In first or second century BC, a variety of rice cake was developed in Korea, leading to the potential migration of the idea to Japan.[1] Rumor has it that mochi’s roots lie in China, although its exact origin has yet to be confirmed.[2] Nevertheless, mochi, its tradition, as well as its protocol (mochitsuki) are exclusive to the Japanese culture.[1]
The first mochitsuki ceremony occurred after the Kami descended to Earth, which was following the birth of rice cultivation in Yamato during the Yayoi period (300BC-300AD). Red rice was the original variation used in the production of mochi. At this time, mochi was eaten exclusively by the Emperor and nobles due to its status as an omen of good fortune. During the Japanese Heian period (794-1192), mochi was used as a ‘Food for the Gods’ and religious offerings in Shinto rituals performed by aristocrats. In addition to good fortune, mochi was also known as a talisman for happy marriages. Following the formalization of a marriage, the couple would find pieces of mochi behind their headrests.[1]
The first recorded accounts of mochi being used as a part of the New Year’s festivities was from the Japanese Heian period (794-1185). The nobles of the Imperial Court believed that long strands of freshly made mochi symbolized a long life and good well-being, while dried mochi acted to make one’s teeth tough and more durable. Accounts of mochi have also been read in the oldest Japanese novel, “The Tale of Genji.”[3]
Mochi continues to be one of the traditional foods eaten around Japanese New Year, as it is sold and consumed in abundance around this time. A special type of mochi, called kagami mochi (mirror mochi) is placed on family altars on December 28 each year. Kagami mochi is composed of two spheres of mochi stacked on top of one another, top with an orange ("daidai").[2] At the end of Japanese New Year, the people of Japan celebrated Kagami Biraki (mirror opening ceremony) on the second Sunday of January.[1] On this occasion, which was originally practiced by samurais, the round rice cakes of kagami mochi would be broken and thus, symbolizing the mirror’s opening and the ending of the New Year’s celebrations.[4]
Mochi became widely available to the masses in Japan’s Edo period (1603-1868).[1] Following this, the Japanese began to make new variations of mochi[1] (see 'Popular uses') while the creation of new technology allowed for the mass production of mochi worldwide (see 'Mass Production').
The traditional raw material for mochi is glutinous or mochi rice. Glutinous rice is washed and soaked with water overnight to increase stickiness. Mass production includes specialty rice, glutinous and waxy, which is bred for certain qualities such as viscoelasticity, compressibility and ease of cutting without sacrificing the desired soft, chewy texture of mochi.[5]
Here, steamed rice in a stone mortar is mashed with a wooden kine during Mochitsuki.
Traditionally, mochi was made from whole rice, in a labor-intensive process. The traditional mochi-pounding ceremony in Japan is Mochitsuki:
Polished glutinous rice is soaked overnight and steamed.
The steamed rice is mashed and pounded with wooden mallets (kine) in a traditional mortar (usu)[6] . Two people will alternate the work, one pounding and the other turning and wetting [7] the mochi.[8]. They must keep a steady rhythm or they may accidentally injure one another with the heavy kine.
The sticky mass can be eaten immediately or formed into various shapes (usually a sphere or cube)[9].
Mochi can also be prepared from a flour of sweet rice (mochiko). The flour is mixed with water to a sticky opaque white mass that is cooked on the stovetop or in the microwave[10] twice and stirred in between[11] until it becomes elastic and slightly transparent.[12]
Cooked rice is automatically pounded in a modern household machine.
With modern equipment, mochi can be made at home with without the labour of traditional production. The modern equipment, seen on the right, can replace the laborious dough pounding[11]. Household mochi appliances provide a suitable space where the environment of the dough can be controlled.
Assembly line settings in mochi production controls the following aspect of mochi:
Viscoelasticity or the products' chewiness by selecting specific species of rice
Consistency of the dough during automated pounding process
Size
Flavourings and fillings
Making mochi with some modern equipment
Varieties of glutinous and waxy of rice is produced as a major raw material for mochi. The rice is chosen according to their tensile strength and compressibility.[13] One study found that in Kantomochi rice 172 and BC3, amylopectin distribution varied and reflected the hardness of mochi. Kantomochi rice produced harder, brittle, grainy textures, all undesirable qualities except for its ease of cutting.[13] For mass production, the rice variety should be chewy but easy to separate.
There are generally two types of machines for mochi production in an assembly line. One machine prepares the dough while the other forms the dough into consistent shapes, unfilled or with filling. The first type of machine controls the temperature at which the rice gelatinizes. One study found that a temperature of 62ºC corresponds to the gelatinization of mochi. When the temperature fell below 62ºC the hardening speed was too slow.[14] It was concluded that a processing temperature below 62ºC was unsuitable for dough preparation.[14]
Chemistry and Structural Composition of Glutinous Rice
Amylose and amylopectin are both components of starch and they are both polysaccharides made from D-glucose units. The big difference amongst the two is that amylose is linear because it only has αlpha-1,4-glycosidic bonds. Amylopectin on the other hand, is a branched polysaccharide because it has αlpha-1,4-glycosidic bonds but with occasional αlpha-1,6-glycosidic bonds [15] approximately every 22 D-glucose units [16]. Glutinous rice is nearly 100% [17] composed of amylopectin (one of the two components that makes up starch) and almost completely lacks its counterpart, amylose, in its starch granules. A non-glutinous rice grain contains amylose at about 10-30% weight by weight and amylopectin at about 70-90% weight by weight. [18] For example, “potato starch, banana, barley, oat and wheat have 20%, 16%, 22%, 27% and 26% of amylose respectively.” [19] Glutinous or waxy type of starches happen to occur in maize, sorghum, wheat, and of course, rice. An interesting characteristic of glutinous rice is that it stains red when iodine is added whereas non-glutinous rice stains blue.[17] This phenomena occurs when iodine is mixed with iodide to form tri-iodide and penta-iodide. Penta-iodide intercalates between the starch molecules and stains amylose and amylopectin blue and red respectively.[20] The gelation and viscous texture of glutinous rice is due to amylopectin being more hygroscopic [21] than amylose, so it has a higher affinity for water. Thus, water will enter the starch granule causing it to swell, while the amylose leaves the starch granule [22] and becomes part of a colloidal solution.[23] In other words, the higher the amylopectin content, the higher the swelling of the starch granule. [24] Even though the amylopectin content plays a major role in the defined characteristic of viscosity in glutinous rice, factors such as heat also play a very important role in the swelling since it enhances the uptake of water into the starch granule significantly. It is estimated that the swelling increases at about 10% in volume per 10ºC temperature increase. [25]
The structure of amylose with alpha 1-4 glycosidic bonds.The structure of amylopectin with alpha 1-4 and alpha 1-6 glycosidic bonds.
The high amylopectin content of waxy or glutinous starches is genetically controlled by the waxy or wax gene. Its quality of greater viscosity and gelation is dependent on the distribution of the amylopectin unit chains. [15] Grains that have this gene are considered mutants which explains why most of them are selectively bread to create a grain that is close to having or has a 0% amylose content. [17] The table below summarizes the amylose and amylopectin content of different starches, waxy and non-waxy:
Table 1. Proportion of Amylose and Amylopectin in various Starch Sources[26]
Starch
Amylose %
Amylopectin %
Potato
20
80
Sweet Potato
18
82
Arrowroot
21
79
Tapioca
17
83
Corn (maize)
28
72
Waxy maize
0
100
wheat
26
74
Rice (long grain)
22
78
The soaking of the glutinous rice is an elemental step in the preparation of mochi, either traditionally or industrially. During this process, glutinous rice decreases in protein content as it is soaked in water. The chemicals that make up the flavour of plain or "natural" mochi are ethyl ester acetic acid, ethanol, 2-butanol, 2 methyl 1-propanol, 1-butanol, 3-methyl 1 butanol, 1-pentanol and propane acid. [27]
The ingredient list of mochi is usually composed only of glutinous rice, however, some variations of mochi may include the additions of salt, spices and flavourings such as cinnamon (cinnamaldehyde).[28] Food additives such as sucrose, sorbitol or glycerol may be added to increase viscosity and therefore increase gelatinization. Additives that slow down retrogradation are not usually added since amylopectin has a very stable shelf life due to its high amylopectin content.[29]
Mochi is relatively simple to make as there are only a handful of ingredients for plain, natural mochi. The main ingredient is either Shiratamako or Mochiko, both are Japanese sweet glutinous rice flours. Both Shiratamako and Mochiko are derived from Mochigome, a type of japanese glutinous short grain rice. The difference between Shiratamako and Mochiko come from their texture and processing methods. Shiratamako flour has been more refined and is a finer flour with a smoother, more elastic feel.[30] Mochiko is less refined and has a doughier texture.
Other ingredients may include water, sugar and cornstarch to prevent sticking.[31] Other ingredients can be added to create different variations of mochi.
The calorie density of a matchbox-sized piece of mochi is comparable to that of a bowl of rice. Japanese farmers were known to consume mochi during the winter in order to increase their stamina while the Japanese samurai would bring mochi on their expeditions as it was easy to carry and prepare.[32] Mochi is gluten and cholesterol free as it made from rice flour.
Nutritional Facts Table for mochi.
A single servingi is 44.0 grams at 96 calories per serving, 1.0 grams of fat, but no trans or saturated fat, 1.0 milligrams of sodium, 22.0 grams of carbohydrates, 0 grams of dietary fiber, 6.0 grams of sugar and 1.0 grams of protein.[33] There are no vitamins or minerals in plain mochi.
Nutritionally, mochi is composed heavily of carbohydrates, most of which take the form of starch. Starches are naturally occurring in foods such as rice, beans and other grains and give the elasticity feel in foods.
Carbohydrates are used to provide energy as it is the human body’s main source. Digestible carbohydrates, sugars and starch, are composed of long chains of glucose compounds. With the help of the hormone insulin the body breaks these carbohydrate chain to extract the glucose during digestion. Glucose is circulated around the body for cells to use as fuel, while extra surplus sugars are stored in different parts of the body or are turned into fats.[34] Mochi is said to be more digestible than cooked rice due to its structural change during cooking with water. One study found that with saliva, glucose was quickly converted into maltose.[35]
The continual excess consumption of carbohydrates can cause high blood sugar which can lead to diabetes. There are three types of diabetes: Type 1, Type 2 and gestational diabetes. Type 2 diabetes is the most common as it accounts for 90% of all cases worldwide. Type 2 diabetes is diagnosed when the body is either not producing enough insulin or the cells are nonreactive to insulin leading to high blood sugar. Foods high in sugars can increase the risk of Type 2 diabetes. For example, drinking one can of soda per day can increase the risk of type 2 by 22%.[36]
Kagami mochi is a New Year decoration, which is traditionally broken and eaten in a ritual called Kagami biraki (mirror opening).
Zōni is a soup containing rice cakes. Zoni is also eaten on New Year's Day. In addition to mochi, zoni contains vegetables like taro, carrot, honeywort and red and white colored kamaboko.
Kinako mochi is a mochi dish that is traditionally made on New Year's Day for luck. This style of mochi preparation includes roasting the mochi over a fire or stove, then dipping it into water, finally coating with sugar and kinako (soy flour).[citation needed]
The cherry blossom (sakura), is a symbol of Japan and signifies the onset of full-fledged Spring. Sakuramochi is a pink-coloured mochi surrounding sweet “an” and wrapped in an edible salted cherry leaf that is usually made during the Spring season.[37]
Children’s Day is celebrated in Japan on May 5th. On this day, the Japanese promote the overall happiness and well-being of children. Kashiwa-mochi and chimaki are made especially for this celebration.[38]
Girl's Day hishi mochi.Kashiwa-mochi is white mochi surrounding a sweet “an” with a Kashiwa oak leaf wrapped around it.[38]
Chimaki is a variation of a dango wrapped in bamboo leaves.[38]
Hishi mochi is a ceremonial dessert that is presented as offerings on the days leading up to Hinamatsuri or “Girl’s Day” in Japan. Hishi mochi is rhomboid shaped mochi with layers of red, green, and white. The three layers of this mochi are coloured with jasmine flowers, water caltrop, and mugwort respectively.[39]
Mochi is a variation of a low-calorie, low-fat rice cake. The cake has two essential raw materials which are rice and water. The sticky rice (also called sweet rice, Oryza Sativa Var/Oryza Glutinosa, Glutinossticky rice, Glutinous rice, Waxy rice, Botan rice, Biroin Chal, Mochi rice, Pearl rice, and Pulut),[40] whether brown or white, is best for mochi making, while long-grain varieties will not expand perfectly. Another important ingredient, water, is essential in the early stages of preparation. The other additives such as salt and other seasonings and flavourings are important in terms of its nutritive value and taste. However, additives can cause breakage of the mass and for this reason, should not be added to the rice before the cake is formed. The cake must be steamed (rather than boiled) until it gains a smooth and elastic texture. The balls of rice will then be flattened, cut into pieces, or shaped into rounds.[41] The machines for mass production are a hugely expensive investment, and the product (the Mochi) should have the proper moisture, to maintain the popularity[42].
The manufacturing process of mochi is as follows[43][44]:
The first step is to sprout the rice, which can be done using the soaking method or the humidity method. The soaking method involves soaking rice in water until the desired moisture level attained (for example 10 kilograms of rice is soaked for 6-12 hours). The final soaked rice volume should be 50% greater than the dried rice. Whereas, in the humidity method, the rice is removed in a circulated manner in the device similar to the grain dryer. The device would blow warm and moist air onto the circulated rice.
After sprouting, the rice should then be dried. For this step, a mechanical dryer or heated environment is essential. Usually, a temperature of 38°-82°C is used. However, the drying time depends on different factors such as rice quantity, chemical composition and the temperature of the environment.
The next step is roasting. The soaked and dried rice is roasted with an oven or a mechanical roaster. The rice would then be transferred on long trays with approximately a 1.3 centimetre depth to a 90°-200°C environment for 30-60 minutes or until the rice become light brown.
Removing the roasted rice to an environment below 27°C, would cool it down.
The cooled rice is then ground by utilizing devices such as: a roller mill, burr mill, attrition mill, disintegrator mill or hammer mill.
The rice flour is then placed in the rice cake machine. Each manufacturer has approximately 80-90 machines and each machine has 1-3 cooking heads, which each makes one mochi cake every 15 seconds.
The rice flour should be soaked to a liquid. Different kinds of mochi are soaked in different types of liquids such as water, milk, broth, juice, gravy, or artificial milk (such as soy and almond).
The soaked rice flour is then placed into the hoppers which are located above the machines.
The soaked rice flour is removed from hoppers to the iron molds or cooking head in the machines by gravity force. The molds are then heated to hundreds of degrees.
While the molds are heated to hundreds of degrees, the plates are opened and the molds exposed to a vacuum (a combination of heat and pressure).
After 8-10 seconds, the lids of the molds expand so that the pressure will increase. At the end of the process of the combination of pressure and temperature, the cake would completely expand into the molds.
Once the desired expansion of molds is acquired, the iron molds/cooking heads would open, leading to the rice cakes would softly falling onto the conveyor belt.
The belt carries the cakes around different spraying heads, where different flavours and additives are sprayed onto them. The diversity flavours will depend on the different types of mochi. However, natural flavours are usually preferred (salt, strawberry, mango, blueberry, apple cinnamon, caramel, almond, salsa, nacho, taco, and tamari seaweed).
After the addition of different flavours, the cakes will be carried to the dryer tunnel by the belt. In the dryer tunnel the moisture of the rice cakes will vanish.
At the last stage, the belt moves the finished mochi to the bagging area. In the bagging area, the cakes, are inspected carefully for any breakage or damage, then are stacked, packaged, sealed, and labelled properly.
The best preservation for mochi is by way of refrigeration for a short storage period. On the other hand, freezing would be highly recommended for preserving larger batches of mochi for an extended period of time. The best method for freezing would involve pre-wrapping each mochi cake tightly in sealed plastic bags. Although mochi can be kept in a freezer for almost one year, the freezed mochi may lose flavor and softness or get freezer burned.[45]
^ abFredriksson, H et al. (1997). The influence of amylose and amylopectin characteristics on gelatinization and retrogradation properties of different starches. Elsevier Publications – Carbohydrate Polymers. 35, 119-134.
^Ghaeb, M., Tavanai, H., & Kadivar, M. (2015). Electrosprayed maize starch and its constituents (amylose and amylopectin) nanoparticles. Polymers for Advanced Technologies, 26(8), 917–923. http://doi.org/10.1002/pat.3501
^ abcWhistler, R., BeMiller, J., & Paschall, E. (1984). Starch. Orlando: Academic Press. https://books.google.com.mx/books?hl=en&lr=&id=Anbz_whRM2YC&oi=fnd&pg=PP1&ots=dXL5oMcw7I&sig=y9gnkb-yYBIU434WbLbNYtSn0xc#v=onepage&q=glutinous&f=false
^Fredriksson, H et al. (1997). The influence of amylose and amylopectin characteristics on gelatinization and retrogradation properties of different starches. Elsevier Publications – Carbohydrate Polymers. 35, 119-134.
