Positional Distribution Of Fatty Acids Research Articles

Enzymatic Analysis of Positional Fatty Acid Distributions in Triacylglycerols by 1(3)-Selective Transesterification with <i>Candida antarctica</i> Lipase B: a Collaborative Study

The positional distributions of fatty acids (FAs) in fats and oils are principally analyzed by selectively transesterifying the target triacylglycerols (TAGs) at the 1(3) position using Pseudozyma (Candida) antarctica lipase, followed by recovering the resulting 2-monoacylglycerols (MAGs) by chromatography. FA compositions were measured by gas chromatography (GC) after methylating target TAGs and 2-MAGs. The method was collaboratively evaluated by 12 laboratories by analyzing the positional FA distributions in soybean, palm, and sardine oils. The maximum reproducibility relative standard deviations for the major FAs and those at the sn-2 positions of soybean, palm, and sardine oils were 4.41% and 3.92% (18:3n-3), 4.48% and 3.82% (18:0), and 8.93 and 8.24% (14:0), respectively. The values at the sn-2 position were always low. Therefore, these results indicated that the variations were mainly caused by the FA analysis procedure, i.e., the methylation and GC analyses, rather than the enzymatic transesterification and chromatography utilized to prepare 2-MAGs from the target oil.

Use of re-esterified palm oils, differing in their acylglycerol structure, in weaning-piglet diets

Re-esterified oils are new fat sources obtained from chemical esterification of acid oils with glycerol (both economically interesting by-products from oil refining and biodiesel industries, respectively). The different fatty acid (FA) positional distribution and acylglycerol composition of re-esterified oils may enhance the apparent absorption of saturated fatty acids (SFA) and, thus, their overall nutritive value. The aim of the present study was to investigate the potential use of re-esterified palm oils, in comparison with their corresponding acid and native oils, and also with an unsaturated fat source in weaning-piglet diets. The parameters assessed were: FA apparent absorption, acylglycerol and free fatty acid (FFA) composition of feces, and growth performance. One-hundred and twenty weaning piglets (average weight of 8.50±1.778 kg) were blocked by initial BW (six blocks) and randomly assigned to five dietary treatments, resulting in four piglets per pen and six replicates per treatment. Dietary treatments were a basal diet supplemented with 10% (as-fed basis) of native soybean oil (SN), native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- (MAG) and diacylglycerols (DAG) (PEL), or re-esterified palm oil high in MAG and DAG (PEH). Results from the digestibility balance showed that SN reached the greatest total FA apparent absorption, and statistically different from PN, PA and PEL (P<0.05). There were no statistical differences among palm-oil sources (P>0.05), but PEH achieved the greatest total FA apparent absorption. Animals fed PEL, despite the fact that PEL oil contained more sn-2 SFA, did not show an improved absorption of SFA (P>0.05). Animals fed PA and PN showed similar apparent absorption coefficients (P>0.05), despite the high FFA content of PA oil. The acylglycerol and FFA composition of feces was mainly composed of FFA. There were no significant differences in growth performance (P>0.05). Results of the present study suggest that, despite the different acylglycerol structure of re-esterified oils, there were no significant differences in digestibility or performance with respect to their corresponding PN and PA oils in weaning-piglet diets.

Use of re-esterified palm oils, differing in their acylglycerol structure, in fattening pig diets

Re-esterified oils are new fat sources obtained from the chemical esterification of acid oils with glycerol (both economically interesting by-products from oil refining and biodiesel industries, respectively). The different fatty acid (FA) positional distribution and acylglycerol composition of re-esterified oils may enhance the apparent absorption of saturated fatty acids (SFA) and, therefore, their overall nutritive value, which might lead to an increased deposition of SFA. The aim of the present study was to investigate the potential use of re-esterified palm oils, in comparison with their corresponding acid and native oils in fattening pig diets, studying their effects on fatty acid apparent absorption, acylglycerol and free fatty acid (FFA) composition of feces, growth performance, carcass-fat depots and fatty acid composition of backfat. Seventy-two crossbred boars and gilts (average weight of 24.7±2.55 kg) were blocked by initial BW (nine blocks of BW for each gender), housed in adjacent individual boxes, and fed one of the four dietary treatments, which were the result of a basal diet supplemented with 4% (as-fed basis) of native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- and diacylglycerols (PEL), or re-esterified palm oil high in mono- and diacylglycerols (PEH). Regarding results from the digestibility balance, PA and PN showed similar apparent absorption coefficients (P>0.05), despite the high, FFA content of the former. However, re-esterified palm oils (both PEL and PEH) showed a higher apparent absorption of total FA than did their corresponding native and acid oils (P<0.001), mainly due to the increased apparent absorption of SFA (P<0.001). This resulted in a greater feed efficiency and an increased deposition of SFA in backfat of pigs fed PEH, when compared with those fed PA (P<0.05), although no differences were found for carcass-fat depots (P>0.05). We conclude that re-esterified oils are interesting fat sources to be considered in fattening pigs.

Positional distribution assessment of essential fatty acids in several fats and oils including plant, fish, and microbial sources and subcutaneous fat of Galician horse

AbstractIn this work, several oils and PUFA‐producing species have been analyzed to know the positional distribution of fatty acids within the triacylgycerol structure. Positional distribution was determined in terrestrial oils by means of enzymatic hydrolysis, while 13C‐NMR was used for marine and processed oils, which contain long‐chain PUFA. In addition to several already known sources, other new ones have been characterized; i.e., α‐linolenic acid was high in the subcutaneous fat of Galician horse (34.5% of total FAs in sn‐2); γ‐linolenic acid in Echium gentianoides and Symphytum caucasicum (47.7 and 40.1% of total FAs in sn‐2, respectively); stearidonic acid in E. plantagineum (20.8% of total FAs in sn‐2); eicosapentaenoic acid in cod liver oil (13.7% of total FAs in sn‐2); docosahexaenoic acid in salmon, cod liver, hake roe, DHASCO© and MARINOL© oils (23.0, 20.9, 19.7, 47.0 and 55.9% of total FAs in sn‐2, respectively); and arachidonic acid in ARASCO© oil (53.0% of total FAs in sn‐2). Bioavailability of some valuable PUFA has been shown to be high in some of the studied samples compared to commonly consumed oils, according to their triacylglycerol positional distribution values.Practical applications: The positional distribution of PUFAs on the glycerol backbone of triacylglycerols is crucial for their bioavailability, since PUFA esterified at sn‐2 position are better absorbed than those located at sn‐1,3 positions. In this work, we have assessed the positional distribution of essential fatty acids in several fats and oils, both obtained from traditional sources as well as from edible species not yet prospected. Some of them might be exploited to be used as dietary PUFA sources.The positional distribution (PD) of essential fatty acids (EFAs) within the triacylglycerol structure determines their bioavailability, since EFAs esterified at sn‐2 position are better absorbed than those located at sn‐1,3 positions. In this work, the PD of EFAs in several fats and oils, obtained from traditional sources as well as from edible species not yet prospected, has been assessed. Bioavailability of valuable EFAs has been shown to be high in some of the newly studied oils compared to commonly consumed oils, as their triacylglycerol PD indicates.

Analysis of intact triacylglycerols in cold pressed canola, flax and hemp seed oils by HPLC and ESI-MS

Cold-pressed canola, hemp and flax seed oils were separated into their respective intact triglycerides via high pressure liquid chromatography (HPLC) and their fatty acids analysed. Molecular weights of the triglycerides were determined by electrospray ionization-mass spectroscopy (ESI-MS). Seven triglycerides were collected for flax seed, and trilinolenoyl-glycerol was the most abundant at 25.9%. Seven triglycerides were separated and collected for canola seed oil with dioleoyl-linolenoyl-glycerol as the most abundant (32.5%). Eight triglycerides were separated and collected from hemp seed oil with trilinoleoyl-glycerol as the most abundant (21.9%). The fatty acid profiles of the separated triglycerides for the three oils were determined to confirm the assignments. Hempseed was found to have the highest content of palmitic acid in the triglyceride fractions collected (5.6%); flax and canola had 4.1% and 3.1% respectively. The results of fatty acid composition analysis of the cold pressed oils showed oleic acid to be the most abundant fatty acid in canola oil at 57.56 ± 0.13%. Linoleic acid was the most abundant in hemp seed oil at 55.64 ± 1.21%, and linolenic acid in flax seed oil at 58.84 ± 0.91%. Enzymatic hydrolysis using pancreatic lipase treatment was performed to analyse positional distribution of fatty acids in the oils. Thin layer chromatography (TLC) was used for separation of 2-monoglycerides and free fatty acids. For all three oils, unsaturated fatty acids marginally preferred the sn-2 position on the glycerol backbone. Flaxseed had 59.1% of linolenic acid on sn-2 position. At 58.6%, oleic acid was the most abundant fatty acid at the sn-2 position in canola oil, and for linoleic acid in hemp seed oil, 58.2%. Higher ratios of saturated fatty acids to unsaturated fatty acids were located on sn-1, 3 positions.

Profiling of polar lipids in marine oleaginous diatom Fistulifera solaris JPCC DA0580: prediction of the potential mechanism for eicosapentaenoic acid-incorporation into triacylglycerol.

The marine oleaginous diatom Fistulifera solaris JPCC DA0580 is a candidate for biodiesel production because of its high lipid productivity. However, the substantial eicosapentaenoic acid (EPA) content in this strain would affect the biodiesel quality. On the other hand, EPA is also known as the essential health supplement for humans. EPAs are mainly incorporated into glycerolipids in the microalgal cell instead of the presence as free fatty acids. Therefore, the understanding of the EPA biosynthesis including the incorporation of the EPA into glycerolipids especially triacylglycerol (TAG) is fundamental for regulating EPA content for different purposes. In this study, in order to identify the biosynthesis pathway for the EPA-containing TAG species, a lipidomic characterization of the EPA-enriched polar lipids was performed by using direct infusion electrospray ionization (ESI)-Q-TRAP-MS and MS/MS analyses. The determination of the fatty acid positional distribution showed that the sn-2 position of all the chloroplast lipids and part of phosphatidylcholine (PC) species was occupied by C16 fatty acids. This result suggested the critical role of the chloroplast on the lipid synthesis in F. solaris. Furthermore, the exclusive presence of C18 fatty acids in PC highly indicated the biosynthesis of EPA on PC. Finally, the PC-based acyl-editing and head group exchange processes were proposed to be essential for the incorporation of EPA into TAG and chloroplast lipids.

Enzymatic Analysis of Positional Distribution of Fatty Acids in Solid Fat by 1,3‐Selective Transesterification with Candida antarctica Lipase B

AbstractA protocol for the analysis of the positional distribution of fatty acids (FA) in solid triacylglycerols (TAG) was developed using sn‐1(3) selective alcoholysis catalyzed by immobilized Candida antarctica lipase B (CALB). One part by weight of solid fat and ten parts by weight of ethanol (99.5 %) were warmed to liquefy the fat. After adding 0.44 parts by weight of CALB, the mixture was shaken at 50 °C for 10 min then at 30 °C for 2.8 h. The recovery of 2‐MAG after the 3‐h transesterification reaction was ca. 85 % of the maximum theoretical yield (33 mol%), with the loss of 15 % attributable to the acyl migration from sn‐2 to sn‐1(3). The recovery was similar to that of the solvent‐free alcoholysis of structured lipids, 1,3‐dipalmitoyl, 2‐oleoyl glycerol and 1,3‐dioleoyl, 2‐palmitoyl glycerol, conducted at 30 °C for 3 h. In contrast, the acyl migration from sn‐1(3) to sn‐2 was hardly observed. Because the detected acyl migration was only in the direction of sn‐2 to sn‐1(3), and not vice versa, it is proposed to determine the FA composition of the sn‐2 position of TAG by the gas chromatographic analysis of 2‐MAG fraction recovered from the enzymatic reaction mixture, and the FA composition of sn‐1(3) position by a mass balance using the FA composition of TAG and of the sn‐2 position as inputs. The procedure was successfully applied to palm oil and shea butter, and docosahexaenoic acid (DHA)‐rich single cell oil from Aurantiochytrium sp. KH105 for the first time.

Positional distribution of fatty acids on hoki and tuna oil triglycerides by pancreatic lipase and 13C NMR analysis

Positional distribution of fatty acids in hoki and tuna oils was carried out in the present study via pancreatic lipase hydrolysis and 13Carbon nuclear magnetic resonance (13C NMR) spectroscopy. The two methods gave consistent results for hoki but conflicting values for tuna oil. Saturated fatty acids (SFA) were generally enriched at sn‐2 while MUFA were preferentially located at sn‐1,3 for hoki by pancreatic lipase treatment. Of the PUFA, DHA in hoki oil was significantly located at sn‐2 position, whereas eicosapentaenoic acid (EPA) was randomly distributed via both methods. DHA and EPA in tuna oil were both preferentially located at sn‐2 position by NMR spectroscopy. The NMR results for n‐3 PUFA were in general agreement with other fish oils studied where DHA showed preference for sn‐2 but EPA displayed preferential differences among species. The ratio of DHA in hoki oil at sn‐2 position was higher than tuna oil, thus enhancing its bioavailability. The opposite was the case for EPA. For pancreatic lipase hydrolysis of tuna oil, results showed that both DHA and EPA were incompletely recovered along with other PUFA confirming that pancreatic lipase hydrolysis is an unreliable method for positional distribution determination in tuna oil compared to 13C NMR analysis. The ratio of long chain PUFA to triglycerides exceeds 1:1 in tuna oil, causing steric hindrance for hydrolysis of the long chain PUFA residue at sn‐1,3 position.Practical applications: Fish oil contains bioactive omega‐3 fatty acids (DHA and EPA), however bioavailability and oxidative stability of these omega‐3 fatty acids depends on their positional distribution. Pancreatic lipase has been used in determination of positional distribution of fatty acids in fish oil, but this method involves heat and is time consuming and not suitable for fish oil with more than one molecule of PUFA in a single triglyceride. NMR has gained popularity in positional distribution determination of n‐3 fatty acids in fish oil as it is a rapid and non‐destructive method compared to the conventional chemical and enzymatic methods.

Lipid Classes and Fatty Acid Regiodistribution in Triacylglycerols of Seed Oils of Two Sambucus Species (S. nigra L. and S. ebulus L.)

The oil content and fatty acid composition of total lipids (TLs) and main lipid classes (NLs- neutral and PLs- polar lipids) in seeds of two wild Sambucus species (S. nigra and S. ebulus) from Transylvania (Romania) were determined by capillary gas chromatography (GC-MS). In addition, the positional distribution of fatty acids in seed triacylglycerols (TAGs) was determined by hydrolysis with pancreatic lipase. The seeds were found to be rich in fat (22.40–24.90 g/100g) with high amounts of polyunsaturated fatty acids (PUFAs) ranging from 68.96% (S. ebulus) to 75.15% (S. nigra). High ratios of PUFAs/SFAs (saturated fatty acids), ranging from 7.06 (S. nigra) to 7.64 (S. ebulus), and low ratios of n-6/n-3, ranging from 0.84 (S. nigra) to 1.51 (S. ebulus), were determined in both oils. The lipid classes/subclasses analyzed (PLs, MAGs—monoacylglycerols, DAGs—diacylglycerols, FFAs—free fatty acids, TAGs and SEs—sterol esters) were separated and identified using thin-layer chromatography. The fatty acid compositions of the TAG fractions were practically identical to the profiles of TLs, with the same dominating fatty acids in both analyzed species. SEs and FFAs, were characterized by high proportions of SFAs. The sn-2 position of TAGs was esterified predominantly with linoleic acid (43.56% for S. nigra and 50.41% for S. ebulus).

Mono‐ and digalactosyldiacylglycerol composition of the marennine‐producing diatom, Haslea ostrearia: Comparison to a selection of pennate and centric diatoms

SummaryDiatoms are one of the largest groups of primary producers in the oceans, yet despite their environmental importance little is known about their plastidial lipid biochemistry. It has been previously reported that Skeletonema species contain primarily C16/C16 and C20/C16 forms of mono‐ and digalactosyldiacylglycerol (MGDG and DGDG, respectively). Likewise, it was also reported that Phaeodactylum tricornutum contains primarily C16/C16 and C20/C20 forms of MGDG and DGDG. We seek to relate their studies to other diatoms, both in the centrics and pennates, with particular focus on the marennine‐producing pennate diatom, Haslea ostrearia. To this end, the composition and positional distribution of fatty acids of MGDG and DGDG were examined using positive‐ion electrospray ionization/mass spectrometry (ESI/MS). Two centric diatoms, Skeletonema marinoi and Thalassiosira weissflogii, and the pennate diatom, P. tricornutum, contained primarily C20/C16 (sn‐1/sn‐2) and C18/C16 forms of MGDG and DGDG. The other pennate diatoms, H. ostrearia and Navicula perminuta, contained primarily C18/C16 or C18/C18 forms of MGDG and DGDG, indicating a previously unrecognized fatty acid diversity in diatom MGDG and DGDG.

Enrichment of Omega‐3 Fatty Acids of Refined Hoki Oil

AbstractEnrichment of the omega‐3 (n‐3) fatty acids of refined hoki oil (RHO) intact triglycerides (TG) and via free fatty acids (FFA), was carried out in the present study using established methods of dry fractionation (DF), low temperature solvent crystallization (LTSC) and urea complexation (UC) and positional distribution of fatty acids in the intact TG was determined by Nuclear Magnetic Resonance (NMR) analysis. Results showed that n‐3 fatty acids were enriched in liquid fractions of all methods except DF, where the highest concentration was obtained via the UC method (83.00 %). The FFA form of the oil produced a higher concentration (40.81 %) of n‐3 fatty acids via the LTSC method compared to the TG form (31.50 %). The percentages of the total saturated fatty acid (SFA) in the liquid fractions in all methods were lower, ranging from 1.60 % (UC) to 21.44 % (DF) compared to the RHO parent oil (24.05 %). The percentages of total monounsaturated fatty acids (MUFA) in the liquid fractions were similar to the solid fractions except for the UC method where total MUFA was six times higher in the solid fraction. In LTSC‐FFA and UC methods, the enrichment factor for EPA was lower, ranging from 1.61 (LTSC‐FFA) to 2.83 (UC), than DHA which ranged from 1.64 (LTSC‐FFA) to 3.88 (UC). EPA was preferentially located at the sn‐1,3 position and DHA was significantly located at the sn‐2 position which is the favoured location for intestinal digestion.

Production and Characterization of DHA and GLA‐Enriched Structured Lipid from Palm Olein for Infant Formula Use

AbstractPalm olein was modified via lipase‐catalyzed acidolysis reaction to obtain fatty acid composition and positional distribution similar to human milk fat. In the reaction, a free fatty acid mix containing 23.23 % docosahexaenoic (DHA), 31.42 % gamma‐linolenic (GLA), and 15.12 % palmitic acid was employed. The DHA and GLA were incorporated into the structured lipid (SL) product to improve its nutritional value. Response surface methodology (RSM) was used to investigate the effects of reaction time and substrate mole ratio (palm olein to a free fatty acid mix) on the amount of palmitic acid at the sn‐2 position of SL triacyglycerols (TAG), and on the total DHA and GLA incorporation. Gram‐scale production of SL was performed using the conditions predicted by RSM to maximize the content of palmitic acid at the sn‐2 position. Verification of the predictions from RSM confirmed its practical utility. The resulting SL had 35.11 % palmitic acid at the sn‐2 position, with 3.75 % DHA and 5.03 % GLA. Differential scanning calorimetry and HPLC analyses of the TAG revealed changes in their polymorphic profiles and TAG molecular species of SL compared to palm olein. The SL from this study can potentially be used in infant formula formulations.

Comparison of postprandial lipaemia between native and palm random esterified acid oils in two different monogastric species (dogs and broiler chickens)

It has been reported that applying a chemical reesterification process to a native fat results in a new fat source with different physicochemical properties due to their different fatty acid (FA) positional distribution within the glycerol moiety and their different proportions of mono (MAG)-, di (DAG)- and triacylglycerides (TAG). Thus, this reesterification could affect fat digestion, absorption and metabolism; and this effect could vary among species given their differences in fat metabolism. The aim of this study was to compare the effect of feeding two different random esterified acid oils (REAO), presenting different MAG, DAG and TAG proportions, with their corresponding native oil on postprandial lipaemia in broiler chickens and dogs. For this purpose, 18 dogs and 54 broiler chickens were fed a basal diet supplemented with palm native oil, palm REAO low MAG or palm REAO high MAG. The inclusion level of the oils was 10% of the diet in dogs and 6% in broiler chickens. Serum postprandial TAG concentration (mg/dl) after feeding a single meal was measured at different time points during 12 h in dogs and 3 h in chickens. Although fasting serum TAG concentration values were similar for both species (47 ± 2.4 mg/dl for dogs and 44 ± 3.0 mg/dl for broilers; p = 0.522), postprandial TAG concentrations tended to be higher in broilers than in dogs (p = 0.058). Treatment had no effect on TAG concentration at any time point in any species (p = 0.768 for dogs, p = 0.947 for broilers). However, the postprandial TAG curves were very different between species; in broiler chickens, TAG concentration returned to the fasting values 3 h after feeding while in dogs, the TAG concentration still had not returned to basal levels 12 h after feeding.

Lipase-catalyzed synthesis and characterization of flaxseed oil-based structured lipids

The biosynthesis of structured lipids (SLs) was carried out by the interesterification of flaxseed oil (FO) and tricaprylin (TC) in an organic solvent medium (OSM), using selected commercial lipases, including Amano DF, Novozym 435, Lipozyme TL-IM and Lipozyme RM-IM. The fatty acyl chains of the synthesized triacylglycerols (TAGs) were identified by atmospheric pressure chemical ionization/mass spectrometric (APCI/MS) analysis, while the fatty acid positional distribution of the MLM- and MML-SLs (M-medium and L-long chain fatty acids) was determined by silver-ion high-performance liquid chromatographic (Ag+/HPLC) analysis. The effects of reaction temperature (Tr, 30–50°C), enzyme concentration (Ec, 0.5–4%, w/v), initial water activity (aw, 0.05–0.43) and reaction time (Rt, 0–72h) on the efficiency of the enzymes, were studied. The bioconversion yield (%) of the synthesized MLM- and MML-SLs was monitored under the established reaction parameters for each lipase. The maximum yield of MLM-SLs was obtained in the order, of Novozym 435>Lipozyme TL-IM>Lipozyme RM-IM>Amano DF. Moreover, considering the ratio of the MLM- to MML-SLs produced by each enzyme, Novozym 435 and Lipozyme TL-IM were selected as the most effective enzymes for interesterification of FO and TC.

Stereospecific Positional Distribution of Fatty Acids of Camellia (Camellia japonica L.) Seed Oil

The stereospecific positional distribution of fatty acids of camellia seed oil (also called camellia oil) was determined. The camellia oil was mainly composed of neutral lipids (88.2%), and the oleic acid (86.3%) was found to be a major fatty acid of neutral lipids. In the glycolipids and phospholipids, the oleic acid was also found to be a major fatty acid at 62.5% and 54.2%, respectively. The oleic acid was distributed abundantly in all sn-1, 2, and 3 positions. It was found that the oleic acid was present more at sn-2 (93.6%) and 3 positions (94.7%), than at sn-1 position (66.0%). Practical Application: The information of stereospecific positional distribution of fatty acids in the camellia oil can be used for the development of the structured lipids for food, pharmaceutical, and medical purposes.

Profiles of Fatty Acid Distribution of Different Acyl Lipids from Red and Black Rices

&lt;p&gt;The present study is focused on the variation in fatty acid (FA) composition of the different acyl lipids in red and black rices. Total lipids were fractionated by TLC into eight subfractions. Significant differences (&lt;em&gt;P&lt;/em&gt; &amp;lt; 0.05) in FA distribution were found among the different acyl lipids when the two cultivars were compared. There were no significant differences (&lt;em&gt;P&lt;/em&gt; &amp;gt; 0.05) in the positional distribution of FA in triacylglycerols; unsaturated FA was predominantly concentrated in the &lt;em&gt;sn&lt;/em&gt;-2 position while saturated FA primarily occupied the &lt;em&gt;sn&lt;/em&gt;-1 position or &lt;em&gt;sn&lt;/em&gt;-3 position in the oils. Significant differences (&lt;em&gt;P&lt;/em&gt; &amp;lt; 0.05) in FA distribution existed when the individual phospholipids were compared. Based on the FA composition of the different acyl lipids, it seems that red and black rices are very similar to each other with a few exceptions. The results suggest that these rice lipids may be well incorporated into our daily diet to improve value of the Japanese diet.&lt;/p&gt;

Characteristic distributions of fatty acids in different lipids from Jack beans (Canavalia gladiata DC.)

AbstractExtracted lipids obtained from Jack beans (white and red) were fractionated by TLC into nine subfractions. The major components were TAGs (TAG: 43.8–45.7 wt%) and phospholipids (PL: 46.7–47.0 wt%), while other components were also present in minor proportions (0.3–2.7 wt%). The principal fatty acids (FA) are generally palmitic (18.8–28.8%), stearic (0.7–6.8%), oleic (42.0–51.8%), linoleic (16.2–22.8%), and α‐linolenic (3.0–8.2%) acids, the distribution of which differs according to these lipid classes. There were no significant differences (p&gt;0.05) in the positional distribution of FA in the TAG; unsaturated FA (97.5%) were predominantly concentrated in the sn‐2 position while saturated FA (33.3%) primarily occupied the sn‐1 position or sn‐3 position. However, significant differences (p&lt;0.05) in FA distribution existed when the individual PL were compared between the white and red beans. Based on the FA composition of these lipids, it seems that the two cultivars of Jack beans are very similar to each other with a few exceptions. The results could be useful to both producers and consumers for our daily diet to improve value of the Japanese diet.Practical applications: The lipid composition suggests that these beans could be a good source of nutraceuticals with providing heath benefits. The white and red beans may be well incorporated into our daily Japanese diets to improve nutritional value. The data obtained in this study provide valuable information for manufacturing functional drinks such as Jack bean tea in Japan.

Effect of Enzymatic Randomization on Positional Distribution and Stability of Seal Blubber and Menhaden Oils

In an effort to investigate the effect of positional distribution on oxidative stability of menhaden and seal blubber oils, Novozyme 435 was used as a random biocatalyst. Positional distribution of fatty acids was determined using gas chromatography. As some of the α-tocopherol was lost during randomization, its content was adjusted to the level prior to the process to eliminate this effect on oxidative stability of oils tested. Conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS) were used as indicators of oxidative stability. The results showed that the polyunsaturated fatty acids were distributed predominantly at terminal positions in randomized menhaden oil, whereas they were distributed more evenly among all positions in enzymatically randomized seal blubber oil, compared to their unrandomized counterparts. Results of CD and TBARS values indicated that randomized menhaden oil was more stable than the original oil, whereas randomized seal blubber oil was more vulnerable to oxidation compared to its counterpart. Changes of oxidative stability after randomization were mainly due to positional redistribution of fatty acids, especially those of the polyunsaturated types.

Diets Enriched in Fish-Oil or Seal-Oil have Distinct Effects on Lipid Levels and Peroxidation in BioF1B Hamsters

Aim:Fish-oil omega-3 polyunsaturated fatty acids (n-3 PUFAs) are mostly esterified to the sn-2 position of triglycerides, while in seal-oil triglycerides, these are mostly esterified to the sn-1 and -3 positions. We investigated whether fish-oil and seal-oil feeding has a different effect on the regulation of lipid metabolism and oxidative stress in BioF1B hamsters.Methods:BioF1B hamsters were fed high fat diets rich in fish-oil or seal-oil for 4 weeks, and fasted for 14 hours prior to blood and tissue collection.Results:Plasma and hepatic lipids and lipid peroxidation levels were significantly lower in seal-oil-fed hamsters as compared to those fed fish-oil. There was a selective hindrance of clearance of lipids in fish-oil-fed hamsters as reflected by higher levels of plasma apoB48.Conclusion:Differences in the fatty acid composition and positional distribution of n-3 PUFAs in triglycerides of fish-oil and seal-oil are suggested to trigger metabolic differences.

MONO- AND DIGALACTOSYLDIACYLGLYCEROL COMPOSITION OF RAPHIDOPHYTES (RAPHIDOPHYCEAE): A MODERN INTERPRETATION USING POSITIVE-ION ELECTROSPRAY/MASS SPECTROMETRY/MASS SPECTROMETRY(1).

Raphidophyte algae (Raphidophyceae) can be divided according to pigment composition and plastid ancestry into two categories, brown- and green-pigmented taxa. We sought to examine if there are any biochemical differences in plastid lipid composition between the two groups. To this end, the composition and positional distribution of fatty acids of the chloroplast lipids, mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively), were examined using positive-ion electrospray/mass spectrometry (ESI/MS) and electrospray/mass spectrometry/mass spectrometry (ESI/MS/MS). Brown-pigmented strains from the genera Chattonella, Fibrocapsa, and Heterosigma primarily consisted of 20:5/18:4 (sn-1/sn-2) MGDG and 20:5/18:4 DGDG, while isolates of the green-pigmented raphidophyte Gonyostomum semen (Ehrenb.) Diesing contained these as well as 18:3/18:4 MGDG and DGDG, thus underscoring its green algal plastid lineage. Although previously unseen without the regiochemical information provided by ESI/MS/MS, Chattonella subsalsa Biecheler possessed 20:5/18:3 DGDG as a major form, a potential biosynthetic intermediate in the production of 20:5/18:4 DGDG. These results provide a modern interpretation of the fatty acid regiochemistry of MGDG and DGDG.