A new technique for the rapid detection and analysis of triterpenic compounds in apple extracts using HPLC was developed and validated. The main advantage of this technique is the short duration of the analysisthis makes this technique superior to others currently applied for the routine HPLC analysis of triterpenic compounds. The developed, optimized, and validated technique was used for the evaluation of triterpenic compounds in samples of different cultivars of apples, their peels, and flesh. In total, four triterpenic compounds were isolated and identified. Ursolic acid was the dominant compound in all the tested apple samples. The highest amounts of triterpenic compounds were detected in the peels of the 'Lodel' apple cultivar, and thus apples of this cultivar may be potentially useful for the isolation of individual compounds and the production of functional food and dietary supplements.

Throughout history, people of different cultures have acknowledged the relationship between food properties and health. The pseudo-fruits of different Rosa species contain high levels of vitamin C and other beneficial biological active agents such as phenolics, and others. The purpose of the research was to determine the variability of the phenolic compound profiles in the fruit of different species of Rosa L. and to evaluate the antioxidant activity of fruit extracts in vitro. The total contents of phenolics, flavonoids, procyanidins, and hydroxycinnamic acid derivatives were performed using the spectrophotometric method. Qualitative and quantitative analysis of individual phenolics in rosehip samples was carried out by applying the HPLC method. The largest amounts of phenolic compounds 26.49 ± 1.32 mg GRE/g were found in rosehip samples of the Rosa pisocarpa species. (+)-Catechin was the predominant phenolic compound in rosehip fruit samples, and the highest content 522.48 ± 26.12 µg/g was found in rosehip samples of the Rosa subcanina species. A strong correlation was found between the total amount of phenolic compounds determined in rosehip extracts and the radical scavenging and reducing the activity of their extracts in vitro (r = 0.759 and 0.761, accordingly, p < 0.001).

As the interest in heirloom cultivars of apple trees, their fruit, and processed products is growing worldwide, studies of the qualitative and quantitative composition of biological compounds are important for the evaluation of the quality and nutritional properties of the apples. Studies on the variations in the chemical composition of phenolic compounds characterized by a versatile biological effect are important when researching the genetic heritage of the heirloom cultivars in order to increase the cultivation of such cultivars in orchards. A variation in the qualitative and quantitative composition of phenolic compounds was found in apple samples of cultivars included in the Lithuanian collection of genetic resources. By the high-performance liquid chromatography (HPLC) method flavan-3-ols (procyanidin B1, procyanidin B2, procyanidin C2, (+)-catechin and (−)-epicatechin), flavonols (rutin, hyperoside, quercitrin, isoquercitrin, reynoutrin and avicularin), chlorogenic acids and phloridzin were identified and quantified in fruit samples of heirloom apple cultivars grown in Lithuania. The highest sum of the identified phenolic compounds (3.82 ± 0.53 mg/g) was found in apple fruit samples of the ‘Koštelė’ cultivar

Apple cultivars are one of the main factors setting the composition of bioactive compounds in apples and the quality of the fruit. However, research has been providing increasing amounts of data on the influence of rootstocks on the variations in the composition of bioactive compounds in apples. The aim of the study was to determine the influence of rootstocks on the changes in the qualitative and quantitative composition of phenolic compounds and their antioxidant activity in vitro in apple flesh and peel. HPLC analyses of phenolic compounds in apple samples were performed. The rootstock–scion combination had a significant effect on the composition and antioxidant activity of phenolic compounds in apple samples. Depending on the rootstock, the total content of phenolic compounds in apple flesh of the ‘Galaval’ cultivar could vary by 2.9 times, and in the peel by up to 90%. The genotype of the rootstock resulted in the highest variation in total flavan-3-ol content in apple flesh—by as much as 4.3 times—while the total content of flavonols varied by 2.1 times. In apple peel, on the contrary, the greatest variation was recorded for the total flavonol content (by 4.4 times), and the total flavan-3-ol content varied the least (by 1.8 times). A proper match of a cultivar and a rootstock can program a fruit tree to grow larger amounts of higher-quality, antioxidant-rich, and high-nutrition-value fruit.

Apples are seasonal fruits, and thus after harvesting apples of optimal picking maturity, it is important to prepare them properly for storage and to ensure proper storage conditions in order to minimize changes in the chemical composition and commercial quality of the apples. We studied the quantitative composition of triterpenic compounds in the whole apple, apple peel and apple flesh samples before placing them in the controlled atmosphere (CA) chambers, and at the end of the experiment, 8 months later. HPLC analysis showed that highest total amount of triterpenic compounds (1.99 ± 0.01 mg g−1) was found in the whole apple samples of the ‘Spartan’ cultivar stored under variant VIII (O2—20%, CO2—3%, N2—77%) conditions. Meanwhile, the highest amount of triterpenic compounds (11.66 ± 0.72 mg g−1) was determined in the apple peel samples of the ‘Auksis’ cultivar stored under variant II (O2—5%, CO2—1%, N2—94%) conditions. In the apple peel samples of the ‘Auksis’ cultivar stored under variant I (O2—21%, CO2—0.03%, N2—78.97%) conditions, the amount of individual triterpenic compounds (ursolic, oleanolic, corosolic, and betulinic acids) significantly decreased compared with amount determined before the storage. Therefore, in the apple flesh samples determined triterpenic compounds are less stable during the storage under controlled atmosphere conditions compared with triterpenic compounds determined in the whole apple and apple peel samples.