Lower nitrogen nutrition determines higher phenolic content of organic apples Juozas Lanauskas1, Darius Kviklys1, Mindaugas Liaudanskas2, Valdimaras

et al. 2022

Plants

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Modern apple orchard systems should guarantee homogeneity of fruit internal and external qualities and fruit maturity parameters. However, when orchards reach productive age, a variation of these parameters takes place and mostly it is related to uneven light distribution within the tree canopy. The aim of the study was to evaluate the canopy position’s effect on fruit internal and external quality parameters. This is the first study where all the main fruit quality and maturation parameters were evaluated on the same trees and were related to the light conditions and photosynthetic parameters. Four fruit positions were tested: top of the apple tree, lower inside part of the canopy, and east and west sides of the apple tree. Fruit quality variability was significant for fruit size, blush, colour indices, total sugar content, dry matter concentration, accumulation of secondary metabolites and radical scavenging activity. Fruit position in the canopy did not affect flesh firmness and fruit maturity parameters such as the starch index, Streif index and respiration rate. At the Lithuanian geographical location (55°60’ N), significantly, the highest fruit quality was achieved at the top of the apple tree. The tendency was established that apple fruits from the west side of the canopy have better fruit quality than from the east side and it could be related to better light conditions at the west side of the tree. Inside the canopy, fruits were distinguished only by the higher accumulation of triterpenic compounds and higher content of malic acid. Light is a main factor of fruit quality variation, thus all orchard management practices, including narrow two-dimensional tree canopies and reflecting ground covers which improve light penetration through the tree canopy, should be applied.

Section: Introductionmentioning

confidence: 99%

Apple Fruit Growth and Quality Depend on the Position in Tree Canopy

Kviklys

Viškelis

et al. 2022

Plants

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Detection and analysis of triterpenic compounds in apple extracts

Butkevičiūtė

International Journal of Food Properties

Kviklys

et al. 2018

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.

Triterpenic acid content in the fruit peel of Malus × domestica Borkh. depends on the growing technology

Viškelis

Uselis

Zemdirbyste-Agriculture

et al. 2018

Please use the following format when citing the article: Viškelis J., Uselis N., Liaudanskas M., Janulis V., Bielicki P., Univer T., Lepsis J., Kviklys D. 2018 AbstractRegardless of the numerous investigations of secondary metabolites, the impact of new growing technologies or individual technological means on fruit internal quality, particularly triterpene concentration in apple fruits has not been studied yet. Apple-tree (Malus × domestica Borkh.) growing technologies and geographical location of the growing site had clear effect on triterpene concentration in apple fruits. The effect of crop load, fruit location in apple-tree canopy, planting distance, apple-tree vegetative growth regulation and geographical location on triterpene content in apples was evaluated in 2015 and 2016. Four triterpenic compounds: corosolic, betulinic, oleonolic and ursolic acids, were quantified in apple peel. Triterpene accumulation in apple fruits was directly correlated with crop load, where 17% more total triterpenes were found at the highest crop load (12 fruits cm -2 trunk cross-sectional area (TCSA)) in comparison to the lowest crop load (4 fruits cm -2 TCSA). Higher concentration of triterpenes was found in the fruits harvested from the inner canopy of the apple-tree. Apple-tree growth regulation affected the synthesis of triterpenes -trunk incision decreased the amount of total triterpenes by 16% compared to the control and by 26% compared to summer pruning. Also, a trend of higher accumulation of triterpenes in fruits was found along with decreasing apple-tree planting distances. Colder climate and shorter vegetation period resulted in significantly higher contents of triterpenes in the fruits of cultivar 'Auksis' in Lithuania and Estonia compared to the fruits grown in Poland. The same trend, yet insignificant, was noticed for the cultivar 'Ligol'.