Sensory and physical characteristics of zucchini

bread prepared by replacing

sugar with stevia and sucralose

Nicole Castro, Deanna Torino, Keisha Brooks

Introduction With the increase in the obesity epidemic in the U.S., there has also been a rise in diseases associated with having a high BMI. Some diseases that could develop from obesity include:

Hypertension

Type II Diabetes

Heart disease and stroke

Osteoporosis

Gallbladder disease

Breathing issues such as sleep apnea

Rates of Obesity in the U.s

According to NHANES the rates of obesity in the U.S. from 2013-2014 were as follows:

37.7% of adults are obese with a BMI >30

40.4% of those adults are females

35.0% of those adults are males

17% of children are obese with 20% of those being in the 12-19 y.o. age group

A major component leading to obesity is dietDiet and eating behaviors play such an important role in the obesity epidemic.

One of the major diseases secondary to obesity is Type II Diabetes.

The average American consumes 82 grams of sugar per day.

Yet the AHA recommendations are are:

Men-> 38 grams (9 tsp)

Women-> 25 grams (6 tsp)

Children-> depending on age/caloric needs ~12-25g (3-6 tsp)

Type II Diabetes: Sugar & Its Alternatives ↑Sugar consumption, ↑Obesity, ↑Type II Diabetes

→ Sugar Alternatives/Replacements:

Sucralose (Splenda) no calories

Aspartame (Equal)- some side effects

Saccharin (Sweet’N Low)

Stevia (natural plant sweetener)

Sugar Alcohols (low calorie sweetener)

Type II Diabetes: Sugar & Its Alternatives

Our PurposeFor our study we decided to address the issue of obesity and its secondary disease Type II diabetes. This is an issue that can be addressed through diet.

We wanted to provide an alternative to Zucchini Bread that would be lower in calories and sugar content.

Why Zucchini Bread?Zucchini is a low calorie vegetable (35 kcal/cup).

Its CHO content is also low with 3.5g/cup.

Glycemic index is only 15 (low).

This versatile vegetable provides fiber too which is beneficial for slowing absorption of sugar and balancing sugar levels.

We decided to use whole wheat flour, too, for a more hearty, complex CHO bread.

Our Recipes Each recipe contained the same ingredients. The varying factor was the sugar content. 1 recipe was the control & the other two were the experiment recipes.

Zucchini bread with 100% sugar (1 cup)

Zucchini bread with 50% sugar/50% sucralose (½ cup of each)

Zucchini bread with 50% sugar/50% stevia (½ cup of each)

Materials The ingredients used for the samples included:

All-purpose flour (Pillsbury unbleached all-purpose flour J.M. Smucker Company Orville, OH),

table salt, baking powder, baking soda, ground cinnamon, ground nutmeg, large eggs, vegetable oil, vanilla extract, zucchini, granulated white sugar, sucralose, stevia.

Methods - Sample PreparationFor each loaf, the dry ingredients (flour, salt, baking soda, baking powder, ground

cinnamon, ground nutmeg) were sifted together in one bowl, and the eggs, oil, vanilla extract, and sugar or sweetener were whisked together in another bowl.

The dry ingredients were then folded into the wet ingredients until just mixed. Next, the grated zucchini was folded into the batter. The batter was poured into a 9x5 inch loaf pan and baked until cooked through, which

was defined for this experiment as reaching an internal temperature of 166 degrees Fahrenheit (75 degrees Celsius).

Sample Preparation

Control 50% Truvia 50% Splenda (100% sugar) (Stevia)

(Sucralose)

Methods - Objective testingA thermometer was used to take the internal temperature of each bread. Each loaf was also subjected to height measurement in three different areas ( the highest

side, the lowest side, and the middle) using a long toothpick and a standard ruler.

MEthods - Sensory EvaluationParticipants for the sensory evaluation included twenty students and faculty members at CUNY Queens College

ages 18-30 who volunteered for the experiment. Panelists were untrained and randomly selected. The sensory evaluation took place in room 301 of Remsen Hall at Queens College on March 29th, 2017, at about 6:00pm.

Each formulation was assigned a three-digit code. The loaves were cut into 2cm by 2cm cubes with the crusts removed, using an electric knife operated by faculty advisor

They were served on plain paper plates which were marked with the three digit codes corresponding to each bread. Cups of water were served alongside the samples.

Panelists were given instructions to evaluate:the appearance (intensity of brown color), sweetness, aftertaste (lingering taste after swallowing), Moistness,overall acceptability of each sample

Methods - NUtrition FActs LAbels

Our nutrition facts labels were created using Nutritionix.com

We input all of the ingredients called for in the recipes and the amounts needed.

We generated three nutrition facts labels - one for each bread.

RESULTS:

SENSORY attributes EVALUATION

RESULTS: sensory attributes

*Mean ± Standard Deviations of 20 panelists using 9-point scale; (where 1: weak and 9: strong)*Means with the same superscripts in rows indicate no significance in difference (Tukey test, p<0.05)

Sensory Evaluation: Average Rating by Panelists

Brownness Sweetness Aftertaste Moistness Overall Acceptability

Control (307) 6.75 + 1.650 5.85 + 2.183 6.05 + 2.235 7.25 + 2.337 7.30 + 1.720

50% sucralose (574)

6.10 + 1.283 5.60 + 1.847 5.55 + 2.438 5.35 + 1.954 5.15 + 2.033

50% stevia (129) 5.50+ 1.638 5.40 + 1.930 5.70 + 2.003 4.60 + 1.818 5.70 + 1.525

Results: sensory attributes BROWNNESS

There was NO SIGNIFICANT DIFFERENCE (p < 0.5) found between the Zucchini breads in the category of BROWNNESS.

A slight significance was found between the Control Zucchini Bread and the 50%/50% Stevia/Sugar Zucchini Bread.

Contributing Factors:● Differences in brownness are related to the decrease in sugar in the two

experimental breads, decreasing the Maillard Reaction

Results: sensory attributes SWEETNESSThere was NO SIGNIFICANT DIFFERENCE (p < 0.05) found between the Zucchini

breads in the category of SWEETNESS.

The Control Zucchini Bread with 100% sugar rated the sweetest. However, the alternative sweeteners (stevia or sucralose) can be used since there was no significant difference found compared to actual sugar.

Contributing Factors:● Sweetness seemed to have decreased due to a total decrease in the amount of added

sugar.● Stevia and Sucralose are both much sweeter than sugar, yet may have altered taste

Results: sensory attributes AFTERTASTE

There was NO SIGNIFICANT DIFFERENCE (p < 0.05) found between the Zucchini breads in the category of AFTERTASTE.

The Control Zucchini Bread with 100% Sugar rated the highest among panelists.

Contributing Factors:● Sucralose may have had a varied effect on aftertaste, as it is much sweeter than

Sugar

Results: sensory attributes MOISTNESS

One of the only characteristics that SHOWED SIGNIFICANCE in our study was MOISTNESS. There was a significant difference between the control recipe (100% sugar) and the experimental recipes (p<0.05).

Moistness(Mean+ SD):Control Recipe: 7.25 + 2.337

50/50 Sucralose Recipe: 5.35 + 1.95450/50 Stevia Recipe: 4.60 + 1.818

Contributing factors:● Sugar adds moisture and tenderness to the overall product● The sucralose and stevia containing recipes turned out more dry and firm.

Results: sensory attributes OVERALL ACCEPTABILITY

A SIGNIFICANT DIFFERENCE was found between the Zucchini Bread containing 100% sugar and the other two experimental recipes containing either 50% stevia or 50% sucralose. The control recipe obtained an overall mean acceptability of 7.30. The Stevia recipe obtained 5.70. Sucralose obtained 5.15.

Contributing Factor:● The major contributing factor was moistness level since this was the only component

with a significant difference among the three recipes. ● Sugar contributes to moistness content which is a characteristic consumers look for in a

zucchini bread.

NUtrition FActs Labels100% Sugar 50/50 Sugar-Stevia 50/50 Sugar-Sucralose

NUtrition facts: BY replacing 50% of the sugar with stevia and Sucralose, we were able to reduce the

amount of sugar in each bread by 8.3 grams (17.1g in the control to 8.8g in the stevia and in the sucralose loaf).

The substitutions also reduced the total amount of calories by 33 calories (222cal in the control to 189cal).

The main difference between the Stevia loaf and the Sucralose loaf was the amount of sodium (174.5mg in the stevia loaf, 185.5 in the sucralose loaf).

Conclusion After conducting our experiment and developing a sensory evaluation, objective evaluation based on height, and a nutritional analysis on the various Zucchini Bread formulations, we concluded that Zucchini Bread with 100% sugar, although not the healthier option, was the most acceptable.

Further research needs to be done to develop a recipe that not only compares in sweetness but also in body structure and moistness levels for an overall acceptability. Possibilities include: using different % of the sugar replacements, using a mix of sugar alcohols, bulking agents, and high-intensity sweeteners.

References Health Risks Linked to Obesity. (2017). Retrieved May 16, 2017, from http://www.webmd.com/diet/obesity/obesity-health-risks#1

How Much Is Too Much? (2014, December 18). Retrieved May 15, 2017, from http://sugarscience.ucsf.edu/the-growing-cocern-of-overconsumption/#.WRufjYWcFbt

Malley, M. O. (2016, May 04). 5 Sugar Substitutes for Type 2 Diabetes. Retrieved May 15, 2017, from http://www.everydayhealth.com/type-2-diabetes/diet/sugar-substitutes-for-diabetes/#06

Obesity in the U.S. (2017). Retrieved May 15, 2017, from http://frac.org/obesity-health/obesity-u-s

Struck, S., Jaros, D., Brennan, C. S. and Rohm, H. (2014), Sugar replacement in sweetened bakery goods. Int J Food Sci Technol, 49: 1963–1976. doi:10.1111/ijfs.12617

Zucchini and Type 2 Diabetes. (2017). Retrieved May 15, 2017, from https://diabetesmealplans.com/8716/zucchini-and-type-2-diabetes/