Foliar application of phenylalanine on nutritional value in Vitis vinifera var. Hosseini

Document Type : Research Paper

Authors

1 Department of Horticulture, Faculty of Agriculture, University of Maragheh, Maragheh, Iran.

2 Department of Horticulture, Faculty of Agriculture, University of Maragheh, Maragheh, Iran

3 Department of Horticulture, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

Abstract

Introduction:
Grape berries contain rather high amounts of polyphenolic compounds such as anthocyanins, which contribute significantly to their quality, appearance, and taste. Grape berries produce significant amounts of phenolic compounds. Phenylalanine ammonia-lyase (PAL), is first enzyme in the phenylpropanoid pathway which catalyses the conversion of phenylalanine to flavonoids, phenolics and anthocyanins. Phenylalanine ammonia-lyase (PAL) (EC 4.3.1.24) is an essential enzyme in the phenolic biosynthesis pathway that catalyzes the conversion of L-phenylalanine to trans-cinnamic acid and ammonia. Thus, PAL is the first and decisive step in the phenylpropanoid pathway and is therefore involved in the biosynthesis of phenolic compounds in the plants.The phenylpropanoid pathway involves in the synthesis of secondary compounds such as phenylalanin and phenolics. Considering the positive impacts of phenolic compounds on human health due to their antioxidant properties, their enhancement in fruits and vegetables especially by natural products such as phenylalanin might be considered as promising strategy to fight against cancerous cells and important diseases. Moreover, the increased concentration of phenolics in berries is a critical property benefitting health. In recent years, widespread attention has been focused on the potential beneficial properties on human health of anthocyanins in grapes and their products. Free radical scavenging, antioxidant, antimicrobial, and antiviral activities, nutraceutical and pharmaceutical activities like prevention of cardiovascular disease, protective effects against hepatic damage and disease, anticancer, antitumor, and antimutagenic activities, suppression of inflammatory responses, protection against age-related decline in cognitive behavior, and neuronal dysfunction are some top health beneficial properties of phenolic compounds.
Material and Methods:
This experiment was conducted in a completely randomized block design using four replications. All reagents and solvents were purchased from Sigma-Aldrich, St. Louis, MO, USA, and used without further purification. Each experimental unit consisted of two plants that each had at least three clusters of approximately the same size, maturity, and development. Vines were sprayed with four concentrations of Phenylalanin (0, 50, 100, and 200 µM) at pre-véraison (in which berries are green and hard) stage. The final volume was reached using distilled water and the pH was set with NaOH (1.0 N) to 7.0. The solutions of Phenylalanin with surfactant TWEEN® 20 were sprayed fifth at 5 days intervals (to ensure that all clusters received sufficient amounts of Phenylalanin solution at pre-véraison stage in case of any rain, deficiency or late development of some berries) on the whole cluster in the early morning. The clusters had little or no evidence of asynchrony and the berries were mostly green and hard. An equal amount of distilled water plus TWEEN® 20 was sprayed to the untreated plants (concentration 0.0 mM). The sprays were carried out with a hand sprayer. At harvest, although not all berries in a cluster were at the same developmental stage, most of the berries should have a particular coloration, softness, and level of development to be harvested.
Result and Discussion:
The results showed that total phenolics and flavonoids content were significantly enhanced in Phenylalanin -treated (100.0 and 200.0 µM) berries compared to untreated ones. Phenylalanin treatment at all concentrations considerably improved the total antioxidant capacity (DPPH) in the berries and, compared with untreated berries, the activity of phenylalanine amino-lyase enzyme was higher in Phenylalanin -treated fruits. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity of the fruits treated with Phenylalanin were significantly higher than those of the untreated berries. The activity of phenylalanine ammonia-lyase (PAL) in phenylalanin treated fruits significantly increased as compared with the untreated clusters. The remarkable effects of the PAL enzyme in increasing production of phenolic compounds in various plant tissues have been established for a long time, and it seems that the increases in concentrations of phenolic compounds in the present study are significantly related to this enzyme. The PAL enzyme causes the production and accumulation of secondary phenolic metabolites in plant tissues by causing a shift from primary to secondary metabolic pathways, and this accumulation usually increases the nutritional value of plant products. The PAL enzyme causes the production and accumulation of secondary phenolic metabolites in plant tissues by causing a shift from primary to secondary metabolic pathways, and this accumulation usually increases the nutritional value of plant products. Therefore, PAL plays a crucial part in improving the quality of crops by stimulating the production of secondary metabolites. The results of current research indicated that the increased activity of the PAL enzyme was entirely related to concentrations of phenylalanin, and its maximum activity was recorded in the treatment with the highest level (200.0 µM) of the phenyalanin. Moreover, a considerable increase was also observed in the evaluation of the total content of flavonoids, one of the major subgroups of phenolic compounds in plants, in grape berries. At the highest concentration of phenyalanin application, an increase of about 100% was recorded in the production of flavonoids, which can significantly help in the marketability of grape berries in addition to their increased nutritional value.
Conclusion:
A general evaluation of the results of the present experiment leads us to the conclusion that phenylalanin might be a suitable and recommendable treatment to improve the quality and nutritional value of grape berries. The phenylalanin is an essential amino acid and is safe for human consumption as it is present in almost all plant tissues that have always been consumed by humans without causing any problems. The improvement in the quality of berries, achieved in this research, is partly due to their improved visual quality and partly due to their increased healthful quality, which results from the increase in their antioxidant property and from the accumulation of compounds in them that enjoy high nutritional value. In summary, therefore, it seems that spraying grape berries at pre-véraison can be a suitable and convenient strategy for increasing the quality and nutritional properties of grape berries.

Keywords


گوهری غ، صفایی ف، رسولی ف، اعظمی م ع و دواتی کاظم نیا ح، 1397، ارزیابی اثرات محلول پاشی اسید سالسیلیک بر فعالیت برخی ترکیبات آنتی اکسیدانی انگور رقم شاهانی (Vitis Vinifera L. cv Shahani). نشریه پژوهش­های صنایع غذایی، 28(2)، 149-159.
Adams AW, Laurie VF and Waterhouse AL, 2012. Tracing phenolic biosynthesis in Vitis vinifera via in situ C-13 labeling and liquid chromatography–diode-array detector–mass spectrometer/mass spectrometer detection. Analytica Chimica Acta 747: 51-57.
Aubert C and Chalot G, 2020. Physicochemical characteristics, vitamin C, and polyphenolic composition of four European commercial blood-flesh peach cultivars (Prunus persica L. Batsch). Journal of Food Composition and Analysis 86: 103-112.
Beltagi MS, 2008. Exogenous ascorbic acid (vitamin C) induced anabolic changes for salt tolerance in chick pea (Cicer arietinum L.) plants. African Journal of Plant Science 2: 118-123.
Brouillard R nad Dangles O, 2017. Flavonoids and flower colour. In the flavonoidsadvances in research since. Routledge 565-588..
DeBolt S, Cook DR and Ford CM, 2006. L-Tartaric acid synthesis from vitamin C in higher plants. Proceedings of the National Academy of Sciences 103: 5608-5613.
FAOSTAT, 2018. Food and Agriculture Organization of the United Nations. http://www.fao.org/faostat/en/#home
Gutiérrez-Gamboa G, Carrasco-Quiroz M, Martínez-Gil AM, Pérez-Álvarez, EP, Garde-CerdánT and Moreno-Simunovic Y. 2018. Grape and wine amino acid composition from Carignan noir grapevines growing under rainfed conditions in the Maule Valley, Chile: Effects of location and rootstock. Food Research International 105: 344-352.
Garde-Cerdán T, López R, Portu J, González-Arenzana L, López-Alfaro I and Santamaría P, 2014. Study of the effects of proline, phenylalanine, and urea foliar application to Tempranillo vineyards on grape amino acid content. Comparison with commercial nitrogen fertilisers. Food chemistry 163: 136-141.
Kim JG, Beppu K  and Kataoka I, 2009. Varietal differences in phenolic content and astringency in skin and flesh of hardy kiwifruit resources in Japan. Scientia Horticulturae 120: 551-554.
Minh ATP,  Paterson J,  Bucknall M and  Arcot J, 2018. Interactions between phytochemicals from fruits and vegetables: Effects on bioactivities and bioavailability. Critical Reviews in Food Science and Nutrition 58: 1310-1329.
Oliveira JC, Manso L and Frías JM, 2001. Modelling ascorbic acid thermal degradation and browning in orange juice under aerobic conditions. International journal of FoodSscience & Technology 36: 303-312.
Oyetade OA, Oyeleke GO, Adegoke BM and Akintunde AO, 2012. Stability studies on ascorbic acid (Vitamin C) from different sources. Journal of Applied Chemistry 2: 20-24.
Portu J, González-Arenzana L,  Hermosín-Gutiérrez I, Santamaría P and Garde-Cerdán T, 2015. Phenylalanine and urea foliar applications to grapevine: Effect on wine phenolic content. Food Chemistry 180: 55-63.
Reisch BI, Owens CL and Cousins PS, 2012. Grape. In Fruit breeding . Springer, Boston 225-262..
Reshef N, Agam N and Fait A, 2018. Grape berry acclimation to excessive solar irradiance leads to repartitioning between major flavonoid groups. Journal of Agricultural and Food Chemistry 66: 3624-3636.
Santamaría P, López R, Portu J, González-Arenzana L, López-Alfaro I and Garde-Cerdán T, 2015. Role of phenylalanine in viticulture and enology, in: phenylalanine: Dietary sources, functions and effects. M-L- Warner, Nova Science publisher, 51–88.
Sharma P, Jha AB,. Dubey RS and Pessarakli M, 2012. Reactive oxygen species, oxidative damage, and antioxidative defense mechanism in plants under stressful conditions. Journal of Botany 20:1-12.
Smirnoff N and Wheeler GL, 2000. Ascorbic acid in plants: biosynthesis and function. Critical Reviews in Plant Sciences 19: 267-290..
Solecka D and Kacperska A, 2003. Phenylpropanoid deficiency affects the course of plant acclimation to cold Physiologia Plantarum 119: 253-262..
Spinardi A, 2004. Effect of harvest date and storage on antioxidant systems in pears. V International Postharvest Symposium. 682:25-34.
Vázquez-Armenta FJ, Silva-Espinoza BA, Cruz-Valenzuela MR, González-Aguilar GA, Nazzaro F, Fratianni, F and Ayala-Zavala JF, 2017. Antibacterial and antioxidant properties of grape stem extract applied as disinfectant in fresh leafy vegetables. Journal of Food Science and Technology 54(10): 3192-3200.
 Wang J, Zheng L, Wu J and Tan R, 2006. Involvement of nitric oxide in oxidative burst, phenylalanine ammonialyase activation and Taxol production induced by low energy ultrasound in Taxus yunnanensis cell suspension cultures. Cell Physiology 14: 391-397.
Wen W, Kong Q, Zhan J, Li M, Wan SB and. Huang WD, 2006. Effect of salicylic acid on phenylpropanoids and phenylalanine ammonia-lyase in harvested grape berries. Postharvest Biology and Technology 40: 64-72.