Abstract:The structural changes induced in extra virgin olive oil (EVOO) by adulteration with soybean oil (SBO) and heat treatment at 185°C for 4 and 8 h were investigated using Attenuated Total Reflectance -Fourier Transform Infrared (ATR-FTIR) spectroscopy. Our results revealed that the band around 3006 cm -1 recorded shifts versus the percentage of adulterant. The changes in the absorbance at 3006 cm -1 (A3006) and in the ratio of the maximum heights of the bands at 3006 and 2925 cm −1 (A3006/A2925) were used to evaluate the EVOO adulteration. The regression analysis of A3006 and A3006/A2925 versus the percentage of adulterant was used to calculate the detection limits of adulteration. The time course of spectral changes showed that the oil heating caused notable modifications in the intensity of the absorption bands and induced no shifts in their exact position. The most relevant changes were reflected by conjugation and cis-trans isomerisation of double bonds, the formation of epoxides and widening of the band in the C=O region due to formation of secondary oxidation products. This study highlights that ATR-FTIR spectroscopy may be a promising means to differentiate among pure and adulterated oils and to study the thermooxidative processes in oils undergoing thermal stress.

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This research was conducted in order to establish the effectiveness of two freeze-dried extracts obtained from blueberry processing byproducts resulting from juice manufacturing compared to butylated hydroxytoluene (BHT) in delaying the lipid oxidation of sunflower oil subjected to high-temperature convective heating at 180 °C up to 12 h under simulated frying conditions. The fruits were harvested from spontaneous flora of two regions of Romania, Arieseni (Alba County) and Paltinis (Sibiu County) and the blueberry byproducts extracts (BBE) were noted according to the origin place as ABBE and PBBE. The progress of lipid thermo-oxidation was investigated in terms of peroxide value (PV), p-anisidine value (p-AV), the response of TBA-malondialdehyde interactions assessed by thiobarbituric acid (TBA) method, the total oxidation (TOTOX) value and inhibition of oil oxidation (IO). The recorded data highlighted that BBE exhibit a high inhibitory response on lipid thermo-oxidation. The inhibitory effect was concentration-dependent, thus, the degree of lipid oxidation was in reverse related to the BBE dose. The exposure of the oil samples supplemented with 800 ppm BBE (ABBE, PBBE) to a high-temperature heating for 12 h led to a significant decrease of the assessed indices compared to additives-free sunflower oil sample as follows: PV (46%; 45%), p-AV (21%; 17%), TOTOX (27%; 24%), TBA value (25%; 11%). Regarding the impact of the origin on the potential of BBE to inhibit the lipid oxidative degradation, it was noted that ABBE derived from blueberries grown in a region with a milder climate with moderate precipitations and higher temperatures showed a stronger inhibitory effect on lipid thermo-oxidation than PBBE. A moderate level of 500 ppm BBE inhibited the lipid oxidation similar to 200 ppm BHT. The reported results reveal that BBE represent efficient natural antioxidants that could be successfully applied to improve the thermo-oxidative stability of sunflower oil used in various high-temperature food applications.

Romania has a wide variety of local landraces and heirloom genotypes. Our study aims to assess the performance of twenty halotolerant tomato landraces, collected from areas with medium and high levels of soil salinity, in terms ofthe accumulation of antioxidant compounds in fruits and to cluster them according to their nutraceutical components. The tomatoes used in the study were harvested once they had attained full ripeness and then analyzed for lycopene (Lyc), ascorbic acid content (AsA), total phenolic content (TPC), and total antioxidant capacity (TAC). The results revealed major differences between genotypes in terms of nutraceutical values. According to principal component analysis, the tomato landraces were grouped into five clusters, characterized by different proportions of compounds with antioxidant activity. The high/moderate nutritional values of Lyc, TAC, TPC, and AsA were obtained from varieties taken from local lands with high soil salinity, over 6.5 dS m−1. These findings support the idea that metabolites and secondary antioxidants are involved in the process of stress adaptation, thereby increasing salinity tolerance in tomatoes. Our results show that there are tomato landraces with a tolerance of adaptation to conditions of high soil salinity and provide information on their ability to synthesize molecules with antioxidant functions that protect plants against oxidative damage.

Apricot (Prunus armeniaca L.) is a fruit tree species widespread in Europe due to the high nutritional value of its fruit. In this study, the changes in the chemical composition of seven apricot cultivars were studied during three fruit ripening stages. Proximate composition (water content, ash, lipids, proteins, carbohydrates) was determined by official AOAC methods, macro-and microelements (potassium (K), calcium (Ca), magnesium (Mg), and iron (Fe)) were detected by atomic absorption spectroscopy (AAS), while antioxidant capacity and total phenolic compounds were determined by spectrophotometric methods. Vitamin C content was determined by titration using 2,6-dichlorophenol indophenol dye. The present research highlighted the variation between chemical composition as related to variety and stage of maturity. Protein and moisture of apricot fruit decreased during the different ripening stages in all cultivars, while lipids, carbohydrates, and ash content increased during ripening. The water content ranged from 79.87% to 88.6%, protein between 0.66% and 1.3%, and lipids between 0.1% and 0.57%. Generally, the highest macro-element content was detected in the first ripening stage. The total phenolic content dynamics displays a significant increase during ripening. The highest value of ferric reducing antioxidant power (FRAP) activity (0.357 μM Fe 2+ g -1 FW) was obtained for 'Sirena' at the halfripe stage, while the lowest value was detected for the same cultivar at the unripe stage (0.045 μM Fe 2+ g -1 ). In conclusion, the study of the chemical composition in different development stages represents a useful tool in horticulture to optimize the management of the nutritional potential of apricot fruit.