Lipids are a major source of energy and provide essential lipid nutrients. In many food products the lipid component plays a major role in determining the overall characteristics, such, as flavour, texture, mouthfeel and appearance (Ross & Smith, 2006). However, fats, oils and lipid-based products deteriorate during heat processing, distribution and long term storage. The chemical deterioration is as a result of lipid oxidation. In some chesses, a limited amount of lipid oxidation is desirable for the generation of a characteristic taste or smell (Sun et al., 2011). On the other hand it is undesirable in high lipid or fat containing food products. Lipid oxidation is a major concern to the food industry due to the increasing emphasis on the use of polyunsaturated vegetable and fish oils, and discontinuing the use of synthetic antioxidants. Unsaturated fats are used extensively in the formulation of many food products and these are the most susceptible to oxidation. Lipid oxidation can lead to several changes to food products which affects shelf-life and consumer acceptance. These include development of rancid flavours and aromas, changes in colour and texture, and a decline in the nutritional value of food products (Hidalgo & Zamora, 2000; Morales & Jaménez-pérez, 2001). Lipid oxidation products decompose lipid soluble vitamins such as vitamin A, D, E and K, and its pro-vitamins carotenes resulting in nutritional losses in food products (Rahman, 2007). In addition, the oxidation of fats in foods can lead to the accumulation of toxic compounds such as peroxides and aldehydes. These are potentially detrimental to human health when consumed in high concentrations and have been implicated in the development of several diseases includi...
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...tion condition that generates MRPs with specific antioxidant activity could therefore be valuable for use during food processing (Kim & Lee, 2009b). Although a wide range of model systems involving sugar-amino acid reactions have been reported, few studies investigated the MRPs form ribose-lysine systems in emulsions or food systems.
Therefore the objective of this study was to determine non-specific browning indicators (browning intensity and pH reduction) and indices (DPPH, peroxyl radical scavenging activity and reducing power) of the antioxidant effect of the ribose-lysine of Maillard reaction products (MRPs), as a function of reaction temperature, time and model phase; and to determine lipid oxidation indices TBARs and Pv in a lipid-rich model system as a function of antioxidant type with the view to find a natural alternative to synthetic food antioxidants.
Esters are defined as molecules consisting of a carbonyl group which is adjacent to an ether linkage. They are polar molecules which are less polar than alcohols but more so than ethers, due to their degree of hydrogen bonding ability. Most often derived from reacting an alcohol with a carboxylic acid, esters are a unique, ubiquitous class of compounds with many useful applications in both natural and industrial processes 1. For example, within mammals, esters are used in triglycerides and other lipids as they are the main functional group attacking fatty acids to the glycerol chain 2. A unique property of esters is their tendency to give off distinct aromas such as the scent of apples (Ethyl caprylate) and bananas (Isoamyl acetate). This is of a unique importance especially in industries that utilize flavors and aromas such as the tobacco, candy and alcohol industry. Consistent research is conducted in order to enhance and increase the effectiveness of esters in these products 3.
To uncover organic compounds like carbohydrates, lipids, proteins and nucleic acid, by using tests like Benedict, Lugol, Biuret and Beta Carotene. Each test was used to determine the presents of different organic molecules in substances. The substances that were tested for in each unknown sample were sugars, starches, fats, and oils. Moreover, carbohydrates are divided into two categories, simple and complex sugars. Additionally, for nonreducing sugars, according to Stanley R. Benedict, the bond is broken only by high heat to make make the molecules have a free aldehydes (Benedict). As for Lipids, there are two categories saturated and unsaturated fats. One of the difference is that saturated fats are mostly solids and have no double bond (Campbell Biology 73). The Beta Carotene test works by dissolving in a lipid, thus giving it color to make it visible. Moreover, proteins are made out of amino acids that are linked by a polypeptide bond (Campbell Biology 75). The purpose of this experiment was to determine whether an unknown class sample or food sample had any carbohydrates, lipids, or proteins in it. The expected result of the lab was that some substances would be present while other would be absent.
Acid or base-catalyzed hydrolysis yields the component fatty acid, some examples of which are given in the following table, together with the alcohol component of the lipid. These long-chain carboxylic acids are generally referred to by their common names, which in most cases reflect their sources. Natural fatty acids may be saturated or unsaturated, and as the following data indicate, the saturated acids have higher melting points than unsaturated acids of corresponding size. The double bonds in the unsaturated compounds listed on the right are all cis (or
The purpose of conducting an experiment using various temperatures, pH levels, and enzyme concentrations was to observe the effects these factors had on the rate of horseradish peroxidase activity. Furthermore, testing how peroxidase reacts to different set ambient conditions and finding the conditions that allow for maximum rates. Enzymes are used in this experiment to demonstrate the importance of certain environmental conditions since they affect the speed of an enzymatic reaction in order to carry out life. An extract from horseradish is used as the enzyme since it contains peroxidase which has a highly accessible active site. The experiment was administered by using a spectrometer as a tool to measure oxygen production using an indicator called guaiacol which would allow the rate of horseradish peroxidase activity to be seen. Environmental circumstances, such as enzyme concentration, temperature, and pH, are tested by using guaiacol as an indicator of oxygen production and H2O2 as an oxygen producing agent. The ending results conclude that higher enzyme concentration can increase the speed of the rate of enzyme activity. The results also conclude
An Investigation into the Effect of Lipase Concentration on the Hydrolysis Of Fats Using the data loggers a recording of the pH was taken every 5 seconds and for each experiment the data loggers produced graphs of the change in pH. From each of these graphs a gradient was calculated which showed the rate of pH change per second. Firstly I calculated the gradients by choosing the steepest section of the graph and dividing the change in pH of this section by the time. However this method proved to be quite inaccurate giving very varied results, for example in these results the average rate of reaction for the 4% lipase solution (-0.457 pH/min) was lower than the 3% lipase solution (-0.471 pH/min). Also the rates in the 2% lipase solution ranged from -0.01 pH/min to -0.95 pH/min showing little reliability in the results. This was partly as I was only guessing which the steepest part of the graph was.
Because of its undeniable and scientifically-proven powerful antioxidant properties, catalase enzyme has a wide commercial application. Primarily in combination with the enzyme glucose oxidase, catalase is used as a preserving system in mayonnaise and egg products such as whole eggs or dried egg white, in the preparation of milk and cheese, in the manufacture of baked goods, beverages, textile industry, cosmetic industry (as face mask), and in cleaning agents for contact lenses, for the elimination of the hydrogen peroxide that is present in some products, (Worthington Biochemical Corporation,
Food additives are substances that are added to food to enhance it; they can be both chemical and natural ("Food Additives: MedlinePlus Medical Encyclopedia"). Recently many food additives have been questioned by both the public and scientists world wide. One example of the food additives that have been studied is sodium stearoyl lactylate. It has recently been looked at due to indications that it might be unsafe for consumption. In this essay a couple main points and questions will be explained; what is sodium stearoyl lactylate, what are its effects both positive and negative, what are some indirect effects SSL has on society, is it ethical to use, and if sodium stearoyl lactylate safe for human consumption.
Enzyme peroxidase is essential in any cell metabolic reaction as it breaks down the harmful hydrogen peroxide to harmful products in the body. The report analyzed its effect on changes in temperatures by determining the optimum temperatures and the effects of its reversibility. Through the method of extracting the enzyme by blending it with potato tissue in phosphate buffer, the effects were analyzed on the effect of the dye guaiacol and the activity measured under different temperatures. The optimum temperature was obtained at 22.20C and above this temperature, the enzyme was denatured. Conclusively, increase in temperature increases
I have chosen Food Irradiation as the non-thermal food technology that shows promise for food applications. Non-thermal methods of food processing have become very interesting to those involved in the food processing industry in the last few years. Thermal methods usually dominated the food processing industry; however, these methods can have an effect on the food flavour, texture and nutritional values. However non-thermal methods are becoming more popular as there is minimal impact on the nutritional value or the flavour, texture and odour of the foods. These methods can also extend shelf life as they kill more microorganisms, while being more energy efficient. I will discuss the types of Food Irradiation processes; the techniques used with this method; discuss how this method affects shelf life, nutritional value and sensory value, and compare the benefits and limitations of non-thermal food processes with the benefits and limitations of thermal food processes.
There are many more lipids than I have mentioned in my research paper, there are over a 100 know lipids. Lipids are very important for our body and cells and they carry out many function. They provide nutrients for our body. Lipids are a category of nutrients. Lipids consist of fats, oils, and waxes and are very important for are body’s health. Lipids are important for the human body because they are for storing energy, they’re good at storing energy because they can concentrate a group of calories in a smaller area. Lipids are also used to make soaps, detergents and waxes. These are things that we use in every day life.
Food has been a common source of necessity in our everyday lives as humans. It helps gives us nutrition and energy to live throughout our life. Over several decades, the development of making foods has evolved. They have changed from natural to processed foods in recent years. Nowadays natural ingredients are barely used in the making of foods like bread, cheese, or yogurt. The food industry today has replaced natural food making with inorganic ingredients. The cause of this switch is due to processed foods being easier, cheaper and faster to make. Artificial nutrition and processed foods have been proven to last longer in market shelves then natural foods. Also, due to artificial additives in processed foods they help satisfy consumers taste more than natural ingredients. The method of producing processed foods is common in today's food industry and helps make money faster and efficiently for companies. Examples of this can be found in all markets that distribute food. Even though processed foods may be easier and faster to make, they are nowhere near as healthy for consumers compared to natural foods. Natural foods are healthier, wholesome, and beneficial to the human body and planet then processed foods.
Food is “composed of synthetic chemical additives, such as colorings, preservatives, sugar substitutes and trans-fats” (Fitzgerald, 2006, p.72). Fitzgerald reported that by the “1970s most meats and dairy products that were factory farmed were laced with growth hormones, antibiotics and a range of pesticides” (p.72). Furthermore, food that is frozen, packaged and canned is considered processed food. A brief explanation of the chemical additives in processed food. 1.
Researchers then hypothesized that the results would indicate the greatest amount of potato enzyme activity level will take place at room temperature. In this experiment, researchers used potato extract and different temperature levels to test the hypothesis. Moreover, researchers wanted to test the color intensity scale and how specific catechol oxidase is for catechol. In this experiment, researchers used dH2O, catechol solution, hydroquinone, and potato extract. Lastly, researchers tested the substrate concentration and how it has an effect on enzyme activity.
Food Preservation is the ways to retain the food quality in a longer times. It is to prevent the food decomposition and fermentation. Besides that, food preservation not only to prevent the food getting spoilt in a long period of time but also preserved the colour, taste and the food nutritive value. Nowadays, food preservation has become more and more important component in the food industry as the consumers expect that able to purchase those foods that are out of season or imported from other countries. Furthermore, there are few reason why food preservation is important in our daily life such as preservation foods when they are in season it may added variety choices in our meals for example smoke meats and
This clearly shows that the fruits and vegetables play a vital role in maintaining our good health. Fruits and vegetables are seasonal and grown in different parts of our country. They need to be stored for longer period and transported to different places. It makes necessary for us to find out whether there is any damage to the useful contents of the fruits and vegetable during the storage and transportation or due to some preservatives or other factors and what kind of nutrients, minerals, etc. are present in their juices. With this idea in mind, the project has been undertaken.