Influence of polyphenolic content on the in vitro allergenicity of old and new apple cultivars: A pilot study.

OBJECTIVES: More than 70% of birch pollen-allergic individuals are affected by a cross-allergy from apples. The aim of this study was to determine if an increased polyphenolic content of apples is inversely related to clinical allergic reactions in sufferers. METHODS: The polyphenolic content of two old and two new apple cultivars was analyzed using high performance liquid chromatography. The in vitro concentration of sulfidoleukotrienes and the CD63 basophil activation of 27 birch pollen sufferers with cross-reactivity to apples were determined with cellular antigen stimulation and basophil activation tests after incubation with different apple cultivars. RESULTS: The flesh of old cultivars was characterized by significantly higher total polyphenolic content (86.1 ± 5.5 µg/g) than that of new cultivars (24.7 ± 7.2 µg/g). The concentration of sulfidoleukotrienes and the CD63 basophil activation of old apple cultivars was up to 62% lower than new ones and decreased as the degree of enzymatic browning increased. CONCLUSION: Old apples cultivars are better tolerated than new ones by birch pollen-allergic individuals. The in vitro allergenicity (activation of effector cells) of apples depends on the total polyphenolic content and the degree of enzymatic browning.

Polyphenolic Compounds Analysis of Old and New Apple Cultivars and Contribution of Polyphenolic Profile to the In Vitro Antioxidant Capacity.

Polyphenols are antioxidant ingredients in apples and are related to human health because of their free radical scavenging activities. The polyphenolic profiles of old and new apple cultivars (n = 15) were analysed using high-performance liquid chromatography (HPLC) with diode array detection (DAD). The in vitro antioxidant capacity was determined by total phenolic content (TPC) assay, hydrophilic trolox equivalent antioxidant capacity (H-TEAC) assay and hydrophilic oxygen radical absorbance (H-ORAC) assay. Twenty polyphenolic compounds were identified in all investigated apples by HPLC analysis. Quercetin glycosides (203 ± 108 mg/100 g) were the main polyphenols in the peel and phenolic acids (10 ± 5 mg/100 g) in the flesh. The calculated relative contribution of single compounds indicated flavonols (peel) and vitamin C (flesh) as the major contributors to the antioxidant capacity, in all cultivars investigated. The polyphenolic content (HPLC data) of the flesh differed significantly between old (29 ± 7 mg/100 g) and new (13 ± 4 mg/100 g) cultivars, and the antioxidant capacity of old apple cultivars was up to 30% stronger compared to new ones.

Comparison of Chemical Profile and Antioxidant Capacity of Seeds and Oils from Salvia sclarea and Salvia officinalis.

Composition of tocopherols, tocotrienols, carotenoids, fatty acids, as well as hydrophilic and lipophilic antioxidant activities, were determined in seeds of two Salvia species and oils obtained from them. Both seeds contained a large amount of oil (around 20%) rich in polyunsaturated fatty acids. While Salvia officinalis seed oil can be classified as oleic-linoleic oil, the predominant fatty acid in Salvia sclarea was α-linolenic acid (around 54%). Among tocols, the main isomers in both seeds and oils were γ-tocopherol, followed by α-tocopherol. Concerning carotenoids, their concentration was around 0.75 mg/100 g of seeds and 0.16 mg/100 g of oils, with a predominance of lutein. Oil and seeds of S. officinalis exhibited higher antioxidant potential compared to S. sclarea investigated samples which could be attributed to higher content of total vitamin E and carotenoids. This study provides results that enables use of two Salvia species as new alternative sources of vegetable oils.

Antioxidant activities of tocopherols/tocotrienols and lipophilic antioxidant capacity of wheat, vegetable oils, milk and milk cream by using photochemiluminescence.

The purpose of this study was to measure the antioxidant activity (AOA) of tocopherols and tocotrienols by using photochemiluminescence (PCL). This method enables to detect total lipophilic antioxidants. The AOA of all vitamin E isomers depended on number and position of methyl groups in the chroman ring. Correlation between the AOA and the redox potential and the biological activity of the tocochromanols was observed. The second aim was to analyse different kinds of wheat, vegetable oils, milk and milk cream on their antioxidant capacity (AOC) by using PCL and α-TEAC. The contents of vitamin E and carotenoids were analysed by HPLC. Correlations between the sum of carotenoids and vitamin E and the AOC were detected. Based on high vitamin E contents, the oils had the highest and in contrast, the product macaroni showed the lowest AOC. A concentration-dependent effect was observed in both assays, PCL and α-TEAC.

Use of photochemiluminescence for the determination of antioxidant activities of carotenoids and antioxidant capacities of selected tomato products.

The purpose of this study was to compare the antioxidant activity of carotenoids to that of α-tocopherol by using a photochemiluminescence method (PCL). Comparisons to results obtained by using other established methods (α-TEAC, FRAP, DPPH, LPSC) were carried out. A relationship between the chemical structure of carotenoids and their antioxidant activity could be discussed. The number of conjugated double bonds and functional groups had a positive influence. Additionally, the lipophilic antioxidant capacities of selected tomato products were analyzed using PCL and α-TEAC. HPLC was used to identify and quantify contents of carotenoids, tocopherols, and tocotrienols. The raw material fresh tomatoes had the lowest antioxidant effect in both assays due to the lower carotenoid content. Tomato ketchup had the highest AOC in PCL, and tomato puree, in α-TEAC. The antioxidant capacities were mainly dependent on the water content of the samples. Furthermore, a concentration-dependent effect could be observed in both assays.