Bitter Almond,Plum and Mango Kernels as Sources of Lipids

The chemical composition of bitter almond, plum and mango kernels and the physico-chemical characteristics of their lipids were studied. Bitter almond and plum kernels contained higher amounts of lipids in comparison to mango kernels. All kernel lipids were found free from hydrocyanic acid. The predominant lipid class of the studied kernel lipids was triglycerides. Oleic acid was the major fatty acid present in bitter almond and plum kernel lipids, while mango kernel lipids were rich in stearic and oleic acid.     

Developmental changes in fatty acid composition of oil in kernel fractions of corn (Zea mays L.)

Gas liquid chromatography was used to determine the change in fatty acid composition of oil from three kernel fractions (pericarp, endosperm and germ) during kernel maturation of four inbred lines of corn. Inbred lines were sibpollinated, and sampling of ears began six days after pollination (DAP) and continued at three day intervals until 33 DAP and then at weekly intervals until 54 DAP. Proportion of palmitic acid in the pericarp oil rapidly decreased between 6 and 12 DAP while oleic and linoleic acids increased during the same period. Changes in fatty acid composition of oil from the endosperm during kernel maturation were erratic and no consistent trends were evident. In the germ oil, palmitic and linolenic acid proportions decreased during kernel maturation, while oleic acid decreased and linoleic acid increased during kernel maturation for three of the four inbred lines. By about 24 to 27 DAP, the fatty acid composition of oil in the mature kernel was established. Since kernel fractions are of different genetic origin, a study of developmental changes in lipid classes or in fatty acid composition of oil should be limited within kernel fractions that have a similar genetic constitution. Approved as Journal Series Paper No. 723, University of Georgia, College of Agriculture Experiment Stations.     

Protein Content and Oil Composition of Almond from Moroccan Seedlings: Genetic Diversity, Oil Quality and Geographical Origin

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.     

Comparative Study of Tocopherol Contents and Fatty Acids Composition in Twenty Almond Cultivars of Afghanistan

Afghanistan is the fourth largest producer of almonds in the world producing 78 native and 6 imported cultivars. However, till date, there have been no comprehensive data on nutrient profiles of the native cultivars. Thus, in the present investigation, tocopherol contents and fatty acid composition from the kernels of 20 selected native almond cultivars of Afghanistan were analyzed. The ranges of variability for the studied nutrients were similar to those already reported for almonds grown in other countries, such as 47.8–66.1% of total lipids (fresh weight basis), 62.54–81.57% of oleic acid in the total lipids, and 139.1–355.0 μg/g α-tocopherol in kernels. With respect to cultivars, significantly (p < 0.05) high content of total lipids were recorded in ‘Belabai’ and ‘Sattarbai’ (Afghan grade), oleic acid in ‘Khairodini’ and of α-tocopherol in ‘Khairodini-161 Samangan’ and ‘Belabai’ cultivars. Kernels from these cultivars can be used for nutrient dense food formulations. Daily consumption of 50 g almonds is sufficient to meet the RDA of α-tocopherol (15 mg/day), considering the average 300 μg/g of α-tocopherol in Afghan almonds. Also, these nutrient rich cultivars can be used in almond breeding programs globally, to focus on improving kernel oil composition and nutrient contents.     

Chemometric classification of olive cultivars based on compositional data of oils

European Union regulations provide important guidelines for maintaining the Protected Designation of Origin (PDO) of olive oil and other foods. This includes characterization of foods based on variety (cultivar) and geographical origin, as this may be used as a criterion for determining authenticity and quality. Therefore, analytical method standards need to be established to ensure these criteria. This study describes how cultivar differences can be established between Italian oils, obtained from single varieties, based on acid, sterol, and TAG differences determined by chemometrics. TAG and FA composition provided the best basis for differentiation of olive oils among cultivars. The results were compared with those obtained using ¹³C NMR analysis, and a similar differentiation between oils of different cultivars was achieved. ¹³C NMR provides useful information on the acyl composition and on the positional distribution of the glycerol moiety and can be used for classification of cultivars based on oil composition. Furthermore, the advantages of this technique come from the rapidity with which information can be obtained and from the very simple preparation procedure required for analysis.     

Storage lipid accumulation and acyltransferase action in developing flaxseed

Investigations of storage lipid synthesis in developing flaxseed (Linum usitatissimum) provide useful information for designing strategies to enhance the oil content and nutritional value of this crop. Lipid content and changes in the FA composition during seed development were examined in two cultivars of flax (AC Emerson and Vimy). The oil content on a dry weight basis increased steadily until about 20 d after flowering (DAF). The proportion of α-linolenic acid (α-18∶3, 18∶3cisΔ^{9, 12, 15}) in TAG increased during seed development in both cultivars while the proportions of linoleic acid (18∶2cisΔ^{9, 12}) and saturated FA decreased. The developmental and substrate specificity characteristics of microsomal DAG acyltransferase (DGAT, Ec 2.3.1.20) and lysophosphatidic acid acyltransferase (LPAAT, EC 2.3.1.51) were examined using cultivar AC Emerson. The maximal acyltransferase specific activities occurred in the range of 8–14 DAF, during rapid lipid accumulation on a per seed basis. Acyl-CoA of EPA (20∶5cisΔ^5,8,11,14,17) or DHA (22∶6cis ^{4,7,10,13,16,19}) were included in the specificity studies. DGAT displayed enhanced specificity for α-18∶3-CoA, whereas the preferred substrate of LPAAT was 18∶2-CoA. Both enzymes could use EPA- or DHA-CoA to varying extents. Developing flax embryos were able to take up and incorporate these nutritional FA into TAG and other intermediates in the TAG-formation pathway. This study suggests that if the appropriate acyl-CoA-dependent desaturation/elongation pathways are introduced and efficiently expressed in flax, this may lead to the conversion of α-18∶3-CoA into EPA-CoA, thereby providing an activated substrate for TAG formation.     

Determination and Comparison of Oil Characteristics in Iranian Almond,Apricot and Peach Nuts

Oil characteristics of sweet and bitter kernels of 5 Iranian cultivars of almond, apricot and peach were determined. Fatty acid composition and fat constants of peach oil were very similar to those of almond oils. Apricot oils were considerably different from almond and peach oils. The differences, however, did not seem to be valuable for any practical use.     

Characterization of laurel fruit oil from Madeira Island,Portugal

The fixed oil extracted from Laurus spp. fruit from Madeira Island, Portugal, is used in local traditional medicine for a wide variety of health complaints. Physical properties, density and refractive index, as well as the TAG FA composition, sterols, and waxes were determined. The oil was found to have an unusually high content of volatiles (ca. 10%), with trans-ocimene and germacrene D predominating. Oleic (30%) and linoleic (20%) acids were the main unsaturated FA, whereas lauric (18%) and palmitic (up to 22.5%) acids were the main saturated FA in the neutral lipid fraction. The oil had a sterol content on the same order as olive oil, with β-sitosterol (84%) predominating. Two sesquiterpene lactones, dehydrocostuslactone and costunolide, accounted for 5% of the overall composition. Madeira laurel oil is not currently used as an edible oil because of its very strong flavor. Its claimed medicinal properties have not yet been validated, and this is the first report on the characterization of the commercial product.     

Classification of Four Almond Cultivars Using Oil Degradation Parameters Based on FTIR and GC Data

Four almond cultivars (Marcona, Guara, Garrigues and Butte) have been classified using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and gas chromatography (GC) data. The data were obtained by completing the first stages of a thermal oxidative degradation process. The degradation process was monitored by using the variations in the main fatty acid methyl esters (FAME) content determined by GC and to changes in the infrared spectra recorded using the ATR-FTIR technique. In order to classify the almond cultivars, a stepwise linear discriminant analysis was applied to the data. The results indicated that, although the four almond oils evaluated here have a similar fatty acid composition, differences in linoleic acid content may be linked to oxidative stability. Butte cultivar samples had higher linoleic acid content and were more prone to oxidative deterioration.     

Composition and seasonal variation of fatty acids of <Emphasis Type="Italic">Diplodus vulgaris</Emphasis> L. from the Adriatic Sea

Muscle tissue from the common two-banded sea bream Diplodus vulgaris L. originating from the Adriatic Sea, Croatia, was analyzed. The FA composition of neutral (TAG) and polar (PE, PC, PI/PS) lipid classes was determined, as well as the lipid and water contents during winter and summer periods. Both the total lipid and water contents were higher in the winter period. We identified 16 different FA. The major constituents of the total FA in both seasons were saturates: palmitic (16∶0) and stearic acids (18∶0); monoenes: oleic (18∶1n−9) and palmitoleic acids (16∶1n−7); and polyunsaturates: arachidonic acid (20∶4n−6), EPA (20∶5n−3), and DHA (22∶6n−3), but their amounts and ratios differed significantly between the two seasons and between lipid fractions. The FA composition showed a noticeable pattern of seasonality that reflected fluctuations mainly in TAG. The diminution of the monounsaturated FA content in the summer was clearly followed by an increase in PUFA content. Diplodus vulgaris is a good source of natural n−3 PUFA and would therefore be suitable for inclusion in highly unsaturated low-fat diets.     

Fatty Acid Profile of Sunshine Bass: II. Profile Change Differs Among Fillet Lipid Classes

Fatty acid (FA) profile of fish tissue mirrors dietary FA profile and changes in a time-dependent manner following a change in dietary FA composition. To determine whether FA profile change varies among lipid classes, we evaluated the FA composition of fillet cholesteryl esters (CE), phospholipids (PL), and triacylglycerols (TAG) of sunshine bass (SB, Morone chrysops x M. saxatilis) raised on feeds containing fish oil or 50:50 blend of fish oil and coconut, grapeseed, linseed, or poultry oil, with or without implementation of a finishing period (100% FO feed) prior to harvest. Each lipid class was associated with a generalized FA signature, irrespective of nutritional history: fillet PL was comprised largely of saturated FA (SFA), long-chain polyunsaturated FA (LC-PUFA), and total n-3 FA; fillet TAG was higher in MC-PUFA and total n-6 FA; and fillet CE was highest in monounsaturated FA (MUFA). Neutral lipids reflected dietary composition in a near-direct fashion; conversely, PL showed evidence of selectivity for MC- and LC-PUFA. Shorter-chain SFA were not strongly reflected within any lipid fraction, even when dietary availability was high, suggesting catabolism of these FA. FA metabolism in SB is apparently characterized by a division between saturated and unsaturated FA, whereby LC-PUFA are preferentially incorporated into tissues and SFA are preferentially oxidized for energy production. We demonstrated provision of SFA in grow-out feeds for SB, instead MC-PUFA which compete for tissue deposition, meets energy demands and allows for maximum inclusion of LC-PUFA within fillet lipids.     

Stereospecific distribution of fatty acids in triacylglycerols of olive oils

The positional distribution of fatty acids (FA) in triacylglycerols (TAG) of 47 virgin olive oils from diverse cultivars grown in distinct areas of North‐Eastern Italy was studied. Few data were previously available on oils from these geographical areas. The effects of climatic and geographical conditions on the stereospecific distribution of TAG in olive oil were confirmed. Moreover, the results of the stereospecific analysis were used to evaluate the preferential esterification position of each FA on the basis of the degree of unsaturation and the chain length. The data of the stereospecific analysis of olive oil TAG can contribute to the determination of the selectivity of olive fruit acyltransferases for distinct FA.     

Tocopherol Content and Fatty Acid Distribution of Peas (<Emphasis Type="Italic">Pisum sativum</Emphasis> L.)

The positional distribution of fatty acids (FA) of triacylglycerols (TAG) and major phospholipids (PL) prepared from four cultivars of peas (Pisum sativum L.) were investigated as well as their tocopherol contents. The lipids extracted from these peas were separated by thin-layer chromatography (TLC) into seven fractions. The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while the other components were also present in minor proportions (5.6–9.2%). γ-Tocopherol was present in the highest concentration, and α- and δ-tocopherols were very small amounts. The main PL components isolated from the four cultivars were phosphatidylcholine (42.3–49.2%), followed by phosphatidylinositol (23.3–25.2%) and then phosphatidylethanolamine (17.7–20.5%). Small but significant differences (P < 0.05) in FA distribution existed when different pea cultivars were determined. However, the principal characteristics of the FA distribution in the TAG and the three PL were evident among the four cultivars; unsaturated FA were predominantly located in the sn-2 position, and saturated FA primary occupied the sn-1 or sn-3 position in the oils of the peas. These results suggest that the regional distribution of tocopherols and fatty acids in peas is not dependent on the climatic conditions and the soil characteristics of the cultivation areas during the growing season.     

Quality Characteristics and Antioxidant Activity during Fruit Ripening of Three Monovarietal Olive Oils Cultivated in China

Numerous olive cultivars have been planted in China, mainly to reap the health benefits of olive oil. This study characterized the quality and investigated the antioxidant activity of olives harvested at three different maturation stages, defined by the skin color of the olives (black, purple, and green), from three newly introduced olive cultivars (Barnea, Manzanilla and Kadesh) grown in China. The oleic acid content of olives from all three olive cultivars decreased significantly during maturation, whereas the linoleic acid content increased. The highest content of total phenols was recorded in Manzanilla cultivar (284.94 mg kg⁻¹), whereas the lowest was recorded in Kadesh cultivar (134.82 mg kg⁻¹). In addition, a total of 13 individual phenolic compounds were obtained, and their concentrations were significantly influenced by the cultivar and maturity (P < 0.05). Secoiridoids were the main group of phenolic compounds, but their quantity decreased during maturation. The content of secoiridoids in the Manzanilla cultivar was significantly higher than that of the Barnea and Kadesh cultivars. In general, a significant decrease (P < 0.05) in the values of antioxidant activity and the contents of pigments, α-tocopherol, and squalene occurred during maturation. Furthermore, principal component analysis was used to classify the nine olive oil samples according to the cultivar and ripening degree.     

Seasonal Variations of Lipid Content and Composition in <Emphasis Type="Italic">Perna viridis</Emphasis>

The total lipid content, composition of main lipid classes, composition of sterols and composition of fatty acids in the main glycerolipids of Perna viridis were analyzed through four seasons using TLC-FID and GLC. Mussel samples were collected during different seasons between 2003 and 2004 from Shengsi Island, Zhejiang Province, China and stored frozen prior to freeze-drying and lipid extraction. Ten grams of dried mussel powder of each season were analyzed. Total lipid content ranged from 14.5 g/100 g in spring month to 7.8 g/100 g dried mussel powder in autumn month. The predominant lipid in spring month was triacylglycerol (TAG), however, in the other three seasons the phospholipids (PL) was the main lipid class. The most abundant fatty acid in TAG, PL and phosphatidylcholine (PC) was 16:0, with the summer samples having the highest proportion (24-30% of total fatty acid) and winter the lowest (14-22%). In phosphatidylethanolamine (PE), the spring samples had the highest proportions of 16:0. The predominant polyunsaturated fatty acids (PUFA) were 22:6n-3 and 20:5n-3 in TAG, PL, PE and PC (25-40%). The proportions of 22:6n-3 and 20:5n-3 were higher in spring than in other seasons in PL and PE. There were nine sterols identified, with cholesterol being the predominant sterol, and other main ones were desmostersol/brassicasterol and 24-methylenecholesterol. Proportions of other fatty acids in different lipid fractions and the sterol compositions as well also varied seasonally. There were subject to the seasonal variations. Differences in lipid content and composition, fatty acid composition in different lipid fractions may be caused by multiple factors such as lifecycle, sex, variation of plankton in different seasons and temperature, which could influence physiological activities and metabolism.     

In‐vitro study on the efficacy of tannin fractions of edible nuts as antioxidants

Tannin fractions were isolated from crude acetonic extracts of defatted walnut, hazelnut and almond kernels using Sephadex LH‐20 column chromatography. The obtained material was characterized by content of total phenolics and electrophoretic separations using capillary zone electrophoresis (CZE). The antioxidant activities of the tannin fractions were analyzed by several methods: DPPH and ABTS assays, photochemiluminescence (PCL) method, as well as in two lipid model systems: emulsion with β‐carotene‐linoleic acid and L ‐α‐lecithin liposomes. The contents of total phenolics in the tannin fractions of walnuts, hazelnuts and almonds were 550, 329 and 83 mg catechin eq/g, respectively. The electrophoretic profiles of hazelnut and almond tannin fractions were similar, in contrast to the walnut profile. All analyzed fractions exhibited strong antioxidant properties. The antioxidant capacity of lipid‐soluble (ACL) compounds determined by PCL method was the highest for the fraction isolated from walnuts – 7.35 mmol Trolox eq/g. The DPPH radical and the ABTS radical cation were scavenged by the walnut tannin fraction with a higher efficacy than by the two other fractions. EC₅₀ values of the DPPH method were 1.8 times higher for the hazelnut fraction and 2.3 times higher for the almond fraction when compared to the walnut tannins. In turn, the total antioxidant activity values were 8.17, 2.82 and 1.98 mmol Trolox eq/g for the walnut, hazelnut and almond fractions, respectively. On the other hand, in both lipid models applied, lower antioxidant activity of walnut tannins than of hazelnut tannins was noted. The antioxidant effect of almond tannins was weaker or similar than that of walnut tannins in the β‐carotene‐linoleic acid emulsion and the L ‐α‐lecithin liposomal system, respectively.     

Composition,anti-inflammatory,and antioxidant activities of avocado oil obtained from Duke and Fuerte cultivars

Avocado (Persea americana Mill.) fruit and oil are traditionally used for their antioxidant, anti-inflammatory and anti-aging properties. We investigated chemical variability between two avocado cultivars (Duke and Fuerte) in relation to their antioxidant and anti-inflammatory activities. Duke cultivar showed higher β-carotene and α-tocopherol content but significantly lower lipid content (36% dry weight) compared to Fuerte (52% dry weight). The ethanolic extract of Duke cultivar showed good antioxidant properties in 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay with IC₅₀ at 27.21 μg/ml, while that of Fuerte showed weak activity. Meanwhile, in rat paw edema anti-inflammatory model, Duke oil (15 mg/kg) was slightly more effective in reducing inflammation by 41.12% after 1 h compared to Fuerte oil (15 mg/kg). However, after 4 h, both oils showed comparable inhibition of edema by 35.39% and 34.14% (15 mg/kg). The study underscores that variability in chemical composition of different avocado cultivars could affect biological activities attributed to the fruit and its oil.     

Changes in olive oil composition due to microwave heating

The effects of microwave heating on some components of extra-virgin olive oil were studied. Traditional parameters, including free acidity, peroxide value and ultraviolet absorbance values at 232 and 268 nm, were determined in six extra-virgin olive oil samples before and after the microwave treatment. Significant differences (P<0.01) were detected for free acidity, peroxide, and ultraviolet absorbance at 268 nm; also, the absorbances at 232 nm showed significant differences (P<0.05) between treated and untreated samples. The glycerolic fractions, triacylglycerols (TAG), diacylglycerols (DAG), and monoacylglycerols (MAG), were isolated by thin-layer chromatography. The respective percentage fatty acid (FA) composition and percentage amount were obtained by high-resolution gas chromatography with an internal standard. For the most abundant TAG fraction, the stereospecific analysis was carried out to obtain the FA percentage compositions of the three sn-positions. Small but significant modifications were observed regarding the decrease in the TAG percentage and increases in the DAG and MAG percentage amounts. No significant changes were observed for the FA compositions of TAG, DAG, and MAG fractions before and after the treatment. Nevertheless, the results of TAG stereospecific analysis showed losses of unsaturated FA in all sn-positions. Higher percentage changes in the sn-1- than in sn-2-position of TAG were observed. Regarding the volatile fraction, different profiles were obtained after the treatment.     

Composition and Structure of Single Cell Oil Produced by Schizochytrium limacinum SR31

Schizochytrium limacinum sp. was commercially utilized to produce single cell oil (SCO), but its detailed lipid profile remains unknown. In order to analyze the composition and structure of SCO produced by Schizochytrium limacinum SR31, the SCO extracted at stationary growth phase was separated into neutral lipids (NL), polar lipids and glycolipids by using silica gel column chromatography. The result of lipid classes in NL revealed that triacylglycerol (TAG) was the primary glyceride (93.81 %). Fatty acid (FA) analysis by gas chromatography–mass spectrometer (GC–MS) proved that palmitic acid (29.78 %) and docosahexaenoic acid (25.64 %) were the major FA. Quadrupole time of flight mass spectrometry in electrospray ionization mode coupled with ultra‐performance liquid chromatography was carried out to investigate TAG structures. More than 80 species were identified. Positional distribution of FA in TAG might contribute to further study of the FA shifts during the lipid turnover stage and nutritional evaluation of the SCO.     

Effect of chemical interesterification on triacylglycerol and solid fat contents of palm stearin,sunflower oil and palm kernel olein blends

Palm stearin (POs) with an iodine value of 41.4, sunflower oil (SFO) and palm kernel olein (PKOo) were blended in various ratios according to a three‐component mixture design and subjected to chemical interesterification (CIE). Triacylglycerol (TAG) and solid fat content (SFC) profiles of the chemically interesterified (CIEed) blends were analyzed and compared with those of the corresponding non‐CIEed blends. Upon CIE, extensive rearrangement of fatty acids (FA) among TAG was evident. The concentrations of several TAG were increased, some decreased and several new TAG might also have been formed. The changes in the TAG profiles were reflected in the SFC profiles of the blends. The SFC of the CIEed blends, except the binary blends of POs/PKOo which experienced an increase in SFC following CIE, revealed that they were softer than their respective starting blends. Randomization of FA distribution within and among TAG molecules of POs and PKOo led to a modification in TAG composition of the POs/PKOo blends and improved miscibility between the two fats, and consequently diminished the eutectic interaction that occurred between POs and PKOo.