Avocado as a Fat Replacement in Cookies



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|Avocado as a Fat Replacement in Cookies |

|DFM 357 |

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|Tiffany Epperson and Cassie Miller |

|12/11/2013 |

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Abstract

As heart disease and obesity are a continuing epidemic in the United States, the experiment was designed with the intention of replacing butter as a fat with a healthier alternative such as avocado. The replacement fat would reduce overall fat, calories and eliminate saturated fat while still providing monounsaturated and polyunsaturated fats. The experiment’s purpose was to examine the overall acceptability of cookies made with avocado rather than butter within the general population. The experiment was designed to subjectively and objectively analyze the the qualities and characteristics of appearance, aroma, texture, tenderness, and overall acceptability of a cookie in which the butter was replaced with avocado. The results showed that avocado is an acceptable replacement for animal fats. Subjective analysis showed that the recipe containing half avocado and half butter was found to be the superior product in all categories. Avocados are an acceptable replacement for saturated fats in baked products.

Introduction

The use of butter in baked goods such as pastries, cakes and cookies lend to better texture, tenderness, color and taste than most other fats.  However, butter is high in overall fat and saturated fat, making this a poor choice for those suffering from Cardiovascular disease (CVD) and obesity, among other weight related diseases. While other, more beneficial fats may create similar texture and color, the taste and tenderness is generally different. By choosing a neutral, solid, plant based fat like avocado, overall fat and saturated fat can be reduced.  In fact, avocado further adds the benefit of fiber, lutein, monounsaturated fat and polyunsaturated fat, making it a much healthier choice.  The texture and taste are similar, however the tenderness is softer and the color is a greenish hue. While butter may create the most pleasing taste, texture, tenderness, and color, it is full of saturated fat which is known to play a role in heart disease. It is important to research other fat sources such as the avocado to discover if this harmful ingredient can be replaced.  

Replacing saturated fats with unsaturated plant based fats benefit the body’s health in many ways. Unsaturated fats consist of monounsaturated and polyunsaturated. These can improve blood cholesterol, stabilize heart rhythms and decrease inflammatory responses. In fact, a recent study performed by Harvard observed that those who consumed more healthy fats such as those found in nuts and walnuts tended to weigh less. Additionally, there is sufficient evidence to claim that those who replace saturated fats with polyunsaturated and monounsaturated fats have a decreased risk of heart attack.(“Fats and Cholesterol: Out with the Bad, In with the Good.” Harvard School of Public Health, 2013.) If more subjects replace their average consumed saturated fats with the alternative unsaturated, obesity could be prevented along with heart disease.

Literature Review

Butter is commonly used in cooking for adding fat which creates a moist and flavorful recipe. Butter when combined with sugar creates caramelization and browning, giving cakes, muffins and cookies their golden brown color. However, butter contains more than 7 grams of saturated fat.  This is about 36% of a person’s limit when eating a 2000 calorie diet. One tablespoon of butter additionally contains 31mg of cholesterol. The only healthful contributions a tablespoon of butter adds to the diet is about 7% of the RDA for vitamin A and nearly 3 grams of monounsaturated fats.

There is some controversy whether or not butter or dairy derived fatty acids have some association with cardiovascular disease and atherosclerosis. Two doctors Peter Huth and Keigan Park performed a thorough review of already existing evidence that may link dairy fats to CVD. Though many studies have failed to link dairy fats to CVD,  few have shown that butter and whole milk fats increase LDL cholesterol but they may also increase HDL cholesterol. Therein lies the difficulty of determining whether or not butter increases incidence of CVD based on the cholesterol and saturated fat content alone. A further review of a study where butter use was increased and carbohydrate intake was decreased, participants showed an increase of HDL cholesterol and lower triglycerides.  This particular study emphasized that there may be a link between the consumption of saturated fat in combination with carbohydrates and CVD. The doctors’ further examination of studies proved to be conflicted whether or not butter fat does increase the risk of heart disease.  According to the literature, there have not been enough long term studies completed to make an definitive assessment. (Huth, PJ, and Park, KM. “Influence of Dairy Product and Milk Fat Consumption on Cardiovascular Disease Risk: a Review of the Evidence.” PubMed, May 1, 2012.)

There are numerous reasons why people choose to substitute avocados for the animal fat of choice in many recipes. The fat content in avocados makes for a nutritious and healthy substitution for less healthy fats such as butter or certain oils. The substitution of avocados adds close to twenty vitamins and minerals as well as additional dietary fiber to recipes that are normally devoid of these nutrients ().  Additionally, substituting avocados for animal fats in baked goods can make a product vegetarian or vegan for those individuals who choose this dietary modification.

           One of the greatest health benefits that avocados have over butter is their lipid profile.  Avocados are high in fat, which makes them an easy substitute for less healthy fats in baked recipes. The fat in avocados, however, is vastly different than the fats in butter or other animal-based fat sources. Avocados contain 2.13 grams of saturated fat per 100 grams, 9.80 grams of monunsaturated fat per 100 grams, 1.82 grams of polyunsaturated fat per 100 grams, and no trans fats (USDA). Butter, on the other hand, contains per 100 grams,  51.37 grams of saturated fat, 21.02 grams of monunsaturated fat , 3.04 grams of polyunsaturated fat and 3.278 g of trans fats. (“National Nutrient Database for Standard Reference: Butter, Without Salt.” USDA, 2013.) While butter may have more polyunsaturated and monounsaturated fats, the overall fat and calories from fat are far greater than that of avocados. Additionally, butter comes from an animal source and contains trans fats whereas avocados do not. Monounsaturated fatty acids, MUFAs, are widely known to lessen the effects of, as well as the risks associated with developing cardiovascular disease, CVD. Diets high in saturated fats, SFAs, greatly increase the risk of cardiovascular disease. A study published in the New England Journal of Medicine, which followed 80,000 women, found that an increase of 5% of energy consumption from MUFAs decreased the risk of developing CVD by 19% and concluded that replacing SFAs with MUFAs is more effective at preventing CVD than reducing total fat consumption (Hu, et al, 1997). Due to the high amount of MUFAs and PUFAs compared to the SFA content, avocados are the more heart-healthy choice of fats in baked products.  

    Another health benefit of substituting avocados for other fats that are high in SFAs is the cancer-preventative qualities of this super fruit. Avocados are a rich source of carotenoids, which have been proven to have antiproliferative and antitumor qualities (Lu, et al, 2005). Of the carotenoids present in avocados, lutein is found to be the most abundant (USDA). In a study funded by UCLA Medical Center, avocado oil extract was shown to cause cell cycle arrest of prostate cancer cells. The researchers were not able to duplicate the results by using pure lutein, which led them to postulate that other bioactive substances present in avocados enhanced the cancer-fighting properties of lutein. Furthermore, due to the high MUFA content of avocados, these compounds are more readily absorbed into the bloodstream because they are lipid soluble (Lu, et al, 2005).

Method and Design

    Preheat oven to 375 degrees fahrenheit. For control recipe: measure 55 grams of butter, 90 grams of brown sugar, 15 grams of white sugar, 1.8 grams of gluten free vanilla extract, 20 grams of egg substitute, 101.3 grams of Gluten Free Pantry all purpose baking flour, 2 grams of baking powder, 2 grams of baking soda, 2 grams of salt, 115 grams of semisweet chocolate chips. Repeat measures for half avocado and full avocado recipes. For the half avocado recipe, measure 27.5 grams of avocado and 27.5 grams of butter. For the full avocado recipe, measure 55 grams of avocado. Mix wet ingredients together (fat, brown and white sugar, egg replacement, and vanilla extract) by creaming on speed one of hand-held mixer for 30 seconds. Add dry ingredients (gluten-free flour, baking soda, baking powder, and salt) by mixing at speed 2 for 45 seconds. Stir in chocolate chips. Repeat for all three recipes. Portion 40 grams of cookie dough onto parchment paper lined aluminum cookie sheets and bake control recipe for 6 minutes, and half avocado recipe for 8 minutes and full avocado recipe for 10 minutes. Remove from oven and place on racks to cool for 5 minutes.

Results

    We performed a rank-order test of five different characteristics utilizing a consumer panel consisting of 25 individuals. We provided a hedonic scale to our panel which we used to rate our samples based on 1. Color and Appearance, 2. Aroma, 3. Texture, 4. Tenderness, and 5. Overall Acceptance. We weighed the rank of liking very much at 9 and weighed the rank of disliking very much at 1. After adding all of the scores provided to us by our subjects and obtaining an average, we determined that the cookies that were made with half avocado and half butter were favored over the control and the fully replaced avocado in every category.  

Graph 1: Subjective analysis of color and appearance of the control (339), ½ modified (571), and fully modified (824).

[pic]

This graph shows that on a hedonic rating scale of 1-9 with 1 representing disliking very much and 9 representing liking very much, our subjects prefered the color and appearance of the cookies make with half avocado and half butter.  The cookies that were made with avocado completely replacing the butter were found to be the least desirable in color and appearance.  Cookie recipe 571 was rated 7.68 out of 9.00, cookie recipe 824 was rated 4.84 out of 9.00, and lastly, cookie recipe 339 was rated 6.00 out of 9.00.

Graph 2: Subjective analysis of aroma of the control (339), ½ modified (571), and fully modified (824)

.[pic]

This graph shows that on a hedonic rating scale of 1-9 with 1 representing disliking very much and 9 representing liking very much, our subjects prefered the aroma of the cookies make with half avocado and half butter. The cookies that were made with avocado completely replacing the butter were found to be the least desirable in aroma. Cookie recipe 571 was rated 7.29 out of 9.00, cookie recipe 824 was rated 5.71 out of 9.00, and lastly, cookie recipe 339 was rated 6.79 out of 9.00.

Graph 3: Subjective analysis of texture of the control (339), ½ modified (571), and fully modified (824).

[pic]

This graph shows that on a hedonic rating scale of 1-9 with 1 representing disliking very much and 9 representing liking very much, our subjects prefered the texture of the cookies make with half avocado and half butter. The cookies that were made with avocado completely replacing the butter were found to be the least desirable in texture. Cookie recipe 571 was rated 7.48 out of 9.00, cookie recipe 824 was rated 5.52 out of 9.00, and lastly, cookie recipe 339 was rated 6.92 out of 9.00.

Graph 4: Subjective analysis of tenderness of the control (339), ½ modified (571), and fully modified (824).

[pic]

This graph shows that on a hedonic rating scale of 1-9 with 1 representing disliking very much and 9 representing liking very much, our subjects prefered the tenderness of the cookies make with half avocado and half butter. The cookies that were made with avocado completely replacing the butter were found to be the least desirable in tenderness. Cookie recipe 571 was rated 7.64 out of 9.00, cookie recipe 824 was rated 5.88 out of 9.00, and lastly, cookie recipe 339 was rated 6.00 out of 9.00.

Graph 5: Subjective analysis of overall acceptance of the control (339), ½ modified (571), and fully modified (824).

[pic]

This graph shows that on a hedonic rating scale of 1-9 with 1 representing disliking very much and 9 representing liking very much, our subjects prefered the overall acceptance of the cookies make with half avocado and half butter. The cookies that were made with avocado completely replacing the butter were found to be the least desirable in overall acceptance. Cookie recipe 571 was rated 7.08 out of 9.00, cookie recipe 824 was rated 5.40 out of 9.00, and lastly, cookie recipe 339 was rated 5.44 out of 9.00.

Nutritional Analysis

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|Cookie 339 |

|Portions: 36 |

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|Limits |

|Amount Per Portion |

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|Total Calories |

|143 Calories |

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|Empty Calories* |

|104 Calories |

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|Solid Fats |

|51 Calories |

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|Added Sugars |

|53 Calories |

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|Alcohol |

|0 Calories |

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|*Calories from food components such as added sugars and solid fats that provide little nutritional value. |

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|Empty Calories are part of Total Calories. |

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|Nutrients |

|Amount Per Portion |

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|Protein |

|1 g |

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|Carbohydrate |

|21 g |

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|Dietary Fiber |

|1 g |

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|Total Fat |

|7 g |

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|Saturated Fat |

|4 g |

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|Monounsaturated Fat |

|2 g |

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|Polyunsaturated Fat |

|0 g |

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|Linoleic Acid |

|0 g |

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|α-Linolenic Acid |

|0.0 g |

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|Omega 3 - EPA |

|0 mg |

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|Omega 3 - DHA |

|0 mg |

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|Cholesterol |

|10 mg |

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|Minerals |

|Amount Per Portion |

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|Calcium |

|20 mg |

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|Potassium |

|58 mg |

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|Sodium |

|120 mg |

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|Copper |

|82 µg |

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|Iron |

|1 mg |

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|Magnesium |

|14 mg |

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|Phosphorus |

|26 mg |

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|Selenium |

|4 µg |

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|Zinc |

|0 mg |

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|Vitamins |

|Amount Per Portion |

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|Vitamin A |

|32 µg RAE |

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|Vitamin B6 |

|0.0 mg |

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|Vitamin B12 |

|0.0 µg |

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|Vitamin C |

|0 mg |

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|Vitamin D |

|0 µg |

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|Vitamin E |

|0 mg AT |

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|Vitamin K |

|1 µg |

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|Folate |

|24 µg DFE |

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|Thiamin |

|0.1 mg |

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|Riboflavin |

|0.1 mg |

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|Niacin |

|1 mg |

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|Choline |

|4 mg |

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|SuperTracker. |

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|Cookie 571 |

|Portions: 36 |

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|Limits |

|Amount Per Portion |

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|Total Calories |

|129 Calories |

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|Empty Calories* |

|89 Calories |

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|Solid Fats |

|36 Calories |

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|Added Sugars |

|53 Calories |

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|Alcohol |

|0 Calories |

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|*Calories from food components such as added sugars and solid fats that provide little nutritional value. |

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|Empty Calories are part of Total Calories. |

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|Nutrients |

|Amount Per Portion |

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|Protein |

|1 g |

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|Carbohydrate |

|21 g |

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|Dietary Fiber |

|1 g |

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|Total Fat |

|5 g |

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|Saturated Fat |

|3 g |

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|Monounsaturated Fat |

|2 g |

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|Polyunsaturated Fat |

|0 g |

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|Linoleic Acid |

|0 g |

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|α-Linolenic Acid |

|0.0 g |

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|Omega 3 - EPA |

|0 mg |

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|Omega 3 - DHA |

|0 mg |

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|Cholesterol |

|5 mg |

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|Minerals |

|Amount Per Portion |

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|Calcium |

|20 mg |

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|Potassium |

|65 mg |

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|Sodium |

|120 mg |

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|Copper |

|85 µg |

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|Iron |

|1 mg |

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|Magnesium |

|14 mg |

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|Phosphorus |

|27 mg |

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|Selenium |

|4 µg |

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|Zinc |

|0 mg |

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|Vitamins |

|Amount Per Portion |

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|Vitamin A |

|16 µg RAE |

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|Vitamin B6 |

|0.0 mg |

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|Vitamin B12 |

|0.0 µg |

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|Vitamin C |

|0 mg |

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|Vitamin D |

|0 µg |

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|Vitamin E |

|0 mg AT |

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|Vitamin K |

|1 µg |

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|Folate |

|26 µg DFE |

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|Thiamin |

|0.1 mg |

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|Riboflavin |

|0.1 mg |

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|Niacin |

|1 mg |

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|Choline |

|4 mg |

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|SuperTracker. |

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|Cookie 824 |

|Portions: 36 |

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|Limits |

|Amount Per Portion |

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|Total Calories |

|114 Calories |

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|Empty Calories* |

|73 Calories |

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|Solid Fats |

|20 Calories |

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|Added Sugars |

|53 Calories |

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|Alcohol |

|0 Calories |

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|*Calories from food components such as added sugars and solid fats that provide little nutritional value. |

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|Empty Calories are part of Total Calories. |

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|Nutrients |

|Amount Per Portion |

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|Protein |

|1 g |

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|Carbohydrate |

|21 g |

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|Dietary Fiber |

|1 g |

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|Total Fat |

|3 g |

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|Saturated Fat |

|2 g |

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|Monounsaturated Fat |

|1 g |

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|Polyunsaturated Fat |

|0 g |

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|Linoleic Acid |

|0 g |

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|α-Linolenic Acid |

|0.0 g |

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|Omega 3 - EPA |

|0 mg |

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|Omega 3 - DHA |

|0 mg |

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|Cholesterol |

|0 mg |

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|Minerals |

|Amount Per Portion |

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|Calcium |

|20 mg |

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|Potassium |

|72 mg |

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|Sodium |

|120 mg |

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|Copper |

|87 µg |

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|Iron |

|1 mg |

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|Magnesium |

|14 mg |

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|Phosphorus |

|27 mg |

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|Selenium |

|4 µg |

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|Zinc |

|0 mg |

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|Vitamins |

|Amount Per Portion |

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|Vitamin A |

|0 µg RAE |

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|Vitamin B6 |

|0.0 mg |

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|Vitamin B12 |

|0.0 µg |

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|Vitamin C |

|0 mg |

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|Vitamin D |

|0 µg |

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|Vitamin E |

|0 mg AT |

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|Vitamin K |

|1 µg |

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|Folate |

|27 µg DFE |

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|Thiamin |

|0.1 mg |

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|Riboflavin |

|0.1 mg |

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|Niacin |

|1 mg |

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|Choline |

|4 mg |

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|SuperTracker. |

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|Objective evaluation |

|Wettability, and index to volume tests were performed on each weighed sample. The wettability test determines the moistness of a cake or baked|

|product. (McWilliams, Margaret. Foods: Experimental Perspectives. 7th Edition. Pearson Education, Inc. Prentice Hall. 2012. (p. 71-73)  In |

|this case, the cookies were evaluated individually. The cookie made with avocado measured at 32 ml. The cookie made with both butter and |

|avocado measured at 31ml as did the control cookie made with butter. During wettability, the more moisture retained, rather than displaced |

|means that the cookie is sufficiently moist.  We were unable to weigh the cookies afterwards as they began to crumble and break apart, however|

|the test still yeilded usable results.  The avocado cookie added ml to the apparatus concluding that it was moister than the other two |

|samples. |

|An index to volume test was the second objective evaluation performed on the cookies as well.  This was performed by tracing a circle around |

|each cookie then measuring the depth of each to determine if one was thicker than the other or expanded more.  Each result varied greatly. The|

|control sample spread the furthest but was only .2 inch thick. The half avocado, half butter sample spread less and was slightly thicker at .5|

|inch. Finally, the complete avocado sample barely spread at all and was 1 inch thick.  The volume for each sample seemed to stay the same due |

|to each sample’s circumferance and thickness differing. The results proved that the more the cookie spread, the thinner it would be and vice |

|versa.  However, the test concluded that the volume for each sample was the same. |

|Due to the limited availability of scientific instruments to perform objective tests, the results may be inconclusive.  If correct instruments|

|were available, a shortometer and volumeter would have been used.  The volumeter would compare more accurate volume measurements per sample |

|which would determine whether the type of fat used creates a denser or lighter cookie. The shortometer is an objective test specifically used |

|on baked goods such as cookies to measure the crispness or tenderness. Such a test would be useful for this experiment because each cookie |

|sample had a different mouthfeel and tenderness when subjectively reviewed.  If the samples’ tenderness were measured objectively, it could be|

|found that two of the samples had similar tenderness, even if appearance or texture differed. |

|Conclusion |

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|Objective and subjective tests concluded that the sample made with half butter and half avocado created an ideal cookie. The cookie was lower |

|in fat and overall saturated fat than the sample made with butter, yet it also had a better flavor, color, texture and tenderness than both |

|the avocado sample and the control sample. This is an appropriate compromise to lower both saturated fat and overall fat for populations |

|suffering from CVD or obesity.  In fact, all objectively measured factors found the half butter, half avocado to be superior to the other |

|cookies. The texture and tenderness may have been improved by the natural moisture of the avocado, but the addition of butter masked the |

|adverse color or taste of the avocado. The overall outcome of the experiment proved that it is possible to replace an unhealthy fat such as |

|butter in a pastry or cookie while still maintaining color, texture, tenderness, aroma and flavor.   |

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|References |

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|"Baking With Avocados." Baking with Avocados : Baking Substitutions with Hass Avocados. N.p., n.d. Web. 10 Dec. 2013. |

|. |

Buttriss, J. , & Stokes, C. (2008). Dietary fibre and health: An overview.Nutrition Bulletin,     33(3),    186-200.

“Fats and Cholesterol: Out with the Bad, In with the Good.” Harvard School of Public Health, 2013. .

Huth, PJ, and Park, KM. “Influence of Dairy Product and Milk Fat Consumption on Cardiovascular Disease Risk: a Review of the Evidence.” PubMed, May 1, 2012. .

Lu, Q. , Arteaga, J. , Zhang, Q. , Huerta, S. , Go, V. , et al. (2005). Inhibition of prostate cancer cell growth by an avocado extract: Role of lipid-soluble bioactive substances. The Journal of Nutritional Biochemistry,16(1), 23-30.

Lunn, J. , & Theobald, H. (2006). The health effects of dietary unsaturated fatty acids. Nutrition Bulletin, 31(3), 178-224.

McWilliams, Margaret. Foods: Experimental Perspectives. 7th Edition. Pearson Education, Inc. Prentice Hall. 2012. p. 71-73.

O’Keeffe M, St-Onge MP. "Saturated Fat and Cardiovascular Disease: A Review of Current Evidence.” Current Cardiovascular Risk Reports. N.p., 01 Apr. 2013. Web. 10 Dec. 2013. .

Pieterse, Z. , Jerling, J. , Oosthuizen, W. , Kruger, H. , Hanekom, S. , et al. (2005). Substitution of high monounsaturated fatty acid avocado for mixed dietary fats during an energy-restricted diet: Effects on weight loss, serum lipids, fibrinogen, and vascular function. Nutrition (Burbank, Los Angeles County, Calif.), 21(1), 67-75.

"Show Foods." Show Foods. N.p., n.d. Web. 10 Dec. 2013. .

Warwick ZS, Shiffman SS. “Role of dietary fat in calorie intake and weight gain" National Center for Biotechnology Information. U.S. National Library of Medicine National Institute of Health. 1992. Web. 10 Dec. 2013.

Lab Work Documentation

Individual Experiment #1

Date: 11/15

Lab conditions: Constant

Purpose:

The purpose of this lab was to make all samples of the cookie, including control, ½ butter and ½ avocado, as well as full avocado to test the recipe. Additionally, we tested each sample and discussed texture, flavor and appearance.  Only informal subjective testing was performed on this day as the recipe was not performed previously.

Procedure:

For Control Recipe: egg substitute measured to 20.2 g, cold butter was mashed for control recipe before mixing. This ensured that each recipe was equal because avocado needed to be mashed in the other samples’ recipes. Butter and sugar were mixed on speed 1 for 30 seconds to cream fat, sugars, vanilla and egg substitute. Next, flour was added and mixed on speed 2 for 45 until all ingredients were incorporated. Finally, chocolate chips were weighed to 114.9g and stirred into the dough mixture. We observed that the mixture was creamy yellow, thick and mildly sticky, mostly likely due to the gluten free flour.

For 1/2 recipe: The recipe used 27.4 g butter, 27.6 g avocado. The  avocado and butter were mashed together before mixing because butter was cold and avocado was solid. The butter, egg replacer were creamed together on speed 1 for 30 seconds. We observed that the avocado was not chunky after mixing with sugar. The flour was then added and mixed on speed 2 for 45 seconds. Lastly, 115.1 g of chocolate chips were added. We observed that the mixture was thick, slightly sticky and had a light green tint.

For Full Avocado: 20.2 g of avocado was measured in this recipe. The avocado, sugars, egg replacer and vanilla were creamed on speed 1 for 30 seconds. We observed that the mixture was chunky and not smooth like both of the other recipes. The flour was added and mixed on speed 2 for 45 seconds. Finally, 114.7g  of chocolate chips were added.  We noted the greenish brown color of the batter. Batter was extremely sticky and slightly less thick than the other two sample batters.

Cookies were weighed to 40g each and baked at 375 for 6 minutes.  The avocado cookies and ½ cookies needed to be baked longer.

Test results:

Subjective testing was performed by both lab partners.  This was an informal testing and no likert or hedonic scales were used.  We simply observed the color of each cookie before and after baking.  It was noted that the full avocado cookie was an unappealing color with a green tint. Both other samples were not unappealing in color, however the control cookie was slightly darker than expected. This was most likely due to the age and inaccuracy of the ovens in the Miele lab.

Discussion:

All three samples were reviewed by both lab partners for appearance, texture, tenderness and taste.  The control sample was found to have a pleasant buttery flavor, and was sweet and chocolatey.  However the cookie was flat, very crunchy and hard.  The ½ avocado cookie was very sweet, had no distinctive butter flavor, but maintained it’s shape slightly.  It was not entirely flat and was a creamy color only with the faintest green tint. The cookie was overly soft though and needed to bake longer.  The full avocado cookie also needed to be baked longer and was doughy in the center.  The color was off-putting as well and could be described as a brownish green color.  There was a strange after taste with the avocado sample which was similar to garbanzo beans, and slightly metallic.

    Some outside influencing factors to the taste, texture and color of the cookies could be contributed to ingredients and lab equipment.  The flour used was Bob’s Redmill  all-purpose gluten free flour.  This flour uses garbanzo bean flour along with a mixture of brown rice flour and starches.  The full avocado sample had a beany after-taste which could have been enhanced with the Avocado.  Avocados do not have a strong, distinct flavor whereas butter has a fairly distinct flavor.  The butter seemed to have masked the flour’s taste in both the control and the ½ butter/avocado recipe. Additionally, the ovens in the Miele Lab are old and the heat output is uneven in the ovens and sometimes either too strong or too weak.  The directions for the cookies were followed and yet the control cookies melted too much and carmelized, the ½ butter/avocado cookies and the full avocado cookies were underdone.

    The recipe for each sample needs to be worked on for ideal texture, flavor and color.  The next experiment performed will most likely use a non evasive, rice flour based, all purpose gluten free blend as to not interfere with the flavor.  By using a mild flour such as rice flour, the taste will be evaluated with more specificity. Additionally, the cookies will need to be baked in a newer, more effective oven.  One lab partner will end up baking all the cookies to create a constant recipe outcome. The baking time may also need to vary per sample recipe.

Individual Experiment #2

Date: 11/29

Lab Conditions: Constant

Purpose:

To bake all three samples of cookies including a control (all butter), a sample with ½ replacement fat (avocado and butter), and a sample with full fat replacement (avocado.) After each sample is baked objective testing will be performed to determine moistness and how much each sample retained its shape and how the volume of each compares to the other.  

Procedure:

Control: Butter was creamed with sugar, brown sugar, egg replacer and vanilla extract on speed 1 for 30 seconds. Dry ingredients were then added including flour, baking soda, baking powder and salt. Dry and wet ingredients were blended on speed 2 for 45 seconds.  Mixture was similar as previous experiment, however the flour used during this trial was Gluten Free Pantry All-Purpose blend.  Each cookie was weighed to about 40g and baked at 375 for 6 minutes

½: Same procedures were used in this trial but the butter was replaced with ½ avocado and ½ butter. Each cookie was weighed to about 40g and baked at 375 for 8 minutes

Full: Same procedures were used in this trial but the butter was replaced with avocado.

Each cookie was weighed to about 40g and baked at 375 for 10 minutes.

Test results:

Wettability test:

- Control: displaced 31 ml

- ½: displaced 31ml

- Avocado: displaced 32ml

**Results suggest that Avocado was the most moist by displacing the most liquid, therefore not absorbing as much due to higher water content.

Index to volume test:

- Control: Spread wide, ¼ inch thick

- ½: spread less, ½ inch thick

- Avocado: little to no spreading, 1 inch thick.

Discussion:

A wettability test was performed on the cookie using a graduated cylinder measured to 100ml for each sample.  Each sample was allowed to sit in the water for approximately 2 minutes.  It was found that the control displaced 31ml, the ½ sample 31ml, and the avocado sample 32ml.  This suggests that by the avocado not absorbing as much water as the other two samples, it was moister. The final test performed was essentially an index to volume test.  This was performed by tracing each cooked sample then measuring the height of each sample.  It was found that the control cookie spread out and was wider but the cookie itself was thin, measuring at only ¼ inch.  The ½ cookie sample spread less than the control and was thicker as well at ½ inch. Finally, the avocado sample did not spread much at all and was the thickest at 1 inch.  These results showed that the volume of each cookie was the same though their spread and thickness differred.

Some issues during testing may have varied due to outside influence of moisture in the air and ingredient variance.  The wettability test could have been compromised if the air was humid that day.  While no humidity was felt on this day, it is possible that the home or facility used for baking retained excess moisture.  Furthermore, the wettability test could have been affected by the amount of chocolate chips differing in each sample used for testing.  More water would be displaced if there was even one additional chocolate chip. The type of flour used could also have an affect on how far the cookies spread.  While gluten free flours were used in the experiment due to gluten allergies, the flour blend used could impact how thick a cookie is or how much it may spread.  It is possible that flours with more starch may hold the fat in place, keeping it from spreading or melting out. Furthermore, the cookies were baked for different amounts of time to ensure that all were cooked to have the most optimal texture.

Each sample was tested during this lab and had varying results.  It is presumed that the avocado cookie retains the most moisture and each of the cookies measures at similar volume.  The recipe was effective during this trial than the first one.  The recipe allowed observance of objective testing and results were what was expected. Avocado, being a vegetable would retain more moisture than butter which is primarily made of milk fat. Milk fat is hydrophobic whereas the plant fibers in avocado are hydrophilic. Each trial performed after this testing day will use the same flour so further results will not vary.

Individual Experiment #3

Date: 12/5

Lab conditions: Constant

Purpose:

The purpose of this trial is to bake and subjectively test each sample using hedonic scales of 1-9 on appearance, aroma, texture, tenderness and overall acceptability. Cookies baked during this trial included the control using butter, ½ modified using butter/avocado, and fully modified using only avocado.  

Procedure:

-Control: Butter was creamed with sugar, brown sugar, egg replacer and vanilla extract on speed 1 for 30 seconds. Dry ingredients were then added including flour, baking soda, baking powder and salt. Dry and wet ingredients were blended on speed 2 for 45 seconds.  Mixture was similar as previous experiment, however the flour used during this trial was Gluten Free Pantry All-Purpose blend.  Each cookie was weighed to about 40g and baked at 375 for 6 minutes

- ½: Same procedures were used in this trial but the butter was replaced with ½ avocado and ½ butter. Each cookie was weighed to about 40g and baked at 375 for 8 minutes

- Full: Same procedures were used in this trial but the butter was replaced with avocado.

Each cookie was weighed to about 40g and baked at 375 for 10 minutes.

(These are the same procedures as the previous lab. They were followed to ensure constant conditions.)

Tests were created measuring color/appearance, aroma, texture, tenderness and acceptance (taste) on a hedonic scale.  Randomized numbers were assigned to each sample to ensure fairness.

Test Results:

571= ½ butter/avocado; 824= avocado; 339= control[pic][pic][pic][pic][pic]

Discussion:

30 subjects observed and blind tasted each sample. A hedonic scale was made measuring how much a person liked a sample.  Numbers 1-9 were used to ensure variance in preference. Each subject was not told what the modified ingredient was so not to influence any decisions when choosing which number to choose on the Likert scale. The ½ modified sample scored highest on all counts of color/appearance, aroma, texture, tenderness, and overall acceptance, the control then followed in second and the full modified avocado sample was least favored. Much of the results were to be expected as the avocado cookie did not appear as appetizing and the texture was not as appealing as the two other samples.  Additionally, most people enjoy the taste of butter which part of a contributing factor as to why obesity and CVD are continuing problems in the United States.  The surprising result was the ½ modified sample being favored by most subjects. Even over the control, the ½ modified sample was superior.

Some errors that occurred within this trial included temperature variance of the oven as well as the amount of time from oven to table. The first batch of cookies made, were placed unknowingly in an oven that had not finished preheating entirely, and was compensated by keeping the cookies in the oven longer.  Temperature may have been lost a couple of times as well due to the opening of the door to check on the samples being baked.  Furthermore, the cookies were made the night before the subjective testing and the aroma was not as strong as a freshly baked cookie.  However, if the cookies were freshly baked, the texture, flavor and tenderness may have also been affected.  

The concluded result of this trial determined that most subjects in the general public prefer the color/appearance, aroma, texture, tenderness and flavor of the ½ modified sample. The avocado contributed to the moistness and superior texture while the butter added flavor and created a Maillard reaction or non-enzymatic browning. The sugars mixed with the butter fat were caramelized slightly whereas too much moisture was present within the fully modified samples, steaming the flour and other ingredients.  The butter in the control melted too much and caramelized the sugar until it was almost crunchy or candied. This was the final trial made for the experiment and all modifications made up to this point produced testable results.

APPENDIX: LAB NOTES

11/15

Procedure:

Control Recipe:

6 servings

measure 55 g butter (for 1/2 measure 27.5)

90 g packed brown sugar

15 g white sugar

2 ml gluten-free vanilla extract= 1.8 grams

20 ml egg substitute= 20 grams

180 ml gluten-free baking mix= 101.3 grams ()

2 g baking powder

2 g baking soda

2 g salt

115 g semisweet chocolate chips

Converted the vanilla and egg substitute to oz

Preheat oven to 375

Notes:

When weighing out butter, scale shifted and did not seem to provide an accurate measurement. We had to re-measure butter. Mixed egg replacer according to directions. 1/2 T of replacement + 2 T water = 1 egg. measured in grams. added before creaming the sugar and butter.

For ½ modified  recipe: 27.4 g butter, 27.6 g avocado

mashing avocado and butter together before mixing because butter is cold

speed 1 for 30 seconds

avocado not chunky after mixing with sugar

115.1 g choc chip

For Control Recipe:

egg substitute measured to 20.2 g

mashed cold butter for control recipe before mixing

speed 1 for 30 seconds to cream fat and sugar

Speed 2 for 45 seconds to add flour

choc chip 114.9

For Full Avocado:

mixture is chunky

speed 1 for 30 seconds to cream fat and sugar

speed 2 for 45 seconds to mix

choc chip 114.7

Extra notes:

mashed the avocado for replacement recipe

used same avocado for each recipe

small amounts of fats were left on forks after smashing

powder egg substitute 6.6 grams and 4 T water

Instead of sifting the flour, baking powder and salt, we stirred with a small spoon to incorporate all the ingredients. Stirred about 7 times.

incorporated choc chips by hand

measured all the cookies to approx 40 g each, 8 cookies of each recipe, 2 racks: 8 full avo + 4 control on one rack, 8 1/2 + 4 control on the other rack

After cooking appearance:

control: super flat, brown (butter might have melted too much between measuring and mixing ingredients

1/2 and full: visually not much different, retained shape approx 1-1 1/2 inches tall, 2 inches in diameter, 1/2 melted a bit so a little flatter, full avo are more green, 1/2 avo not green at all

**need to cook avocado and 1/2 a little longer

Taste:

control: sweet, buttery (too much butter), garbonzo bean aftertaste

1/2: weird aftertaste, garbonzo bn, avocado, sweet

full: aftertaste less weird, tastes more like avocado, sweet

Texture:

control: crunchy, sticky

1/2: gooey, crunchy on outside, doughy

full avo: creamy, slight crnch, doughy

after mixed but before baked

full avocado: very sticky, green

1/2 creamy slightly green

control: more crumbly

*** cooked all for the same amount of time. Need to cook both full avocado and 1/2 longer.

Tiffany measured

Cassie Mixed

Brands:

Bob's Red Mill All Purpose Gluten Free Baking Powder

Karlin's finest Baking soda

Safeway Plain Salt

Rumford Aluminum Free Baking Powder

Kirkland GF Pure Vanilla Extract

Safeway brand light brown sugar

Better Butter

11-29 / 11/26

Same recipe and procedures

New flour: Gluten Free Pantry

180 mL= 92.82 g

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