Edible Oleogels (eBook)

Structure and Health Implications

Nissim Garti, Alejandro G. Marangoni (Herausgeber)

eBook Download: PDF | EPUB

2015 | 1. Auflage
352 Seiten
Elsevier Science (Verlag)
978-1-63067-009-2 (ISBN)

Infos

In an effort to provide alternatives to trans and saturated fats, scientists have been busy modifying the physical properties of oils to resemble those of fats. In this fashion, many food products requiring a specific texture and rheology can be made with these novel oil-based materials without causing significant changes to final product quality. The major approach to form these materials is to incorporate specific molecules (polymers, amphiphiles, waxes) into the oil components that will alter the physical properties of the oil so that its fluidity will decrease and the rheological properties will be similar to those of fats. These new oilbased materials are referred to as oil gels, or 'oleogels,' and this emerging technology is the focus of many scientific investigations geared toward helping decrease the incidence of obesity and cardiovascular disease. - Presents a novel strategy to eliminate trans fats from our diets and avoid excessive amounts of saturated fat by structuring oil to make it behave like crystalline fat - Reviews recent advances in the structuring of edible oils to form new mesoscale and nanoscale structures, including nanofibers, mesophases, and functionalized crystals and crystalline particles - Identifies evidence on how to develop trans fat free, low saturate functional shortenings for the food industry that could make a major impact on the health characteristics of the foods we consume

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In an effort to provide alternatives to trans and saturated fats, scientists have been busy modifying the physical properties of oils to resemble those of fats. In this fashion, many food products requiring a specific texture and rheology can be made with these novel oil-based materials without causing significant changes to final product quality. The major approach to form these materials is to incorporate specific molecules (polymers, amphiphiles, waxes) into the oil components that will alter the physical properties of the oil so that its fluidity will decrease and the rheological properties will be similar to those of fats. These new oilbased materials are referred to as oil gels, or "e;oleogels,"e; and this emerging technology is the focus of many scientific investigations geared toward helping decrease the incidence of obesity and cardiovascular disease. - Presents a novel strategy to eliminate trans fats from our diets and avoid excessive amounts of saturated fat by structuring oil to make it behave like crystalline fat- Reviews recent advances in the structuring of edible oils to form new mesoscale and nanoscale structures, including nanofibers, mesophases, and functionalized crystals and crystalline particles- Identifies evidence on how to develop trans fat free, low saturate functional shortenings for the food industry that could make a major impact on the health characteristics of the foods we consume

Textauszug

2

Novel Strategies for Nanostructuring Liquid Oils into Functional Fats

Alexander K. Zetzl and Alejandro G. Marangoni,     Department of Food Science, University of Guelph, Guelph, Ontario, Canada

Introduction

The study of fats and oils and their effect on human health has been one of the most studied topics in human nutrition to date. Over decades of study, several indicators of human cardiovascular health have been identified, including blood serum cholesterol, triacylglycerols, and free fatty acid levels. Blood serum cholesterol levels have been extensively studied and are believed to be one of the most effective of these indicators. One of the first reviews on diet and its effect on serum cholesterol was conducted by Keys et al. in 1965. This group showed that serum cholesterol is greatly affected by the amount and composition of the fat that is consumed in one’s diet. The group also believed that an individual’s serum cholesterol could be predicted fairly accurately based on their diet (Keys et al., 1965). In the 40 years after the publication of this groundbreaking study, a much more detailed understanding of fat and its affect on serum cholesterol has been attained. Total fat can be broken down into saturated, cis monounsaturated, trans monounsaturated, and cis polyunsaturated fatty acids (Mensink et al., 2003). Serum cholesterol also consists of separate fractions, low density lipoprotein (LDL) and high density lipoprotein (HDL). Low density lipoprotein is commonly referred to as the “bad cholesterol” and has been used for many decades as the specific indicator for coronary artery disease (CAD) (Mensink et al., 2003). Saturated fatty acids were shown to greatly increase our levels of LDL and because of this were believed to have a deleterious effect on our cardiovascular health (Mensink et al., 2003). A temporary solution for the partial replacement of saturated fats appeared to be trans fatty acids. They provided a very similar functionality to saturated fats and were derived from highly unsaturated vegetable oils, which gave us the belief that they would be much healthier. Ironically, however, trans fatty acids have since been shown to have an even greater negative effect on our cardiovascular health than saturated fats (Mensink et al., 2003). This can be partially explained by the effects that trans fatty acids have on our serum cholesterol levels.

It has been recently shown that the ratio of total cholesterol to HDL may be a more effective and specific indicator for CAD than simply looking at the total change in cholesterol, or the LDL levels alone (Mensink et al., 2003). Mensink et al. compiled the results from selected studies between the years 1970 and 1997 to create one of the most extensive looks at serum cholesterol to date. From their results it was clear that the ΔTotal:HDL cholesterol ratio for saturated fatty acids increased slightly, while trans fatty acids increased greatly. Saturates do induce an increase in LDL levels, however, they also induce an increase in the amount of HDL. Contrary to LDL, increased concentrations of HDL in the blood through one’s diet has actually been shown to decrease the risk of CAD. As the large increase in LDL may be offset by the corresponding increase in HDL, the effects of saturated fatty acids on CAD are not as pronounced when considering these two specific indicators simultaneously. Trans fatty acids on the other hand show an even greater increase in LDL levels than the saturated fats, yet they cause a decrease in HDL levels instead of an increase. This leads to a significantly greater increase in the ΔTotal:HDL cholesterol ratio and provides insight as to why trans fats have a larger deleterious effect on cardiovascular health than the saturated fats (Mensink et al., 2003). Cis mono- and polyunsaturated fatty acids caused a decrease in the amount of LDL and an increase in the amount of HDL. As mono- and polyunsaturated fatty acids cause increases in the levels of HDL and lead to decreases in the ΔTotal:HDL cholesterol ratio, they are beneficial to cardiovascular health and may prevent CAD (Mensink et al., 2003). Polyunsaturated fatty acids induced a slightly greater decrease in the amount of LDL compared to monounsaturated fatty acids and were shown to be the most beneficial in reducing the risk of CAD. This study showed that LDL alone should not be used as a marker of CAD but rather the corresponding change in both types of cholesterol should be noted. An increase in LDL may be offset by a corresponding increase in HDL levels, showing that the total serum cholesterol to HDL ratio might be the most effective method for determining the true risk that each fat, oil, or fatty acid imposes on cardiovascular health (Mensink et al., 2003).

Based on the total evidence from decades of research it can be concluded that diets high in trans and saturated fats have numerous deleterious health effects. These range from adverse effects on lipoprotein (cholesterol) profiles, increased incidence of heart disease and metabolic syndrome (Aro et al., 1997). By 2010, it is projected that in excess of 230 million people will be affected by metabolic syndrome, a diet-related disease, associated with an elevated risk of developing type II diabetes mellitus, cardiovascular disease (CVD) and premature death (Isomaa et al., 1993). Negative health effects associated with consuming trans and saturated fats may be reversed by altering the intake of these heart unhealthy fats and replacing them with polyunsaturated fats. It is estimated that replacing 5% of our daily energy intake from saturated fats with either equivalent energy from carbohydrates, mono-, or polyunsaturated fats would be associated with a decreased risk of CVD in the range of 22 to 37% (Roche, 2005).

In an attempt to curb these diet-related epidemics, governments across the globe are passing aggressive legislation to limit and in some cases ban the use of trans fats. Denmark was the first country which restricted the amount of trans fatty acids in industrially produced fats and oils to 2% (w/w) or less (Danish Order No. 160 of March 2003). In January 2006 the United States Food and Drug Administration and the Canadian Food Inspection Agency enacted mandatory labeling of trans fatty acid content in food products containing more than 0.5 g of trans fatty acids. Also, California and Connecticut recently passed state legislation banning all artificial trans fats from food products (CA AB 97, 2008, enacted, Chapter No. 207). Florida has proposed restrictions on trans fats in schools via the “Florida Healthier Child Care and School Nutrition Act,” and one state after another is considering enacting “hard-line” legislation restricting or banning trans fat (National Conference of State legislatures, 2008). The American Heart Institute believes even greater restrictions are necessary, advocating that no more than 10% of daily energy should be consumed in the form of trans AND saturated fats combined (American Heart Association 2009). In 2007, Health Canada stated that trans fat should consist of no more than five percent of a food product’s total fat content, and when dealing with cooking oils and margarines, it should be no more than two percent. The levels of trans fats in specific goods was monitored by Health Canada every six months for two years. The recently released results reported that the levels of trans fat in our diet is still dangerously high. Health Canada reported that 26% of chicken products, 21% of French fries, and 50% of baked good still contain higher levels of trans fat compared to their recommendations in 2007 (Health Canada, 2009).

With this in mind, it becomes more evident than ever that novel technologies need to be implemented when attempting to curb the associated epidemics and to address the resultant gigantic food manufacturing problem.

To fulfill these new legislative requirements, the food industry must vigorously investigate alternatives to traditional triacylglyceride (TAG) structuring. TAGs provide structure in numerous food products including ice cream, cheese, butter, lard, etc. Unfortunately, it is the trans and saturated lipids that provide the structure and solid-like properties of these foods. Although the structure they confer on products is desirable, and indeed required in many products, both types of fatty acids have been shown to negatively influence human health. Since it is the hardstock TAGs that are responsible for network structure, it is often difficult or impossible to eliminate these ingredients to improve the health characteristics of a food product without sacrificing some of the quality associated with that particular food product. Food manufacturers are very reluctant to change the characteristics of successful industrially produced food products to any extent! Thus, the task of replacing a major ingredient responsible for many of the quality attributes of a food product is an extremely difficult task, and an even harder sell. Pernetti eloquently states that finding alternatives to TAGs with healthy properties, versatility, and performance is a tremendous challenge (Pernetti et al.,...

Produkt-Details

• Erscheint lt. Verlag: 24.8.2015
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Chemie ► Analytische Chemie
• Themenwelt: Technik ► Lebensmitteltechnologie
• ISBN-10: 1-63067-009-X / 163067009X
• ISBN-13: 978-1-63067-009-2 / 9781630670092