L6 Alternative sweeteners and fat replacers Flashcards
What is the definition of lipids?
A family of compounds soluble in organic compounds but not in water
What are the functions of lipids?
Source of high energy value
Contains fat-soluble vitamins and essential fatty acids.
Lipids combined with proteins are important constituents of the cell membranes and mitochondria of the cell.
Lipids are storage compounds, triglycerides serve as reserve energy of the body.
What are the sensory profiles of Lipids?
Appearance Gloss, color, surface uniformity, crystallinity Texture Viscosity, elasticity, hardness Flavor Carriers of flavours Mouthfeel Creaminess, lubricity, thickness, mouth feel of the product
What are the issues with lipids?
Fats that are highly unsaturated, are not expected to be stable at room temperature thus producing early onset of rancidity and possible shelf-life issues. If shelflife is increased through the process of hydrogenation, saturation and production of trans fats as by-products happen, thus posing health concern to consumers. Thus fat replacers are used to replace fats
How does the degree of saturation affect melting point?
Gain this melting point is related to the degree of saturation in fats. Higher saturated fats have high melting points compared to unsaturated fats as shown in the example
What are the uses of omega 3 fatty acids?
Omega 3 fatty acids cannot be made by the body and must be gotten thru food.
Integral part of cell membranes and affect the function of cell receptors in these membranes.
Provide a starting point for making hormones
Bind to receptors that regulate genetic functions
Help prevent heart disease and stroke
How do fats exist in food?
Fats exist in emulsions in 2 phases continuous and dispersed. Continous is the one surrounding everything and dispersed is the one suspended.
Why are fat replacers needed and what is the challenges in replacing fats?
Consumer awareness on different types of fats and their impacts on health
The challenge is to produce low-fat/no-fat products with physical and sensory characteristics as close as possible to full-fat quality
Considerable changes in traditional recipes for food industries- another major challenge
What are some requirements of fat replacers?
Fat replacers need to
Provide a similar mouth feel to fat – thick, viscous, creamy
Provide bulk to the food
Heat stable so that it can be used for frying and baking
Not so easily digested as fats
What are the 3 categories of fat replacements and what are they made out of?
Carbohydrate-based
Starch and starch hydrolysis products
Fiber based (gums, gels, thickeners, bulking agents)
Protein-based
Specially processed proteins
Protein/fiber combinations
Lipid-based
Synthetic fat substitutes
Low-calorie fats
Emulsifiers
Explain the product Simplesse.
Made of microparticulated whey protein
Microparticulation:
process produces uniform microparticles averaging 1 mm in diameter, and prevents the formation of large protein agglomerates.
Microparticulated protein has been proven to be more digestible than other proteins.
Microparticles, in suspension, behave like a creamy fluid so give the same mouthfeel as fat
Less calories per g – approx 4 cal/g [cf fat – 9 cal/g]
Not so good for cooking so found more in salad creams, ice-cream
Explain the product Olestra.
Chemically similar to a triglyceride
It is part fatty acids and part sucrose
Fatty acids are so bulky that enzymes
Cannot penetrate to hydrolyse the sucrose-fatty acid bond
Olestra passes through gut undigested.
So effectively 0 cal/g
Heat stable so can be used in cooking
Side effects: abdominal cramping, loose stools and inhibits the absorption of certain vitamins and other nutrients.
Explain the product miracle whip.
One of the earliest low fat products using fat replacer
Introduced in 1930’s
Miracle Whip was formulated to provide about half the fat of conventional mayonnaise using a starch gel at about one tenth the level of the fat that it was replacing
Miracle Whip is made from water, soybean oil, high-fructose corn syrup, vinegar, modified corn starch, eggs, salt, natural flavor, mustard flour, potassium sorbate, spice, and dried garlic
Issues with sugar?
Our bodies are not designed to consume such large quantities of refined and pure carbohydrates.
Releasing large quantities of sugar into the bloodstream creates a shock to the system, and the body reacts by producing insulin.
This can put a strain on the pancreas and liver and over time lead to the development of diabetes.
What is the glycemic effect/index?
The Glycemic Index is an indication of how quickly a specified amount of food will cause a rise in blood sugar level.
Foods which are easy to digest generally have a high glycemic effect
(standard is pure glucose).
High glycemic foods – should be avoided by diabetics
The glycemic index (or GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar (glucose) levels after eating. Foods with a high GI are those which are rapidly digested, absorbed and metabolised and result in marked fluctuations in blood sugar (glucose) levels. Low GI carbohydrates – the ones that produce smaller fluctuations in your blood glucose and insulin levels
What is the GI Scale for : Glucose White Wheat Bread Whole Wheat/Whole Meal Bread Specialty Grain Bread White Rice Boiled Brown Rice Boiled Cornflakes Muesli
and what is considered low,med,high GI.
Glucose 100 White Wheat Bread 75+-2 Whole Wheat/Whole Meal Bread 74+-2 Specialty Grain Bread 53+- 2 White Rice Boiled 73+-4 Brown Rice Boiled 68+-4 Cornflakes 93 Muesli 66
GI (based on glucose reference)
Low GI 0 to 55
Intermediate GI 56 to 69
High GI ≥ 70
What is ideal for a sugar replacer?
Low calorie/no calorie –
Not metabolised in digestive tract – so does not enter circulation
Or much sweeter than sugar – so do not need to eat so much
Stable to heat – e.g. when used in cooking
No bitter after-taste
Do not cause tooth decay
Can be consumed by diabetics
What are the 3 types of sugar substitutes?
Artificial sweeteners
Not metabolized by the body (no kcals)
Metabolized by the body
Natural sugar replacers
Explain Saccharin.
Not metabolised by humans – so 0 calories –
but 200 to 700 times sweeter than sugar
Stable at high temperature
It has a zero glycemic index, contains no calories and is suitable for diabetics.
Developed in 1878 but found to cause cancer in lab rats
Explain Acesulfame K.
Not metabolised by body 0 calories/g – 200x sweeter than sugar
Stable to heat
It is approx 200 times sweeter than sugar, though it has a slightly bitter
Aftertaste.
Zero glycemic index.
Usually mixed with other sweeteners to mix bitter aftertaste.
Explain Sucralose. (Splenda)
Same as sucrose but 3 –OH groups replaced by Cl
Not metabolised by body 0 calories/g – 600x sweeter than sugar
It does not break down under heat and so is suitable for cooking and in
processed foods.
Number one artificial sweetener in the USA
Explain Aspartame.
Dipeptide of aspartic acid and phenylalanine
Metabolised by body 4 calories/g – 180x sweeter than sugar
So less likely to eat large quantities of aspartame
Not sweet after heating
Why does foods with aspartame state unsuitable for phenylketonurics?
A by-product of the metabolism of aspartame is phenylalanine and people with a genetic disorder called phenylketonuria (PKU) are unable to metabolize it.
People with a rare hereditary disease known as phenylketonuria (PKU) have a difficult time metabolizing phenylalanine, a component of aspartame and should control their intake of phenylalanine from all sources, including aspartame. Labels of aspartame-containing foods and beverages must include a statement that informs individuals with PKU that the product contains phenylalanine.
PKU is caused by lack of phenylalanine hydroxylase an enzyme which helps digest phenylalanine.
Explain Stevia.
Extracted from a S. American plant Stevia rebaudiana
Sweet compounds Stevioside and Rebaudioside,
Not metabolised by body 0 calories/g – 300x sweeter than sugar
Heat stable
Zero glycemic index
Sold as dried and powdered leaves or as concentrated stevioside. Coca cola have a product called truvia, and pepsi have a product called purevia. Both of these are mixtures of rebaudioside
Explain sugar alcohols and draw structure.
Sugar alcohols are less in sweetness compared to sucrose and these are energy providers but calorie production is less compared to sucrose.
Sorbitol 2.6cal/g
Xylitol 1.5-3cal/g
Why is aspartame have a GI index of 0 but has 4 calories/g?
Aspartame breaks down into 2 amino acids which are not sugars thus don’t spike calories.
