What is the avarage of fat in coffee?
The determination of the avarage fat content in coffee has been yet very ambiguous and difficult to determine. Some studies, like the one performed by Rtanayake in 1993, claimed that the lipid content in coffee varies depending on the preparation method. In this experiment it was found less than 7 mg of fat in filtered brewed coffee to 60’160 mg in 150 mL cup of boiled unfiltered coffee (Ratnayake et al., 1993).
However, data on health effects of particular fatty compounds of coffee are kept being uncertain for severals scientists. Although the study of (Shen et al., 2010), show that diterpenes have numerous beneficial effects including chemopreventive, antitumorigenic, hepatoprotective, antioxidative and anti-inflammatory effects, others authors like Ricketts, suggested that cafestol and kahweol, diterpene alcohols found in the lipid fraction of coffee, are responsible for the observed hypercholesterolemic effects and the modulation of liver enzymes (Ricketts et al., 2007).
Finally with the previous studies and analysis of Urgert made in 1995, which resumes that the content of the dipertene alcohols in coffee have a strongly dependance on both the coffee blends used and the method of preparation the following study is going to use the previous astudies to find out, compare and prove the quantity of avarage fat found in both kinds of coffee, in the filtered coffee as well as in the unfiltered or unused ground coffee.
What are triglycerides?
Fat is one of the three main macronutrients: fat, carbohydrate, and protein. Fats are a wide group of compounds whose basis is a long-chain of organic acids, called fatty acids. More particularly fats are esters of such organic acids formed with the alcohol glycerol. Glycerol is a triol, meaning that it has three chemically active -OH (hydroxyl) groups. Fats are made when each of these three -OH groups reacts with a fatty acid. The resulting fats are called triglycerides. Because of their preponderant aliphatic structure, fats are hydrophobic, generally soluble in organic solvents but generally insoluble in water. (McKinley Health Center)
Fats and oils are categorized according to the number and bonding of the carbon atoms in the aliphatic chain. Fats that are saturated fats have no double bonds between the carbons in the chain. Unsaturated fats have one or more double bonded carbons in the chain. Some oils and fats have multiple double bonds and are therefore called polyunsaturated fats. Unsaturated fats can be further divided into cis fats, which are the most common in nature, and trans fats, which are rare in nature. Unsaturated fats can be altered by reaction with hydrogen effected by a catalyst. This action, called hydrogenation, tends to break all the double bonds and makes a fully saturated fat. To make vegetable shortening, then, liquid cis-unsaturated fats such as vegetable oils are hydrogenated to produce saturated fats, which have more desirable physical properties. They are able to melt at a desirable temperature (30’40 ??C), and store well, whereas polyunsaturated oils go rancid when they react with oxygen in the air. However, trans fats are generated during hydrogenation as contaminants created by an unwanted side reaction on the catalyst during partial hydrogenation. (Donatelle, R., 2005)
This study will use the previous investigations made by Donatella and Hayes in order to determine specifically which type of fatty acids are found in filtered coffe and which others are presented in the unfiltered ground coffee.
What is the difference between healthy and unhealthy fatty acids?
Mozaffarian, 2006 claims in the article published in the New England Journal of Medicine in 2006 that the avarage percentage of trans fatty acids consumed by people from the United States had increased from 2 to 3 percent of the total colaries that should be consumed per day in a balance diet. The author also explains with futher investigation made from especialized institutions, like the Harvard School of Public Health and Medice and the Wageningen Center for Food Sciences highly consumption of trans fatty acids increases the risk of coronarry heart disease (CHD) and diabetes because shifts the physiologic state to one that is prothrombotic and proaggregatory, characterized by increases in blood viscosity, vasospasm, and vasoconstriction and decreases in bleeding time.
However, an other investigation from Simopoulos, (1999) discusses the antiinflammatory, antithrombotic, antiarrhythmic, hypolipidemic, and vasodilatory properties some fatty acids can have. The autor explains in his study that these beneficial effects from n’3 fatty acids have been shown in the secondary prevention of coronary heart disease, hypertension, type 2 diabetes, and, in some patients with renal disease, rheumatoid arthritis, ulcerative colitis, Crohn disease, and chronic obstructive pulmonary disease.
The two previous studies show important information about the propersties fatty acids have. They defined which type of fatty acid contributes to human health and which other cause a negative impact on the human organism. With both investigations, the present study wants to know what type of fatty acid is presented in filtered and unfiltered coffee and furthermore know if actually the drinking of coffee gives positive effects to human health.
What are the risks of petroleum ether?
As the confidential source of Material Safety Dta Sheet (MSDS) says, Petroleum ether is a highly flammable compound. As a consequence of its low flash point (40??C-60??C) it is easily ignited by heat, sparks or flames. When petroleum ether ignites the vapors formed may produce explosive mixtures with air.
Concerning the health conditions, petroleum ether vapors irritates respiratory tract, causes coughing and mild depression. Aspiration causes severe lung irritation with coughing, gagging, and rapidly developing pulmonary edema. Ingestion of the cmpund irritates mouth and stomach, causes nausea, vomiting, swelling of abdomen, cardiac arrhythmias. (USCG, 1999).
Petroleum ether cotains Saturated aliphatic hydrocarbons. These hydropacarbons can be incompatible with strong oxidizing agents like nitric acid. This means that a charring of the hydrocarbon can be produced, followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, aliphatic saturated hydrocarbons, which are the ones present in fats and oils are mostly unreactive. They are not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents. When heated sufficiently or when ignited in the presence of air, oxygen or strong oxidizing agents, they burn exothermically to produce carbon dioxide and water. This means that aliphatic saturated hydrocarbons can be ignited by strong oxidizers.
This important information serves in the presented study to know specific precautions and to know different methods when working with different kinds of compunds. The Material Safety Data Sheet is a useful source material when performances of chemistry experiments are needed. (CAMEO Chemicals).
To date, based on (MSDS, 1997) and Acros Organics information, petroleum ether presents the follow hazardous symbols:
F: Highly flammable
N: Dangerous for the environment
Why is petroleum ether used as extracting agent?
For the problem to investigate an extraction procedure is required. The aim of all extraction procedures is to separate cellular or fluid lipids from the other constituents, proteins, polysaccharides, small molecules (amino acids, sugars…) but also to preserve these lipids for further analyses.
The study of Speer explains that there is a great diversity of methodologies because biological tissues are not similar when considering their structure, texture, sensitivities and lipid contents. Removing the non-lipids without losing some lipids is a complex challenge, extracting some specific lipids is not always reliable for other kinds of lipids. For this resason, the high sensitivity of the analytical methods needed for low amounts of extracted lipids requires the use of very pure solvents and clean glassware.
As the study continues to explain, all lipids must be protected against degradation through oxidation by solvent, oxygen, enzymes in combination with temperature and light. For this reason, the autor claims that in order to avoid peroxidation of the extracted lipids all solvents should be used as peroxide-free. (Ishida BK et al., J Agric Food Chem 2009, 57, 1051).
To sum up, the investigation made by Ishida (2009) helps this research to determine the best solvent to treat the experiment that will be analyzed in this study. the risk of peroxide formation is particularly high with ethers. As it is known The term “petroleum ether” is an old term used to refer to a mixture of hydrocarbons with a specific boiling point range. In other words, there is no ether in petroleum ether. Due to the peroxide free property petroleum ether has the presented work of investigation is going to use petroleum ether as the main solvent in the extraction of fatty acids in grounded and ungrounded coffee.
Which method was used in the experiment?
Different methods are used nowadays for quatitying fat and fatty acid composition in feedstuffs. This methods require solvent extraction, purification and esterification. The Soxhlet method is a hybrid continuous’discontinuous technique. (Adnan, 2008). This means that inasmuch as the solvent acts stepwise, the assembly can be considered as a batch system; however, since the solvent is recirculated through the sample, the system also bears a continuous character.
Eventhough the Soxhlet extraction compared with other conventional analitical methods has many disavantages; it requires and takes a long time for the extraction and produce a large amount of solvent wasted, which is not only expensive to dispose off but which can itself cause additional environmental problems; the Soxhlet extraction still brings a lot of benefit; the sample is repeatedly brought into contact with the fresh portions of the solvent, thereby helping to displace the transfer equilibrium. The temperature of the system remains relatively high since the heat applied to the distillation flask reaches the extraction cavity to some extent. No filtration is required after the leaching step. Sample throughput can be increased by simultaneous extraction in parallel, since the basic equipment is inexpensive. (Castro, 1998).
Because the Soxhlet extraction method has a very simple methodology which needs little specialized training and has the possibility to extract more sample mass than other methods (microwave-extraction, supercritical fluids, etc.) and is non-matrix dependent, the present experiment of this study will be carried using the method of the Soxhlet extraction.
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