EPSA Science! Monthly: The science of Cooking by EPSA

The Science of Cooking May Edition 2022

Introduction Dear readers, Ready for this delicious dish (read: edition) where you are served only the best knowledge on the Science of Cooking? Our entrée will be about artificial sweeteners and their advantages and disadvantages. Next, our main course is quality information on food thickeners, how they work, and the various sorts of food thickeners. Finished so soon? Don’t forget our dessert! For this month it will be on the science of ice creams. Still not satisfactory filled and water toothing? Don’t worry and enjoy our diverse multicultural menu as we have included recipes for you to try out. We recommend the Authentic Greek Moussaka, the Romanian Tripe (Pork belly) Soup (Ciorbă de burtă), the Slovak Halušky with bryndza (Potato dumplings with sheep cheese), and the sweet and soft marshmallows. Enjoy reading!

Yong Xin Cao Science Coordinator 2021/2022

EPSA – European Pharmaceutical Students’ Association

Artificial sweeteners - the way of losing weight or losing health? Do you know what an artificial sweetener is? Artificial sweeteners (in abbreviation: AS) are substances of synthetic origin, classified as food additives, intended to provide a "sweet alternative" to sucrose. They are also called: „non-nutritive sweeteners” (NNS). They differ from the sucrose in that they are many times sweeter and contain fewer calories. Products containing artificial sweeteners may be sold with a "healthy" or "diet" label; however, there is much controversy regarding their safety and adverse health effects1. The group of six artificial sweeteners approved by the FDA (Food and Drug Administration, USA) as food additives include acesulfamepotassium (acesulfame-K), aspartame, neotame, saccharin, sucralose, and advantame2. Key information on selected artificial sweeteners Acesulfame-K is about 200 times sweeter than sucrose. The acceptable daily intake (ADI, the maximal amount of NNS considered to be safe for human consumption) designated by the FDA is 15 mg/kg body weight/day3. Acesulfame-K has high water solubility and heat stability, so it can be used in baking and cooking. When used alone, it may cause a bitter taste; therefore, it is mainly used in combination with other sweeteners to mask this flavour. This artificial sweetener is suitable for low calorie and diabetic beverages, jams and marmalade, confectionary items, sugarless chewing gums, reduced-calorie baked goods, fruit flavoured dairy products, oral hygiene products, pharmaceuticals, or tobacco products4. Aspartame is a sugar substitute whose sweetness is comparable to acesulfame-K and ADI is 50 mg/kg body weight/day3. It is quite sparingly soluble in water (better in hot water)4 and unstable on prolonged heating; therefore, it cannot be used for cooking3. Aspartame can be used in dry products including cold breakfast cereals, chewing gum, dry beverage mixes, instant tea and coffee, gelatines, puddings, fillings, and tabletop sweeteners4. Sucralose is a substance 300 times sweeter than sugar with ADI=5 mg/kg body weight/day3. It is used in a wide range of products around the world due to its intense sweetness and other physicochemical properties such as high-water solubility and stability over a wide pH and temperature range5. In turn, saccharin is a sweetener with twice as much sweetness as sucralose. The ADI value for saccharin is 5 mg/kg body weight/day3. It has a slightly bitter after flavour4 and it is used in products like carbonated and noncarbonated beverages, dairy products, tabletop sweeteners, juice, jams, chewing gum, confections, desserts, puddings and jellies3. Neotame is a derivative of aspartame approximately 40 times sweeter than it. The ADI value is estimated at 2 mg/kg body weight/day Neotame is slightly soluble in water3. It does not provide kilojoules and is thermally stable during cooking and baking. Neotame has a pure, sweet taste like sucrose and unique flavour enhancing properties4. It serves EPSA – European Pharmaceutical Students’ Association

as a sweetener in drinks, baked goods, gelatine, chewing gums, jams, jellies and many other foods as a flavour enhancer3. Figure 1: Chemical structure of advantame The record holder in the field of sweetness is another derivative of aspartame - advantame. This sweetener is approximately 37,000 times sweeter than sucrose. ADI was set to 5 mg/kg body weight/day. It is a high-intensity sweetener with a flavour similar to that of aspartame. It does not have a bitter or sour aftertaste. Advantame is stable at low pH and high temperature. It has been proven to be an excellent sweetener in iced tea, coffee and powdered drinks recipes. It is used to enhance the flavour of beverages, chewing gum and yoghurt3. Benefits of using artificial sweeteners (see infographic) The use of artificial sweeteners can have some benefits. The first is the enhancement of the flavour of the dishes, which can help people with an appetite deficiency eat their meals. People predisposed to the occurrence of tooth decay will also find their allies in AS. Consuming artificial sweeteners does not increase the risk of caries, unlike sucrose, because they are not a breeding ground for bacteria. In addition, NNS reduces the incidence of episodes of reactive hypoglycemia, which consist of excessive insulin release in response to a meal. Consumption of AS could also be beneficial in cases of diabetes mellitus or in reducing and controlling weight, but in both cases, the potential benefits may not outweigh the risks, as will be discussed in the next section1. Limitations and potential risks associated with the use of artificial sweeteners (see infographic) It is worth bearing in mind some limitations in the use of non-nutritive sweeteners. They include an unpleasant taste in the mouth after eating some sweeteners4, no nutritional value, may not manage the craving for sweets and inability to boost metabolic response after high-calorie intake1. In addition, one limitation is avoiding artificial sweeteners during pregnancy. A systematic review showed that daily consumption of artificially sweetened soft drinks by pregnant women can increase the likelihood of prematurity and the consumption of artificially sweetened drinks by pregnant women may be associated with the diagnosis of asthma in their children up to the age of 7 years6. The potential risks associated with AS include the risk of osteoporosis, which is associated with the presence of phosphoric acid in sweeteners1. Phosphoric acid interferes with calcium absorption and contributes to an imbalance that leads to additional loss of calcium from the bones7. One of the possible side effects of artificial sweeteners is neurological and behavioural disturbances, such as hypersensitivity reactions and impaired learning abilities5. Chronic consumption of AS may be associated with an increased risk of weight gain and other metabolic dysfunctions, such as hyperglycaemia and hyperlipidaemia, through some default mechanisms, including increasing intestinal glucose absorption by activating sweet taste receptors (T1R)2 in the EPSA – European Pharmaceutical Students’ Association

gut, compensatory energy intake by reducing the ability to predict food content, increasing insulin secretion and obesity, and changes in the gut microbiota5,8. Moreover, AS can exacerbate, not stop, metabolic disorders such as type 2 diabetes. However, more research is required1,9. There is also a hypothesis that the long term use of artificial sweeteners may induce a carcinogenic effect through some mechanisms like increasing oxidative stress and nucleic acid oxidation5, but so far there is no sufficient evidence to show whether the use of artificial sweeteners increases or decreases the risk of cancer10,11. The infographic shows groups of people who may gain or lose their health from using artificial sweeteners1. Safety first and foremost As you can see, artificial sweeteners have their ups and downs. To use them safely, it is worth following these seven commandments proposed by ul-Ain and Khan (2015): 1. Discuss AS use with your physician 2. Use an FDA/EFSA (European Food Safety Authority) approved AS 3. Use AS in moderate amount 4. Prefer natural sweeteners, wherever possible 5. Limit the use of AS in pregnancy and lactation 6. Limit the use of AS in children 7. Remember AS may lead to weight gain1.

Author: Daria Frisch, Nicolaus Copernicus University in Toruń, Poland; this year’s graduate of Pharmacy, PPSA Poland

EPSA – European Pharmaceutical Students’ Association

Hydrocolloids in food thickening. Culinary foams Thickening is the process of increasing viscosity. There are different ways to improve food thickness. Among them, the most recent one is adding food thickeners. Food thickeners are compounds used to modify the rheological properties of food at low concentrations, therefore, changethe texture, structure, and appearance of food, maintaining other properties1. Hydrocolloids are the most widely used food thickeners. In addition to that, they can function as stabilisers, emulsifiers, and gelling agents1. Chemically, hydrocolloids are long-chain polymers, either polysaccharides or proteins. They are very good at forming viscous dispersions in water. The name “hydrocolloids” is derived from two properties of these polymers 1. Having a big affinity for water because they have ubiquitous hydroxyl groups; 2. Dispersions formed from these polymers have colloid properties. Colloids are two-phase systems, where the particles of the dispersed phase are large enough not to form a solution and small enough not to settle down like in suspensions, they are typically smaller than 1 µm2. In an aqueous medium, hydrocolloids swell and gain larger hydrodynamic volumes. Which leads to the increased viscosity of the system3. One of the biggest advantages of these substances is that only a small concentration can achieve high viscosity. Polymers with higher molecular weight, charge density, rigidity, and the ones that are less branched confer higher viscosity at lower concentrations3. Starch is an example of a food thickener that gains its properties from the unbranched polymer. It’s composed of amylose and amylopectin, where the first is not branched while the second is a branched polymer. Starch extracted from root plants such as potatoes, despite containing more amylopectin than amylose, still provides good thickening properties to gravies and broths. In addition, starch is a cheap and affordable additive, which makes it the most used hydrocolloid thickener2,4. Agar is composed of agarose and agaropectin. Its gelation property is thanks to agarose. Agarose has applications in the vegetarian food universe as it’s considered an excellent alternative to gelatine. It gives a better texture when added to cheese and frozen desserts. It’s also a good additive in retarding bread staling4. Furthermore, there are many other hydrocolloids with wide applications in the food industry. They can be extracted from different sources and used in many domains of the food industry, such as the production of sauces, creams, toppings, and salad dressing. Owing to their abilities to modify food texture, they have an essential role in controlling swallowing difficulties (dysphagia), making swallowing a safer process5. Some examples of thickeners are described below. EPSA – European Pharmaceutical Students’ Association

Figure 2: Xhemixal formula of Xanthan gum.

Xanthan gum Xanthan gum (XG) is an extracellular polysaccharide produced by the bacterium Xanthomonas campestris. Its chemical structure is composed of a β1,4-glycosidic bond as the main chain and a trisaccharide sidechain consecutively containing mannose, glucuronic acid, and mannose (figure 1). It is used at very low concentrations, sometimes in the order of 1% or less, to produce very thick solutions, modifying the rheological properties of fluids1. These properties offer a broad spectrum of applications in the food industry namely in bakeries. A study showed that adding up to 1% of XG increased the softness and volume of bread loaves, giving them more stability. This could be attributed to increased dough viscosity and thereby further stabilisation of gluten-starch interactions during baking6. In addition to the bakery, this gum has remarkable importance in preparing salad dressings and sauces, and in the stabilisation of emulsions and suspensions.

Figure 3: Salad dressing

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For example, it’s added to food dressings. Salad Dressings are O/W emulsions that incorporate vinegar, sugar, emulsifying agent, and flavours. Adding only 0.25% of this gum provides stability for up to one year. Moreover, XG has pseudoplastic rheological properties, which makes it an excellent option in the dressings industry, as bottles can be filled easily, and it flows smoothly from it during use7 (figure 2) XG is also very important in the beverages industry. It is considered an effective suspensive agent for fruit pulps. Its contribution is also evident in sugar-free drinks, where the absence of sugar’s rheological effect decreases viscosity and gives rise to thin consistency. Adding XG helps in retaining consistency in such beverages8. XG has also very interesting uses in improving flavour perception. When XG is added to liquid food, like low calorie soups, the good flavour is released while the food thins in the mouth7. Figure 4: Soft drink

Carrageenan (CRG) Carrageenan (CRG) is extracted from red seaweeds. It’s a linear, negatively charged, sulfated galactan polysaccharide with differing degrees of sulfation (figure 3)9. It has many applications in different domains of food preparation, like in the preparation of ice cream where it functions as a stabiliser. In milk-based drinks it is an important stabiliser, it also provides a mouthfeel. In the case of chocolate milk, the negative charges of CRG interact with the positively charged casein proteins in milk to form a weak gel network that traps cocoa particles. Owing to the variable texture properties of iota, kappa and lambda (Figure 4), CRG is considered a very versatile texture agent. It is used as a texture modifier in desserts. Figure 5: Molecular structural comparison for three carrageenan categories

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Culinary foams10 Foams are aerated systems, composed of gas bubbles as the dispersed phase and a liquid as the continuous phase. They are important in increasing food volume and modifying its texture. Its effect is felt when we have an ice cream, as the embedded air bubbles give a special mouthfeel. There are many other food foams, such as angel food cake, yeast-leavened bread, and marshmallow which is well known for their aerated structure. Figure 6: Marshmallows There are two necessary conditions in the production of culinary foams. Firstly, an energy supplement such as whipping and secondly, a foaming agent to reduce the surface tension by forming a film around the bubbles. The most used foaming agent is proteins, and on the top of the list, we have egg white proteins which are incorporated in many desserts. Milk and gelatine are also good foaming agents. There are three steps to produce foam using proteins: 1. Diffusion of the soluble protein to the air/water interface, where it concentrates and reduces surface tension; 2. Upon whipping, proteins unfold at the interface. The hydrophilic part is directed toward the water and the hydrophobic towards the gaseous phase; 3. Polypeptides interact to form a film on the interface around bubbles.

Author: Rahaf Alsayyed, University of Algarve, fifth year pharmaceutical scientist student, APEF Portugal EPSA – European Pharmaceutical Students’ Association

EPSA – European Pharmaceutical Students’ Association

Ice cream – What are we eating on a molecular level? Warmer days are coming, and you may have already been desiring the sweetness and cool feeling of ice creams. But have you ever thought of how ice cream is made and what it contains? To answer this, we will have to take a look at its chemistry. Chemical background of ice creams Ice creams are emulsions of water and fat as liquid fat particles – also known as fat globules – dispersed throughout the water/ice crystal phase. The structure of ice cream contains pores, typically measured as one-tenth of a millimetre. As there is air present, ice creams can be considered foams as well. Foams in chemistry are defined as a colloidal system in which gas bubbles, usually air, are dispersed in the liquid medium1. Figure 7: Structure of ice creme

A rough distribution of the composition can be described as the following: ice cream consists of 30% ice crystals, 50% air bubbles, 5% fat droplets and 15% liquid syrup2. Water becomes ice crystals during the freezing process. For smooth ice cream, smaller crystals are needed. While ice cream freezes, beating and aeration occur at the same moment. Consequently, air bubbles are formed, which are stabilised by de-emulsified fat. Ice creams tend to have a better quality when there is less air, and a higher density. Higher air content is related to more rapid melting1,2. Liquid sugar, such as sucrose and vanillin, give ice cream its sweetness, and lowers the freezing point of water, in turn, reducing the amount of ice. Sugar also affects the hardness of the ice cream. Ice creams are softer when they contain less ice1. As ice creams are emulsions, you would expect the fat and water phase to separate after a certain period due to coalescence. In ice creams fat droplets coated with milk proteins prevent fat droplets from interacting with one another, thereby preventing the separation of the water and fat phase. Those milk proteins work as an emulsifier, however as they contain nonpolar groups that attract nonpolar fat particles, the fat droplets cannot trap air effectively. Another emulsifier (e.g., lecithin) has to be added to replace some milk proteins on the surface of a fat particle, in order to trap the air more efficiently1,2. EPSA – European Pharmaceutical Students’ Association

Lastly ice cream contains stabilisers as well, which affects the viscosity of the liquid. These stabilisers are water-soluble molecules, such as sodium alginate and carrageenan. They reduce the melting rate and give a smoother texture to the ice cream2. Too much sugar in ice creams? Ice creams contain sugars from milk such as lactose and additional sugars, as milk sugar is not sufficiently sweet. Usually, sucrose or glucose are added to sweeten the ice cream. As cold often tends to desensitise the taste buds, more sugar needs to be added to the ice cream to produce the desired sweet taste. When ice cream is melted at room temperature, you may taste an overly sweet liquid ice cream1.

Why do ice creams lead to brain freeze? Brain freeze is a phenomenon often associated with ice creams. It is a brief intense pain in the front part of the head which is caused by the intake of cold food or drinks, such as ice creams. The scientific term for brain freeze is sphenopalatine ganglioneuralgia3. The exact mechanism is unknown. It is hypothesised that when cold substances come into contact with the palate or posterior pharyngeal wall, it triggers rapid constriction and dilation of blood vessels with activation of nociceptors of the vessel walls. Changes to cerebral blood flow appear to occur in cold stimulus headaches. Reduced mean cerebral blood flow velocity has been reported in patients with cold stimulus headaches (CSH) and was rather not seen in those without CSH4. To treat the brain freeze, the temperature of the mouth and throat should get back to a normal temperature. Hence, people should stop eating or drinking cold food or beverages and drink a room-temperature liquid. Another method is to press the tongue against the roof of the mouth to transfer warmth to the tongue3.

Yong Xin Cao Science Coordinator 2021/2022

EPSA – European Pharmaceutical Students’ Association

References Infographic: The use of artificial sweeteners [1] ul-Ain, Q., & Khan, S. A., (2015). Artificial sweeteners: safe or unsafe?. Journal of Pakistan Medical Association, 65(2), 225-227. The infographic was created by using Canva. Article: Artificial sweeteners - the way of losing weight or losing health? [1] ul-Ain, Q., & Khan, S. A., (2015). Artificial sweeteners: safe or unsafe?. Journal of Pakistan Medical Association, 65(2), 225-227. [2] U.S. Food & Drug Administration. How Sweet It Is: All About Sugar Substitutes. [Online]. Available from: https://www.fda.gov/consumers/consumer-updates/howsweet-it-all-about-sugar-substitutes. [Accessed at: April 11, 2022]. [3] More, T.A., et al., (2021). Artificial Sweeteners and their Health Implications: A Review. Biosciences Biotechnology Research Asia, 18(2), 227-237. doi: 10.13005/bbra/2910. [4] Nishal, S., (2015). A review on artificial sweeteners. World Journal of Pharmaceutical Research, 4(6), 776-792. [5] Ebrahimzadeh, V., et al., (2018). A review of the health hazards of artificial sweeteners: are they safe?. Progress in Nutrition, 20, 36-43. doi: 10.23751/pn.v20i2-S.5901. [6] Bernardo, W.M., et al., (2016). Adverse effects of the consumption of artificial sweeteners – systematic review. Revista da Associacao Medica Brasileira, 62(2), 120-122. doi: 10.1590/1806-9282.62.02.120. [7] Tucker, K.L., et al., (2006). Colas, but not other carbonated beverages, are associated with low bone mineral density in older women: The Framingham Osteoporosis Study. The American Journal of Clinical Nutrition, 84(4), 936-942. doi: 10.1093/ajcn/84.4.936. [8] Belloir, C., et al., (2017). Sweeteners and sweetness enhancers. Current Opinion in Clinical Nutrition and Metabolic Care, 20(4), 279-285. doi: 10.1097/MCO.0000000000000377. [9] Sanyaolu, A., et al., (2018). Artificial sweeteners and their association with Diabetes: A review. Journal of Public Health and Nutrition, 1(4), 86-88. [10] Liu, L., et al., (2021). The relationship between the use of artificial sweeteners and cancer: A meta-analysis of case–control studies. Food Science & Nutrition, 9, 4589– 4597. doi: 10.1002/fsn3.2395. EPSA – European Pharmaceutical Students’ Association

[11] Mishra, A., et al., (2015). Systematic review of the relationship between artificial sweetener consumption and cancer in humans: analysis of 599,741 participants. The International Journal of Clinical Practice, 69(12), 1418–1426. doi: 10.1111/ijcp.12703. Images: Figure 1: https://commons.wikimedia.org/wiki/File:Advantame.svg Infographic: Types of Food Thickeners [1] Science of Cooking. Food Thickening Agents. [Online]. Available from: https://www.scienceofcooking.com/food-thickening-agents.html. [Accessed at: 18 April 2022]. The infographic was created by using Canva. Article: Hydrocolloids in food thickening. Culinary foams [1] Himashree, P., Sengar, A. S., & Sunil, C. K. (2022). Food thickening agents: Sources, chemistry, properties and applications - A review. International Journal of Gastronomy and Food Science, 27. https://doi.org/10.1016/j.ijgfs.2022.100468. [2] Kralchevsky PA, Danov KD, Denkov ND. Handbook of Surface and Colloid Chemistry. Taylor & Francis Group, LLC; 2009. [3] O’Sullivan, J. J., & O’Mahony, J. A. (2016). Food Ingredients. Reference Module in Food Science. https://doi.org/10.1016/b978-0-08-100596-5.03407-7 [4] Zeece, M. (2020). Food additives. In Introduction to the Chemistry of Food (pp. 251– 311). Elsevier. https://doi.org/10.1016/B978-0-12-809434-1.00007-4 [5] O. S. Schmidt, H., Komeroski, M. R., Steemburgo, T., & de Oliveira, V. R. (2021). Influence of thickening agents on rheological properties and sensory attributes of dysphagic diet. Journal of Texture Studies, 52(5–6), 587–602. https://doi.org/10.1111/JTXS.12596 [6] Shittu, T. A., Aminu, R. A., & Abulude, E. O. (2009). Functional effects of xanthan gum on composite cassava-wheat dough and bread. Food Hydrocolloids, 23(8), 2254–2260. https://doi.org/10.1016/J.FOODHYD.2009.05.016 [7] Kang, K. S., & Pettitt, D. J. (2012). Xanthan, Gellan, Welan, and Rhamsan. In R. ; N. B. J. L.Whistler (Ed.), Industrial Gums: Polysacharides and Their Derivatives (3rd ed., pp. 341–397). Academic Press, INC. https://doi.org/10.1016/B978-0-08-092654-4.500176. [8] Katzbauer, B. (1998). Properties ans applocations of xanthan gum. Polymer Degradation and Stability, 59, 81–84. EPSA – European Pharmaceutical Students’ Association

[9] Saha, D., & Bhattacharya, S. (2010). Hydrocolloids as thickening and gelling agents in food: a critical review. Journal of Food Science and Technology 2010 47:6, 47(6), 587– 597. https://doi.org/10.1007/S13197-010-0162-6 [10] Zayas, Joseph. F. (1997). Foaming Properties of Proteins. In Functionality of Proteins in Food (1st ed., pp. 260–309). Springer. https://doi.org/https://doi.org/10.1007/978-3642-59116-7 Images: • Figure 1: https://www.sciencedirect.com/science/article/pii/S0734975000000501?casa_t oken=y7wAvXHxu4EAAAAA:_DKm9v71OrHjui6gFyCrZm_65exkqpYqvw5Sxl8l7Xuma0Q3vK_Y1WnA_vWdmmfCSI1q2uwWE#FIG1 • Figure 2: https://www.freepik.com/free-photo/salad-with-chicken-chunksserved-platecloseup_25469078.htm#query=salad%20dressing&position=27&from_view=sea rch • Figure 3: https://www.gerbes.com/p/7up-cherry-soda/0007800001182 • Figure 4: https://pubs.rsc.org/en/content/chapterhtml/2019/bk978178801216400001?isbn=978-1-78801-216-4#fig5 • Figure 5: https://www.freepik.com/free-photo/top-view-colorful-marshmallowscattered-from-glass-jarrustic_8446585.htm#query=marshmallows&from_query=marshmellows&positio n=8&from_view=search#position=8&query=marshmallows Infographic: Types of food thickeners • • •

https://malaysia.exportersindia.com/z-methoda-enterprise/food-grade-xanthangum-4252291.htm https://www.carlroth.com/com/en/agar/agar-agar-kobe-i/p/5210.1 https://www.pngaaa.com/detail/2417632

The infographic was created by using Canva. Infographic: Ice cream [1] Healthline. Gelato vs. Ice Cream: What’s the Difference? [Online]. Available from: https://www.healthline.com/nutrition/gelato-vs-ice-cream. [Accessed at: 19 April 2022].

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Article: Ice cream – What are we eating on a molecular level? [1] ACS. Ice, Cream... and Chemistry. [Online]. Available from: https://www.acs.org/content/acs/en/education/resources/highschool/chemmatters/pa st-issues/archive-2013-2014/ice-cream-chemistry.html. [Accessed at: 20 April 2022]. [2] Compound Chem. The Chemistry of Ice Cream – Components, Structure, & Flavour. [Online]. Available from: https://www.compoundchem.com/2015/07/14/icecream/. [Accessed at: 20 April 2022]. [3] Cleveland Clinic. Brain Freeze. [Online]. Available from: https://my.clevelandclinic.org/health/diseases/21478-brain-freeze. [Accessed at: 20 April 2022]. [4] Chebini, A., Dilli, E. Cold Stimulus Headache. Curr Neurol Neurosci Rep 19, 46 (2019). https://doi.org/10.1007/s11910-019-0956-5 Front page image: https://unsplash.com/photos/kImU-9S9uh8 by Red Long.

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