Variability of oil content and of major fatty acid composition in almond (Prunus amygdalus Batsch) and its relationship with kernel quality

Screening and Characterization of 1,8-Cineole-Based Solvents as an Alternative to Hexane for Obtaining Nonpolar Compounds from Plant-Based Milk Coproducts

The design of new hydrophobic solvents is essential for replacing the toxic hexane for extracting nonpolar compounds such as fatty acids. On the other hand, the full use of plant matrices seeking to obtain new food and pharmaceutical products from their coproducts has also been the focus of sustainable processes. This study proposed new solvents for replacing hexane to extract fatty acids and hydrophobic bioactive compounds from coproducts obtained from almond- and peanut-based milk processing. The COSMO-RS method was used to select terpene-based mixtures to substitute hexane. Experimentally, four liquid solvents were formed from 1:2 tetradecanol/1,8-cineole (TE/EU), 1:2 camphor/1,8-cineole (CA/EU), 1:1 oleic acid/1,8-cineole (OL/EU), and 1:1 menthol/1,8-cineole (ME/EU). DSC analyses indicated the reduction of the CA/EU, OL/EU, and ME/EU melting points concerning their components. However, the melting point values predicted by the COSMO for obtaining eutectic mixtures differed. CA/EU was the only mixture with a melting point lower than the COSMO-RS-predicted one. In contrast, the FTIR spectra did not provide a clear visualization of the hydrogen bond formation between camphor and 1,8-cineole. This could be due to the formation of weak hydrogen bonds, a phenomenon observed in other studies. Nevertheless, these solvents have the advantage of low viscosity, a promising feature that likely facilitated mass transfer in the extraction of hydrophobic compounds from almond and peanut coproducts. ME/EU provided the same global extraction yield as hexane and higher phytosterol extraction from almond coproducts. On the other hand, CA/EU provided the same global yield and squalene content as hexane from peanut coproducts. The extracts can be directly used in food and pharmaceutical applications since the solvents are usually part of the formulations. However, DSC and TGA-DTA analyses indicated possible ways to separate the solvents.

Effects of regulated deficit irrigation and foliar kaolin application on quality parameters of almond [Prunus dulcis (Mill.) D.A. Webb]

BACKGROUND

Water stress during the growing season of the almond tree is the factor that most limits its yield. Different strategies have been studied in recent years to reduce its negative effects, such as deficit irrigation and the application of reflective spray compounds. A 3-year experiment (2019-2021) was set in a factorial design in which the effect of regulated deficit irrigation and foliar kaolin spray was evaluated on morphological characteristics (weight, length, width, and thickness of the nut and kernel, shell thickness, kernel yield, double kernels, and damaged kernels), color properties, nutritional value (carbohydrates, fat, proteins and ash) and chemical parameters (free sugars and fatty acids profiles).

RESULTS

In general, the significant differences between the treatments did not have a similar trend in the 3 years of the study. Regulated deficit irrigation and kaolin had no detrimental impact on almond morphological and color characteristics. The almond free sugars concentration was relatively stable under deficit irrigation and kaolin application. On the other hand, kaolin application positively affected the synthesis of linoleic acid.

CONCLUSION

Reducing the amount of irrigation water applied to almonds contributes to the sustainability of production without negatively affecting quality and even improving some quality parameters. In general, the foliar application of kaolin did not show significant differences in the evaluated morphological parameters. However, in terms of chemical composition, kaolin led to an increase in the concentration of linoleic acid and sucrose. © 2023 Society of Chemical Industry.

The effect of α-tocopherol incorporated into different carriers on the oxidative stability of oil in water (O/W) emulsions

The effect of the antioxidant activity of α-tocopherol incorporated into different carriers on the oxidative stability of oil in water emulsion was investigated. The antioxidant activity of free and encapsulated α-tocopherol was measured in a 2,2-diphenyl-1-picrylhydrazyl reaction. Apart from α-tocopherol micelles, the samples showed similar antioxidant activity. The number of primary oxidation products in the emulsion with tocopherol liposomes and niosomes was lower than in the emulsion with micelles. During storage, the lipid peroxides gradually increased, whereas in emulsion with no α-tocopherol carriers added they remained constant. The content of the conjugated dienes first increased, and after 14 days at the end of testing time it remained stable in both types of emulsions. Our results might suggest that α-tocopherol when encapsulated into carriers exhibits lower antioxidant activity. The results obtained could be due to the better solubility of α-tocopherol in lipid droplets and thus the lower availability for the interfacial region, which is thought to be the place of the most pronounced lipid oxidation.

Harnessing sponge gourd: an alternative source of oil and protein for nutritional security

Luffa cylindrica (L.) Roem. is an important cucurbit crop that assures food security and dietary diversity among the poor communities. In the present study, seeds of 42 genotypes of Luffa cylindrica were evaluated for their potential use as oil seed crop. Seed moisture, oil and protein content and fatty acids profile were estimated along with total phenol and sugar content. Significant differences were observed among the various genotypes where oil content ranged from 15.4-29.8% and protein 19.9-30.8%. Total phenol content was high 6.43-12.84 mg/100 g, which bodes well for the sponge gourd seeds' ability to act as antioxidants. Significant correlation were found between important constituents studied like protein and oil, palmitic acid, stearic acid and oleic acid. Total unsaturated fatty acids were in higher amount comparable to saturated fatty acids signifying the good quality of Luffa seed oil. Our research revealed that the NDSG-1, Pusa Sneha, DSG-95, DSG-98, DSG-108, and DSG-26 genotypes were very nutritious due to their high levels of protein, oleic acid, and oil output. Additionally, selection of traits having considerable correlation will be beneficial and help in improved varietal development for usage as an alternative oilseed crop. Our research sheds light on the nutritional value of sponge gourd seeds and suggests using them as a potential source for oil and protein, particularly in underdeveloped countries.

Chemical Compositions of Walnut (Juglans Spp.) Oil: Combined Effects of Genetic and Climatic Factors

Walnut oil is a high-value oil product. Investigation of the variation and the main climatic factors affecting the oil’s chemical composition is vital for breeding and oil quality improvement. Therefore, the fatty acid, micronutrients, and secondary metabolites compositions and contents in walnut oil were determined in three species: Juglans regia L. (common walnut), J. sigillata Dode (iron walnut), and their hybrids (Juglans sigillata Dode × J. regia L.), which were cultivated aat different sites. The major fatty acids were linoleic (51.39–63.12%), oleic (18.40–33.56%), and linolenic acid (6.52–11.69%). High variation in the contents of fatty acids, micronutrients, and secondary metabolites was found between both species and sites. Interestingly, myristic, margaric, and margaroleic acid were only detected in the hybrids’ walnut oil, yet α-tocopherol was only detected in common and iron walnut oil. Climatic factors significantly affected the composition and content of fatty acid, whereas δ-tocopherol was mostly dependent on the genetic factors. The average relative humidity explained the most variation in the fatty acids, micronutrients, and secondary metabolites, which showed a significant positive and negative effect on the monounsaturated fatty acids and polyunsaturated fatty acids, respectively. These findings contribute to the provision of better guidance in matching sites with walnut trees, and improvement of the nutritional value of walnut oil.

A Detailed Comparative Study on Some Physicochemical Properties, Volatile Composition, Fatty Acid, and Mineral Profile of Different Almond (Prunus dulcis L.) Varieties

In the present investigation, the main purpose of the research was to reveal the differences among the almond genotypes in terms of their physicochemical properties, volatile composition, fatty acid, and mineral profile. For that reason, ten different almond genotypes originated from different countries were subjected to relevant analysis. The results showed that the total oil, protein, and ash levels of the almond samples ranged between 30.84–41.43%, 17.43–22.72%, and 2.90–3.40%, respectively. Additionally, total phenolic content of the samples was in the range of 38.7–101.03 mg GAE/100 g sample. It was revealed that the almond samples were rich in monounsaturated fatty acids, and oleic acid was the major one with levels of 61.22–77.63%. For all samples, potassium, magnesium, and phosphorus were the major minerals, and the highest concentration was for potassium with levels of 6192.08–11,046.05 mg/kg. Volatile profile analysis showed that the toluene, 4-octanone, pinacol, and 2-methylpentanal were the dominant volatile compounds for all almond genotypes. The results revealed that the different almond varieties showed significant differences depending on the origin.

Prunus mira Koehne in Sichuan, China: Recorded History as a Medicine and Food, Modern Applications, Distribution, and Ethnobotanical Investigations

Prunus mira Koehne, a Prunus plant in the Rosaceae family, is named ཁམབུ། in Tibetan and "Guang he tao" in Chinese. It is mainly distributed in Tibet Autonomous Region, Yunnan Province, and Sichuan Province in China. It is also a rare "living fossil group" of peach genetic resources in the world. It is used in traditional Chinese medicine for the treatment of dysmenorrhea, injury, intestinal dryness, constipation, and other diseases, and is used in Tibetan medicine for the treatment of hair, eyebrows, and beard shedding. In this article, the botanical characteristics, medicinal history, modern applied research, and ethnobotanical investigation of P. mira were recorded and evaluated. P. mira was first recorded in Dumu Materia Medica. P. mira in Sichuan Province is mainly distributed in Ganzi Tibetan Autonomous Prefecture, and has certain economic and medicinal value. P. mira has high nutritional composition. It is made into high-quality edible oil, cosmetic base oil, fruit juice, fruit wine, fruit vinegar, "Liang guo", and other products. Oleic acid and linoleic acid are the main fat-soluble components of P. mira, which has an anti-inflammatory medicinal value and promotes hair growth. Its longevity and cold resistance can bring great genetic value and play an important role in maintaining peach genetic diversity. At present, there are few studies on the pharmacological effects of specific active components of P. mira and there are also few clinical studies. We can continue to study these aspects in the future. At the same time, products of P. mira have great market potential. All in all, P. mira is very worthy of further research and development.

Influence of Pressure Extraction Systems on the Performance, Quality and Composition of Virgin Almond Oil and Defatted Flours

Almond is the most cultivated nut throughout the world. The oil content of almonds in most varieties exceeds 50%, which encourages the oil extraction to be used in gastronomy or in the cosmetic industry. The preferred system to extract almond oil is by means of pressure, which leads to obtaining a virgin oil ready for consumption. In this work, almond oil has been obtained using two pressure systems: screw press (SP) and hydraulic press (HP). The performance of both methods, as well as their influence on quality and composition characteristics of the almond oils obtained are analyzed from both a physical-chemical and sensory point of view. From an industry perspective, the highest oil yield is obtained with the SP when it operates at temperatures of 100–150 °C. Regarding the quality and chemical composition, the oils obtained by HP showed better quality indices, as they are subjected to a less aggressive treatment without influence of temperature, but lower content in total sterols. Fatty acid pattern, characterized by the predominance of unsaturated fatty acids (>90%), was not affected by the pressing system. The different operational conditions tested did not greatly affect the performance or composition of the oils obtained, but sensory tests showed two clearly differentiated products, the oil obtained by HP and that obtained by SP, according to consumer preferences. The defatted almond flours obtained as a by-product of the oil extraction process are characterized by a high content in protein and fiber, and a higher content in fat when the flour is produced from the pressing cake of HP.

Variability of Chemical Profile in Almonds (Prunus dulcis) of Different Cultivars and Origins

Almonds show a great variability in their chemical composition. This variability is a result of the existence of a diverse range of almond cultivars, the self-incompatibility of most almond cultivars, and the heterogeneous harvesting conditions found around the different locations where almons are grown. In the last years, the discrimination among almond cultivars has been the focal point of some research studies to avoid fraud in protected geographical indications in almond products and also for selecting the best cultivars for a specific food application or the most interesting ones from a nutritional point of view. In this work, a revision of the recent research works related to the chemical characterization and classification of almond cultivars from different geographical origins has been carried out. The content of macronutrients, tocopherols, phytosterols, polyphenols, minerals, amino acids, and volatile compounds together with DNA fingerprint have been reported as possible cultivar and origin markers. The analysis of the results showed that no individual almond compound could be considered a universal biomarker to find differences among different almond cultivars. Hence, an adequate selection of variables or the employment of metabolomics and the application of multivariate statistical techniques is necessary when classification studies are carried out to obtain valuable results. Meanwhile, DNA fingerprinting is the perfect tool for compared cultivars based on their genetic origin.

Effects of Different Processing Treatments on Almond (Prunus dulcis) Bioactive Compounds, Antioxidant Activities, Fatty Acids, and Sensorial Characteristics

Almond is one of the most commonly consumed nuts worldwide, with health benefits associated with availability of bioactive compounds and fatty acids. Almond is often eaten raw or after some processing steps. However, the latter can positively or negatively influence chemical and sensorial attributes of almonds. This work was carried out to assess the effects of two processing treatments, namely; roasting and blanching on (i) contents of bioactive compounds, (ii) contents of fatty acids (3) antioxidant activities (4), sensorial characteristics of four neglected Portuguese almond cultivars (Casanova, Molar, Pegarinhos and Refêgo) and two foreign cultivars (Ferragnès and Glorieta). Results showed that in general, levels of bioactive compounds and antioxidant activities increased with roasting and decreased with blanching. Fatty acid profiles of raw kernels of all cultivars were generally identical although Refêgo exhibited a high content of α-linolenic acid. Following roasting and blanching, content of polyunsaturated fatty acids increased while saturated fatty acids, monounsaturated fatty acids and several health lipid indices decreased. Roasting positively affected perception of skin color and sweetness of Ferragnès and Glorieta as well as skin roughness of Molar and Pegarinhos. Blanching on the other hand led to positive changes in textural properties of Refêgo and Pegarinhos. This study reveals the nutritive benefits of consuming neglected almond cultivars in Portugal, and the novel data reported here could be of interest to growers, processing companies and consumers.

Effect of almond genotypes on fatty acid composition, tocopherols and mineral contents and bioactive properties of sweet almond (Prunus amygdalus Batsch spp. dulce) kernel and oils

Oil content of almond kernels ranged from 36.7% in the cultivar T12 to 79.0% in genotype T27. The major fatty acid in almond oil is oleic (62.43% in T7-76.34% in T4) followed by linoleic (13.97% in T4-29.55% in T3) and palmitic (4.97% in T2-7.51% inT3). The main tocopherol in almond oil was α-tocopherol (44.25 mg/100 g in T25-75.56 mg/100 g in T13) that was 44 folds higher than other tocopherols in the oil. Total tocopherol contents of almond oils ranged between 47.42 mg/100 g (T14) and 80.15 mg/100 g (T16). Among macro minerals, K was the highest (5238-14,683 mg/kg), followed by P (3475-11,123 mgkg), Ca (1798-5946 mg/kg), and Mg (2192-3591 mg/kg), whereas Na was the least (334-786 mg/kg) in almond kernel. The total polyphenol was observed in T16 (98.67 mg GAE/100 g), while the least was found in T24 (23.75 mg GAE/100 g). Antioxidant activity was high in T7 (91.18%) and low in T12 (44.59%).

The effect of the subcritical fluid extraction on the quality of almond oils: Compared to conventional mechanical pressing method

This study investigated the effect of different almond oil extraction techniques, namely, cold-press extraction (CP), hydraulic press extraction (HP), and subcritical fluid extraction (SFE), on the fatty acid composition, physicochemical properties, bioactive substances, and thermal stability. The results showed that oleic acid and linoleic acid were the main unsaturated fatty acids in almond oil (AO). The overall physicochemical properties of the AO (SFE) had the better oil quality compared to cold-press extraction and hydraulic press extraction in three kinds of varieties. Almond oil extracted from SFE contained the highest levels of total phenolics (9.58-11.75 mg/100 g), total phytosterols (92.86-244.21 mg/100 g), total tocopherols, and tocotrienols (48.03-55.74 mg/100 g). Meanwhile, the TG/DTG curves showed AO (SFE) were more thermally stable than AO (CP) and AO (HP) consistent with the result of oxidative induction time. Subcritical fluid extraction may be a useful extraction technology to produce high-quality almond oils in the future.

Phenolic and fatty acid profiles, α-tocopherol and sucrose contents, and antioxidant capacities of understudied Portuguese almond cultivars

Almonds have recognized health benefits, which are largely attributed to their chemical composition, including fatty acids, phenolics, vitamin E, and sucrose. This study was carried with the aim of providing information on the levels of the aforementioned bioactive compounds and antioxidant activities in six understudied Portuguese cultivars (Amendoão, Bonita, Casanova, Molar, Pegarinhos-Moncorvo, Pegarinhos-Murça and Refêgo), in comparison with two foreign cultivars (Ferragnès and Glorieta). A cultivar effect was observed for all the parameters evaluated, with some Portuguese cultivars comparing well and even favorably with the foreign ones. A multivariate analysis of the data allowed a clear discrimination of cultivars and that statistical tool could be used for authenticity purposes, especially for cultivars included in the Protected Designation of Origin "Amêndoa Douro." PRACTICAL APPLICATIONS: Almonds are among the most consumed nuts worldwide, with a considerable number of cultivars recorded around the world, although research has been neglecting the local cultivars. This work studies the chemical composition of several understudied cultivars and compares them to two widespread commercial ones. The results not only provide new information about these neglected cultivars, but also provide data for stakeholders to select more interesting cultivars with particular characteristics/or rich in compounds of interest.

Nutritional quality of almond, canarium, cashew and pistachio and their oil photooxidative stability

Daily consumption of nuts is recommended as a part of a healthy diet as they contain protein and are rich in beneficial fatty acids and essential nutrients. The nutritional qualities of nuts are affected by their fatty acid composition and other factors such as maturity. Oil oxidative stability is important to determine nut nutritional quality in terms of fatty acid composition over storage. Therefore, this study aimed to (a) assess the nutritional quality (photooxidative stability and nutrient composition) of almond, cashew, pistachio and canarium (a newly commercialised indigenous nut); and (b) explore differences in nutrient concentrations between immature and mature canarium nuts. A decrease in polyunsaturated fats after photooxidation in almond and pistachio was observed. Canarium oil did not change following photooxidation suggesting canarium may display a long shelf life when stored appropriately. Our study indicated that almond provided over 50% of the recommended daily intake for manganese whereas canarium intake provided 50% of the recommended daily intake for iron (for males). Pistachio was richer in potassium compared with other nuts and canarium was richer in boron, iron and zinc than other nut species. Mature canarium kernels were richer in boron, iron and zinc but contained less potassium than immature canarium. Therefore, the current study recommended to store kernels in dark to decrease oil photooxidation, and maturity of canarium kernels at the harvest time was important affecting nutrient concentrations of kernels.

Genotypic and Environmental Effects on Tocopherol Content in Almond

Almond is the most important nut species worldwide and almond kernels show the highest levels of tocopherols among all nuts. In almond, tocopherols not only play a substantial role as a healthy food for human consumption, but also in protecting lipids against oxidation and, thus, lengthening the storage time of almond kernels. The main tocopherol homologues detected in almond in decreasing content and biological importance are α-, γ-, δ-, and β-tocopherol. Tocopherol concentration in almond depends on the genotype and the environment, such as the climatic conditions of the year and the growing management of the orchard. The range of variability for the different tocopherol homologues is of 335-657 mg/kg of almond oil for α-, 2-50 for γ-, and 0.1-22 for β-tocopherol. Drought and heat have been the most important stresses affecting tocopherol content in almond, with increased levels at higher temperatures and in water deficit conditions. The right cultivar and the most appropriate growing conditions may be selected to obtain crops with effective kernel storage and for the most beneficial effects of almond consumption for human nutrition and health.

Fatty acid profiling and multivariate analysis in the genus Leucas reveals its nutritional, pharmaceutical and chemotaxonomic significance

Genus Leucas with about 41 species found in India, is an Asian genus with separation from its close relatives in Africa based on phylogenetic evidence. Present study represents the only comprehensive phytochemical investigation on this genus. We have analyzed the seed fatty acid compositions of 26 species and five varieties of Leucas for nutritional, pharmaceutical and chemotaxonomic perspectives. The fatty acids and their composition in seeds of Leucas species, collected from different geographical regions in India, were analyzed by gas chromatography and mass spectrometry. Significant variations have been observed in fatty acid profiles among species and their varieties. We observed major fatty acids as palmitic, stearic, oleic, linoleic and laballenic acid; whereas myristic, palmitoleic, cis-vaccenic, linolenic, eicosanoic, eicosenoic, phlomic and docosanoic acid were detected in minor quantities. Laballenic and phlomic acids are unusual allenic fatty acids found in few Lamiaceae members from order Lamiales. Laballenic acid, a proven molecule of pharmaceutical importance, was observed in all the Leucas species studied. Three species of Leucas; L. helianthimifolia, L. ciliata var. vestita and L. hirta were found to contain ≥40% laballenic acid and can act as potential source for isolation of pharmaceutical compounds. This study also reports the presence of another allenic fatty acid, phlomic acid, in several Leucas species. Principal component analysis and hierarchical cluster analysis showed a distinct separation among the species based on abundance of similar fatty acids. The fatty acid profile appears to be overlapping at higher level and does not support separation of Asian Leucas from its African relatives and the inclusion of Asian taxa in morphologic sections. However, hierarchical clustering of L. helianthimifolia, L. ciliata var. vestita and L. hirta supported treatment under the morphologic section Astrodon. Multivariate analysis on the chemometric data also supported this cluster as the most prominent source of medicinally useful laballenic acid. Based on the FAs profile, a reconsideration of species boundaries in L. ciliata and L. marrubioides species complex is proposed.

Effects of roasting on kernel peroxide value, free fatty acid, fatty acid composition and crude protein content

Roasting nuts may alter their chemical composition leading to changes in their health benefits. However, the presence of testa may alleviate the negative effects of thermal treatments. Hence, this study aimed to explore the effects of roasting on kernel chemical quality and colour development of Canarium indicum and examine to what extent testa would protect kernels against damage from roasting. Roasting decreased peroxide value but increased free fatty acid, probably due to increased cell destruction and lack of enzyme inactivation, respectively. Protein content of kernels significantly decreased after roasting compared to raw kernels. However, testa-on kernels contained significantly higher protein content compared to testa-off kernels. Whilst colour development and mottling were observed in temperatures beyond 120°C, roasting did not alter fatty acid compositions of kernels. The mild roasting and presence of testa in kernels can be used to enhance health benefits of kernels.

Antioxidant and Antiproliferative Activities of Purslane Seed Oil

The aim of this study was to evaluate the antioxidant and antiproliferative activities of PSO in vitro and its application in horse oil storage. We determined the reducing power of PSO and its scavenging effects on hydroxyl (•OH) and 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH•) and tested its stabilizing effects on horse oil storage. The results showed that PSO had remarkable, dose-dependent antioxidant activities, and it effectively prevented horse oil lipid oxidation. We treated cervical cancer HeLa cells, esophageal cancer Eca-109 cells and breast cancer MCF-7 cells with PSO using non-neoplastic monkey kidney Vero cells as controls. The results indicate that PSO significantly inhibited tumor cell growth in a time- and dose-dependent fashion. Our studies suggest that PSO may be used as a substitute for synthetic antioxidants in food preservation and may be potentially useful as a food and cosmetic ingredient. Meanwhile, the oxidative stress can cause hypertension, so PSO is expected to develop a health care products for the prevention and mitigation hypertensive symptoms.

Impact of Species and Variety on Concentrations of Minor Lipophilic Bioactive Compounds in Oils Recovered from Plum Kernels

The profile of bioactive compounds (carotenoids, tocopherols, tocotrienols, phytosterols, and squalene) in oils recovered from the kernels of 28 plum varieties of hexaploid species Prunus domestica L. and diploid plums Prunus cerasifera Ehrh. and their crossbreeds were studied. Oil yields in plum kernels of both P. cerasifera and P. domestica was in wide ranges of 22.6-53.1 and 24.2-46.9% (w/w) dw, respectively. The contents of total tocochromanols, carotenoids, phytosterols, and squalene was significantly affected by the variety and ranged between 70.7 and 208.7 mg/100 g of oil, between 0.41 and 3.07 mg/100 g of oil, between 297.2 and 1569.6 mg/100 g of oil, and between 25.7 and 80.4 mg/100 g of oil, respectively. Regardless of the cultivar, β-sitosterol and γ-tocopherol were the main minor lipophilic compounds in plum kernel oils and constituted between 208.5 and 1258.7 mg/100 g of oil and between 60.5 and 182.0 mg/100 g of oil, respectively. Between the studied plum species, significant differences were recorded for δ-tocopherol (p = 0.007), 24-methylenecycloartanol (p = 0.038), and citrostadienol (p = 0.003), but they were insufficient for discrimination by PCA.

Influence of storage on volatile profiles in roasted almonds (Prunus dulcis)

Hexanal, peroxide value, and lipid hydroperoxides are common indicators of lipid oxidation in food products. However, these markers are not always reliable as levels are dynamic and often can be detected only after significant oxidation has occurred. Changes in the volatile composition of light- and dark-roast almonds were evaluated during storage over 24 weeks at 25 or 35 °C using headspace solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS). Several volatile changes were identified in association with early oxidation events in roasted almonds. Hexenal decreased significantly during the first 6 weeks of storage and did not increase above initial levels until 20-24 weeks of storage depending upon the degree of roast. In contrast, levels of 1-heptanol and 1-octanol increased at 16-20 weeks, depending upon the degree of roast, and no initial losses were observed. Seventeen new compounds, absent in raw and freshly roasted almonds but detectable after 6 weeks of storage, were identified. Of these, 2-octanone, 2-nonanone, 3-octen-2-one, 2-decanone, (E)-2-decenal, 2,4-nonadienal, pentyl oxirane, and especially acetic acid increased significantly (that is, >10 ng/g). The degree of roasting did not correlate with the levels of these compounds. Significant decreases in roasting-related aroma volatiles such as 2-methylbutanal, 3-methylbutanal, furfural, 2-phenylacetaldehyde, 2,3-butanedione, 2-methylpyrazine, and 1-methylthio-2-propanol were observed by 4 weeks of storage independent of the degree of roast or storage conditions.

Pollination and plant resources change the nutritional quality of almonds for human health

Insect-pollinated crops provide important nutrients for human health. Pollination, water and nutrients available to crops can influence yield, but it is not known if the nutritional value of the crop is also influenced. Almonds are an important source of critical nutrients for human health such as unsaturated fat and vitamin E. We manipulated the pollination of almond trees and the resources available to the trees, to investigate the impact on the nutritional composition of the crop. The pollination treatments were: (a) exclusion of pollinators to initiate self-pollination and (b) hand cross-pollination; the plant resource treatments were: (c) reduced water and (d) no fertilizer. In an orchard in northern California, trees were exposed to a single treatment or a combination of two (one pollination and one resource). Both the fat and vitamin E composition of the nuts were highly influenced by pollination. Lower proportions of oleic to linoleic acid, which are less desirable from both a health and commercial perspective, were produced by the self-pollinated trees. However, higher levels of vitamin E were found in the self-pollinated nuts. In some cases, combined changes in pollination and plant resources sharpened the pollination effects, even when plant resources were not influencing the nutrients as an individual treatment. This study highlights the importance of insects as providers of cross-pollination for fruit quality that can affect human health, and, for the first time, shows that other environmental factors can sharpen the effect of pollination. This contributes to an emerging field of research investigating the complexity of interactions of ecosystem services affecting the nutritional value and commercial quality of crops.

Lipidomic fingerprint of almonds (Prunus dulcis L. cv Nonpareil) using TiO₂ nanoparticle based matrix solid-phase dispersion and MALDI-TOF/MS and its potential in geographical origin verification

A matrix solid-phase dispersion (MSPD) procedure with titanium dioxide (TiO2) nanoparticles (NP) as sorbent was developed for the selective extraction of phospholipids from almond samples, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) was employed for analysis. A remarkable increase in the signals of phospholipid accompanied by a decrease in those of triacylglycerols and diacylglycerols was observed in the relevant mass spectra. The proposed method was applied to five batches of almonds originating from four geographical areas, whereas principal component analysis (PCA) was utilized to normalize the relative amounts of the identified phospholipid species. The results indicated that the lipidomic fingerprint of almonds was successfully established by the negative ion mode spectrum, and the ratio of m/z 833.6 to 835.6 as well as m/z 821.6 could be introduced as potential markers for the differentiation of the tested almonds with different geographical origins. The whole method is of great promise for selective separation of phospholipids from nonphospholipids, especially the glycerides, and superior in fast screening and characterization of phospholipids in almond samples.

Herbal supplements in pregnancy: unexpected results from a multicentre study

STUDY QUESTION

How common is the use of herbal supplements during pregnancy and does it adversely affect the pregnancy outcome?

SUMMARY ANSWER

The use of herbal products during pregnancy is very common and daily almond oil spreading is associated with preterm birth (PTB).

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Herbal drugs are often promoted as 'natural' and 'safe' and such claims attract pregnant women. More than a quarter of Italian pregnant women consume herbs every day for at least 3 months during pregnancy. We raise an alert over the habit of daily almond oil spreading since it seems to be associated with PTB.

DESIGN

A multicenter retrospective cohort study performed over a 15-month period.

PARTICIPANTS AND SETTING

Seven hundred women interviewed within 3 days of childbirth, in three public hospitals in northern Italy.

MAIN RESULTS AND ROLE OF CHANCE

One hundred and eighty-nine women were considered 'regular users', since they consumed herbs every day, for at least 3 months. Almond oil, chamomile and fennel were the most commonly used herbs. Both length of gestation and birthweight were affected by herb consumption. Almond oil users showed more pre-term birth (29 of 189) than non-users (51 of 511). After adjusting for multiple pregnancies, smoking, advanced age and drug intake, almond oil users maintained an increased risk to give birth <37th week (odds ratio = 2.09, 95% confidence interval: 1.08-4.08).

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

The association between daily spreading of almond oil and PTB only raises a hypothesis that requires confirmation in larger trials devoted to this topic. The relatively small sample size did not allow the investigation of other adverse pregnancy outcomes in herb users.

GENERALIZABILITY TO OTHER POPULATIONS

The population under investigation did not significantly differ from the general population attending the same hospitals.

STUDY FUNDING/COMPETING INTEREST(S)

No conflict of interest exists. The study has been supported by a public grant from the University of Modena and Reggio Emilia.

TRIAL REGISTRATION NUMBER

None.

Mapping quantitative trait loci for kernel composition in almond

BACKGROUND

Almond breeding is increasingly taking into account kernel quality as a breeding objective. Information on the parameters to be considered in evaluating almond quality, such as protein and oil content, as well as oleic acid and tocopherol concentration, has been recently compiled. The genetic control of these traits has not yet been studied in almond, although this information would improve the efficiency of almond breeding programs.

RESULTS

A map with 56 simple sequence repeat or microsatellite (SSR) markers was constructed for an almond population showing a wide range of variability for the chemical components of the almond kernel. A total of 12 putative quantitative trait loci (QTL) controlling these chemical traits have been detected in this analysis, corresponding to seven genomic regions of the eight almond linkage groups (LG). Some QTL were clustered in the same region or shared the same molecular markers, according to the correlations already found between the chemical traits. The logarithm of the odds (LOD) values for any given trait ranged from 2.12 to 4.87, explaining from 11.0 to 33.1 % of the phenotypic variance of the trait.

CONCLUSIONS

The results produced in the study offer the opportunity to include the new genetic information in almond breeding programs. Increases in the positive traits of kernel quality may be looked for simultaneously whenever they are genetically independent, even if they are negatively correlated. We have provided the first genetic framework for the chemical components of the almond kernel, with twelve QTL in agreement with the large number of genes controlling their metabolism.

Postprandial effects of almond consumption on human osteoclast precursors--an ex vivo study

Consumption of almonds has been associated with increased bone mineral density, but the direct effects of almonds on bone cells are not known. We determined whether serum obtained following the consumption of a meal containing 60 g of almonds affects human osteoclast formation, function, and gene expression in vitro. Human osteoclast precursors were cultured in medium containing 10% serum obtained from 14 healthy subjects at baseline and 4 hours following the consumption of 3 test meals containing almonds, potatoes, and rice and balanced for macronutrient composition. Osteoclast formation was determined by the number of tartrate-resistant acid phosphatase (TRAP)(+) multinucleated cells, and osteoclast function was assessed by measuring TRAP activity in the culture medium and calcium released from OsteoAssay (Lonza Walkersville, Walkersville, MD, USA) plates. The expression of cathepsin K, receptor activator of nuclear factor kB, and matrix metalloproteinase-9 genes was measured by real-time reverse transcriptase-polymerase chain reaction. Compared with serum obtained at baseline, serum obtained 4 hours following the consumption of the almond meal reduced osteoclast formation by approximately 20%, TRAP activity by approximately 15%, calcium release by approximately 65%, and the expression of cathepsin K, receptor activator of nuclear factor kB, and matrix metalloproteinase-9 by 13% to 23%. No effects were observed with serum obtained from the other test meals. Serum obtained 4 hours following the consumption of an almond meal inhibits osteoclast formation, function, and gene expression in cultured human osteoclast precursors, and provides evidence for a positive effect of almonds on bone health.

Tocopherol concentration in almond oil: genetic variation and environmental effects under warm conditions

The concentration of the different tocopherol homologues in almond kernel oil was determined in 17 almond cultivars grown in two different experimental orchards, in Spain and Morocco. The three main homologues showed a large variability, ranging from 210.9 to 553.4 mg/kg of oil for α-tocopherol, from 4.64 to 14.92 mg/kg for γ-tocopherol, and from 0.2 to 1.02 mg/kg for δ-tocopherol. The year effect was significant, independent of the experimental site, for all homologues and total tocopherol, the values of α-tocopherol, γ-tocopherol, and total tocopherol being higher in 2009 than in 2008, whereas the value of δ-tocopherol was higher in 2008. The location effect was also significant, the values of γ- and δ-tocopherol being higher in Spain than in Morocco, whereas for α-tocopherol the location effect was dependent on the genotype. These effects could not be explained by the temperature differences between sites, but probably other undetermined environmental factors might explain the effect of the location, such as rainfall and irrigation supplementation during fruit growing and ripening.