Analysis of Persian lime essential oil

Commercially produced Persian lime essential oil was qualitatively and quantitatively analyzed by GC-MS. The oxygenated components represent 25% of the total composition. The major and most of the minor components we isolated from essence oil had been previously identified from coldpressed oil or aqueous essence. Three minor components, 3-methyl-2-butanol, trans carvyl and cis carvyl acetate, not previously found in lime, were identified in this study.     

The volatile aroma components of fermented ciders: Minor neutral components from the fermentation of sweet coppin apple juice

The minor neutral components present in a 1,2-propanediol-washed trichlorofluoromethane extract of a cider distillate have been examined by gas chromatography and gas chromatography-mass spectrometry. This led to the identification of ten alcohols, seven carbonyls, 52 esters and five other components, and to tentative evidence for the identity of a further 32 compounds. Fifty-five of these compounds have not previously been reported in ciders. Odour evaluation of the separated components as they were eluted from the gas chromatograph suggested that many of the esters contribute to the apple fruit character of this beverage.     

Analysis of minor volatile constituents of wine

The analysis of minor volatile constituents in alcoholic beverages presents difficulties because of the relatively high concentrations of a few higher alcohols. Volatile components were extracted from a freshly prepared Riesling white table wine using the solvent trichlorofluoromethane, and analysed by combined gas chromatography-mass spectrometry. The higher alcohols were then removed from the trichlorofluoromethane extracts by treatment with propylene glycol, and the remaining components, mainly esters, were concentrated further. The final concentrate, whose volume represented about 0·01% of that of the wine, was analysed again, and in all, over 40 components were identified. Some of the esters observed, including the mixed ester, 3-methylbutyl ethyl succinate, have not been reported previously.     

Evaluation of a reversed phase high performance liquid chromatographic column for estimation of legume seed oligosaccharides

The retention characteristics of the major legume seed oligosaccharides (sucrose, raffinose, stachyose and verbascose), and also those of some minor oligosaccharide components of soybeans, lupin seeds and fermented soybean products, were investigated using an RP-18 reversed phase column. Excellent separation of sucrose, raffinose and stachyose from one another and from minor oligosaccharide components was achieved using distilled water as the mobile phase, but verbascose could not be determined separately as it coeluted with raffinose. Addition of salts to the mobile phase increased retention and improved selectivity of separation. Rapid and reasonably efficient separation of sucrose, raffinose, stachyose and verbascose was achieved when 0.3 m ammonium sulphate was used as the mobile phase. These oligosaccharides were clearly resolved from minor oligosaccharide components. A comparison of the retention characteristics of the reversed phase column with those of a continuously modified plain silica column, using an acetonitrile/water/ amine modifier mixture as mobile phase, revealed major differences in selectivity which may be of value for separation and identification purposes.     

Separating Tocotrienols from Palm Oil by Molecular Distillation

Crude palm oil contains approximately 1% minor components, including carotenoids and vitamin E (tocopherols and tocotrienols), which contribute to the stability and nutritional properties of palm oil. Palm oil is considered one of the best sources of vitamin E. The vitamin E content in palm oil is unique because it is composed of tocotrienols rather than tocopherols. Palm fatty acid distillate (PFAD) is the volatile organic material recovered as a valuable by-product in the deodorization of palm oil. Several processes have been proposed for recovering tocopherols and tocotrienols from PFAD. For this separation process, it is necessary to develop a processing procedure to extract the valuable tocotrienols and other minor components from PFAD using molecular distillation. Molecular distillation occurs at low temperatures and reduces the problem of thermal decomposition. High vacuum also eliminates oxidation that might occur in the presence of air. The rate of evaporation is controlled by the rate at which the molecules escape from the free surface of the liquid and condense on the condenser. The effects of feed-flow rate and temperature of distillation on extraction of minor components from PFAD are based on concentrations, distribution coefficients, and relative volatilities. The separation of tocotrienols from PFAD approached maximum values at low temperatures and fell drastically as temperature increased. For the optimum conditions for the extraction of tocotrienols with high yield and purity, it is necessary to determine the effect of processing variables on the extraction of minor components (i.e., tocotrienols, α-tocopherol) from the PFAD in terms of concentrations in the liquid and vapor phases, to reveal the behavior of target components in the evaporation process, and to determine the evaporation and volatility properties of tocotrienols and other minor components from PFAD.     

Minor components in food oils: a critical review of their roles on lipid oxidation chemistry in bulk oils and emulsions

Food oils are primarily composed of triacylglycerols (TAG), but they may also contain a variety of other minor constituents that influence their physical and chemical properties, including diacylglycerols (DAG), monoacylglycerols (MAG), free fatty acids (FFA), phospholipids (PLs), water, and minerals. This article reviews recent research on the impact of these minor components on lipid oxidation in bulk oils and oil-in-water emulsions. In particular, it highlights the origin of these minor components, the influence of oil refining on the type and concentration of minor components present, and potential physicochemical mechanisms by which these minor components impact lipid oxidation in bulk oils and emulsions. This knowledge is crucial for designing food, pharmaceutical, personal care, and other products with improved stability to lipid oxidation.     

两种不同产地的榛子油中脂肪酸成分的GC/MS分析

利用索氏提取法对产于辽宁凤城和黑龙江伊春的榛子中的油性成分进行了提取。用硫酸-甲醇法酯化后,对其进行了GC/MS分析。从黑龙江伊春和辽宁凤城的榛子的油性成分中均分离并确定了11种脂肪酸,其中大多数为不饱和脂肪酸,但辅助成分不甚相同。     

The Effect of Minor Components on Milk Fat Microstructure and Mechanical Properties

ABSTRACT: Although minor polar components affected the kinetics of milk fat crystallization, its structure and mechanical properties remained unchanged. At 5 °C, a granular microstructure was observed, while at 20 °C, a combination of granular and spherulitic microstructures were observed. By 27.5 °C, only spherulites were present after 24 h. There were no differences observed in the fractal dimension (D) determined by microscopy or rheology for anhydrous milk fat, milk fat triacylglycerols and MF‐TAGs with added diacylglycerols at 5 °C. There was, however, a strong temperature effect on D, increasing from 1.87 at 5 °C to 1.98 at 22.5 °C. The yield force and storage modulus were unaffected by removal of minor components.     

小宗粮豆蛋白多肽研究进展

小宗粮豆是我国传统粮食作物,富含蛋白质、脂类、纤维素及低聚糖、多酚类等多种营养和功能性成分。目前,我国有关小宗粮豆深加工及综合利用研究很少,该文综述国内外小宗粮豆多肽生物活性研究现状及存在问题。     

顶空固相微萃取-气相色谱/质谱分析啤酒微量香味组分的研究

采用顶空固相微萃取 (HS SPME)技术结合气相色谱 质谱法 (GC/MS)对啤酒的微量香味组分进行了分析研究 ,共分离和鉴定了 41种化合物 ,它们分别属于酯类、醇类、酸类、醛类、酚类、含硫化合物和含氧杂环化合物。这些结果拓展了SPME技术在啤酒香味组分研究中的应用 ,它不仅可成为高级醇、挥发酯定量分析的基础 ,而且使啤酒酵母味、酒花香、氧化味的量化评价成为可能。文中除表列了分析结果外 ,还对SPME方法的特点及所分析组分与啤酒质量控制之间的相关性作了研讨。     

Volatile Constituents of Loquat (Eriobotrya japonica Lindl.) Fruit

Eighteen volatile compounds have been identified in a methylene chloride extract of a distilled fraction from loquat fruit. Individual compounds were identified by comparison of gas chromatographic retention times and mass spectra with those for authentic compounds. Major components phenyl ethyl alcohol, 3-hydroxy-2-butanone, phenylacetaldehyde and hexen-1-ols, and minor components, ethyl acetate, methyl cinnamate and β-ionone probably contribute to the fruity-floral flavor of the fruit.     

Some Effects of the Minor Components of Wheat Starch on Glucose Syrup Production

The recent increase in demand for vital wheat gluten has led to an expansion of the starch/gluten separation industry, resulting in increased availability of wheat starch. The vast majority of the starch used in the U. K. is derived from N. American maize. The majority of this starch is used for glucose syrup production. In studying possibilities for extending the potential use of starch from the European wheat crop for syrup production, we have investigated the factors which influence the commercially-important properties of glucose syrups derived from wheat and maize. In this paper we illustrate the importance of the minor components found in wheat starch preparations, and give details of the techniques used for their selective removal in the laboratory: some of these techniques have potential for industrial application. Procedures for syrup production from these selectively extracted starches are described, together with an assessment of the effects of the minor components on both process and product characteristics. Although both wheat and maize starches contain similar levels of minor components, the effects and fate of these during syrup production differed. However, it was found that with suitable pretreatments to wheat starch, syrups of similar process and product characteristics may be obtained from wheat and maize starches.     

FLAVOR QUALITY OF EXPLOSION PUFFED DEHYDRATED POTATO. 3. Contribution of Pyrazines and Other Compounds to the Toasted Off-flavor

SUMMARY– Potato volatile concentrates were prepared from samples of explosion puffed and conventionally dehydrated potatoes by steam distillation, extraction of distillates with diethyl ether and solvent evaporation and were analyzed by GLC. Peak heights of ten components were associated with the intensity of a toasted off-flavor produced by the puffing process. Four of these and two additional minor components were found to have pyrazine-like aromas; two components had aromas characteristic of the thermal degradation of dry proline-glucose mixtures and two components had burnt aromas. 2-Methylpyrazine, 2, 5-dimethylpyrazine, furfural, 5-methylfurfural, benzaldehyde, and phenylacetaldehyde were identified by mass spectrometry and retention time. An ethylmethylpyrazine, an ethyldimethylpyrazine, and trimethylpyrazine were tentatively identified by mass spectrometry. These results suggest that the toasted off-flavor is due to the presence of alkylpyrazines, compounds derived from proline, products of sugar pyrolysis, and products of Strecker degradation reactions.     

Characterisation of the Essential Oils of some Cultivated Aromatic Plants of Industrial Interest

The compositions of the essential oils of Rosmarinus officinalis L, Salvia lavandulifolia V and Lavandula latifolia M, obtained by steam distillation from plants cultivated in the northeast of Spain, have been studied by gas chromatography and gas chromatography/mass spectrometry. The essential oil of rosemary appears to be more complex and richer in flavour notes than other previously studied Spanish rosemary oils, and has an intermediate ratio of α-pinene and of 1,8-cineole in relation to essential oils of rosemary of different geographical origins, but higher proportions of camphor, verbenone and linalool. The essential oil of sage has proportions of 1,8-cineole, camphor, endo-borneol, trans-caryophyllene and α-humulene closer to commercial Salvia officinalis L than to other Spanish sages of different geographical locations, and the difference from commercial Salvia officinalis L is due principally to the higher ratio of terpene hydrocarbons and the lower proportion of thujone in the Spanish sage studied here. The essential oil of the spike lavender has the same main components and similar proportions as other Spanish wild and commercial spike lavender essen-tial oils, but shows differences in the nature of the minor components (rhodinol fraction).     

Effect of Further Processing Systems on Selected Microbiological Attributes of Turkey Meat Products

Effects of carcass transfer and line transport, deboning, protein extraction and product wrapping, meat blending, product packaging and cooking-smoking procedures on microbiological concentrations were evaluated. Increased mesophilic bacterial numbers were associated with carcass transfer and line transport with no effects on other bacterial concentrations. Hand deboning increased bacteria on breast and thigh tissue. Mechanical deboning increased bacterial content. Protein extraction and product wrapping produced minor effects. Bacterial numbers from meat blends reflected combination of input components. Product packaging exerted minor effects on numbers of bacteria from raw product. Handling required in packaging cooked product produced increases in tissue bacterial content. Cooking and smoking procedures were equally effective in reducing bacterial contents to essentially negative concentrations.     

Membrane applications in functional foods and nutraceuticals

The functional foods and nutraceuticals market is growing at a rapid pace. Membrane processing offers several advantages over conventional methods for separation, fractionation, and recovery of those bioactive components. In this review, membrane applications of lipid-, carbohydrate-, and protein-based nutraceuticals and some minor bioactive components have been critically evaluated. Both non-porous and porous membranes were employed for lipid-based nutraceuticals separations. The use of non-porous membranes together with non-aqueous solvents brought about the impact of solution-diffusion theory on transport through membranes. Both organic and inorganic membranes gave encouraging results for the recovery of lipid components with single- and/or multi-stage membrane processing. Two-stage ultrafiltration (UF)-nanofiltration (NF) systems with polymeric membranes provided an efficient approach for the removal of high- and low-molecular weight (MW) unwanted components resulting in higher purity oligosaccharides in the NF retentate. The charged nature of protein-based nutraceutical components had a major effect on their separation. Operating at optimizal pH levels was critical for fractionation, especially for low MW peptide hydrolysates. Processing of minor components such as polyphenols, utilized all types of porous membranes from prefiltration to concentration stages. Coupling of membrane separation and supercritical fluid technologies would combine unique advantages of each process resulting in a novel separation technology offering great potential for the nutraceutical and functional food industry.     

Characterisation of the Colloidal Haze in Commercial and Pilot Scale Belgian White Beers

Hazes from four commercial Belgian white beers were studied. Proteins (7–74%) and polyphenols (1.1–7.7%) were the major components, although hazes with a high content of glucose polymers also occurred. The glucose polymers are mainly starch or degraded starch (9–65%) and only to a minor extent β‐D‐glucan (0‐0.5%). Arabinoxylans and metal ions (mainly calcium) were minor constituents. The hazes also contained arabinogalactan‐peptide in minor quantities due to the large level of wheat used in the grist. A high mannose content (0.9‐3.3%), originating from yeast cell wall mannans, was also found in the hazes. Characterisation of the haze of three pilot scale brews with different production processes showed that the composition of the hazes was strongly influenced by the process employed. Hazes can be enriched in proteins or starch/dextrins by changing the raw materials and/or the brewing process.     

Photooxidative stability of stripped and non-stripped borage and evening primrose oils and their emulsions in water

Minor components in edible oils affect both their autooxidative and photooxidative stabilities. Thus, stripping of minor components may influence stability of oils being studied. The impact of natural endogenous pigments on photooxidative stability of stripped and non-stripped borage and evening primrose oils and their emulsions in water was studied. Peroxide values (PV) of non-stripped borage and evening primrose oils and their emulsions in water were significantly (P<0.05) higher than corresponding values for stripped oils and their emulsions in water. A similar trend was observed when considering hexanal contents of bulk oils and their corresponding oil-in-water emulsions. These results indicate that minor components, especially endogenous chlorophylls, play a major role in the photooxidation of borage and evening primrose oils and their emulsions in water.     

Formation of toxic 2-nonyl-p-benzoquinones from α-tertiary 4-nonylphenol isomers during microbial metabolism of technical nonylphenol

In many environmental compartments, microbial degradation of α-quaternary nonylphenols proceeds along an ipso-substitution pathway. It has been reported that technical nonylphenol contains, besides α-quaternary nonylphenols, minor amounts of various α-H, α-methyl substituted tertiary isomers. Here, we show that potentially toxic metabolites of such minor components are formed during ipso-degradation of technical nonylphenol by Sphingobium xenophagum Bayram, a strain isolated from activated sewage sludge. Small but significant amounts of nonylphenols were converted to the corresponding nonylhydroquinones, which in the presence of air oxygen oxidized to the corresponding nonyl-p-benzoquinones-yielding a complex mixture of potentially toxic metabolites. Through reduction with ascorbic acid and subsequent analysis by gas chromatography-mass spectrometry, we were able to characterize this unique metabolic fingerprint and to show that its components originated for the most part from α-tertiary nonylphenol isomers. Furthermore, our results indicate that the metabolites mixture also contained several α, β-dehydrogenated derivatives of nonyl-p-benzoquinones that originated by hydroxylation induced rearrangement, and subsequent ring and side chain oxidation from α-tertiary nonylphenol isomers. We predict that in nonylphenol polluted natural systems, in which microbial ipso-degradation is prominent, 2-alkylquinone metabolites will be produced and will contribute to the overall toxicity of the remaining material.     

Characterization of multiple forms of lactophorin isolated from bovine milk whey

A glycoprotein that reacted to the antisoluble glycoprotein of bovine milk fat globule membrane was purified from the proteose-peptone of whey and designated lactophorin. Lactophorin was separated into seven components. Lactophorin and the seven components were rich in aspartic acid, threonine, serine, glutamic acid, leucine, and lysine. The content of threonine, glycine, isoleucine, lysine, and arginine varied in each component. The ratio of fucose, mannose, galactose, N-acetylgalactosamine, N-acetylglucosamine, and sialic acid of lactophorin, which contains about 18% saccharide, were 1, 6.6, 10.3, 5.5, 9.7, and 11.6, respectively, while the respective ratio of the seven components were 1, 5 to 6, 7 to 9, 3 to 4, 6 to 8, and 4 to 12. Sialic acid content varied in each component. Protein-carbohydrate linkage was N- and o-glucoside linkage. Lactophorin consisted of seven polypeptides (I to VII) with apparent molecular weights 17,000 to 67,000. Bands I, II, VI, and VII were glycoprotein. Bands VI and VII were major and had antigenicity to anti-soluble glycoprotein, while bands I to V were minor polypeptides. Component 1 consisted of only one polypeptide (VII), whereas the components 2 to 7 contained two major (VI, VII, or both) and several minor polypeptides. The sedimentation pattern of each component was a single and almost symmetrical peak. Sedimentation coefficient was 3.79 to 5.64 S and also varied in lactophorin. The results indicate that lactophorin has multiple forms.