Amount Of Total Lipids Research Articles

Macromolecular Changes in Nilotinib Resistant K562 Cells; an In vitro Study by Fourier Transform Infrared Spectroscopy

Nilotinib is a second generation tyrosine kinase inhibitor which is used in both first and second line treatment of chronic myeloid leukemia (CML). In the present work, the effects of nilotinib resistance on K562 cells were investigated at the molecular level using Fourier transform infrared (FT-IR) spectroscopy. Human K562 CML cells were exposed to step-wise increasing concentrations of nilotinib, and sub-clones of K562 cells resistant to 50nM nilotinib were generated and referred to as K562/NIL-50 cells. Antiproliferative effects of nilotinib were determined by XTT cell proliferation assay. Changes in macromolecules in parental and resistant cells were studied by FT-IR spectroscopy. Nilotinib resistance caused significant changes which indicated increases in the level of glycogen and membrane/lipid order. The amount of unsaturated lipids increased in the nilotinib resistant cells indicating lipid peroxidation. The total amount of lipids did not change significantly but the relative proportion of cholesterol and triglycerides altered considerably. Moreover, the transcriptional status decreased but metabolic turn-over increased as revealed by the FT-IR spectra. In addition, changes in the proteome and structural changes in both proteins and the nucleus were observed in the K562/NIL-50 cells. Protein secondary structural analyses revealed that alpha helix structure and random coil structure decreased, however, anti-parallel beta sheet structure, beta sheet structure and turns structure increased. These results indicate that the FT-IR technique provides a method for analyzing drug resistance related structural changes in leukemia and other cancer types.

Fatty‐Acid Profile of Total and Polar Lipids in Cultured Rainbow Trout (Oncorhynchus mykiss) Raised in Freshwater and Seawater (Croatia) Determined by Transmethylation Method

Fatty acids from total lipids and polar lipids in cultured rainbow trout (Oncorhynchus mykiss) raised in seawater (SW) and freshwater (FW) were identified and quantified from the muscle samples in January, April, and July. The highest total lipid and polar lipid amounts were found in April. July contents of total lipids were low, but percent of the polyunsaturated fatty acids (PUFAs) was high in SW and FW environment (particularly n-3 PUFAs). Variety of 17 fatty acids was identified by GC-FID after transmethylation. The predominant fatty acids in rainbow trout from SW and FW were: docosahexaenoic acid among n-3 PUFAs, palmitic acid among saturated fatty acids (SFAs), and oleic acid among monounsaturated fatty acids (MUFAs). Appreciably higher n-3/n-6 ratio was found in total lipids in April (6.40, FW fish) and in polar lipids in July (18.76; SW fish). High n-3/n-6 ratio in total lipids and polar lipids of rainbow trout from SW and FW, besides beneficial n-3/n-6 ratio in the commercial fish food, could be characteristic for the local environmental conditions (Croatia).

Validation of liposomal lipid composition by thin-layer chromatography

Liposomes of different sizes are frequently used model systems for cellular membranes. To mimic the cellular environment, these liposomes are often prepared from a mixture of different lipids in organic solution. The preparation involves, at some point, the transfer into aqueous solution. Thus, both the total amount of lipid and the relative amount of each lipid species might deviate from the original composition in the organic solvent. We used thin-layer chromatography combined with a lipid extraction step to check whether the liposomes in the final aqueous solution have the intended composition. This allows determination of the lipid composition not only for large unilamellar vesicles, but was also applied, for the first time, to giant lamellar vesicles (GUVs), which typically are available only with a low amount of lipid per preparation. For different ternary and quaternary mixtures of cholesterol, phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and sphingomyelin, the final composition agreed within 15% with the intended composition in most cases, but in certain cases, such as GUVs prepared with a large fraction of phosphatidylethanolamine, the deviation can be significant. This shows that in those cases where the composition plays an important role, it is advisable to check the final composition of these model membranes.

Correlation between lipid, cholesterol and fatty acid contents in the shoulder of castrated and non-castrated Santa Inês lambs

The objective of this study was to establish a correlation between the content of total lipids, cholesterol and fatty acid profile of the edible portion of the shoulders of 12 castrated and 12 non-castrated Santa Ines lambs, slaughtered at different ages (84, 168, 210, 252 days). Shoulders and the edible portion (muscle and fat) were weighed and stored at -5 °C. Castrated and uncastrated lambs increased their body weight and half carcass weight, respectively. The shoulder weight increased in the carcasses of uncastrated animals. The edible portion of the shoulders of castrated lamb has greater amount of total lipids (16.09 g/100 g). The cholesterol content was influenced by castration, reducing with age. Santa Ines castrated lambs, under semi-extensive conditions, presented larger amounts of C18:1 T11 and CLA in the edible portion of the shoulder. Castration causes no significant correlation between total lipids, cholesterol and total saturated and unsaturated fatty acids of the edible portion of Santa Ines shoulder lambs from 84 to 252 days of age.

Resolution of Parenteral Nutrition–associated Jaundice on Changing From a Soybean Oil Emulsion to a Complex Mixed‐Lipid Emulsion

Resolution of parenteral nutrition (PN)-associated jaundice has been reported in children given a reduced dose of intravenous fat using a fish oil-derived lipid emulsion. The aim of the present study was to examine the effect on PN-associated jaundice of changing from a soybean oil-derived lipid to a mixed lipid emulsion derived from soybean, coconut, olive, and fish oils without reducing the total amount of lipid given. Retrospective cohort comparison examining serum bilirubin during 6 months in children with PN-associated jaundice who changed to SMOFlipid (n=8) or remained on Intralipid (n=9). At entry, both groups received most of their energy as PN (SMOFlipid 81.5%, range 65.5-100 vs Intralipid 92.2%, range 60.3-100; P=0.37). After 6 months, both tolerated increased enteral feeding but still received large proportions of their energy as PN (SMOFlipid 68.4%, range 36.6-100 vs Intralipid 50%, range 37.6-76; P=0.15). The median bilirubin at the outset was 143 μmol/L (range 71-275) in the SMOFlipid group and 91 μmol/L (range 78-176) in the Intralipid group. After 6 months, 5 of 8 children in the SMOFlipid and 2 of 9 children in the Intralipid group had total resolution of jaundice. The median bilirubin fell by 99 μmol/L in the SMOFlipid group but increased by 79 μmol/L in the Intralipid group (P=0.02). SMOFlipid may have important protective properties for the liver and may constitute a significant advance in PN formulation. Randomised trials are needed to study the efficacy of SMOFlipid in preventing PN liver disease.

Starvation Resistance in a Stenothermal Species from the Indian Subcontinent: Mechanistic Basis of Clinal Variation

Parallel clines for starvation resistance and lipid content are well documented among drosophilids on the Indian subcontinent. However, the mechanistic basis of these clines has not been investigated so far. Here, we investigate the utilization of lipids during starvation as a function of duration of stress in D. ananassae. We found higher lipid content responsible for high starvation resistance at lower latitudes. Lipids were utilized during starvation only; not during any other climatic stresses like desiccation or thermal stresses. We also found a cline for consumption of total body lipids; as more content (out of total amount of lipids) was utilized by flies at lower latitudes and lesser at higher latitudes. But, there was no latitudinal cline for threshold lipid amount in the case of females while for males there was a positive cline. Lastly, parallel clines have evolved under contrasting climatic conditions i.e. drier and colder northern localities have flies with lower lipid and reduced starvation resistance while hot and humid localities favor flies with higher lipid levels and greater starvation tolerance. Thus, the evolution of clines associated with starvation and lipid content might have resulted due to specific ecological conditions i.e. humidity gradient on the Indian subcontinent.

Effect of solvent to sample ratio on total lipid extracted and fatty acid composition in meat products within different fat content

The effect of solvent to sample ratio on total extracted lipids and fatty acid (FA) composition in meat products with different fat contents was evaluated. Total lipids were extracted according to the Folch et al. (1957) method, using a 20:1 ratio of chloroform:methanol (2:1, v/v) to sample (A), and also testing the solvent:sample ratio of 10:1 (B). Higher amounts of total lipids and total FA from neutral lipids were obtained using the A ratio, which could be due to an insufficient chloroform:dry-weight sample proportion which could be insufficient for solubilizing the total amount of lipids. In the polar lipid fraction, the total amount of FA was higher using the B rather than the A ratio, which may be caused by the higher volume of added water when using A than B. When studying the FA composition of different lipid fractions, the volume of both the solvent and the water for total lipid extraction should be considered.

Differential roles of pyruvate decarboxylase in aerial and embedded mycelia of the ascomycete Gibberella zeae

The pyruvate-acetaldehyde-acetate (PAA) pathway has diverse roles in eukaryotes. Our previous study on acetyl-coenzyme A synthetase 1 (ACS1) in Gibberella zeae suggested that the PAA pathway is important for lipid production, which is required for perithecia maturation. In this study, we deleted all three pyruvate decarboxylase (PDC) genes, which encode enzymes that function upstream of ACS1 in the PAA pathway. Results suggest PDC1 is required for lipid accumulation in the aerial mycelia, and deletion of PDC1 resulted in highly wettable mycelia. However, the total amount of lipids in the PDC1 deletion mutants was similar to that of the wild-type strain, likely due to compensatory lipid production processes in the embedded mycelia. PDC1 was expressed both in the aerial and embedded mycelia, whereas ACS1 was observed only in the aerial mycelia in a PDC1-dependent manner. PDC1 is also involved in vegetative growth of embedded mycelia in G.zeae, possibly through initiating the ethanol fermentation pathway. Thus, PDC1 may function as a key metabolic enzyme crucial for lipid production in the aerial mycelia, but play a different role in the embedded mycelia, where it might be involved in energy generation by ethanol fermentation.

Fucoxanthin Extractions of Brown Seaweeds and Analysis of Their Lipid Fraction in Methanol

In this present study, fucoxanthin has been successfully extracted and purified from two species of Malaysian brown seaweeds, namely Sargassum binderi and S. duplicatum. The purity of the fucoxanthin obtained was > 99% as indicated by HPLC analysis. Both fucoxanthincontent, and analysis of lipid fraction of the seaweeds in methanol showed that both samples contained a considerable amount of fucoxanthin and total lipids. The amount of fucoxanthin and total lipid farcation in methanol of S. duplicatum (1.01 ± 0.10 and 21.3 ± 0.10 mg/g dry-weight, respectively) was significantly higher than those of S. binderi (0.73 ± 0.39 and 16.6 ± 4.10, respectively). Both types of seaweeds also contained a considerable amount of unsaturated fatty acids. However, in terms of docosahexanoic acid, eicosapentanoic acid, arachidonic acid, linoleic acid and alpha-linolenic acid contents, S. duplicatum was found to be higher (0.76, 2.55, 13.64, 5.81 and 5.35 %, respectively) than S. binderi (0.70, 1.82, 9.13, 6.37 and 4.39%, respectively). For saturated fatty acids, palmitic (C16:0) was found to be the major fatty acid in both samples studied.

Densitas dan Kandungan Total Lipid Mikroalga Spirulina platensis Yang Dikultur pada Tingkatan Perbedaan Fotoperiod

Spirulina platensis is belong to divisi of Cyanophyta which has ability for good adaption in fluctuativ condition where environment factors can influent the composisition of nutrion (lipid, protein, carbohydrate). Lipid has function for fatty acid resources, vitamins and for bioenergy resources. This research aims to know influence of photoperiod with density and total lipid microalga Spirulina platensis which is has been cultured in different photoperiod as a purpose. This research uses complete random plan and treatment of photoperiod 4 hours light 20 hours dark, 8 hours ligth 16 hours dark, 12 hours light 12 hours dark, 24 hours light. The results shows that the highest density of S.platensis on experiment 24 hours light is 1591± 16 x 103 sinusoidal/mL and lowest density on photoperiod 4 hours light 20 hours dark 1087 ± 62 x 103 sinusoidal/mL while higest total lipid amount presentation of lipid on photoperiod 4 hours light 20 hours dark 46,08 ±27,93 %-dw and the total lipid 24 hours light treatment is 24,76 ±5,23 %-dw.

Properties of Calanus finmarchicus biomass during frozen storage after heat inactivation of autolytic enzymes

Calanus finmarchicus is a marine zooplankton of interest for the aquaculture industry, as well as for nutraceuticals and the cosmetic industry. The chemical composition of C. finmarchicus rapidly changes postmortem due to autolytic processes; in particular phospholipids rapidly degrade to give free fatty acids. The aim of this study was to inactivate autolytic enzymes in C. finmarchicus by applying heat (72°C, 5–30min) through mixing with boiling, fresh water, and further to explore the effects of heat (70°C, 15min) combined with long time storage (−20°C, 12months) of treated and untreated material. Heat treatment (5min) inactivated all tested enzymes and maintained the initial amount of phospholipids, total lipids and crude protein. Storage of untreated material led to complete degradation of all phospholipids, whereas heat treatment resulted in a stable product containing the initial amount of phospholipids and astaxanthin.

Biochemical composition of seven species of cyanobacteria isolated from different aquatic habitats of Western Ghats, Southern India

The aim of this work was to study the biochemical constituents of seven species of cyanobacteria namely, Calothrix fusca, Gloeocapsa livida, Lyngbya limnetica and Scytonema bohneri isolated from Panekal sulfur spring. The species namely, Oscillatoria acuminata from petrochemical refinery, O. calcuttensis from dairy effluent and O. foreaui from a sewage drain located in the Western Ghats of Southern India under laboratory culture conditions. The biochemical constituents were analyzed in terms of total carbohydrates, total protein, total free amino acid, total lipid, fatty acid and mineral contents. The analysis showed that maximum amount of total carbohydrate in S. bohneri (28.4% dry weight) and minimum in O. foreaui (8.0% of dry weight). Maximum amount of total protein and total free amino acid were in O. foreaui (7% of dry weight). O. calcuttensis showed higher amount of total lipid (20% dry weight). A total of 12 types of fatty acids were detected among which lauric acid was in highest quantity in all the seven species. Among the polyunsaturated fatty acids, oleic acid was present in all the species ranging from 1.68 to 3.89%. O. foreaui showed highest quantities of copper, manganese, ferrous and zinc. Nickel was maximum in S. bohneri (11.05 µgmL-1). O. acuminata showed highest quantity of magnesium (21.050 mg g-1) and it was least in O. foreaui (12.812 mg g-1).

Seasonal variation of fixed and volatile oil percentage of four Eucalyptus spp. related to lamina anatomy

This experiment was conducted during the four seasons: Spring, summer, autumn and winter of two successive annual cycles; 2008/2009 and 2009/2010 (starting from May 2008). Four Eucalyptus species were under investigation; Eucalyptus camaldulensis Dehnh., Eucalyptus cinerea F. Muell. ex Bentham, Eucalyptus citriodora Hook. and Eucalyptus globulus Labill. Seasonal variations in the amount of fixed and volatile oils in Eucalyptus spp. matured leaves were investigated. It was determined that the amount of total lipids and essential oils significantly varied by the seasons (P < 0.01). The amount of total lipids in Eucalyptus spp. reached its peak mostly in spring. But the amounts of essential oils in different species were determined to be higher in summer, autumn and spring seasons, than in winter. Furthermore, the amount of total lipids and essential oils was higher in E. camaldulensis and E. cinerea than in other species. The anatomical investigation in the four studied Eucalyptus species, in relation to lipids percentage indicated that, the best lipids percentage amounts in this study were exhibited in E. cinerea and E. camaldulensis, for spring and winter; and were in agreement with these species highest lamina thickness. In general, fluctuation in lipids percentage is more correlated to the internal structure of lamina (duct average diameter, ducts total numbers, and open ducts numbers) in the same season; whereas, among seasons, it is thought that metabolism contributed more greatly. Cuticle thickness is true correspondence to seasonal environmental fluctuation, since it increases in all species, by shifting up from spring to summer then decrease to winter. Essential oils secretion which coincided with lipids percentage may be due to environmental stress influence over metabolism rather than structural adaptation. Key words: Eucalyptus, seasons, fixed and volatile oils, lamina, anatomy, glands.

Fucoxanthin extraction and fatty acid analysis of Sargassum binderi and S. duplicatum

Fucoxanthin has been successfully extracted and purified from two species of Malaysian brown seaweeds, namely S. binderi and S. duplicatum. The purity of the fucoxanthin is >99% as indicated by HPLC analysis. Fucoxanthin content, total lipid and fatty acid composition of the seaweeds showed that both samples contained a considerable amount of fucoxanthin and total lipid. The amount of fucoxanthin and total lipid contents of S. duplicatum (1.01 ± 0.10 and 21.3 ± 0.10 mg/g dry-weight, respectively) was significantly higher than those of S. binderi (0.73 ± 0.39 and16.6 ± 4.10, respectively). Both types of seaweeds also contained a considerable amount of unsaturated fatty acids. However, in terms of docosahexanoic acid, eicosapentanoic acid, arachidonic acid, linoleic acid and alpha-linolenic acid contents, S. duplicatum was found to be higher (0.76, 2.55, 13.64, 5.81 and 5.35%, respectively) than S. binderi (0.70, 1.82, 9.13, 6.37 and 4.39%, respectively). For saturated fatty acids, palmitic (C16:0) was found to be the major fatty acid in both samples studied. Key words: Sargassum binderi and S. duplicatum, fucoxanthin; fatty acids, total lipids.

Echium acanthocarpum hairy root cultures, a suitable system for polyunsaturated fatty acid studies and production

BackgroundThe therapeutic and health promoting role of highly unsaturated fatty acids (HUFAs) from fish, i.e. eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are well known. These same benefits may however be shared by some of their precursors, the polyunsaturated fatty acids (PUFAs), such as stearidonic acid (SDA, 18:4 n-3). In order to obtain alternative sources for the large-scale production of PUFAs, new searches are being conducted focusing on higher plants oils which can contain these n-3 and n-6 C18 precursors, i.e. SDA and GLA (18:3n-6, γ-linolenic acid).ResultsThe establishment of the novel Echium acanthocarpum hairy root cultures represents a powerful tool in order to research the accumulation and metabolism of fatty acids (FAs) in a plant particularly rich in GLA and SDA. Furthermore, this study constitutes the first example of a Boraginaceae species hairy root induction and establishment for FA studies and production. The dominant PUFAs, 18:2n-6 (LA, linoleic acid) and 18:3n-6 (GLA), accounted for about 50% of total FAs obtained, while the n-3 PUFAs, 18:3n-3 (ALA, α-linolenic acid) and 18:4n-3 (SDA), represented approximately 5% of the total. Production of FAs did not parallel hairy root growth, and the optimal productivity was always associated with the highest biomass density during the culture period. Assuming a compromise between FA production and hairy root biomass, it was determined that sampling times 4 and 5 gave the most useful FA yields. Total lipid amounts were in general comparable between the different hairy root lines (29.75 and 60.95 mg/g DW), with the major lipid classes being triacylglycerols. The FAs were chiefly stored in the hairy roots with very minute amounts being released into the liquid nutrient medium.ConclusionsThe novel results presented here show the utility and high potential of E. acanthocarpum hairy roots. They are capable of biosynthesizing and accumulating a large range of polyunsaturated FAs, including the target GLA and SDA fatty acids in appreciable quantities.

Effects of dissolved oxygen level on cell growth and total lipid accumulation in the cultivation of Rhodotorula glutinis

The total amount of lipids produced in Rhodotorula glutinis is a subject which has attracted increasing attention due to the potential biodiesel conversion from these microbial oils. The effects of the dissolved oxygen (DO) level in lipid accumulation were examined in this study. Variations of different medium volumes (30, 40 and 50ml) and shaking speed (60, 150 and 210rpm) in the flask trials were adopted to explore the DO effects on lipid production. All of the results revealed that a low DO could retard cell growth, while enhancing lipid accumulation. The 5l-fermentor results also confirm that a low DO (25 ± 10%) batch could have higher lipid content than that of high DO batch (60 ± 10%). Nevertheless, the DO level would not obviously affect the lipid composition profile. Oleic acid (C18:1) was the primary fatty acid in both batches. Due to the slow biomass growth rate resulting from the low DO, a two-stage DO controlled strategy (consisting of a high DO stage and following a low DO stage) was performed to improve the cell growth and lipid accumulation simultaneously. However, the strategy was not successful on the enhancement of total lipid production as compared to other batches. Conclusively, even a low DO could retard cell growth; the total production of lipids in the batch with low DO was higher that of the high DO batch due to the enhancement of lipid accumulation. Therefore, the batch operation of R. glutinis at the low DO was suggested for the purpose of lipid production.

Attenuation of Fatty Liver and Prevention of Hypercholesterolemia by Extract of Curcuma longa through Regulating the Expression of CYP7A1, LDL‐Receptor, HO‐1, and HMG‐CoA Reductase

The extract of Curcuma longa, better known as turmeric, was orally administered to experimental rats that were fed a high-cholesterol diet to investigate whether it could regulate plasma lipids and cholesterol levels and possibly improve hepatic conditions. With turmeric supplements, rats showed a significant decrease in total plasma cholesterol and low-density lipoprotein cholesterol but an increase in high-density lipoprotein cholesterol when compared with rats that were fed a high-cholesterol diet alone. Fatty liver developed in hypercholesterolemic rats with the high-cholesterol diet treatment, and this condition was markedly improved when rats were provided with turmeric supplements at 100 mg/kg or 300 mg/kg of body mass. The turmeric treatment resulted in a significant decrease in the total amount of hepatic lipid. Histological staining of liver tissues with Sudan III and hematoxylin showed that rats fed with a high-cholesterol diet alone had more and larger granular fat bodies than rats having turmeric extract supplementation in their high-cholesterol diet. Reverse-transcription polymerase chain reaction was used to assess the expression levels of enzymes involved in fat metabolism and cellular homeostasis in experimental rat livers. The results showed that rats fed a high-cholesterol diet supplemented with turmeric extract had a significant increase in the expression of cholesterol 7 α-hydroxylase, hemeoxygenase 1, and low-density lipoprotein receptors but a significant decrease in 3-hydroxy-3-methyl-glutaryl-CoA reductase level when compared with rats fed a normal or high-cholesterol diet, showing that turmeric prevents hypercholesterolemia and the formation of fatty liver by the modulation of expressions of enzymes that are important to cholesterol metabolism. Turmeric may be considered a functional food for regulating plasma cholesterol levels and preventing the development of fatty liver in people who frequently consume a high-cholesterol diet.

Liver lipids of Indian and Atlantic Ocean spinner Carcharhinus brevipinna and blacktip Carcharhinus limbatus sharks

Shark liver oils are rich in polyunsaturated fatty acids, especially the n3 moieties. Data on the liver fatty acids of sharks from African waters, however, are limited. Liver samples from sharks from the western Indian Ocean off the east coast of South Africa and those from the Atlantic Ocean and Gulf of Mexico were examined. This study reports on the fatty acids found in the total lipid fractions from the livers of two shark species found in these regions, the spinner Carcharhinus brevipinna and blacktip Carcharhinus limbatus. Greater amounts of total lipids were found in sharks from the Indian Ocean than in those from the Atlantic Ocean (spinner 0.431 g g−1 vs 0.324 g g−1, p = 0.004; blacktip 0.426 g g−1 vs 0.261 g g−1, p = 0.004). The individual fatty acids in the same animals showed reduced amounts of saturates (spinner 26.22% vs 30.68%, p = 0.013; blacktip 28.94% vs 35.14%, p = 0.007) and slightly increased n3 polyunsaturates (spinner 33.67% vs 22.89%, p = 0.001; blacktip 24.77% vs 18.68%, p = 0.025). Generally, the geographical location rather than the shark species was most important in determining the proportions of hepatic lipids.

Examination of Human Meibum Collection and Extraction Techniques

To compare various meibum collection methods and extraction techniques. Sixty subjects, all successful contact lens wearers, were seen on two visits. Meibum was collected from the lower lid of the right eye with a glass microcapillary tube, and with a Dacron swab, cytology microbrush, or spatula from the left eye. Extraction with 2:1 chloroform:methanol was done either immediately or after data collection was complete. Individual samples were divided into four equal aliquots for analysis of total lipids, cholesterol, and inorganic phosphates by assay-based techniques. Effects of collection method, extraction, and dry eye status were examined using repeated measures analysis of variance and logistic regression. Total lipids showed significance for collection device (p < 0.0001) but not for extraction technique (p = 0.13) or dry eye status (p = 0.97). Dacron swab collection was associated with more total lipid on average than each other collection device (p < 0.0001). The cholesterol assay showed significance of collection device (p < 0.0001) and extraction technique (p = 0.0002) but not dry eye status (p = 0.55). Spatula collection was associated with more cholesterol on average than each other collection device (p < 0.0001). For inorganic phosphates, immediate extraction (p < 0.0001), cytology microbrush collection (p < 0.0001), and non-dry eye status (p = 0.03) were associated with the greater likelihood of detection. Dacron swab collection was associated with the highest average amount of total lipid detected, whereas spatula collection and immediate extraction was associated with the highest average amount of cholesterol detected. Cytology microbrush collection with immediate extraction on non-dry eye subjects was associated with the highest probability of detection of inorganic phosphates.

Impact of citric acid and calcium ions on acid solubilization of mechanically separated turkey meat: Effect on lipid and pigment content

Increased demand for poultry products has resulted in an increased availability of by-products, such as the neck, back, and frame, that can be processed into mechanically separated poultry meat. The major problems with mechanically separated poultry meat are its high lipid content, color instability, and high susceptibility to lipid oxidation. The present work was undertaken to determine the effect of different concentrations of citric acid and calcium ions on protein yield, color characteristics, and lipid removal from protein isolates prepared using an acid-aided extraction process. Six levels of citric acid (0, 2, 4, 6, 8, and 10 mmol/L) and 2 levels of calcium chloride (0 and 8 mmol/L) were examined. The entire experiment was replicated 3 times, resulting in 36 extractions (3 × 6 × 2). The highest (P < 0.05) protein yield was found for the treatment with 6 mmol/L of citric acid. In general, all the combinations removed an average of 90.8% of the total lipids from mechanically separated turkey meat, ranging from 86.2 to 94.7%. The lowest amount (1.14%) of total lipids obtained was for samples treated with 4 mmol/L of citric acid. Maximum removal of neutral lipids (96.5%) and polar lipids (96.4%) was attained with the addition of 6 and 2 mmol/L of citric acid, respectively. Polar lipid content was found to be significantly (P = 0.0045) affected by the presence of calcium chloride. The isolated proteins were less (P < 0.05) susceptible to lipid oxidation compared with raw mechanically separated turkey meat. The most efficient removal of total heme pigment was obtained with the addition of 6 or 8 mmol/L of citric acid. Addition of calcium chloride had a negative effect on total pigment content. The study revealed that acid extractions with the addition of citric acid resulted in substantial removal of lipids and pigments from mechanically separated turkey meat, improved stability of the recovered proteins against lipid oxidation, and appreciable protein recovery yields.