SLIP MELTING POINT ESTIMATION OF FAT BLENDS BEFORE AND AFTER INTERESTERIFICATION BASED ON THEIR FATTY ACID COMPOSITIONS

In this study the relationship between slip melting point (SMP) and fatty acid composition of blends before and after interesterification were investigated. Forty-four blends were prepared using sunflower, canola and cottonseed oils as well as palm stearin and/or fully hydrogenated palm stearin in different proportions. Fatty acid compositions and SMP of samples were determined and then SMP of the blends before and after interesterification were defined as a function of five fatty acids. Specific constants of C_16:0, C_18:0, C_18:1, C_18:2 and C_18:3 fatty acids were determined as 0.455, 0.821, 0.622, 0.215 and -1.653, respectively, for the blends before interesterification and 0.532, 0.614, 0.399, 0.055 and -2.471, respectively, for the blends after interesterification by using least squares method. Slip melting point of blends were calculated using these constants and fatty acid compositions and then compared with the experimental values. No linear relationship existed between the calculated and experimental results of the blends before interesterification, but SMP of the blends after interesterification could be estimated with high (r=0.956) accuracy.     

FATTY ACIDS FROM LARVAL SULCASCARIS SP. (NEMATODA) AS POSSIBLE INDICATORS OF INFECTION OF CALICO SCALLOPS (ARGOPECTEN GIBBUS)

Fatty acid profiles of larval nematodes (stage- 4 Sulcascaris sp.), of tissue from their intermediate host (calico scallops, Argopecten gibbus), and of the host capsule that surrounds the larvae were prepared in an attempt to identify infected scallops. Nematode tissue showed lower ratios of C_14:O/C_14:1, C_16:0/C_16:1 and C_18:0/C_18:1 than did scallop tissue. The nematodes contained relatively less C_16:0 and more C_18:2 than did scallops. Fatty acids shorter than C_14:0 were found in small amounts in both organisms. Fatty acid profiles of capsules differed little from those of normal scallop tissue.     

PROXIMATE AND LIPID COMPOSITION OF NONDAIRY IMITATION MILK IN COMPARISON WITH MILK

Comparative studies of milk and nondairy imitation milks showed that their proximate compositions were similar. Qualitative and quantitative studies revealed that saturated fatty acids were abundant in milk, while unsaturated fatty acids (C _18:1 and C _18:2 ) were predominant in nondairy imitation milks. This was confirmed by the higher melting points of the fat fractions of milk compared with those of nondairy imitation milks. Finally, lipid peroxidation level of samples were low as determined by the 2-thiobarbituric acid test.     

Specificity in Thermal Hydrolysis of Triglycerides

SUMMARY— Samples of triglycerides and triglyceride mixtures were heated in the presence of water under controlled conditions and the released fatty acids quantitatively analyzed by gas chromatography. Experiments with both a mixture of monoacyl-triglycerides and glycerides with equimolar amounts of randomly distributed fatty acids showed a preference for the hydrolysis of the shorter chain and the unsaturated fatty acids. The C₄, C₈, C₁₂, and C_18:1, fatty acids were used in the above mixtures. A trilaurin, in which the fatty acid in the P-position is labelled with C¹⁴, was synthesized. When the free acids released by heat were analyzed by a combination gas chromatographic-radioactivity detector system, no evidence for a positional specificity was apparent.     

Triacylglycerol Species of Less Common Edible Vegetable Oils

Chromatographic and spectroscopic methods used for the detection and quantification of triacylglycerol (TAG) species present in less common edible vegetable oils (almond, hazelnut, pumpkin seed, safflower, sesame, walnut, and wheatgerm oils) are reviewed. For these oils, as well as for thistle oil and high-oleic sunflower oil, for which no data exist on their TAG composition, both high-performance liquid chromatography (HPLC) and gas chromatography (GC) chromatographic plus spectrometric techniques have also been performed. Triacylglycerol comparison of the data found in the literature is also presented. Five fatty acyl moieties (palmitoyl-, stearoyl-, oleoyl-, linoleoyl-, and linolenoyl-) are found to mainly contribute to the formation of TAG species of the aforementioned edible vegetable oils, whereas six more (palmitoleoyl-, arachidoyl-, gadoleoyl-, heptadecenoyl-, margaroyl-, and erucoyl-) are reported as minors. Only 19 to 33 TAG make up the mass of these oils. These TAG are also found in most common edible oils, thus indicating a “uniformity” in the minor and main TAG composition of edible vegetable oils. Trioleoyl-glycerol predominates in almond (13.3-48.6%), hazelnut (35.3-57.9%), and high oleic sunflower (44.2% and 52.9%) oils, trilinoleoyl-glycerol in safflower (40.1-49.7%), thistle (36.9% and 46.0%), walnut (25.9-38.1%), and wheatgerm (15.7-33.0%) oils. Sesame and pumpkin seed oils are rich in dioleoyl-linoleoyl-glycerol (5.9-17.5%, 9.5% and 18.6%, respectively) and oleoyl-dilinoleoyl-glycerol (8.0-18.7% and 12.8-21.1%, respectively).     

Preparation and characterisation of the C10 to C18 even-numbered triethanolamine alkyl sulphates

The preparation and characterisation of purified C₁₀ to C₁₈ even-numbered triethano-lamine alkyl sulphates are described. Critical micelle concentrations were determined at 25°C, using both conductance and drop volume methods. The authenticity and purity of the products are established, and evidence presented for amending the accepted melting points for two of the compounds.
Preparation et identification des alkysulfates de triethanolamine en C₁₀, C₁₂, C₁₄, C₁₆, C₁₈     

A comprehensive study of hazelnut oil composition with comparisons to other vegetable oils,particularly olive oil.

Crude and refined hazelnut oils from different countries were characterised by major and minor compounds. Fatty acids, triacylglycerides, waxes, sterols, methyl-sterols, terpenic and aliphatic alcohols, tocopherols, tocotrienols and hydrocarbons were identified and quantified by gas chromatography and high-performance liquid chromatography. The levels of these chemical compounds in hazelnut oils together with the equivalent carbon numbers and triacylglyceride carbon numbers, were compared with the results of analyses of samples of other vegetable oils. The statistical procedure of cluster analysis was used to characterise hazelnut oils versus other edible oils.     

LIPID CLASSES, FATTY ACID COMPOSITIONS AND TRIACYLGLYCEROL MOLECULAR SPECIES FROM ADZUKI BEANS (VIGNA ANGULARIS)

The lipids extracted from adzuki beans grown in Japan were classified by thin-layer chromatography (TLC) into eight fractions. Molecular species and fatty acid distributions of triacylglycerols (TAGs) isolated from the total lipids in the beans were determined from a combination of argentation-TLC and gas chromatography. The major lipid components were phospholipids (PL; 63.5%) and TAG (21.2%), while hydrocarbons (5.1%), steryl esters (7.5%), free fatty acids (0.9%), diacylglycerols (1.3%) and monoacylglycerols (0.5%) were also present in minor proportions. Both major samples had high amounts of total unsaturated fatty acids, representing 62.1% for TAG and 65.9% for PL. Seventeen different molecular species were detected. The major TAG components were SMD (5.0%), S₂T (19.3%), SD₂ (13.8%), SMT (9.3%), MD₂ (4.5%), SDT (7.0%), D₃ (8.8%) and ST₂ (15.9%), where S, M, D and T denote a saturated fatty acid, a monoene, a diene and a triene, respectively.

PRACTICAL APPLICATIONS

This article describes the characteristics of lipid components, fatty acid compositions as well as the profiles of triacylglycerol (TAG) molecular species of adzuki beans. α-Linolenic (18:3 n -3) acid was detected as 24.8, 21.2 and 15.2% in the TAG, total lipids and phospholipids, respectively. The oil from legumes, except the profitable fatty acid content, could be a potential source of tocopherols. The data obtained in this study would be useful to both consumers and producers for manufacturing traditional adzuki confectionaries ( wagashi ) in Japan and elsewhere.     

EFFECT OF VITAMIN E SUPPLEMENTATION ON INTRA- AND INTERMUSCULAR FATTY ACID COMPOSITION OF AWASSI LAMBS

This research was carried out to determine the effects of vitamin E supplementation on inter- and intramuscular fatty acid composition in meat of Awassi lambs. Lambs were divided into two groups, control (CG) and experimental (VG), at the beginning of the fattening period. The CG and VG lambs were fed the same concentrate and hay. The VG also received a supplement of 45 mg vitamin E (DL-α tocopheryl acetate) per lamb per day for the 75-day fattening period prior to slaughter. After slaughtering, carcasses were stored at 4 0.5C for 24 h. Then , M. longissimus dorsi (LD) muscles were excised from carcasses, and the intra- and intermuscular fats from LD muscles were used as study material. Results showed that vitamin E supplementation had no significant effect on fatty acid composition in intra- and intermuscular fats (P < 0.05). Fatty acid content in intramuscular fats were different than those in intermuscular fats (P < 0.01) except for lauric (C₁₂), linoleic (C_18:2) and linolenic (C_18:3) acids (P < 0.05). Total saturated fatty acids in the intramuscular fats were lower than in intramuscular fats (P < 0.01). In addition, the majority of fatty acids, both intramuscular and intermuscular, in Awassi lambs were oleic (C_18:1), palmitic (C₁₆ and stearic (C₁₈) acids.     

INFLUENCE OF TIME THICKENING ON THE WHIPPABILITY OF CREAMS

Flow properties of creams containing milk fat (Cream A), vegetable fat (Cream C), and vegetable fat plus milk fat (Cream B) were determined with a coaxial cylinder viscometer for a wide range of shear rates. All creams examined showed time thickening. The viscosity increase with shearing time was expressed by two stage equations as follows: (1) (1) where η_o and η_t are cream viscosity at zero and t shearing time, K₁ and K₂ are rate constants and C₁ and C₂ are constants. The first stage (Eq. 1) was assumed to occur in the course of primary clustering of the independent fat globules, and the second stage (Eq. 2) was assumed to occur in the course of coagulation of the fat globule clusters. Both K₁ and K₂ increased as shear rate increased.
At the same time, the whippability of each cream was determined with a household mixer to which was attached a strain gauge transducer unit for measuring consistency of the whipped creams. There was a tendency for a higher ratio of milk fat/vegetable fat in the creams to decrease the whipping time or to increase whippability of the creams.
Correlations of stability, whippability, and flow properties were examined. A cream which was high stability showed a low K₁ value, and a cream which has high whippability showed a high K₂ value. K₁ and K₂ values at a suitable shear rate will be quite helpful in the determination of the physical properties of cream.     

INHIBITION OF MICROORGANISMS IN SALAD DRESSING BY SUCROSE AND METHYLGLUCOSE FATTY ACID MONOESTERS

The antimicrobial activity of sucrose and methylglucose esters of medium to long chain fatty acids was studied with two microorganisms involved in the spoilage of salad dressings, Zygosaccharomyces bailii and Lactobacillus fructivorans. The microorganisms were inhibited to various degrees by 0.1, 0.5, and 1.0% synthesized sucrose or methylglucose monoesters using a modified broth dilution method. Sucrose monoesters were most inhibitory when the esterified fatty acid was myristic (C₁₄) or palmitic acid (C₁₆). Methylglucose monoesters with lauric (C₁₂) or myristic acid (C₁₄) exhibited greater inhibition than those with longer chain fatty acids. The least inhibition was generally observed with sucrose and methylglucose oleate (C_18:1). Sucrose monoesters were usually more inhibitory than methylglucose monoesters of the same fatty acid, especially for palmitic and stearic (C₁₈) acids. In salad dressing, 1% sucrose monoesters of lauric, myristic, or palmitic acid significantly (P < 0.05) inhibited the growth of Z. bailii and L. fructivorans, and were comparable with or more effective than 0.1% sodium benzoate. Z. bailii growth was nearly completely inhibited by sucrose laurate, myristate and palmitate by 9 days of salad dressing storage. Sucrose monoesters did not delay the lag phase of L.     

The influence of fatty alcohols on the structure and stability of creams prepared with polyethylene glycol 1000 monostearate/fatty alcohols

Liquid paraffin in water emulsions stabilized by PEG 1000 monostearate and alcohols cetostearyl (c/s) myristyl (C₁₄), cetyl (C₁₆) or stearyl (C₁₈) and ternary systems prepared by dispersing each fatty alcohol and surfactant in water were examined during 30 days using a Ferranti-Shirley cone and plate viscometer. Microscopical diffusion experiments investigated interaction between PEG 1000 monostearate solution and each alcohol at high and low temperature.
The rheological properties of each ternary system and corresponding emulsion were similar. Formulations prepared from pure C₁₄, C₁₆ or c/s alcohols were semisolid immediately after preparation. Flow curves were in the form of anticlockwise hysteresis loops with spur points. On ageing for 24 h, structure built-up over a time scale similar to that observed in diffusion experiments, so that apparent viscosities increased. However, on further ageing the pure C₁₄ and C₁₆ alcohol systems were not as stable as those prepared with c/s alcohol. In contrast, the pure C₁₈ systems were mobile liquids and the emulsion cracked within days. This correlated with diffusion experiments where little interaction was observed between stearyl alcohol and PEG 1000 monostearate.
Emulsion consistencies and stabilities were related to the low temperature structures formed in the continuous phases.
L'influence des alcools gras sur la structure et la stabilité des crèmes préparées à partir de systèmes monostéarate de polyéthylène glycol 1000/alcools gras.     

THE LIPIDS OF EGG YOLK. 5. Presence of Ceramide

SUMMARY —Ceramide (an N-acyl sphingosine) was isolated from egg yolk lipid and examined for composition of fatty acids and long-chain base constituents. Yolk ceramide was observed to contain sixteen fatty acids; C _24:0 (35.7%), C _22:0 (22.7%), C _23:0 (15.1%) and C _24:1 (13.5%) were predominant. The component long-chain bases were identified as sphingosine and dihydrosphingosine, the former being the major component (88.6%).     

Oxidative changes in hazelnut,olive, soybean,and sunflower oils during microwave heating

The effects of microwave heating for 3, 6, and 9 min at a frequency of 2450 MHz on fatty acid composition, tocopherols, iodine value, free fatty acids (%), peroxide value, conjugated dienes and trienes, and hexanal contents of refined hazelnut, soybean, sunflower, and virgin olive oils were investigated. A significant (p < 0.05) decrease was observed in linoleic and linolenic acids contents of soybean oil during exposure to microwave heating. Tocopherol contents of oil samples significantly decreased (p < 0.05) during microwave heating. Free fatty acids of the samples slightly increased and iodine value showed reduction throughout the process. Conjugated dienes contents of samples showed an increasing trend up to the 6 min, followed by a reduction at 9 min. Conjugated triene fatty acids of all the samples significantly increased (p < 0.05) throughout the application. While peroxide value showed increasing trend up to the 3 min and sharply decreased at 9 min, hexanal contents of refined hazelnut, virgin olive, soybean, and sunflower oils increased 63, 28, 55, and 389 fold, respectively, after 9 min exposure to microwave heating. Kinetic analysis of data showed that the reaction orders for peroxide and hexanal formation were zero and first order, respectively, and in the tested oils the reaction rate followed the order: soybean oil ? sunflower oil ? hazelnut oil ? virgin olive oil for peroxide, and sunflower oil ? soybean oil ? hazelnut oil ? virgin olive oil for hexanal formation. It was concluded that hexanal could be considered as a parameter for evaluation of the quality of oils exposed to microwave heating.     

The rate of phospholipid hydrolysis in frozen fish

Summary. Phospholipid hydrolysis was studied in lemon sole and haddock between -7°C and -29°C. the rate of reaction was much faster in the Gadoid. the haddock data showed evidence for a rapid first order reaction in which lecithin and phosphatidylethanolamine containing C_16:0, C_18:1 and C_20:5 acids were preferentially hydrolysed. the reaction proceeded to an asymptote which decreased with lowering temperature. the amount of free water available in the frozen state seemed important in these hydrolytic reactions.
The relation of these findings to protein denaturation and taste panel assessment of texture are discussed.     

Detection of the adulteration of olive oils by solid phase microextraction and multidimensional gas chromatography

The presence or absence of filbertone in 21 admixtures of olive oil with virgin and refined hazelnut oils obtained using various processing techniques from different varieties and geographical origins was evaluated by solid phase microextraction and multidimensional gas chromatography (SPME–MDGC). The obtained results showed that the sensitivity achievable with the proposed procedure was enough to detect filbertone and, hence, to establish the adulteration of olive oil of different varieties with virgin hazelnut oils in percentages of up to 7%. The very low concentrations in which filbertone occurs in some refined hazelnut oils made difficult its detection in specific admixtures. In any case, the minimum adulteration level to be detected depends on the oil varieties present in the adulterated samples. In the present study, the presence of R- and S-enantiomers of filbertone could be occasionally detected in olive oils adulterated with 10–20% of refined hazelnut oil.     

EFFECT OF BLENDING ON SENSORY ODOR PROFILE AND PHYSICO-CHEMICAL PROPERTIES OF SELECT VEGETABLE OILS

Edible oils of common use in households are mainly of vegetable origin. The present trend of globalization and emphasis on nutritional enrichment has led to the exploration of usage of blended oils. Binary blends studied in this work consisted of 80% base oil (mustard, groundnut and sunflower oil) and 20% blending oil (sesame, refined palm and rice bran oil). The sensory odor profiling of base oils, namely sesame blending oils and their blends was monitored by Sniff test method. The characteristic notes of mustard oil were more of sulfury, pungent and sour while that of palm oil was more husk-like; sesame oil, seedy and earthy notes; rice bran oil was branny, earthy and groundnut oil more nutty, and had a fresh oil-like note on the profilogram. Profilogram of blends showed a decrease in the intensities of dominating notes of the base oils. The color measurement of blended oils showed variation in L*, a*and b*values with a⁺(redness) for refined palm oil blends, b⁺(yellowness) for sesame and mustard oil blends and a^-(greenness) for rice bran oil blends. The sensory color perception values and CIE color values for L*, a*and b*were negatively correlated for lightness (L*) and sensory redness color values (r=-0.67; p<0.05), while a positive correlation existed between a*and sensory redness values (r=0.72; p<0.05). The apparent viscosity of the oil blends indicated a pseudoplastic shear thinning behavior. The apparent viscosity of the base oils increased when blended with sesame or rice bran oil, while it decreased upon blending with refined palm oil.     

拉曼光谱-聚类分析法快速鉴别掺伪花生油

目的建立快速鉴别掺伪花生油的拉曼光谱.聚类分析方法。方法以不同产地、不同品牌的多批次花生油、大豆油、玉米油、菜籽油、葵花籽油、精炼棕榈油、精炼棉籽油及精炼地沟油为样品,在780 nm和532 nm激光光源下,扫描和比较其普通、扩展及导数拉曼光谱的形态。结果在532 nm激光光源的扩展光谱及一阶导数光谱中,花生油与低价植物油及精炼地沟油光谱的信息量最大,样品间光谱形态的差异显著,谱峰得到有效分离。基于此全波段光谱信息和形态建立的多步聚类分析模型及鉴别程序对36份不同花生油、105份不同低价植物油、30份仿冒花生油和38份不同精炼地沟油的判别正确率均为100%,对180份5%及以上的掺假花生油的判别正确率达86%以上,对75份5%及以上的掺杂花生油的判别正确率为92%,对72份5%及以上的掺杂植物油的判别正确率达92%以上。样品测量时无需制备样品及消耗化学试剂,测量和分析一份样品仅耗时5 min左右。结论所建立的拉曼光谱.聚类分析模型既可准确鉴定花生油,还可准确鉴定各种类型的掺伪花生油,可实现对掺伪花生油的快速、无损和准确鉴别。     

CARBOISIYL AND FATTY ACID ANALYSIS OF ANTELOPE AND BEEF FAT

Characterization of kidney fat from twelve antelope and four beef was accomplished by monocarbonyl, ketoglyceride and fatty acid analysis. Antelope lipids are highly saturated, possessing strong odor and flavor characteristics which many people find objectionable. The antelope fat had a stearic acid content of 42% and an oleic acid content of only 20% while beef fat contained 28% stearic and 34% oleic acid. The lipid was further analyzed by reacting on a 2, 4-DNPH Celite impregnated column. The derivatives were separated from unreacted lip-id, and monocarbonyls and ketoglycerides fractionated using column chromatography. The ratio of monocarbonyls to ketoglycerides was about 1:3 in beef and 1:1 in antelope. Amounts of monocarbonyls average 0.70 μM/g of fat for beef and 1.47 μM/g of fat for antelope. Further analysis of the monocarbonyls indicated 7% methyl ketones, 70% saturated aldehydes, 18% enals and 6% 2,4 dienals in beef while antelope had 15%, 70%, 11% and 4%, respectively. Major constituents of the saturated aldehydes were C₂ through C₈ for both species and C₁₀ for beef while the major methyl ketones were C₃ through C₇ for both species. Methyl ketone, saturated aldehyde and enal fractions showed similar trends in composition with short-chain components higher in antelope and long-chain components higher in beef. Considerable variation occurred among animals of the same species.     

Short communication: Linear discriminant analysis and type of oil added to dairy goat diets

Gas chromatography fatty acid (FA) analysis of 112 milk fat samples from dairy goats fed a basal diet with no added oil or the same diet with 1 of 3 vegetable oils added [high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO)] was used to identify the type of diet consumed through linear discriminant analysis. Twenty variables (19 FA and 1 FA ratio) were selected as valid predictors out of 84 variables tested. The Mahalanobis squared distance was minimal between HOSFO and RSFO groups and maximal between control and LO groups. Cross-validation showed that only one observation from RSFO group was misclassified into the HOSFO group. We concluded that linear discriminant analysis is a useful method to classify milk fat samples from dairy goats according to the particular vegetable oil (of the 3 oils tested here) added to the basal diet.