Experimental Food Study Laboratory Notebook

Transcription

1 Experimental Food Study Laboratory Notebook Jennifer Hamilton DFM 357 PM Lab November 14, 2014

2 2 Table of Contents Lab # Page # Lab #1: Basic Measuring Techniques 3 Lab #2: Sensory Evaluation 7 Lab #3: Crystallization 17 Lab #4: Starch and Thickening Agents 29 Lab #5: Fiber 37 Lab #6: Fats and Oils 43 Lab #7: Milk Proteins 48

3 3 Lab#1: Basic Measuring Techniques Date: September 5, 2014 Conditions: Warm Purpose: The purpose of the lab was to explore different measurement techniques and to observe the difference in weights of the products it produced. Experimental Procedures: The instructions were given for Lab #1 by instructor Maryann Smitt and they were listed in Table s #1-3 included below. Students measured an assortment of common household baking goods, three times. Results: For data and results, please refer to Table #1-3 attached. Discussion: In the basic measurement technique lab, different measuring techniques were used to measure out an assortment of household products. The way items were measured differed by sifting vs not sifting, packed vs unpacked, liquid vs solid and coarse vs fine. The texture of a product or type of product and how it was measured affected the weighed outcome of the product. For example, in measuring different types of flour in Table #1, sifting and packing affected the average weight of all purpose flour with an average weight of 179.4g. While sifted all-purpose flour that was not packed had an average weight of 100.7g. This is a difference of almost 79g.

4 4 In Table #2, brown sugar that was packed vs not packed also showed a difference in average weight. The packed brown sugar average weight was 49.3g, while the brown sugar not packed weighed on average 27.4g. It became evident that how a substance was measured, would affect the actual quantity of the product produced. According to Better Homes and Gardens Cook Book, getting consistent successful results from your product begins with measuring the ingredients with the correct tools. Therefore it is important to use dry measuring cups for household items like flour, sugar and solid fats, and to use a liquid measuring cup for household items such as water and oil. While conducting the experiments with the sugar and fats there were several notable possible errors that occurred. First, the bowl that was used to place the powdered sugar in was slightly wet. Even though the scale was zeroed before weighing anything, some powdered sugar would stick to the bowl. Also the powder sugar stuck in the measuring cup. So the weight may be slightly underrepresented as a result of residual in the measuring cup. Second, while measuring hydrogenated oil, some of the hydrogenated oil remained in the measuring cup. Another notable error is a dry measuring cup was used instead of a liquid measuring cup while measuring the vegetable oil. This could place more oil in the cup due to surface tension as opposed to using the meniscus of a liquid measuring method. The vegetable oil we used also contained remnants of hydrogenated oil. This could alter the weight by having a lower volume than what might otherwise be. Lastly, while measuring the butter, there was residual butter in the measuring cup. Thus the results of the average weight of butter could be lower than what it might otherwise be. These are examples of measurement bias that were discussed in the Research Process lecture by Christine Batten on August 27, Ideally you would like to remove bias to make sure results are consistent and accurate.

5 5 It was observed that the types of fat weighed had considerably different average weights. The average weight for hydrogenated fat was 46.2g, vegetable oil was 49.6g and butter was 53.1g. Butter was the heaviest possibly due to the milk solids, while hydrogenated fat is the lightest due to water being removed from the product. In Table #3, different types of salts were measured ranging from fine to coarse. Table salt was the heaviest with an average weight of 6.4g while Kosher salt was the lightest with an average weight of 3.3g. The size of Kosher salt granules took up more room in the measuring spoon and thus potentially account for why the weight was almost half the weight of table salt, which was finer and more compact. Coarse vs fine texture seemed to impact amount of product delivered and must be kept in mind when preparing dishes. The objective evaluation of the data has shown that measurement technique can and will alter the desired amount of product. Therefore, in order to reduce measurement bias, it is important to be aware of the proper technique and tools to use. References Batten, C. (2014). DFM 357 Research Process [PowerPoint Slides]. Retrieved from Darling, J.D. (Ed.). (2012). Better Homes and Gardens Cook Book (12 th ed.). Des Moines, Iowa: Better Homes and Gardens Books.

6 DFM 357 Lab 1 Basic Measuring Techniques 1 Cup 6 Table #1 1 a-1 Bread flour, unsifted, fill cup by a spoon 2 a-2 Bread flour, unsifted, minus 2 tablespoons Trial 1 Trial 2 Trial 3 Average 126.5g 125.8g 119.7g 124.0g 110.7g 109.9g 109.1g 109.9g 3 a-3 Bread flour, sifted, lightly fill cup by a spoon, no packing or shaking. Level top with edge of a straight knife or spatula 114.4g 111.9g 115.5g 113.9g 4 a-4 All purpose flour, sifted, packed and tapped into a cup with a spoon 180.0g 176.6g 181.7g 179.4g 5 a-5 All purpose flour, sifted, lightly fill cup by spoon, no packing or shaking. Level top with edge of a straight knife or spatula, then minus 2 tablespoons, level top with edge of a straight knife carefully. 6 b-1 Water 9.5g 102.4g 100.3g 100.7g 232.7g 229.1g 231.5g 231.1g 1/4 Cup Table #2 Trial 1 Trial 2 Trial 3 Average 7 c-1 Brown sugar, packed and tapped into a cup with a spoon. 50.9g 50.1g 46.8g 49.3g 8 c-2 Brown sugar, lightly fill cup by a spoon, no packing or shaking. Shake and level top with edge of a straight knife or spatula 9 c-3 Granulated sugar or powder sugar, fill cup by a spoon. 10 d-1 Hydrogenated fat 11 d-2 Oil 12 d-3 Butter Table #3 13 e-1 Table salt 14 e-2 Kosher salt 15 e-3 Sea salt 27.8g 27.2g 27.1g 27.4g 26.9g 26.8g 27.8g 27.7g 45.8g 45.1g 47.7g 46.2g 49.2g 48.7g 50.8g 49.6g 52.3g 54.1g 53.0g 53.1g 1 teaspoon Trial 1 Trial 2 Trial 3 Average 6.5g 6.4g 6.4g 6.4g 3.2g 3.4g 3.3g 3.3g 6.0g 6.2g 5.9g 6.0g

7 7 Lab #2: Sensory Evaluation Date: September 12, 2014 Conditions: Noisy, busy, warm Purpose: The purpose of the lab was to explore how appearance, odor, taste and texture impact our experience with food. Experimental Procedures: A sequence of exercises was given to experience tasting through a series of solutions that were coded. The instructions for each station within Lab #2 were given by instructor Maryann Smitt and were listed in Series A-L of the attached. Students tasted in silence the assortment of solutions that were sweet, salty, sour, bitter or umami and recorded results in Series A-L. We used three different types of test: descriptive, affective and difference tests. Results: For data and results, please refer to Series A-L, attached. Discussion: In the sensory lab, different solutions were evaluated by using difference tests as well as incorporating different flavor enhancers and inhibitors to solutions. In Series A, Identification of the Primary Tastes, we had to taste five different solutions and match them to either bitter, sour, salty, sweet or umami the fifth taste. My four taste receptors were able to identify the five different solutions very distinctly and easily with bitter on the back of the tongue, sour on the sides of my tongue, and sweet & salty on the tip of the tongue.

8 8 In series B, Effect of Acid on Sweetness: Paired Comparison Sensory Test, several different applications were occurring. First, we used the paired comparison test. McWilliams (2012) defines it as a test of difference in which a specific characteristic is designated. Then the taster is given two samples to compare and they must identify the sample with the greater amount of the characteristic being measured. The other application was the addition of citric acid to the solution. Per Christine Batten lecture on September 3, 2014, we learned that acid increased the saltiness of a solution. When tasting samples #142 and #293, #142 was less sweet and was a little salty compared to #293. Per the key attached, #142 was confirmed to be less sweet. Series C, Effect of Salt on Sweetness: Triangle Sensory Test, used two different applications. First, it used the triangle sensory test which is defined by McWilliams (2012) as a test given with three samples presented simultaneously. The taster must identify the sample that is different from the other two samples presented, which are the same. Tasting three samples became a little more challenging to identify which sample was different. However, the solution with the salt tasted slightly sweeter and was ultimately the different sample. This leads to the other application used, using salt as flavor enhancer. As learned in lecture, salt enhances sweetness, which was evidenced in sample #256. Series D, Effect of Sugar on Saltiness: Paired Comparison Sensory Test, used sugar as a flavor inhibitor along with the paired comparison test. When comparing solution #876 to #190, #876 was less salty than #190. Solution #876 had salt and sugar added to the solution, thus blocking taste sites, preventing the normal taste response in the solution (McWilliams 2012). Therefore, sugar decreased the saltiness. One notable event was other tasters were reacting to the saltiness of the solution. Even though the lab was supposed to be conducted in silence,

9 9 participants were making faces and sounds to what they tasted. It gave other tasters a perception the solution was unpalatable, but in reality it was just very salty, thus creating bias. Series E, Effect of Sugar on Sourness (Acidity): Paired Comparison Sensory Test, used sugar as a flavor inhibitor in a paired comparison test. In the presence of sugar, the sourness of the solution was decreased. Solution #186 was very sour tasting, while #453 was less so. Series F, Effect of Sugar on Bitterness: Paired Comparison Sensory Test, paired two solutions one of which was sweet and the other bitter. Solution was #468 had sugar added to tea, while #739 was tea that had been over steeped and was extremely bitter. The addition of sugar to compensate for the bitterness of the tea, made it taste less bitter, but the amount of sugar added made it almost too sweet and unpalatable. Series G, Effect of Different Type of Sugar: Duo-Trio Test, was a test that used the duotrio test. This is a test where a taster is given one sample, the control, and then given two more samples, and then they have to determine which the control is. This test was particularly challenging to determine which solutions were similar. It was not clear at first which was the control, thus making it difficult to compare. In addition, the sweetness of the solutions were very similar, which made it hard to tell them apart. At the point in time when series G was tested, the taster was getting saturated by the tastes of the previous solutions, to the point where all solutions started to taste the same. This contributed to possible bias. Series H, Effect of Above Threshold Levels of Salt on Sweetness: Triangle Test, compared three samples to determine which was the sweetest sample. The standard provided was #129, which was salty and sample #253 matched the standard. The application of large amounts of salt decreased the sweetness of the solution. Sample #308 was found to be the sweetest, yet

10 10 was only made with sucrose per the sensory lab key. Samples #129 and #253 had more of a salty taste and were less sweet. They were made with sucrose and salt. Series I, Effect of Processing Method on the Flavor of Lemonade: Consumer Preferences Hedonic Scale Sensory Test, used an affective testing method. The hedonic scale sensory test is defined as a rating scale used to measure the degree of pleasure experienced with each sample (McWilliams 2012). Affective testing method evaluates acceptability of the samples (McWilliams, 2012). Sample #598, dried lemonade mix, was preferred over frozen lemonade and fresh lemonade with a rating of neither like nor dislike. Sample #470 was disliked very much, because it was extremely sweet, off putting and had a chemical taste. Sample #229, fresh lemonade, was disliked moderately due to the sour acidic nature of the solution. Therefore the dried lemonade was more acceptable out of the three samples. It was not overly sweet, nor was it overly tart, it was just ok. Series J, Effect of Color on Flavor, used appearance/color as a test measure to see if the taster would perceive a different flavor based on color. There were four different color samples: blue, green, red and yellow. Color somewhat influenced perception of flavor. For example, blue tasted sweet while green was tart. Overall, the samples tasted sweet and tart/sour. Per the sensory lab key, the samples were all the same with the exception of color. Series K, Effect of Genetic Predisposition on Tasting Phenylthiocarbamide (PTC), was a test to see if the taster was a supertaster. After placing the PTC taste paper on the tongue there was a metallic, acidic and tin like taste. Series L, Perception of Flavor Without Visual Cues, explored flavor without sight. Without sight other senses like taste and smell became more dominant in the flavor experience. With eyes closed, jelly bean placed on the tongue and chewing begun, sweetness was the initial

11 11 flavor of the candy. But as the jelly bean dissolved further, the tartness became more prominent and taste was like lemon. However, the sweetness made it hard to decipher exactly what the flavor was so it could have been pear. Later I found out the actual jelly bean was lemon and lime. The sensory evaluation lab demonstrated the role different foods have to either enhance or inhibit flavor. Salt is a flavor inhibitor and enhancer, while sugar reduces saltiness and bitterness, and acid enhances saltiness. Flavor is made of four components: 1 taste, 2 odor, 3 mouth feel and 4 trigeminal perception. To explore flavor further a variety of tasting methods from affective to difference testing can be used. Taste is a subjective measure because it will be unique for each person. This was evident in the Series I test where the hedonic scale was used. References: Batten, C. (2014). DFM 357 Sensory Evaluation [PowerPoint Slides]. Retrieved from McWilliams, M. (2012). Foods Experimental Perspectives (7 th ed.). Upper Saddle River, NJ: Prentice Hall.

12 DFM 357 Lab 2 Sensory Evaluation 12 The sensory quality of food encompasses many complex factors: appearance, odor, taste, and texture (mouthfeel). The flavor of food is derived from a combination of odors and tastes and is influenced by its temperature and texture. The primary tastes are generally considered to be bitter, salt, sour, sweet, and umami. Substances that contribute to taste must be in solution before they can be detected. Individuals vary in their ability to identify specific tastes. Goal: To experience sensory evaluation of primary tastes and the effect of color on flavor using sensory evaluation methods. Outcomes: o To recognize the basic tastes and to identify the effect that one has on the others. o To recognize the effects of color on taste. o To use a variety of sensory evaluation tests: specifically the paired comparison, triangle, duotrio, and the hedonic scale. o To increase sensitivity to taste. Questions for study: How does one taste affect another? What characteristics of a food are important to your ability to taste? Procedure: Preparation: Solutions are prepared according to directions in Appendix A. Experiment: Below are a series of exercises that will give you some experience in tasting. A series of solutions have been made and coded so that you will not know what they are. You will rotate through each series. For each series, pour a one-teaspoon sample into a clean cup, taste, and evaluate according to the testing method indicated. Following each taste, rinse your mouth with water. When you have finished, you can compare your results with the composition of each solution. Note: this experiment must be conducted in silence. Series A: Identification of the Primary Tastes Taste each of the labeled solutions and place the number in the column that corresponds to the taste sensation you received from the solution. Identification Bitter Sour Salt Sweet Umami Individual Correct key # Series B: Effect of Acid on Sweetness: Paired Comparison Sensory Test Place the code under the correct category. Identification Less Sweet More Sweet No Difference Individual Correct key # Conclusion: How did acid affect sweetness? Acid increased the saltiness of the solution and made it sweeter.

13 13 Describe a paired comparison sensory test. A paired comparison is when a specific characteristic is designated. The person judging then has to test the two samples to identify the sample with the greater amount of the specified characteristic. Series C: Effect of Salt on Sweetness: Triangle Sensory Test Choose the sample that is different from the other two. Is it sweeter or less sweet? Identification Two of the Same Different Sample Different Sample: Less Sweet Individual 621, (more sweet) 879 Correct key # Conclusion: How did salt affect sweetness? Salt enhances sweetness Describe a triangle sensory test. A triangle test is when you are given three samples and you have to identify the sample that is different. Two will be the same. Series D: Effect of sugar on saltiness: Paired Comparison Sensory Test Place the code under the correct category. Identification Less Salty More Salty No Difference Individual Correct key # Conclusion: Sugar (decreases/increases) saltiness. Series E: Effect of Sugar on Sourness (Acidity): Paired Comparison Sensory Test Place the code under the correct category. Identification Less Sour More Sour No Difference Individual Correct key # Conclusion: Sugar (decreases/increases) sourness. Series F: Effect of Sugar on Bitterness: Paired Comparison Sensory Test Place code under the correct category. Identification Less Bitter More Bitter No Difference Individual 468 sweet bitter Correct key # Conclusion: Sugar (decreases/increases) bitterness. Series G: Effect of a different type of sugar: Duo-Trio Test Identification Different Individual 438,724,

14 Correct key # Conclusion: 14 Describe the duo-trio test. In the duo-trio test the control is presented first, followed by two other samples, one of which is the same as the control. The person judging must identify which of the two samples are different from the control. Series H: Effect of Above Threshold Levels of Salt on Sweetness: Triangle Test Choose the sample that is different from the standard. Is it sweeter or less sweet? Identification Identical to Standard Sweeter/Less Sweet Individual Standard:129-salt & 253 sweet & salt Less Sweet & Salty Correct key # Conclusion: sweet, 308-Sweet Salt in larger amounts (decreases/increases) sweetness. Describe the triangle test. The triangle test is when you are given three samples and you have to identify the sample that is different. Two will be the same. Series I: Effect of Processing Method on the Flavor of Lemonade: Consumer Preference Hedonic Scale Sensory Test Rate the 3 lemonade samples from dislike extremely to like extremely by checking the appropriate box. Sample #470 Dislike Dislike Dislike Neither Like Like Like Very Moderately Slightly Like nor Slightly Moderately Very Much Dislike Much Dislike Extremely Like Extremely Sample #598 Dislike Dislike Dislike Neither Like Like Like Very Moderately Slightly Like nor Slightly Moderately Very Much Dislike Much Dislike Extremely Like Extremely Sample #229 Dislike Dislike Dislike Neither Like Like Like Very Moderately Slightly Like nor Slightly Moderately Very Much Dislike Much Dislike Extremely Like Extremely Conclusion:

15 15 How do frozen lemonade, a dried lemonade mix, and lemonade made from fresh lemons compare? For my experience, I preferred the dried lemonade mix to the frozen and fresh lemonade. I really did not care for the frozen because it was extremely sweet and off putting. It had a chemically taste. For the fresh lemonade it was a little more tart than I would have cared to have it. Therefore the dried lemonade was ok. It was not overly sweet, nor was it overly tart, it was just ok. Describe the consumer preference hedonic scale sensory test. The hedonic scale is a pleasure scale where samples are ranked in order of preference. Series J: Effect of Color on Flavor Identify the flavor of each solution. Code Flavor 382 blue- Sweet 296 green - tart 432 red sweet, tart 871 yellow sour, sweet Conclusion: Did color affect your perceived flavor? Color somewhat influenced my perception of flavor. However, I found that most of the samples to be sweet and tart/sour tasting. Series K: Effect of Genetic Predisposition on Tasting Phenylthiocarbamide (PTC) Taste a PTC taste paper. Do you taste anything, and if you do, what is the quality? What I tasted was tin like, metallic, acidic. Series L: Perception of flavor without visual cues: Have your lab partner choose a jellybean flavor for you. With your eyes closed, have your partner place the jellybean in your palm. Eat the jellybean. Guess what flavor it is and compare it to the actual flavor. Describe what happened. When I closed my eyes and placed the jelly bean on my tongue and began to chew I initially got the sweetness of the candy, but then I started to taste tartness like a lemon. But the sweetness was throwing me so I thought it could have been pear. It was hard to identify without seeing the sample, but the other senses like taste and smell became more dominant. In actuality the jelly bean that I was given was lemon & lime. So I was close to the flavor profile.

16 Series A: Identification of the Primary Tastes Identification Bitter Sour Salt Sweet Umami Correct key # Series B: Effect of Acid on Sweetness: Paired Comparison Sensory Test Identification Ingredients 293 Sucrose 142 Sucrose + Citric Acid (less sweet) Series C: Effect of Salt on Sweetness: Triangle Sensory Test Identification Ingredients 621 Sucrose (621 & 879 are the same) 256 Sucrose + Salt (more sweet) 879 Sucrose Series D: Effect of Sugar on Saltiness: Paired Comparison Sensory Test Identification Ingredients 190 Salt 876 Salt + Sucrose (less salty) Series E: Effect of Sugar on Sourness (Acidity): Paired Comparison Sensory Test Identification Ingredients 186 Citric Acid 453 Citric Acid + Sucrose (less sour) Series F: Effect of Sugar on Bitterness: Paired Comparison Sensory Test Identification Ingredients 739 Caffeine 468 Caffeine + Sucrose (less bitter) Series G: Effect of a different type of sugar: Duo-Trio Test Identification Ingredients 222 & 438 Sucrose both the same 724 Agave Syrup sweeter with bitter after taste Series H: Effect of Above Threshold Levels of Salt on Sweetness: Triangle Test Identification Ingredients 308 Sucrose (the different sample) 253 Reference Sucrose + Salt 129 Sucrose + Salt Series I: Effect of Processing Method on the Flavor of Lemonade: Consumer Preference Hedonic Scale Sensory Test Identification Ingredients 470 Frozen Lemonade 598 Dried Lemonade Mix 229 Fresh Lemonade Series J: Effect of Color on Flavor Identification: 382, 296, 432, 871. All samples were the same (lemonade), only the colors were different

17 17 Lab #3: Crystallization Date: September 19, 2014 Conditions: Hot Purpose: The purpose of the lab was to understand the process of crystallization in crystalline and amorphous candies by applying temperature, time and air incorporation as controls. Experimental Procedures: The instructions were given for Lab #3, Crystallization by instructor Maryann Smitt and are listed in the Lab 3 Crystallization handout, see attached. Students made an assortment of crystalline candies such as fondants, fudge, divinity, and amorphous candies such as caramels, lollipops and peanut brittle. Students recorded in designated tables data for cooking temperature, beating temperature, beating time, color, texture, consistency and flavor. Results: For data and results, please refer to Fondant Results, Fudge and Divinity Results and Caramels, Peanut Brittle & Lollipop Results below. Discussion: Crystalline candies come in several forms. They come either saturated, as much as a solute can hold; or supersaturated, solution containing more than it theoretically can at a specific temperature. They have an organized crystalline area where some small amount of liquid is trapped inside the crystals, otherwise known as mother liquor. This provides a smooth texture to

18 18 the candy. There are several well-known candies that are classified as crystalline candies such as fondant, fudge and divinity. The function of cream of tartar in crystalline candy is to create invert sugar. Per Christine Batten (2014) lecture, cream of tartar is a weak acid which hydrolyses sucrose to form equal portions of glucose and fructose and promote inversion. This process makes invert sugar, which ultimately makes a sweeter, smoother product. Cream of tartar can be replaced with corn syrup because corn syrup is mostly glucose. It acts as a buffer between sucrose molecules preventing them from joining together in one giant mass and ruining the crystalline structure. Also corn syrup has already been hydrolyzed to glucose and fructose. Temperature affects crystalline candies quite dramatically. Beating candies at a certain temperature disrupts the crystals as they attempt to form. The viscosity at a certain temperature and agitation results in a finished product that is smooth and velvety. However, if crystallization occurs before the candy has reached super saturation, then beating must begin immediately until the candy solidifies. The agitation will disrupt the crystals and keep their size small to provide a texture that is pretty smooth when finished. This was evident in the Fudge & Divinity Results table. As the cooking temp was increased, the fudge became less smooth and more crumbly. Several candies in the lab were made using cream, such as fudge and fondant. Cream affects the crystal size by interfering with the formation of crystals. The cream fondant was creamy and buttery while the fondant made with water was very sweet and more firm. Some common ingredients found in fudge are milk, cream, chocolate and egg whites. The reason why these items are added to crystalline candies is because of they all contain fat. The fat makes a finer texture by interfering with crystallization and enhancing flavor. The fat will produce a smooth texture and enhance flavor, which is desirable in crystalline candies (McWilliams 2012).

19 19 We did not have corn syrup as a sample fondant. The group that was making the sample cooled their fondant below 40ºC unknowingly because their thermometer was placed in their bowl incorrectly. The tip of the thermometer was touching the bottom of the bowl and gave a false reading. As result of this error, the fondant was cooled to 35ºC and was unable to be beaten because it was too rigid. However, color difference of the fondant could be attributed to the translucency of the item used. For example, cream of tartar is a white powder giving an opaque white appearance, while corn syrup would make the product a little more clear and glossy. The temperature at which you beat a candy affects the crystalline nuclei formation. By cooling a mixture to about 40ºC it will favor the formation of more nuclei and finer crystals. The thickness of the solution is also greater at lower temperatures. However, if too low of a temperature is reached it may delay the formation of a lot of nuclei (Srilakshmi, 2003). This is important because agitation keeps many of the small nuclei in the supersaturated solution and prevents it from attaching to already developed crystals. This was seen with Fudge 2, temperature of beating & speed of beating on crystal size in the Fudge & Divinity Results table. At a low beating speed and cooler temperature, it took longer for the candy to go from glossy to dull. It also produced a dry fudge. As the beating temperature increased, the time it took to show a change lessened and the product was grainier. Lastly, as beating speed increased with a low beating temperature, the beating time decreased making for smoother and thick fudge. As temperature is increased in a crystalline candy, it will become harder due to the increased concentration of sugar. If the temperature is decreased and the water vapor evaporates more slowly, then it yields a softer, more watery candy. While making fudge in the microwave there are several factors to consider. First, each microwave has a different power/strength. Some get hotter more quickly while others are not as

20 20 powerful and thus take longer to heat items. The microwave in lab is quite old and may not be powerful enough to generate sufficient heat to dissolve the sugar to the desired temperature. Also you have to keep agitating the substance to make sure the product is heated through correctly because the outside is usually exposed to more heat than the inside. In addition, the group making the fudge was not able to get the cooking temperature above 95 C and the beating temperature was below the suggested 40 C. It was between 32 C and 35 C. As a result, the fudge was very runny and not very stable. Non-crystalline candies or amorphous candies, lack organized crystalline structures due to their very high concentration of interfering substances such as margarine. In addition it takes a very high temperature for amorphous candies to form as they have a higher sugar concentration than crystalline candies. However, one has to be careful while making these candies and make sure not to scorch the viscous substance. In the third table, Caramels, Peanut Brittle, & Lollipop Results, the lollipops that were made had a burnt taste because they were scorched. In addition, extreme high temperatures accelerate the chemical breakdown and caramelization of amorphous candies. Adding cream will contribute to the Maillard reaction and produce the browning of the sugar at the end stage of boiling (McWilliams, 2012). This could be seen in particular with the caramels. Using light cream and evaporated milk to make caramels yielded two different outcomes. With the light cream, caramels had a glossy appearance but had a very hard chew. With the evaporated milk, caramels were chunky looking with air bubbles and had a gritty, runny consistency. The reason for this difference is attributed to the percent of milk fat in the two products. Light cream on average has about 18-30% milk fat while evaporated milk is about 0.5-8% milk fat (Alden, 2005). The reduction in fat in the evaporated milk made for less interfering substances and thus a runnier and grittier consistency.

21 21 Peanut Brittle was the last amorphous candy that was tested. It is made by heating water, margarine, salt, sugar and corn syrup to a high temperature until it reaches a soft-ball stage. It s very malleable and flattens out of its own accord when picked up with fingers (Batten, 2014). Next peanuts are added and the candy is cooked further until the syrup turns light brown. Then the mixture is removed from the heat and baking soda is added, which causes a chemical reaction to occur, releasing CO 2, which causes air bubbles. While we were making the peanut brittle we constantly stirred. However, by constantly stirring it took longer for the mixture to heat and get to the softball stage. In the instructions it said to go to C, but we ended up having to go to 150 C to reach softball stage. The over agitation could have caused crystals to form. However, the end product still turned out brittle, crunchy and had a good flavor of salty and sweet. Reference: Batten, C. (2014). DFM 357 CHO: SUGARS [PowerPoint Slides]. Retrieved from McWilliams, M. (2012). Foods Experimental Perspectives (7 th ed.). Upper Saddle River, NJ: Prentice Hall. Srilakshmi, B. (2003). Food Science (3 rd ed.) pp Daryaganj, New Delhi: New Age International (P) Limited, Publishers. Alden, Lori (2005). The Cook s Thesaurus: Milk & Cream Retrieved October 31, 2014 from

22 22 DFM 357 Lab 3 Crystallization A. Fondant 250 g water 0.4 g cream of tartar or 400 g sugar 41 g light corn syrup General Directions: Before beating, rinse plate with cold water. Dry plate. Place thermometer with mercury column up on a plate (on wire rack), and tape thermometer in position. Pour candy on plate to cool. Leave undisturbed until desired temperature is reached (don t move or jar!!). Beat with a heavy spoon or heavy mixer. Procedure: Mix ingredients, stir, and heat to boiling point on high heat. Turn heat down to medium. Cook without stirring to temperature indicated in your variable. Wash crystals from sides of pan as they form, or cover pan a few minutes while cooking to dissolve them. Pour mixture onto a prepared plate as indicated under general directions. Cool to temperature indicated in your variable. When cooled appropriately, stir and work back and forth until mixture is white and creamy. Then knead until smooth. 1. Effect of temperature of beating Procedure: Prepare 1½ times recipe. Read general directions (use cream of tartar in place of corn syrup) Cook to soft ball stage: C (237 0 F). Divide cooked fondant between three plates: Variables: a. Beat immediately b. Cool to 70 o C (158 0 F); beat as indicated above c. Cool to 40 o C (104 0 F); beat as indicated above A. Fondant 250 g water 0.4 g cream of tartar or 400 g sugar 41 g light corn syrup General Directions: Before beating, rinse plate with cold water. Dry plate. Place thermometer with mercury column up on a plate (on wire rack), and tape thermometer in position. Pour candy on plate to cool. Leave undisturbed until desired temperature is reached (don t move or jar!!). Beat with a heavy spoon or heavy mixer. Procedure: Mix ingredients, stir, and heat to boiling point on high heat. Turn heat down to medium. Cook without stirring to temperature indicated in your variable. Wash crystals from sides of pan as they form, or cover pan a few minutes while cooking to dissolve them. Pour mixture onto a prepared plate as indicated under general directions. Cool to temperature indicated in your variable. When cooled appropriately, stir and work back and forth until mixture is white and creamy. Then knead until smooth. 2. Effect of addition of other sugars Procedure: Prepare ½ recipe Read general directions (use corn syrup in place of cream of tartar) Cook to soft ball stage: 114 o C (237 0 F). Cool to 40 o C (104 0 F) before beating Effect of cream in place of water

23 23 3. Cream Fondant 245 g half & half cream 400 g sugar 0.4 g cream of tartar Procedure: Read general directions. Mix ingredients and heat on medium heat, stirring constantly until mixture boils. Adjust heat so that it continues to boil but does not scorch. Wash crystals from side of pan. Cook to 114 o C (114 0 F). Pour onto plate and cool as indicated in general directions. Cool to 60 o C (140 0 F). Stir until creamy and knead until smooth. Fondant Results: Record cooking temperature, beating temperature, and beating time needed to crystallize. Rate on a 9-point hedonic scale Texture 9 = extremely white color and extremely smooth texture to 1 = extremely gray color and extremely course. Consistency 9 = extremely firm 5 = moldable 1 = extremely runny Variation Cooking Temp. o C Beating Temp. o C Beating Time Color Texture Consistency Flavor A. Fondant 1. Beating temp. a min b c min 30sec 3min 8sec egg shell wht Wht Pearl wht 2 dull 8 glossy, glisten 8 smooth, shinny Sweet Really Sweet Sweet Vanilla 2. Corn Syrup N/A N/A N/A N/A N/A 3. Cream Fondant min cream 8 - polished Conclusions: What are the functions of cream of tartar in a crystalline candy? The function of cream of tartar in crystalline candy is to create invert sugar. Cream of tartar is a weak acid which hydrolyses sucrose to form equal portions of glucose and fructose, which ultimately make a sweeter, smoother product. Why may cream of tartar be replaced with corn syrup? Cream of tartar can be replaced with corn syrup because corn syrup is mostly glucose, and acts as a buffer between sucrose molecules preventing them from joining together in 4 creamy butter

24 24 one giant mass and ruining crystalline structure. Also corn syrup has already been hydrolyzed to glucose and fructose. How does temperature of beating affect crystal nuclei formation? Temperature effect crystalline candies quite dramatically. By beating at a certain temperature it disrupts the crystals as they attempt to form. The viscosity at a certain temperature and agitation results in a finished product that is smooth and velvety. However, if crystallization occurs before the candy has reached super saturation, then beating must begin immediately until the candy solidifies. The agitation will disrupt the crystals and keep their size small to provide a texture that is pretty smooth when finished. It still may not be as smooth as when crystallization is avoided. What is the effect on crystal size of replacing water with cream? Why? Cream affects the crystal size by interfering with the formation of crystals. The fat will produce a smooth texture. Why is there a color difference in fondant made with cream of tartar vs. fondant made with corn syrup? We did not have Corn Syrup as a sample fondant, as a result of an error on the group making. However, the color difference would most likely be attributed to the translucency of the item used. For example, cream of tartar is a white powder giving an opaque white appearance, while corn syrup would make the product a little more clear and glossy. B. Fudge 70 g evaporated milk 1.5 g salt 225 g sugar 35.5 g baking chocolate (1 sq. = 28 g) 45 g water 19 g margarine 27 g light corn syrup 2.5 g vanilla extract Procedure: Mix sugar, milk, water, corn syrup, salt, and chocolate. Cook and stir over medium heat until sugar dissolves and chocolate melts. Cook to temperature indicated in experiment below. Add vanilla. Add margarine. Remove from heat. Cool as indicated in experiment below. Beat until candy is creamy and goes from glossy to dull. Pour quickly into oiled pans, making a ¾ to 1-inch layer. 1. Effect of temperature of cooking: Correlation of end point temperature and concentration Procedure: Prepare 1 ½ times recipe a. Pour out ½ recipe at 110 o C (230 0 F); cool to 40 o C (104 0 F); beat with heavy mixer b. Pour out ½ recipe at 113 o C (235 0 F); cool to 40 o C (104 0 F); beat with heavy mixer c. Cook ½ recipe at 118 o C (244 0 F); pour out; cool to 40 o C (104 0 F); beat with heavy mixer B. Fudge 70 g evaporated milk 1.5 g salt 225 g sugar 35.5 g baking chocolate (1 sq. = 28 g) 45 g water 19 g margarine 27 g light corn syrup 2.5 g vanilla extract

25 25 Procedure: Mix sugar, milk, water, corn syrup, salt, and chocolate. Cook and stir over medium heat until sugar dissolves and chocolate melts. Cook to temperature indicated in experiment below. Add vanilla. Add margarine. Remove from heat. Cool as indicated in experiment below. Beat until candy is creamy and goes from glossy to dull. Pour quickly into oiled pans, making a ¾ to 1-inch layer. 2. Effect of temperature of beating and speed of beating on crystal size Procedure: Prepare 1 ½ times recipe. Cook to 113 o C (235 0 F) Variables: a. Beat immediately on low speed b. Cool to 40 o C (104 0 F); beat on low speed c. Cool to 40 o C (104 0 F); beat on high speed 3. Microwave Fudge 200 g sugar 20.5 g light corn syrup 28.2 g cocoa 60 g margarine 78 g half & half cream 7.5 g vanilla extract Procedure: Variables: Lightly butter plate. Mix sugar and cocoa in 2 qt Pyrex bowl. Add half & half, corn syrup, and margarine. Cook for time specified below. Remove immediately. Add vanilla, place thermometer into bowl, and record temperature after 1 ½ min. Pour into mixing bowl of electric counter-top mixer. Beat on high speed until mixture goes from glossy to dull. Pour onto plate. Prepare one recipe for each variable a. Cook on high 3 minutes, then cook on medium 5 minutes b. Cook on high 3 minutes, then cook on medium either 4 ½ - 5 ½ minutes C. Divinity: 255 g sugar 1.5 g salt 61.5 g light corn syrup 6.2 g egg white 75 g water 2.5 g vanilla extract Effect of protein addition Procedures: Cook sugar, syrup, water, and salt to hard-ball stage (127 o C) (260 0 F). Using electric counter-top mixer, beat egg whites until stiff peak is reached. Pour slightly cooled sugar solution over egg whites while constantly beating on high speed. Beat until candy holds its shape. Add vanilla. Pour into oiled pans. Cut into squares when cold. Candy may be formed into irregular pieces by dropping it from tip of spoon onto wax paper. Fudge & Divinity Results: Record end point cooking temperature and beating temperature and time. Rate color from extremely dark to extremely light. Rate texture from extremely course to extremely fine. Rate consistency from extremely firm to extremely runny.

26 26 Variation Cooking Temp. o C Beating Temp. o C Beating Time Color Texture Consistency Flavor B. Fudge 1. Cooking temp. 2. Beating temp. & speed 3. Microwave C. Divinity a :46 brown smooth smooth b c :09 drk brown chalky :20 lt brown dry chalky Choc, pwdr sugar buttery, chalk nutty choc drk soft, supple, grainy choc brown light a b lt brown dry sticky choc c med smooth thick choc brown drk sweet, runny smooth a brown choc b :50 brwn smooth thick choc :03 wht grainy chalky to smooth sweet Conclusions: What functions do milk, cream, chocolate, and egg white serve in crystalline candies? Milk, cream, chocolate, and egg whites bring an element of fat to crystalline candies. It makes for a finer texture by interfering with crystallization and enhances flavor. How does temperature of beating affect crystalline nuclei formation? By cooling a mixture to about 40ºC it will favor the formation of more nuclei and finer crystals. The thickness of the solution is also great at lower temperatures. However, if too low of a temperature it may delay the formation of a lot of nuclei. Srilakshmi, B. (2003). Food Science (3 rd ed.) Daryaganj, New Delhi: New Age International (P) Limited, Publishers. Pg This is important because agitation keeps many small nuclei in the supersaturated solution and prevents it from attaching to already developed crystals. How are the colligative properties of solutions illustrated in these experiments? The colligative properties have to do with the concentration of sugar. Therefore, by increasing the concentration of sugar it required a higher boiling point for the water. How does cooking temperature affect sugar concentration? As temperature is increased, the candy will become harder due to the increased concentration of sugar. If the temperature is decreased and the water vapor evaporates more slowly, then you get a softer, more watery candy.

27 27 Why may microwave times be difficult to determine when making fudge? First off, each microwave has a different power/strength. Some get hotter quicker while others are not as powerful and thus take longer to heat items. The microwave in lab is quite old and may not be as powerful to generate enough heat to dissolve the sugar to the desired temperature. Also you have to keep agitating the substance to make sure the product is heated through correctly because the outside is usually exposed to more heat than the inside. A. Vanilla Caramels: Cook to end point temperature of 118 o C (144 0 F). 130 g sugar 14 g margarine 65 g brown sugar 1 g salt 54 g light corn syrup 5 g vanilla extract 149 g light cream Effect of fat and protein content of milk products on consistency: Procedure: Mix all ingredients except vanilla. Place on medium high heat initially and lower heat as cooking continues. Stir occasionally at beginning of cooking and constantly toward end of process. Cook to firm-ball stage (118 o C) (144 0 F). Add vanilla. Turn into oiled pan. Cool. This is a soft, rich, chewy caramel. A. Vanilla Caramels: Cook to end point temperature of 118 o C (144 0 F). 130 g sugar 14 g margarine 65 g brown sugar 1 g salt 54 g light corn syrup 5 g vanilla extract 149 g evaporated milk Effect of fat and protein content of milk products on consistency: Procedure: Mix all ingredients except vanilla. Place on medium high heat initially and lower heat as cooking continues. Stir occasionally at beginning of cooking and constantly toward end of process. Cook to firm-ball stage (118 o C) (144 0 F). Add vanilla. Turn into oiled pan. Cool. This is a soft, rich, chewy caramel. B. Peanut Brittle 200 g sugar 19 g margarine 113 g light corn syrup 190 g raw peanuts 75 g water 5 g vanilla extract 3 g salt 7 g baking soda Procedure: Cook sugar, syrup, water, salt, and margarine to soft-ball stage ( o C) (234 0 F F). Add peanuts. Continue cooking slowly until syrup is light brown and meets hard-crack test (152 o C) (306 0 F). Remove from heat. Add vanilla and soda. Mix ingredients well. Pour onto oiled baking sheet, spreading as thin as possible. When mixture is nearly cool, wet hands in cold water, and turn candy over, stretching to desired thinness. Break into pieces. C. Lollipops 65 g light corn syrup vegetable coloring 75 g water 5 g flavoring 100 g sugar Procedure: Cook sugar, syrup, and water to 155 o C (310 0 F). Stir only until sugar is dissolved. Remove any crystals that form on sides of pan. Cook slowly toward end process so syrup does not scorch. Cook

28 28 to extreme hard crack stage 155 o C (310 0 F). Remove from heat and add coloring and flavoring, stirring only enough to mix. Drop mixture from tip of a tablespoon onto a smooth, oiled surface, taking care to make drops round. Press a toothpick or skewer into edge of each before it hardens. Any decorations are pressed on at same time. Candies should be loosened from slab before they are quite cold to prevent cracking. Caramels, Peanut Brittle, & Lollipop Results: Variation A. Vanilla caramels Cooking Temp. (C ) Color Texture Consistency Flavor 1. Light cream 118 light brown glossy hard chew caramel 2. Evaporated milk 118 light brown chunky, air bubbles B. Peanut brittle 150 tan, light glossy, brown, smooth peanut outside with butter chunky inside C. Lollipop 152 amber smooth, glistens gritty, chewy crunchy, brittle light caramel salty, sweet viscous lemon w/ slight burnt taste Conclusions: Why do these candies not crystallize? Amorphous candies do not have organized structures and do not crystallize due to the interfering substances used such as margarine. Also it takes a higher heat for amorphous candies to form. Why do light cream and evaporated milk cause differing consistencies in caramel? Light cream has more milk fat while evaporated milk has less fat which will change the interfering substances in the amorphous candies. Aeration of peanut brittle mixture is obtained by what process? After removing the sugar mixture from the heat, we added the baking soda to it. This caused a chemical reaction to occur and CO 2 was released causing air bubbles in the mixture. What does the boiling temperature tell you about concentration of these sugar solutions? A very high temperature is needed in order for amorphous candies to form as they have a higher sugar concentration than crystalline candies.

29 29 Lab #4: Thickening Agents Date: September 26, 2014 Conditions: Warm Purpose: The purpose of the lab was to prepare and observe the results of a variety of starch-based agents in food products after being cooked and after being frozen-thawed. Experimental Procedures: The instructions were given for Lab #4 by instructor Maryann Smitt and were listed in Comparative Thickening Power of Thickening Agents section listed below. Students made an assortment of thickening agents using collectively 11 different flours/starches. Results: For data and results, please refer to Lab 4 Thickening Agents Evaluation Sheet 1a through 11c attached. Discussion: Starch is made up of two granules, amylose and amylopectin. Amylose is a linear, coiled chain of glucose molecules that are slightly soluble (McWilliams, 2012). This structure allows for good gel formations. Amylopectin is a branched, sticky, transparent substance that does not form gels well, if at all, but is good for sauces (Batten, 2014). Some examples of sources of amylopectin are tubers and waxy rice. The process of gelatinization is when a starch granule is heated causing the hydrogen bonds to break and allowing water to enter and swell the granule (McWilliams, 2012). Pasting is

30 30 achieved when change takes place in starch granules due to continued heating after gelatinization has taken place (McWilliams, 2012). Per Christine Batten s lecture on Starch, you do not want to over stir the starch granules because this could also lead to pasting. Starches with greater amounts of amylose present will gelatinize quicker and have better pasting ability. Amylopectin is usually found in higher proportion in starches, but the starches that contain 17-30% amylose make better gels (Batten, 2014). Sources of starch containing higher amylose are corn, wheat, and rice, which are all cereal grains. The data collected and presented in Thickening and Evaluation Sheet showed that on average soy flour, sweet rice flour, oat flour, buck wheat flour and semolina flour produced the most consistent products after being cooked. The addition of sugar to starch delays gelatinization by competing for water, thus preventing bonding. It also must be cooked at higher temperature and for a longer period of time for gelatinization to occur. Sugar affects gelatinization by increasing translucency and decreasing the viscosity and strength of the gel (Batten, 2014). According to McWillams (2012), root starches see the greatest increase in translucency during gelatinization. In the lab evaluation sheet, 4a-4c, tapioca was observed to be the most translucent. However, it was hard to have consistent rating results. It would have been helpful to have a gauge or example of what was considered transparent and what was considered opaque. This left a lot of room for subjectivity and interpretation of what could be considered transparent. With methodological bias aside, the flour/starch that had more sugar added should have yielded a more transparent result. Heating water and starch is important to swell the granules, but it is also allows for hydrogen bonds within the granules to break and release some amylose into the surrounding water (McWilliams 2012). Gel strength is optimal when starch paste has been heated until