TFAs with )= 1 trans double bond increased from 0.91 to 1.71% in control samples; this increase was significantly less with both rosemary extract (1.55%) and lutein (1.43%) additions. Among the individual TFAs, significant increases were seen for C18:1,t-9, C18:2,t-9,t-12 and C18:2,c-9,t-12/9-t,12-c. Polar compounds also increased, with the highest concentrations in control samples, and significantly less with both rosemary extract and lutein additions. According to results of our study, we can summarize that addition of lutein have greater effect on reduction of TFA formation than rosemary extract.
COBISS.SI-ID: 3827576
The purpose of this study was to evaluate the contribution of extractable antioxidants and non-extractable phenolics to the total antioxidant activity (TAA) of plums. Therefore, the antioxidant activity was determined (ABTS assay) in aqueous-organic extracts, as well as the extraction residues which were a subject of two different acidic treatments to release hydrolysable tannins and non-extractable proanthocyanidins (NEPA). In addition, the changesin TAA during the last week of ripening were investigated. Extractable antioxidants contributed less than 18 % to the TAA, considerably higher values of antioxidant activity were associated with hydrolysable tannins and NEPA, suggesting that the antioxidant activity of plums may be underestimated in the literature. The ripening resulted in an increase of TAA up yto 38 % in excess of the value determined on the first sampling date. TAA showed a similar pattern over the ripening period for all cultivars studied.
COBISS.SI-ID: 3012140