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Phenolic compounds have an important influence on fruit and nut quality. Almonds have been shown to be rich sources of phenolic compounds, which possess health-beneficial properties. The objectives of the study were to optimize an extraction method to determine the total amount of polyphenols, flavonoids and proanthocyanidins as well as the antioxidant capacity. In addition, the same extract was used for the identification and quantification of flavonoids by HPLC. The study was conducted on 11 Spanish almond genotypes. The results highlight the differences in the content of antioxidants, which add value to the quality of the fruit. It has been shown that genotype may strongly influence antioxidant capacity and total phenolic compounds. In this work, the almonds with higher results were (Belona, Guara and Vialfas) varieties This research was funded by the Spanish Research State Agency (AEI), grant numbers RTI2018-094210-R-100 (2019–2022). An Integrative Approach for Optimization of Almond Rootstocks and Scion Breeding I-ALMOND almond; polyphenols; flavonoids; proanthocyanidins; antioxidant capacity; quality; high performance liquid chromatography almendra; polifenoles; flavonoides; proantocianidinas; capacidad antioxidante; calidad; cromatografía líquida de alta resolución Published

The production and consumption of nuts are increasing in the world due to strong economic returns and the nutritional value of their products. With the increasing role and importance given to nuts (i.e., walnuts, hazelnut, pistachio, pecan, almond) in a balanced and healthy diet and in the prevention of various diseases, breeding of the nuts species has also been stepped up. Most recent fruit breeding programs have focused on scion genetic improvement. However, the use of locally adapted grafted rootstocks also enhanced the productivity and quality of tree fruit crops. Grafting is an ancient horticultural practice use in nut crops to manipulate scion phenotype and productivity and overcome biotic and abiotic stresses. There are complex rootstock breeding objectives and physiological and molecular aspects of rootstock–scion interactions in nut crops. In this review, we provide an overview of these, considering the mechanisms involved in nutrient and water uptake, regulation of phytohormones, and rootstock influences on the scion molecular processes, including long-distance gene silencing and trans-grafting. Understanding the mechanisms resulting from rootstock × scion × environmental interactions will contribute to developing new rootstocks with resilience in the face of climate change, but also of the multitude of diseases and pests and of the possible increase of their aggressiveness. They will also have to offer the premises of economic production, respectively yield and the quality, according to multiple destinations of nuts in the current consumption and food industry, but also the increasing exigencies of the consumer market and the profile industry.

This paper investigated the effects of Prunus pedunculatus (P. pedunculatus) seed pre-treatment, including microwaving (M), roasting (R), steaming (S) and roasting plus steaming (RS) on crude oil quality in terms of yield, color change, fatty acid composition, and oxidative stability. The results showed an increase in monounsaturated fatty acid content and oxidative stability of the oils obtained from different processing treatments compared to the oil obtained from raw seeds (RW) without processing. The oils, obtained from pretreated seeds, had higher conjugated diene (CD) and 2-thiobarbituric acid (2-TBA) values, compared to that obtained from RW when stored in a Schaal oven at 65 °C for 168 h. However, polyphenol and tocopherol contents decreased in all oil samples, processed or unprocessed. The effect of pre-treating the seeds was more prominent in the oil sample obtained through the RS technique, and showed higher oxidative stability than the other processed oils and the oil from RW. Se investigó los efectos del pretratamiento de las semillas de Prunus pedunculatus, incluyendo microondas (M), tostado (R), cocción al vapor (S) y torrefacción más vapor (RS), sobre la calidad del aceite crudo, el rendimiento, cambio de color, composición en ácidos grasos y estabilidad oxidativa. Los resultados mostraron un aumento en el contenido de ácidos grasos monoinsaturados y en la estabilidad oxidativa de los aceites obtenidos con diferentes tratamientos de procesamiento en comparación con el aceite obtenido a partir de semillas crudas (RW) sin procesamiento. Los aceites obtenidos a partir de semillas pretratadas presentaron mayores valores de dienos conjugados (CD) y de ácido 2-tiobarbitúrico (2-TBA), comparado con el obtenido de RW cuando se almacenaron en horno a 65 °C durante 168 h. Sin embargo, el contenido de polifenoles y tocoferoles disminuyó en todas las muestras de aceites, procesadas o no procesadas. El efecto del pretratamiento de las semillas fue más destacado en la muestra de aceite obtenida mediante la técnica RS, mostrando mayor estabilidad oxidativa que los otros aceites procesados y que el aceite de RW.

In this paper the extraction methods of virgin almond oil and its chemical composition are reviewed. The most common methods for obtaining oil are solvent extraction, extraction with supercritical fluids (CO2) and pressure systems (hydraulic and screw presses). The best industrial performance, but also the worst oil quality is achieved by using solvents. Oils obtained by this method cannot be considered virgin oils as they are obtained by chemical treatments. Supercritical fluid extraction results in higher quality oils but at a very high price. Extraction by pressing becomes the best option to achieve high quality oils at an affordable price. With regards chemical composition, almond oil is characterized by its low content in saturated fatty acids and the predominance of monounsaturated, especially oleic acid. Furthermore, almond oil contains antioxidants and fat-soluble bioactive compounds that make it an oil with interesting nutritional and cosmetic properties.En este trabajo se revisan los métodos de extracción del aceite de almendra virgen y su composición química. Los métodos más habituales para la obtención del aceite son la extracción con disolventes, la extracción con fluidos supercríticos (CO2) y los sistemas de presión (prensas hidráulica y de tornillo). El mayor rendimiento industrial, pero también la peor calidad de los aceites, se consigue mediante el uso de disolventes. Además, los aceites obtenidos por este método no se pueden considerar vírgenes, pues se obtienen por medio de tratamientos químicos. La extracción con fluidos supercríticos da lugar a aceites de mayor calidad pero a un precio muy elevado. La extracción mediante prensado se convierte en la mejor opción de extracción, al conseguir aceites de alta calidad a un precio asequible. En cuanto a su composición química, el aceite de almendra se caracteriza por su bajo contenido en ácidos grasos saturados y el predominio de los monoinsaturados, en especial en ácido oleico. Además, el aceite de almendra contiene compuestos bioactivos liposolubles y antioxidantes que lo convierten en un aceite con interesantes propiedades nutricionales y cosméticas.

The present work aims at determining the changes in the chemical components of almond kernels after roasting in pan with sand at during 25 min, as done in Northern Morocco. After roasting, oil content varied between 56% and 58.8%, protein content between 18.24% and 23.27%, and sugar content between 5.47% and 6.84%. These results show that the kernels maintain their nutritional value after roasting. Fatty acid composition was affected, with significant decreases in the percentage of palmitoleic, oleic and linoleic acids. The ratio of oleic to linoleic acids, a good index of resistance to rancidity, also decreased after roasting, although it was still similar to that of raw kernels of some commercial cultivars. The amount of the different tocopherol homologues was altered after roasting: α-tocopherol decreased, mainly in ‘Beldi’, characterised by low values before roasting, whereas in ‘Marcona’, with higher tocopherol concentration, the decrease was not so drastic. On the other side, γ-tocopherol increased in all samples after roasting. These results clearly show that the fatty acid profile and the tocopherol concentration are affected, but not drastically, by this roasting method. As a consequence, the quality of these roasted kernels is not significantly altered as compared to the raw kernels Published

21 Pags., 5 Tabls., 3 Figs. The final editor version is available at: http://link.springer.com/journal/11295, Almond breeding is increasingly taking into account kernel quality as a breeding objective. Although information on nut and kernel physical parameters involved in almond quality has already been compiled, the genetic control of these traits has not been studied. This genetic information would improve the efficacy of almond breeding programs. A linkage map with 56 simple-sequence repeat markers was constructed for the “Vivot” × “Blanquerna” almond population showing a wide range of variability for the physical parameters of nut and kernel. A total of 14 putative quantitative trait loci (QTLs) controlling these physical traits were detected in the current study, corresponding to six genomic regions of the eight almond linkage groups (LG). Some QTLs are colocated in the same region or shared the same molecular markers, in a manner that reflects the correlations between the physical traits, as well as with the chemical components of the almond kernel. The limit of detection values for any given trait ranged from 2.06 to 5.17, explaining between 13.0 and 44.0 % of the phenotypic variance of the trait. This new genetic information needs to be taken into account when breeding for physical traits in almond. Increases in the positive quality traits, both physical and chemical, need to be considered simultaneously whenever they are genetically independent, even if they are negatively correlated. This is the first complete genetic framework map for physical components of almond nut and kernel, with 14 putative QTLs associated with a large number of parameters controlling physical traits in almond., his research was funded by the Spanish grant AGL2010-22197-C02-01 and the Research Group A12 of Aragón.

The protein and oil content and the fatty acid profile of the kernels of selected almond genotypes from four different Moroccan regions were determined in order to evaluate the kernel quality of the plant material of these different regions. The ranges of oil content (48.7–64.5 % of kernel DW), oleic (61.8–80.2 % of total oil), linoleic (11.4–27.0 %), palmitic (5.6–7.7 %), stearic (1.3–3.1 %), and palmitoleic (0.4–0.9 %) acid percentages agreed with previous results of other almond genotypes, but the protein content (14.1–35.1 % of kernel DW) showed that some genotypes had higher values than any previously recorded in almond. Some genotypes from mountainous regions showed kernels with very high oil content as well as high and consistent oleic and linoleic ratio, establishing a possible differentiation according to the geographical origin. These differences may allow establishing a geographical denomination for almond products. In terms of genetic diversity, oleic and linoleic acids were confirmed to be the most variable components of almond oil chemical composition among genotypes. Additionally, the genotypes with extreme favorable values, such as high protein content, could be incorporated into an almond breeding program aiming at an increase in kernel quality. Peer Reviewed Prunus amygdalus Protein content Oil content Fatty acids Quality Genetic resources Breeding Published

Almond (Prunus amygdalus Batsch) in Morocco is still propagated by farmers mostly from seed, generating a large genetic diversity. Evaluation of the almond diversity in Morocco from the point of view of kernel quality, oil and protein contents, and major fatty acid composition were determined. Principal component analysis (PCA) was used to compare the kernel components among 46 genotypes selected from different production regions, as well as five introduced cultivars. Oil and protein contents were highly variable between genotypes, ranging respectively from 48.29 to 65.19% and from 14.07 to 36.48% of the total kernel dry weight. Fatty acid composition of the oil fraction ranged between 5.6-8.34% for palmitic acid, 0.37-0.87% for palmitoleic acid, 1.3-3.3% for stearic acid, 57.95-81.97% for oleic acid, and 9.69-29.98% for linoleic acid. Clustering of genotypes from similar regions suggested the existence of parental relationship among these genotypes and, as a consequence, a common ancestral origin. The Moroccan genotypes did not cluster separately from the introduced varieties. Two genotypes had very high oil contents whereas four genotypes had exceptionally high protein contents (>30%). One genotype had a very high oleic content (82%). The large variability observed for oil and fatty acid composition and the presence of genotypes with higher oil and fatty acid contents than the foreign cultivars represent a very promising base to obtain new Moroccan almond cultivars with oil of higher quality. Peer Reviewed Prunus amygdalus Oil content Fatty acids Genetic resources Breeding Published

The chemical components of the almond kernel are traits contributing to almond quality and must be considered in breeding programs searching for high-quality almonds. Thus, total protein, oil content, fatty acid composition and tocopherol content were determined in 200 genotypes from four progenies from the almond (Prunus amygdalus Batsch) breeding program of Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Spain. All components showed significant differences among genotypes, as well also among progenies, showing a significant effect of the pollen parent in the average composition of each family. The protein content ranged between 8.4 and 24.7%, and the oil content between 37 and 67.5% of dry matter (DM). The major fatty acid was oleic, followed by linoleic. Alphatocopherol was predominant among the different tocopherol homologues (α, δ, and γ). Significant correlations were found among some components, such as total oil, oleic acid, and γ- and δ-tocopherol, but not with α-tocopherol. Heritability estimates were high for oil content and γ-tocopherol, medium for linoleic acid and α-tocopherol, and low for the rest of components. These results remark the importance of the genetic background of an individual for the quality profile of its kernels and the significant and positive effect of the pollen on the transmission of most chemical components of the almond kernel. Los componentes químicos de la pepita del almendro son productos que contribuyen a la calidad del almendro y deben considerarse en los programas de mejora para almendras de mayor calidad. Por ello, se determinaron los contenidos en proteína total, en aceite y en tocoferol, así como la composición en ácidos grasos, en 200 genotipos de cuatro familias del programa de mejora genética del almendro (Prunus amygdalus Batsch) del Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), España. Todos los componentes mostraron diferencias significativas entre genotipos, así como entre familias, resultando en un efecto significativo del parental masculino en la media de las composiciones en cada familia. El contenido en proteína osciló entre 8,4 y 24,7%, y en aceite entre 37 y 67.5% del peso seco (DM). El ácido graso más abundante fue el oleico, seguido por el linoleico. El α-tocoferol fue el homólogo predominante entre los tres mayoritarios (α, δ, y γ). Se encontraron correlaciones significativas entre algunos componentes, como el aceite total, el ácido oleico y los γ- y δ-tocoferol, pero no con el α-tocoferol. La heredabilidad fue elevada para el contenido en aceite y en γ-tocoferol, media para el ácido linoleico y el α-tocoferol, y baja para el resto de los componentes. Estos resultados resaltan la importancia de la base genética de un individuo para el perfil de calidad de sus pepitas, así como el efecto positivo del polen en la transmisión de la mayoría de los componentes químicos de la pepita del almendro.

8 páginas, 4 figures, 1table., [ES] La aparición de embriones múltiples dentro del mismo tegumento es un fenómeno espontáneo que ocurre en semillas de algunas variedades de almendro [Prunus dulcis (Mill.) D.A. Webb] como "Nonpareil" o "Mission". Las plántulas procedentes de estas semillas poliembriónicas son viables, aunque a menudo muestran un crecimiento más débil y retrasado. Estas plántulas enanas han sido caracterizadas como haploides en trabajos previos. En este trabajo hemos estudiado 450 plántulas procedentes de semillas poliembriónicas de la variedad californiana "Nonpareil" y 100 plántulas procedentes de semillas poliembriónicas de las selecciones españolas "D97396" y "D97407", observando su germinación y posterior crecimiento. Estas plántulas han sido caracterizadas molecularmente mediante marcadores isoenzimáticos y microsatélites. Además, hemos identificado los cariotipos mitóticos en los ápices radiculares. El porcentaje de semillas con embriones múltiples donde una de las plantas procedente de uno de estos embriones mostró un crecimiento aberrante fue del 25%, con un índice de mortalidad de las plántulas aberrantes procedentes de estos embriones del 90%. Se ha observado un origen sexual de estos embriones múltiples. En algunos casos estos dos embriones son genéticamente iguales y dan lugar a dos plantas idénticas, mientras que en el caso de semillas con embriones aberrantes el embrión secundario pierde parte de la dotación genómica, dando lugar a plantas aneuploides junto a las plantas diploides procedentes del embrión primario. El uso y utilización de este material en los programas de mejora genética del almendro se discute también en este trabajo., [EN] Twin seeds (multiple embryos within the same seedcoat) occur spontaneously in certain almond cultivars including ‘Nonpareil’ and ‘Mission’. The occurrence of these multiple embryos varies greatly and is strongly influenced by environmental conditions. Seedlings from the same twin seed are frequently viable, though often, one of the seedlings shows weak growth and develops poorly. These dwarf seedlings are generally thought to be haploid. In this work, we characterized several seedlings from 'Nonpareil' almond twin seed, including their germination and later growth. Isozyme and Simple Sequence Repeat (SSR) markers were utilized to genetically analyze seedling genetic structure. For isozymes, AAT and PGM were analyzed using horizontal starch gel systems. For SSRs, 3 different markers were assayed using Metaphor agarose gel. In addition, individual (mitotic) karyotypes were determined from staining of root tips. Results suggest that the percentage of twin embryos showing aberrant growth was approximately 36% and that the majority of these aberrant seedlings appear to be aneuploids. The possible origin of these multiple embryos is discussed.