Effect of Acylglycerol Composition and Fatty Acyl Chain Length on Lipid Digestion in pH‐Stat Digestion Model and Simulated In Vitro Digestion Model

In this study, a pH‐stat digestion model and a simulated in vitro digestion model were employed to evaluate the digestion degree of lipids depending on different acylglycerols and acyl chain length (that is, diacylglycerol [DAG] compared with soybean oil representing long‐chain triacylglycerol compared with medium‐chain triacylglycerol [MCT]). In the pH‐stat digestion model, differences were observed among the digestion degrees of 3 oils using digestion rate (k), digestion half‐time (t_1/2), and digestion extent (Φmax). The results showed the digestion rate order was MCT > soybean oil > DAG. Accordingly, the order of digestion half‐times was MCT < soybean oil < DAG. In simulated in vitro digestion model, digestion rates (k′) and digestion half‐times (t′_1/2) were also obtained and the results showed a digestion rate order of MCT (k′ = 0.068 min^?1) > soybean oil (k′ = 0.037 min^?1) > DAG (k′ = 0.024 min^?1). Consequently, the order of digestion half‐times was MCT (t′_1/2 = 10.20 min) < soybean oil (t′_1/2 = 18.74 min) < DAG (t′_1/2 = 29.08 min). The parameters obtained using the 2 models showed MCT was digested faster than soybean oil, and that soybean oil was digested faster than DAG.     

Analysis of isomeric diacylglycerolic classes to evaluate the quality of olive oil in relation to storage conditions

The % content and the % fatty acid (FA) composition of the three isomeric classes of diacylglycerol (DAG) fraction (sn-1,2-, sn-2,3-, sn-1,3-DAG) were valued in four groups of extra virgin olive oils, stored in different conditions of temperature and time, with the objective to study the influence of the cited parameters on olive oil DAG classes. The separation and % quantitation of all isomeric DAG classes were carried out by normal phase-high performance liquid chromatography (NP-HPLC) on total DAG fraction previously isolated by TLC and subjected to derivatization step with (S)-(+)-(1-naphtyl)-ethylisocyanate; moreover the % FA composition of each DAG class was determined by HRGC analysis. The results showed notable differences on the % content of each DAG class as well as the ratios between the classes. The samples analysed as soon as they were produced showed the highest % contents for sn-1,2-DAG and the lowest for sn-1,3- and sn-2,3-DAG. The samples stored at 30 °C generally showed the highest % contents of sn-1,3-DAG, because of the isomerization processes of sn-1,2-DAG to the more stable sn-1,3-DAG. The results of structural analysis of the sn-1,2-DAG class besides confirmed that isomerization processes occurred and that the storage temperature had a predominant role; this research emphasizes the importance of the valuation of % contents together with the structural analysis of the isomeric DAG classes as useful analytical parameters to evaluate the storage conditions and the conservation status of olive oils.     

Production of Beta-Carotene from Synthetic Medium by Blakeslea trispora in Fed-batch Culture

Abstract

The production of β-carotene from a synthetic medium by Blakeslea trispora in fed-batch culture was investigated. A maximum β-carotene concentration of 85.0?mg?L^?1 with productivity of 0.16?mg?L^?1?h^?1 and specific β-carotene production rate of 0.01?mg?g^?1?h^?1 was obtained by feeding the cells constantly with olive oil, cottonseed oil, soybean oil, antioxidant, and low concentration of growth factors at feeding rate of 4.2?mL?h^?1 from the beginning of the fermentation. In this case, the fed-batch culture supported high values of biomass dry weight (11.0?g?L^?1) and sugar utilization (0.976?g?g^?1). The morphology of the fungus was studied during growth in fed-batch fermentation system using an image analysis system. Zygospores are the morphological forms, which are responsible for the production of the pigment. The highest percentage of zygospores (11.44%) was correlated with the highest percentage of intracellular β-carotene (0.72%) in the total biomass dry weight. Moreover, high percentages of vacuolated hyphae, evacuated cells, and degenerated hyphae of the microorganism were observed. This was due to the formation of high amount of H₂O₂ by exposure of the microorganism to high dissolved oxygen concentration.     

Effect of essential oils of cinnamon,clove, lemon grass,oregano and palmarosa on growth of and fumonisin B1 production by Fusarium verticillioides in maize

The ability of cinnamon, clove, lemon grass, oregano and palmarosa essential oils to prevent growth of and fumonisin B₁ (FB₁) production by Fusarium verticillioides at different water activity (0.95 and 0.995 a_w) and temperature (20 and 30 °C) levels in irradiated maize grain was evaluated. All the essential oils inhibited growth of F verticillioides isolates under all conditions tested, but FB₁ production was only inhibited at 30 °C and 0.995 a_w. Moreover, stimulation of toxin production was found under certain environmental conditions. None of the essential oils showed a significantly greater ability to inhibit FB₁ production when compared with the others. At 1000 mg essential oil kg^?1 maize the essential oils showed a greater inhibitory effect on growth of F verticillioides than at 500 mg kg^?1, but there was no difference in FB₁ production between the two levels of essential oil. Copyright © 2004 Society of Chemical Industry     

Fatty acid composition and oxidative stability of oils recovered from acid silage and bacterial fermentation of fish (Sea bass – Dicentrarchus labrax) by‐products

Lipid quality and fatty acid compositions of fish oils recovered from fish (Sea bass – Dicentrarchus labrax) waste silages produced with formic acid (FA) and five different LAB strains (Lactobacillus plantarum (LP), Pediococcus acidilactici (PA), Enterococcus gallinarum (EG), Lactobacillus brevis (LB) and Streptococcus spp. (ST)) were assessed to ensure for the usage for human consumption. Generally, it was observed that there were no significant differences between PUFA contents (23.27–23.64%). Peroxide (PV) (2.12 meq active O₂/per kg of oil) and TBA values (1.07 mg malonaldehyde (MA) g^?1 oil) of fish oils from acid silage were significantly higher than those of the fermented ones (1.14–1.91 meq active O₂ kg^?1, 0.67–0.81 mgMA g^?1 oil, respectively). Anisidine values (AV) were determined in range of 8.04–11.14 for fermented silages and 13.08 from acid silage. The highest totox value (17.33 ± 0.88) was also detected in acid silage oil whereas fermented groups gave totox value in the range of 10.40–13.88. It can be concluded that the initial lipid quality of fermented fish waste silages was better than the initial lipid quality of acid fish waste silage. Therefore, fish oils recovered from fermented silages can be used as food additives or supplements for animal and human diets.     

Improving the quality of fried oils by using different filter aids

The present study aimed to improve the quality of fried soybean, sunflower, palm and cottonseed oils. Synthetic (Magnesol XL) and natural (diatomaceous earth and kaolin) filter aids were used at various levels (1, 2 and 4%) to adsorb the secondary oxidation products of the oil. The metal patterns (the cations Si, Mg, Ca, Fe, Na, K, Al, Cu, Mn, Zn and the anions CO₃^2?, HCO₃^?, Cl^?, NO₃^?, NO₂^?, SO₄^2?) of Magnesol XL, diatomaceous earth and kaolin were determined. Some physical and chemical properties (refractive index, viscosity, colour, foam height, acid value, peroxide value, thiobarbituric acid value, iodine value, and conjugated diene and polymer contents) of non‐fried, fried and fried–treated soybean, sunflower, palm and cottonseed oils were determined. The frying process was performed at 180 °C ± 5 °C for 12 h continuous heating. The fried oils were treated with the synthetic and natural filter aids at 105 °C for 15 min. The results indicate that Magnesol XL, diatomaceous earth and kaolin contained Si + Mg, Si + Ca and Si + Al, respectively, as the basic metals. Frying soybean, sunflower, palm and cottonseed oils led to significant increases in refractive index, colour, foam height, viscosity, acid value, peroxide value, TBA value, conjugated diene and polymer contents and decrease in iodine value. Treatment of fried oils with Magnesol XL, diatomaceous earth and kaolin at the 1, 2 and 4% levels greatly improved the quality of fried oils. These findings indicate the high efficiency of the filter aids used in the present study in adsorbing the products of oil degradation. Copyright © 2006 Society of Chemical Industry     

基于指纹图谱相似度的米糠油掺伪检测方法研究

为快速准确对掺伪米糠油进行定量检测,将棕榈油、棉籽油、菜籽油、大豆油掺入纯米糠油,气相色谱法测定C10∶0、C14∶0、C16∶0、C16∶1、C18∶0、C18∶0、C18∶1、C18∶1、C18∶2、C18∶3、C20∶0、C20∶1、C22∶0、C22∶1的含量,利用向量夹角余弦法计算纯米糠油与掺伪米糠油的相似度,建立了掺伪量与相似度的线性模型.米糠油掺混棕榈油,计算模型为y =5.802 3x3-17.469x2-0.269 2x +99.99(R2 =0.999 6).米糠油掺混菜籽油,计算模型为y=-23.62x3-8.380 6x2-6.138 3x+ 100.12(R2=0.999 4).米糠油掺混棉籽油,计算模型为y=-240.52x5+ 677.8x4-697.92x3+ 312.09x2-66.998x+ 99.97(R2=0.999 3).米糠油掺混大豆油,计算模型为y=12.33x3-26.047x2-2.6855x+100.05(R2=0.999 1).     

Chemical composition,antioxidant activity and anti‐lipase activity of Origanum vulgare and Lippia turbinata essential oils

This study reported the chemical composition, phenolic content, antioxidant and anti‐lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ‐terpinene (32.10%), α‐terpinene (15.10%), p‐cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α‐limonene (76.80%) and 1,8‐cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL^?1) and DPPH scavenging activity (IC₅₀ 0.357 μg mL^?1) than Lippia essential oil (7.94 mg gallic acid mL^?1 and IC₅₀ 0.400 μg mL^?1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti‐lipase activity (IC₅₀ 5.09 and 7.26 μg mL^?1). Higher phenolic content in the essential oils was related with higher scavenging and anti‐lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products.     

Xylitol bioproduction from wheat straw: hemicellulose hydrolysis and hydrolyzate fermentation

A 2² central composite design with five center points was performed to estimate the effects of temperature (120, 130 and 140 °C) and acid loading (100, 150 and 200 mg g^?1) on the yield of monomeric xylose recovery from wheat straw hemicellulose (Y_S/RM). Under the best hydrolysis condition (140 °C and 200 mg g^?1), a Y_S/RM of 0.26 g g^?1 was achieved. After vacuum concentration and detoxification by pH alteration and active charcoal adsorption, the hydrolyzate was used as source of xylose for xylitol bioproduction in a stirred tank reactor. A xylitol production of 30.8 g L^?1 was achieved after 54 h^?1 of fermentation, resulting in a productivity (Q_P) of 0.57 g L^?1 h^?1 and bioconversion yield (Y_P/S) of 0.88 g g^?1. The maximum specific rates of xylose consumption and xylitol production were 0.19 and 0.15 g g^?1 h^?1, respectively. Copyright © 2006 Society of Chemical Industry     

Effects of feeding rapeseed oil, soybean oil, or linseed oil on stearoyl-CoA desaturase expression in the mammary gland of dairy cows

Stearoyl-CoA desaturase (SCD) is an important enzyme in the bovine mammary gland, and it introduces a double bond at the Δ⁹ location of primarily myristoyl-, palmitoyl-, and stearoyl-CoA. The main objective of this study was to compare the effects of various fatty acids (FA) typically present in dairy cow rations on the expression of SCD1 and SCD5 in the mammary gland of dairy cows. Twenty-eight Holstein-Friesian cows were randomly assigned to 1 of 4 dietary treatments. The dietary treatments were a basal diet supplemented (dry matter basis) with 2.7% rapeseed oil as a source of C18:1 cis-9; 2.7% soybean oil as a source of C18:2 cis-9,12; 2.7% linseed oil as a source of C18:3 cis-9,12,15; or 2.7% of a 1:1:1 mixture of the 3 oils. The oil supplements were included in the concentrate, which was fed together with corn silage and grass silage. In addition, cows were grazing on pasture, consisting mainly of perennial ryegrass, during the day. Biopsies from the mammary gland were taken and analyzed for mRNA expression of SCD1 and SCD5 by using quantitative real-time PCR. Milk yield as well as milk protein and fat contents did not differ among the 4 dietary treatments. Dietary supplementation with rapeseed oil and linseed oil increased proportions of C18:1 cis-9 and C18:3 cis-9,12,15 in blood plasma, respectively, compared with the other treatments. Supplementation with soybean oil and linseed oil increased milk FA proportions of C18:2 cis-9,12 and C18:3 cis-9,12,15, respectively, but supplementation with rapeseed oil did not increase C18:1 cis-9 in milk. Mammary SCD1 expression was reduced by supplementation of soybean oil compared with rapeseed oil and linseed oil. In contrast, SCD5 expression did not differ among the 4 treatments. The C16 and C18 desaturation indices, representing proxies for SCD activity, were lower for the soybean oil diet compared with the diet supplemented with a mixture of the 3 oils. In conclusion, our study shows that mammary SCD1 expression is significantly downregulated in dairy cows by feeding unprotected soybean oil compared with rapeseed oil or linseed oil, and this is partially reflected by the lower desaturase indices in the milk. Furthermore, mammary SCD5 expression appears to be differently regulated than expression of SCD1.     

Structural changes in squid (Loligo japonica) collagen after modification by formaldehyde

BACKGROUND: Formaldehyde (FA) has been suggested to cause changes in texture and functional properties in some marine species. It was therefore hypothesised that FA may affect collagen, a fundamental constituent of the extracellular matrix in squid. RESULTS: Two types of collagen, I and V, were isolated by pepsin digestion and differential salt precipitation. Type V collagen contained higher proportions of isoleucine, leucine, and lysine and lower proportions of alanine and hydroxyproline. The effects of FA on pepsin‐solubilised squid collagen were examined by differential scanning calorimetry and Raman spectroscopy. The squid collagen showed a transition temperature (T_m1) of 37.2 ± 0.2 °C, which was significantly reduced in the presence of 2 and 10 mmol L^?1 FA. In the presence of 1, 2 and 10 mmol L^?1 FA an additional peak (T_m2) was also observed at 77.7 ± 0.1, 78.4 ± 0.1 and 62.7 ± 0.2 °C respectively, suggesting FA–collagen interactions. Treatment with 2 mmol L^?1 FA increased the I₉₄₀/I₁₀₀₅ ratio from 1.09 to 1.66 and shifted the 990 and 1245 cm^?1 bands. The tyrosine doublet ratio (I₈₅₀/I₈₃₀) was also increased about threefold, suggesting that α helix, β sheet type and random coil structures were changed by FA. CONCLUSION: The secondary structure of squid collagen can be affected by FA through hydrophobic interactions. Copyright © 2008 Society of Chemical Industry     

Determination of aflatoxins in edible oil from markets in Hebei Province of China by liquid chromatography–tandem mass spectrometry

Analysis of aflatoxin B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁) and G₂ (AFG₂) in 76 edible oil samples (peanut oil, soybean oil, corn embryo oil and blended oil) was performed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The oils were sampled from three areas (Shijiazhuang, Baoding and Tangshan) of Hebei Province of China. AFB₁ was detected in 22 samples representing 28.9%, followed by AFB₂ (7.89%) and AFG₁ (3.95%), while no AFG₂ contamination was detected in any samples. AFB₁ levels in oil samples ranged 0.14–2.72?µg?kg^?1 and AFB₂ ranged 0.15–0.36?µg?kg^?1, while lower levels of 0.01–0.02?µg?kg^?1 for AFG₁ were recorded. The paper is part of an on-going investigation of aflatoxin contamination in Chinese edible oils.     

Ileal digestibility of defatted soybean,lupin and chickpea seed meals in cannulated Iberian pigs: II. Fatty acids and carbohydrates

Five castrated male Iberian pigs (100 ± 2 kg mean live body weight) fitted with T‐shaped ileal cannulas were used to determine ileal digestibility of legume seed meals. The diets were based on defatted soybean (256 g kg^?1), lupin (451 g kg^?1) or chickpea (731 g kg^?1) seed meals and contained similar amounts of digestible energy (14.2–15.1 kJ g^?1) and protein (107 g kg^?1). Only myristic acid (C14:0) ileal apparent digestibility was higher (p < 0.05) in lupin than in chickpea meal. Ileal apparent digestibility of unsaturated fatty acids (FA) (710–920 g kg^?1) was higher (p < 0.05) than that of saturated (480–710 g kg^?1) FA for both seed meals. Ileal digestibility of chickpea starch was 850 g kg^?1. Ileal digestibility of oligosaccharides (sucrose, raffinose, stachyose, verbascose and ciceritol) in lupin (820 g kg^?1) and chickpea (690 g kg^?1) was higher (p < 0.05) than that of defatted soybean (510 g kg^?1). However, total amounts of oligosaccharides digested were higher (p < 0.05) for lupin and chickpea meals (29.6 and 24.6 g kg^?1 feed respectively) than for soybean (15.2 g kg^?1 feed). Among individual non‐starch polysaccharide (NSP) sugars, ileal digestibility values for rhamnose and xylose in lupins were higher (p < 0.05) than those for soybean or chickpea. Ileal digestibility of lupin meal NSP (650 g kg^?1) was higher (p < 0.05) than those of soybean (560 g kg^?1) or chickpea (430 g kg^?1). Up to the terminal ileum, higher (p < 0.05) amounts of lupin total NSP (94.1 g kg^?1) than for soybean (24.3 g kg^?1) or chickpea (27.1 g kg^?1) were digested. Lactate, acetate and isobutyrate concentrations were higher (p < 0.05) in ileal contents of pigs fed lupin and chickpea seed meals compared with soybean‐fed animals. It is concluded that higher lactate and short chain fatty acids concentrations in ileal contents of pigs fed lupin or chickpea seed meals compared with soybean are likely to be the result of higher total amounts of lupin NSP and/or lupin and chickpea oligosaccharides digested up to the terminal ileum. This might have a protective effect on Iberian pig's intestinal physiology. Both lupin and chickpea meals are likely to constitute a valuable alternative to defatted soybean in Iberian pig feeding. Copyright © 2005 Society of Chemical Industry     

Assessment of the Influence of the Decanter Set-up During Continuous Processing of Olives at Different Pigmentation Index

New generation decanters allow operators to make real-time adjustments during the virgin olive oil extraction process in order to gain the best performance possible. However, the opportunity to act in line requires a deep understanding of the consequences of changing machine parameters. To this purpose, an experiment was carried out at industrial scale. The decanter feed rate (Fr), ranging from 4075 to 5820 kg h^?1, the bowl/screw conveyor differential speed (?n), set at 18 and 22, and two ripening degrees of the olives were considered as process variables. Two combinations Fr-?n, namely 4620 kg h^?1 at ?n-18 and 5210 kg h^?1 at ?n-22, were found to similarly maximize the process efficiency, regardless the raw material features. After pointing out the best working settings, the corresponding virgin olive oils were compared. The analysis of variance showed that peroxide value, K ₂₃₂, K ₂₇₀, phenols, chlorophylls, β-tocopherol, fruity and bitter notes, and C6 volatile compounds were significantly affected by the machine parameters. An inverse proportionality was observed between the combination Fr-?n and the phenolic compounds. On the whole, the sampling factor exerted a larger influence on the product quality than the decanter set-up.     

HPLC analysis for trans-vitamin K1 and dihydro-vitamin K1 in margarines and margarine-like products using the C30 stationary phase

A C₃₀ column successfully separated the cis and trans isomers of vitamin K₁ in margarines, reduced-fat margarine-like products and in their ingredient oils. We also measured the compound 2′3′-dihydro-vitamin K₁, a derivative formed during hydrogenation of oils containing vitamin K₁. We compared an enzymatic procedure, currently under AOAC collaborative study for milk and infant formulas, with a more direct extraction method in analyzing margarines and margarine-like products. Both methods have good precision and were applicable to the majority of products examined. Margarines or margarine-like products identifying liquid soy-bean oil, hydrogenated soybean oil or liquid canola oil as their primary ingredients contained about 50–160 μg vitamin K₁/100 g. Blends of sunflower and soybean oils contained <50 μg vitamin K₁/100 g. Hardened or “stick” margarines contained more 2′3′-dihydro-vitamin K₁ than “soft” or “tub” products (122–285 μg/100 g vs 38–131 μg/100 g, respectively). Eight of 18 products (44%) contained 10% or more of the Reference Daily Intake for vitamin K₁ per serving. Higher-fat margarines contained more vitamin K₁ than their lower-fat counterparts.     

Assessment of thermo‐oxidative rancidity in sunflower oil and fried potato chips stabilised with oleoresin sage (Salvia officinalis L.) and ascorbyl palmitate by altered triglycerides and electronic nose

Oleoresin sage (Salvia officinalis) (SAG) (200–1500 mg kg^?1), ascorbyl palmitate (AP) (100–300 mg kg^?1) and TBHQ (200 mg kg^?1) were assessed for delaying the thermo‐oxidation in sunflower oil (SO) during 18 h of frying (180 °C). Electronic nose compared the global aroma fingerprints of potato chips fried in oils. The chemical rancidity indices viz., fatty acids, total polar compounds (TPC), altered triglycerides (dimers, polymers, oxidised monomers, diglycerides), free fatty acids, conjugated dienes and induction periods were monitored along with physical indices viz., viscosity and colour. SO_SAG+AP (1309.62 + 270.71 mg kg^?1) outperformed SO_TBHQ by preserving polyunsaturated fatty acids (60.48% vs. 56.23%), retarding TPCs (28.16% vs. 29.91%), triglyceride dimers (90.24 vs. 95.82 mg g^?1) and polymers (25.40 vs. 26.98 mg g^?1) concomitantly extending the oil disposal time (basis 25% TPC) (15.9 vs. 14.7 h). The postfrying viscosity, colour values and global aroma fingerprints of fried chips indicate a close match between SO_SAG+AP and SO_TBHQ.     

EFFECT OF PHYSICAL FACTORS ON ACETIC ACID PRODUCTION IN BRETTANOMYCES STRAINS

Four species of Brettanomyces (intermedius, bruxellensis, custersianus, clausenii) were examined to ascertain their acetic acid production capacity. The results showed that B. bruxellensis was the strain with the best volumetric productivity and specific production rate (P = 0.065 gL^?1 h^?1; V_p = 0.43 gg^?1h^?1). The best kinetic parameters were reached (P = 0.133 gL^?1 h^?1; Y_p/s = 0.23; P_max = 11.64 gL^?1) at an airflow of 288 Lh^?1 (0.6 vvm, OTR = 124 mgO₂L^?1 h^?1), and substrate inhibition was not observed. The influence of temperature and agitation on acetic acid production by B. bruxellensis in a glucose medium was investigated at different levels, 26, 30, 34C and 250, 350, 450 rpm, respectively. Temperature and agitation were shown to be deci‐sive factors (P < 0.05) in acetic acid production at 288 Lh^?1(0.6 vvm, OTR = 124 mgO₂L^?1 h). The optimal conditions for a high volumetric productivity were 30C and 250 rpm, respectively.     

Effect of residual fertility and direct fertilisation on kernel,protein and oil yield of peanut (Arachis hypogaea L) grown in rice fallows

Kernel (2814–3467 kg ha^?1), protein (555–759 kg ha^?1) and oil (124–1556 kg ha^?1) yields of peanut (Arachis hypogaea L) varied significantly due to the residual effect of organic manures and inorganic fertilisers together. It was also observed that direct application of recommended fertilisers (25 N, 72 P₂O₅ and 37-5 K₂O kg ha^?1) gave the highest kernel (3669 kg ha^?1), protein (786 kg ha^?1) and oil (1606 kg ha^?1) yields. The reduction in kernel, protein and oil yield from the recommended level of fertilisers to half the recommended level of fertilisers was about 16, 15 and 12% while it was about 25, 33 and 27% with no fertiliser. Thus, the results revealed that the nutrients applied partly through organic manures and inorganic fertilisers to Kharif rice exhibits significant residual effects on the succeeding upland crop and hence the fertilisation must be considered not only for individual crops but also for the cropping system as a whole.     

Variation in oil content and fatty acid composition of the seed oil of Acacia species collected from the northwest zone of India

BACKGROUND: The oil content and fatty acid composition of the mature seeds of Acacia species collected from natural habitat of the northwest zone of the Indian subcontinent (Rajasthan) were analyzed in order to determine their potential for human or animal consumption. RESULTS: Oil content varied between 40 and 102 g kg^?1. The highest oil content was obtained in Acacia bivenosa DC. (102 g kg^?1) among the nine Acacia species. The fatty acid composition showed higher levels of unsaturated fatty acids, especially linoleic acid (～757.7 g kg^?1 in A. bivenosa), oleic acid (～525.0 g kg^?1 in A. nubica) and dominant saturated fatty acids were found to be 192.5 g kg^?1 palmitic acid and 275.6 g kg^?1 stearic acid in A. leucophloea and A. nubica respectively. Seed oils of Acacia species can thus be classified in the linoleic–oleic acid group. Significant variations were observed in oil content and fatty acid composition of Acacia species. CONCLUSION: The present study revealed that the seed oil of Acacia species could be a new source of high linoleic–oleic acid‐rich edible oil and its full potential should be exploited. The use of oil from Acacia seed is of potential economic benefit to the poor native population of the areas where it is cultivated. The fatty acid composition of Acacia seed oils is very similar to that reported for commercially available edible vegetable oils like soybean, mustard, sunflower, groundnut and olive. Hence the seed oil of Acacia species could be a new source of edible vegetable oil after toxicological studies. Copyright © 2012 Society of Chemical Industry     

Seasonal changes of CLA isomers and other fatty acids of milk fat from grazing dairy herds in the Azores

BACKGROUND: Season of the year associated with dietary changes has been recognized as a factor implicated in milk fat fatty acid (FA) profile in dairy cows. However, a lack of information exists concerning cows grazing all year round as is practiced in the Azores, where cows are supplemented in winter with maize silage plus concentrates, while in spring the higher grass allowance only requires supplementation with concentrate. The main objective of this study was to detect any seasonal variation of FA profile of milk fat from milk sampled in bulk tanks of 12 Azorean dairy herds. RESULTS Compared to winter milk, milk fat from spring presented a higher proportion of CLA cis‐9,trans‐11 (14.3 versus 9.6 g kg^?1 FA), C18:1 trans‐11 (32 versus 22 g kg^?1 FA), C18:2 trans‐11,cis‐15 (3.7 versus 2.2 g kg^?1 FA), CLA trans‐11,cis‐13 (0.34 versus 0.23 g kg^?1 FA) and C18:3 n‐3 (5.7 versus 5.4 g kg^?1 FA). The C18:2 n‐6/C18:3 n‐3 ratio was lower (P < 0.05) in spring. Branched‐chain FA, except the anteiso‐C15:0, were higher in spring, while odd‐chain FA (C15:0) were higher in winter. CONCLUSION: Dairy herd management in the Azores presents a seasonal variation of milk fat FA composition, where the spring milk may present increased potential benefits for human consumers. Copyright © 2008 Society of Chemical Industry