The Effects of the Cultivar and Environment on the Phenolic Contents of Hazelnut Kernels

Different climatic conditions are known to affect the synthesis of primary and secondary metabolites. Therefore, the phenolic contents in new growing areas could affect the quality and flavor of hazelnuts. The aim of this study was to determine the variability of the phenolic contents of the kernels in different commercial hazelnut cultivars depending on their growing area. Five cultivars (‘Tonda Gentile delle Langhe’, ‘Merveille de Bollwiller’, ‘Pauetet’, ‘Tonda di Giffoni’, and ‘Barcelona’ (syn. ‘Fertile de Coutard’)) grown in different European collection orchards were included in the study. High-performance liquid chromatography coupled with mass spectrometry was used to identify and quantify the phenolic compounds. Thirteen phenols were identified in the hazelnut kernels, including 7 flavanols, 2 hydroxybenzoic acids, 3 flavonols, and one dihydrochalcone. Catechin and procyanidin dimers were the main phenolic compounds found in the hazelnut kernels. The highest contents of catechin and total flavanols were determined in cultivars cultivated in Spain and northern Italy, and the lowest in Slovenia and France. Flavanols were the major phenolic groups independent of the place of cultivation, as they accounted for more than 50% of all phenolic compounds identified. The flavanols were followed by hydroxybenzoic acids, flavonols, and dihydrochalcones. Higher contents of flavanols and flavonols were found in kernels from areas characterized by higher natural irradiation, which stimulates their accumulation. The contents of hydroxybenzoic acids correlated with altitude, which stimulated phenolic acid synthesis. A negative correlation was observed between the dihydrochalcone content and annual rainfall, probably due to hydric stress.info:eu-repo/semantics/publishedVersio

Simultaneous analysis of ascorbic and dehydroascorbic acid in fruit juice using HILIC chromatography coupled with mass spectrometry

A HILIC-MS/MS method was developed for the simultaneous analysis of ascorbic acid (AA) and dehydroascorbic acid (DHA). Ammonium acetate buffer and acetonitrile were used as mobile phases under gradient elution mode at a flow rate of 0.3 mL/min. A SCIEX Triple QUAD 5500+ system was operated under MRM mode to acquire data with 175 → 115 and 173→113 as the quantifier ions for AA and DHA, respectively. Samples were prepared with a simple dilute and shoot method. A calibration and accuracy study was performed as part of method validation in fruit juices. The accuracy profiles were estimated from the measurement uncertainty determined from the validation data according to the ISO/DTS 21748. The recoveries of the analytes were between 92 – 130 %. The LOQs achieved in the current study for AA and DHA were 4.5 μg/L and 18 μg/L, respectively. These LOQs were substantially lower than what has been previously reported in the literature. The study concludes with a straightforward analytical method for the determination of total vitamin C content that does not involve timing consuming steps i.e., reduction or derivatization reaction. The method can be implemented in quality control labs for routine analysis of food samples

Determination of the yield, enzymatic and metabolic response of two Capsicum spp. cultivars to deficit irrigation and fertilization using the stable isotope 15^{15}N

Background Climate change is increasingly impacting agriculture all over the world, with extended periods of drought, flooding, hail, winds and temperature extremes. To negate the effects of climate change, researchers are trying to find new agricultural production techniques, to save resources without losing yield quality and quantity. A study on Capsicum annuum L. ’Chili-AS Rot’ and Capsicum chinense Jacq. ’Naga Morich’ chilies, grown under field capacity, deficit irrigation (50% field capacity) and full and half dose of mineral fertilizer in peat soil substrate was conducted. Both cultivars were marked with the stable isotope $^{15}$N, to follow nitrogen translocation in chili plants under stress conditions. Results The yield and plant biomass, capsaicin synthase (CS), phenylalanine ammonia lyase (PAL), and peroxidase (POX), as well as total and individual capsaicinoids were studied. In ’Chili-AS Rot’ the deficit irrigation with the fullfertilization (Diff ) dose showed the highest yield and fruit number, compared to other treatments. In the ’Naga Morich’ cultivar the deficit irrigation and half-fertilization (Dihf ), showed the highest yield, fruit number and dry weight of chilies, compared to other treatments. In the cultivar ’Chili-AS Rot’, deficit irrigation was found to reduce the utilization of N fertilizer when the plant (leaves, stems, and roots) and fruit were considered. The utilization of nitrogen fertilizer was 60 to 70% under deficit fertilization, regardless of the irrigation treatment. The half dose fertilized plants of ’Chili-AS Rot’ had higher CS activity and PAL activity (from 50 to 80%) than fully fertilized plants, with deficit irrigation having about 10% higher enzymatic activity than field-capacity irrigated plants. In ’Naga Morich’, irrigation treatment affected lower enzymatic activity than field-capacity irrigated plants. Conclusions The results indicate that deficit irrigation and fertilization can be used to maintain enzymatic activity and thus capsaicinoid content, which could reduce the economic cost of irrigation water and fertilizer. It was confirmed that the yield was better under deficit irrigation and fertilization for the more pungent ’Naga Morich’. The result of the study shows that when water and fertilizer use is reduced by up to 50%, chili yield losses are minimal or non-existent

The brown marmorated stink bug (Halyomorpha halys Stål.) influences pungent and non-pungent Capsicum cultivars\u27 pre- and post-harvest quality

Halyomorpha halys is an important invasive pest that causes severe damage to fruits and vegetables. Peppers are susceptible to infestation by H. halys, resulting in yield losses. Plants respond to the insect infestation with a metabolic response. With this study, we attempted to determine the intensity of the metabolic response of infested peppers, how pungent and non-pungent peppers react to the infestation, and how the H. halys affects the post-harvest quality of both cultivars. The shelf life of the infested peppers did not change compared to the control treatments. We observed a drastic decrease in metabolite levels after storage in all three treatments in both cultivars, especially capsaicinoids, with an approximate decrease of 30% in the pericarp and 95% in the placenta of the pungent ‘Eris F1’. In some cases, the accumulation of metabolites was not limited to the fruit exposed to the H. halys infestation, but to the entire plant. We observed a 15-fold increase in capsaicinoid content in the infested fruits of cultivar ‘Eris F1’ and a 4-fold increase in the pericarp of cultivar ‘Lombardo tago’, which could lead to a possible further study on the defensive function of capsaicinoids and their use against H. halys