Pempek : Traditional fishcake dish from South Sumatra, Indonesia

Pempek is a traditional fishcake dish from South Sumatra, Indonesia. Its primary ingredients are narrow-barred Spanish mackerel (Scomberomorus commerson) and sago starch. As a dish, Pempek is usually served with a sweet and sour sauce called kuah cuko, containing palm sugar, vinegar, tamarind, and chili pepper. Historically, Pempek is highly influenced by Chinese cuisine. Pempek exists in different varieties, most of which are widely known and available in many Indonesian cities. The variation among different types of Pempek appears due to different additional ingredient, shape, filling, cooking method, and serving style. Some well-known types of Pempek include Pempek adaan (round shaped), Pempek lenjer (cylindrical shaped), Pempek kapal selam (egg stuffed), Pempek keriting (curly shaped), and Pempek kulit (made with fish skin). New innovations on Pempek recipe are also thriving owing to people’s creativity. The popularity of Pempek has made this dish the symbol of identity and pride for the people of South Sumatra. It is also rich in historical and philosophical values that represent the South Sumatran traditional way of life. In addition, Pempek is currently considered to be an Intangible Cultural Heritage by the UNESCO. This review discusses the history, traditional production process, philosophy, nutritional aspects, and different varieties of Pempek .

the region (4). Today, Islam is the major religion in Indonesia (87.2%), including in South Sumatra (97.2%) (5,6). The other official religions embraced by the South Sumatrans include Christianity (Catholicism and Protestantism), Buddhism, Hinduism, and Confucianism. Pempek is a widely-known traditional food from South Sumatra consumed in all regions of Indonesia (7). It is a savory fishcake delicacy made with fish and starch. Pempek is commonly served with sweet and sour dark-colored sauce called kuah cuko made of vinegar and some local spices. The dish is often eaten with noodles and diced cucumber to balance out the sourness of the vinegar. Throughout the time, Pempek has become the identity for South Sumatrans that is rich in historical and philosophical values (8,9). Nowadays, Pempek exists in different varieties and can be easily found in many cities in Indonesia. It has also been drafted to be listed as an Intangible Cultural Heritage by the UNESCO (10). Considering the importance of Pempek as an ethnic food of Indonesia, this review discusses the history, traditional production process, philosophy, nutritional aspects, and different varieties of Pempek. With regard to novelty, this is the first international review that focuses on Pempek, its varieties, and the values it harbors in a comprehensive and thorough manner.

Food Culture and Traditional Cuisine of South Sumatra
The food culture of South Sumatra is strongly influenced by Chinese culture initially entering the region along with the Chinese Muslim traders from the eastern coast of China in the 15 th century (11). Such traders, who were mostly men, married local women and settled down in the region, thus being integrated in the local community. The acculturation between the local and Chinese food culture gave birth to the Peranakan or Nyonya cuisine (12). Since the majority of South Sumatrans are Muslim, the Peranakan food developed in South Sumatra is halal (allowed to be consumed according to the Sharia Islamic Law) and does not contain pork, a common ingredient found widely in traditional Chinese cuisine (13,14).
Due to the paramount role of the Musi River (750 km long) crossing the whole province and dividing it into two parts, freshwater fish and prawns are the most common ingredients used in the South Sumatran cuisine. Some popular freshwater that are often consumed on daily basis include Pangas catfish or ikan patin (Pangasius pangasius), ikan baung (Hemibagrus sp.), catfish or ikan lele (Clarias batrachus), ikan lais (Kryptopterus cryptopterus), snakehead or ikan gabus (Channa striata), carp or ikan mas (Cyprinus carpio), and gourami or gurame (Osphronemus goramy) (15). Historically, giant featherback or ikan belida (Chitala lopis) was a famous endemic freshwater fish in the Musi River that was widely used in South Sumatran cuisine (16). It was valued for its succulent flavor and soft texture. However, due to overfishing, it is now considered extinct and has been immortalized as the official animal mascot of Palembang City (17). Since South Sumatra is adjacent to the Java Sea in the east, seafood is also often incorporated in South Sumatran cuisine in addition to fresh water fish. Figure 2 shows some well-known traditional South Sumatran foods. Pempek (Figure 2A) is undoubtedly the most famous dish from South Sumatra. Mi celor ( Figure 2B) is a savory & sweet noodle dish immersed in a savory sauce made from coconut milk, shrimp broth, and ground dried shrimp (ebi) (18). It is often served with chicken egg, beansprout, chopped leek, celery, and fried shallot. Martabak HAR ( Figure 2C) is a popular stuffed pancake made from duck or chicken eggs, chopped leek, and other spices (19). The word HAR is an acronym for Haji Abdul Razak, the inventor of its original recipe who appeared to be a Muslim Indian trader marrying a local woman from Palembang in the past (19). Indeed, the dish is believed to be derived from mamaks, a multi-layered pancake originating in the state of Kerala, India (20). Martabak HAR is usually served with chunks of potatoes cooked in a goat curry sauce. Pindang patin ( Figure 2D) refers to a sour and spicy fish soup made from Pangas catfish with a strong hint of tamarind (Tamarindus indica) (21). Brengkes tempoyak ( Figure 2E) is made from Pangas catfish slowly cooked with traditional spices mixed with tempoyak, a fermented paste made from a strong-flavored fruit called durian (Durio zibethinus) (22,23). This food is usually cooked and served within banana leaves. Burgo ( Figure 2F), a popular choice for breakfast among South Sumatrans, is a folded rice pancake served in savory coconut milk-based soup flavored with fish (24). Malbi ( Figure 2G) is a South Sumatran spiced beef or goat stew braised in seasoned thick brown gravy commonly served during traditional weddings and the family celebration of the Islamic holiday Eid al-Fitr marking the end of the fasting month of Ramadan (25). Sambals, traditional chili pastes with additional spices, are widely consumed as condiments with all kinds of dishes. Some popular sambals in South Sumatra are sambal mangga made from sliced unripe mango ( Figure 2H), sambal kweni made from kweni mango (Mangifera odorata), sambal jokjok made from tamarind, and sambal tempoyak (26). While the main common aspect of these sambals is the spiciness aspect, different fruits and herbs allow for various flavor combination and unique property of each sambal. Kemplang ( Figure  2I) is South Sumatran traditional fish crackers made of narrow-barred Spanish mackerel and tapioca commonly consumed with daily meal or as snacks (27). By itself it has a mild savory flavor from the fish meat mixture, but it is also commonly consumed along with concentrated cuko based condiment to provide sweet and spicy contrast. In general, common Indonesian traditional foods derived from soybeans are also widely consumed in South Sumatra, including tofu, tempeh, and oncom (28,29). Kue delapan jam ( Figure 2J, literally translated to 8-hour cake), is a traditional cake made from duck eggs, sugar, butter, and sweet condensed milk without any flour added (30). As its name implies, the making of this cake requires a long cooking process involving constant stirring for approximately 8 hours. Served as a delicacy during the era of the Sultanate of Palembang, kue delapan jam has become a must-eat during Eid al-Fitr family celebration. Its sticky texture symbolizes proximity among the members of a family while its sweet taste represents the sweet moment of togetherness shared within a family (31).

History of Pempek
The history behind the creation of Pempek is unclear. According to the traditional folklore, the original Pempek recipe is believed to be developed by an old Chinese immigrant settling down near the Musi river in Palembang around the 16 th century during the reign of the 2 nd Sultan Mahmud Badaruddin in the Sultanate of Palembang-Darussalam (32). He noticed an abundance of fish caught by the local fishermen daily. With the absence of refrigeration technology at the very moment, most of the unsold fish decayed and were wasted. The indigenous people, however, had limited knowledge and techniques regarding fish processing. During that period, most fish were processed through mainly boiling, frying, and grilling instead of adding other ingredients to create new dishes. The old Chinese man bought some unsold fish at the market in the afternoon at a lower price, mixed them with sago and other spices, and created a sort of fishcake with which the local people was not familiar. He then sold the fishcakes on an ambulant cart around the village. The people referred to this old man as apek, a Hokkien (Chinese dialect) slang word to call an old man. Since the people wanting to buy the fishcake shouted "pek… apek" to attract the attention of the old man selling the fishcakes, the dish became slowly known as Pempek (32).
Pempek was suggested to be the local adaptation of Chinese fishcake (鱼饼) that has been present for more than 4,000 years in China according to Chinese traditional folklores (33). While wheat flour is used to make fishcake in China, sago starch is used to make Pempek in Indonesia since sago is a native Indonesian plant and the country does not grow wheat. Another theory suggested that the old man inventing Pempek was inspired by ngo hiang (五 香), a sausage-like roll made from minced pork and ground fish (or prawn) seasoned with the famous Chinese five-spice powder consisting of star anise (Illicium verum), cloves (Syzygium aromaticum), Chinese cinnamon (Cinnamomum cassia), Sichuan pepper (Zanthoxylum bungeanum), and fennel (Foeniculum vulgare) seeds (34). Such a hypothesis is strengthened by the fact that most Chinese immigrants in South Sumatra were mainly Hokkien and Teochew people coming from Fujian and Guangdong provinces in Southern China and ngo hiang originated in those very areas (35). However, some historians also suggested that Pempek originated from an ancient cuisine called kelasan, a steamed dish made of the mixture of fish flesh with sago, dated as early as Srivijayan era circa 7th century (36).

Ingredients of Pempek
Pempek dough is made from a mixture of ground fish filet with sago starch and other spices. The most common fish used to make Pempek dough is the narrow-barred Spanish mackerel (Scomberomorus commerson) (37), commonly known in Indonesia under the name of ikan tenggiri. It is a marine predator fish with an elongated body and razor sharp teeth that belongs to the mackerel family, Scombridae ( Figure 3A). An adult narrow-barred Spanish mackerel has an average total length between 70-100 cm and an overall weight in the range of 30-80 kg, even though it can grow to a maximum length of 220 cm and weigh over 100 kg (37). Naturally, narrow-barred Spanish mackerels are ubiquitous in Indonesian waters, including the Java Sea bordering South Sumatra in the east (38). Outside Indonesia, narrowbarred Spanish mackerels can also be found in a wide-ranging marine area in Southeast Asia, north coast of Indian Ocean, east coast of Africa, and as far east as the South West Pacific Ocean (38). Nowadays, these fish are widely cultivated in Indonesia, particularly in the coastal areas of Java and in Gorontalo (Sulawesi Island). Due to its ubiquity in Indonesian waters, narrow-barred Spanish mackerels are widely used in many regions in Indonesia as local food ingredients. They can be easily found in many traditional markets or fish markets and are sold fresh or as dry-cured fermented fish. In West Java, narrow-barred Spanish mackerels are used to make siomay, Chinese shumai-derived steamed fish dumplings with tofu and vegetables served in peanut sauce (39). In Sumatra and Java, these fish are commonly processed as ingredients for traditional chips (40). The use of narrow-barred Spanish mackerel as a Pempek ingredient is pivotal since such a fish has a strong and unique flavor that is distinguishable from other fish. Using other marine fish or even fresh water fish to replace narrow-barred Spanish mackerel as a Pempek ingredient would be easily detected by the consumers. However, some other fish are traditionally also used to make Pempek dough in addition to narrow-barred Spanish mackerel, including Indonesian red snapper or ikan kakap merah (Lutjanus bitaeniatus), striped snakehead or ikan gabus (Channa striata), mackerel tuna or ikan tongkol (Euthynnus affinis), catfish or ikan lele (Clarias batrachus), Nile tilapia or ikan nila (Oreochromis niloticus), yellowback fusilier or ikan ekor kuning (Caesio xanthonota), and sulphur goatfish or ikan kuniran (Upeneus sulphureus) (41). These fish are used to enrich the flavor of Pempek and reduce the production cost since the market price of narrow-barred Spanish mackerel is relatively higher compared to these fish. Traditionally, in the past, Pempek was commonly prepared using giant featherback or ikan belida (Chitala lopis) ( Figure  3B) that is now considered extinct (16,17). Sago is a starch extracted from the pith, or spongy core tissue of sago palms (Metroxylon sagu), a plant native to Southeast Asia (42). Indigenously, sago is the staple food of traditional coastal communities in Papua and Maluku islands in the eastern Indonesia (42). Today, it is also widely cultivated in other islands in Indonesia, including Sumatra, Java, and Kalimantan (Borneo). The role of sago in the formation of Pempek dough is to bind the water and fish meat to form a sticky and chewy dough. Sago is preferred in Pempek making compared to other kinds of starch or flour (e.g. wheat flour, tapioca starch from cassava, or maizena from corn) since it gives a softer and chewier texture in Pempek dough (43). However, tapioca starch is commonly used to replace or complement sago in Pempek dough to reduce production cost. Adding some tapioca into the dough can also render the Pempeks crispier. Sometimes, wheat flour is also added to improve the texture of Pempek dough, particularly if the dough is too soft and cannot be formed. Salt and flavor enhancer (monosodium glutamate/MSG) are usually added to enrich the taste of Pempek. Baking powder containing sodium bicarbonate (NaHCO3) is also often added to expand the volume of the dough during deep frying, thus resulting in bigger Pempeks. The proportion of fish and sago starch in Pempek dough is essential to determine the sensory characteristics of Pempek, particularly the texture. Ideally, 6-7 parts of sago should be added to 10 parts of fish (43). If the proportion of sago and fish reaches 1:1, the flavor of the fish would be covered and the dough would be brittle, too sticky, and hard to shape (43). However, using more flour and less fish to make Pempek dough is a common practice among ambulant vendors selling cheap Pempek, albeit sacrificing the taste to some extent.
Kuah cuko is an essential part of a Pempek dish. It is a sweet and sour dark-colored sauce made from palm sugar, garlic, vinegar, and salt (7). Traditionally, ground red chili pepper is also incorporated in kuah cuko to give a hint of spiciness since most Indonesians like to eat spicy food. However, to accommodate some people who desire unspicy kuah cuko or are not able to eat hot and spicy sauce, the ground red chili pepper is often separated as sambal (26).

Production and Serving of Pempek
The common steps implemented in Pempek production is presented in Figure 4 and Figure 5. Firstly, the fish filet is ground using blender. It is essential to use fresh fish that had not yet undergone postmortem rigidity (rigor mortis) to make a smooth dough. Contrary to post-rigor fish, pre-rigor fish has a higher water holding capacity that allows it to incorporate water in a better manner to make a well-mixed dough with a smoother texture (44). In addition, post-rigor fish often exhibit off-odor and rancidity due to oxidation and microbial activities yielding volatile compounds. To make a Pempek dough, the ground fish filet, sago, and other additional ingredients (salt, flavor enhancer, and baking powder) are mixed together ( Figure 5A). Cooking oil is seldom added since Spanish mackerels are relatively high in fat. The dough is then formed into small chunks of Pempek ( Figure 5B) that are further boiled in hot water or steamed until they harden and form partly-cooked dumplings ( Figure  5C). These latter are usually stored or frozen to be deep-fried later in cooking oil just prior to serving ( Figure 5D). Perfectly fried Pempeks exhibit an appetizing golden brownish color with a shiny and crispy surface. Kuah cuko is prepared by boiling water with main ingredients including palm sugar, vinegar, tamarind, salt, and dried shrimp flakes (ebi) ( Figure 5E). Fried Pempeks are then cut in bite-size and showered in hot kuah cuko ( Figure 5F). Yellow noodles and chopped fresh cucumber can be added to the mix. Pempek is also often consumed with kemplang chips (32). An example of Pempek recipe is presented in Appendix (45). Generally, Pempeks made by different producers differ in the recipes used. The proportion of fish and sago used is primordial to determine the texture of Pempek (43). The type of fish used, either only narrowbarred Spanish mackerels or combined with other fish, determines mainly the flavor of Pempek (41). The proportion of each ingredient present in kuah cuko would influence its final flavor profile. Some varieties are dominantly sweet due to the high concentration of palm sugar while others tend to be sour due to the high concentration of vinegar used in its formulation. Sometimes, tongcai (Tianjin-styled pickled Chinese cabbage) and ebi (ground dried shrimp) are also added to kuah cuko to enrich its flavor (7,32). In general, kuah cuko is cooked to form a concentrated solution that has a longer shelf-life and is diluted with hot water prior to consumption.

Varieties of Pempek
There are different existing varieties of Pempek with different additional ingredients, shapes, filling, cooking methods, and serving styles ( Figure 6). Pempek adaan ( Figure 6A) and Pempek lenjer ( Figure 6B) are the most commonly sold Pempek varieties with round and cylindrical shape respectively (46). Usually, Pempek adaan has a stronger taste and aroma compared to Pempek lenjer due to the addition of coconut milk in the dough. While most Pempeks are made from fish flesh, Pempek kulit or skin Pempek ( Figure 6C) is made with scaled fish skin. It has more pungent/fishy flavor and different texture compared to other Pempeks due to the higher amount of subcutaneous fat within the mixture (46). Pempek kulit is always flattened before frying, thus giving it a thin appearance and a good balance of crunchiness and chewiness. Pempek keriting or curly Pempek is another type of Pempek with unique shape ( Figure 6D) due to its preparation process that involves extrusion of dough mixture, overlapping with each other, to form a wrinkly-tangled form before being steamed to give soft chewy texture (46). Its shape resembles a ball of rounded noodles. It is also noteworthy that there is also a cheaper variant of Pempek which exclusively uses sago starch (without any fish added) called Pempek dos (47).
Pempek can also have multiple types of fillings. Pempek kapal selam or submarine Pempek ( Figure 6E) is one of the most well-known types of Pempek. It is given such a name due to the presence of a whole egg in the middle of the dough, its oval shape of the outer layer resembling submarine, and its serving method by drenching in kuah cuko -as if the Pempek was floating in one (46). Compared to the other types, Pempek kapal selam is generally the biggest in term of size. It is commonly served with noodles, diced cucumbers, and topped with dried shrimp flakes (ebi) to give a contrasting texture and highlight the fishy flavor. A smaller version of Pempek kapal selam is called Pempek telor, which contains egg yolk instead of a whole egg (46). There is another type called Pempek pastel ( Figure 6F) whose name comes from the shape resemblance to a common Indonesian pastry called pastel. It is generally filled with shredded young papaya (46). Unique Pempek preparations in banana leaves are known as Pempek sate ( Figure 6G) and Pempek otak-otak ( Figure 6H). Pempek sate is made from Pempek dough filled into banana leaves that are subsequently folded into triangles prior to steaming, thus lending its signature look and fragrant smell during serving (48). Pempek otak-otak is also made from Pempek dough wrapped in banana leaves, but has a flattened cylindrical shape and is grilled on charcoal (49).
In terms of cooking method, while some varieties (such as Pempek adaan and Pempek kulit) are commonly deep fried directly after forming the dough into the intended shape, some others (such as Pempek lenjer) undergo an additional step of boiling/steaming in between to lend a firmer rigid shape before deep frying (46). Some varieties are prepared without involving deep frying at all, which means they are either steamed or boiled prior to serving, such as Pempek keriting, Pempek sate, and Pempek pastel (46,48). Another popular method of Pempek cooking involves grilling on charcoal, thus providing a crispy outer layer with a smoky flavor. Pempek otak-otak is prepared using such a method (49). Pempek panggang or Pempek tunu ( Figure 6I) is a popular Pempek prepared by grilling previouslysteamed or -boiled Pempek dough (46). It has a dry and crunchy texture and is often filled with dried shrimp flakes (ebi), which sometimes are mixed with palm sugar and chili paste. The shape of Pempek panggang can be either cylindrical with a middle cut for the aforementioned filling, or flat oval with a horizontal slit to place the filling. Pempek lenggang ( Figure 6J) is made from chopped pre-boiled or pre-steamed Pempek dough that is put in a small container made of woven banana leaves, mixed with spiced beaten eggs, and then grilled (46). It has an omelette-like appearance. In recent days, Pempek lenggang is also made by pan frying. There are various ways to serve Pempek and the most common one is dipping it in kuah cuko. Pempek can also be served in different types of broth to lend different mouthfeel, thus resulting in other signature dishes derived from Pempek such as tekwan, model, laksan, celimpungan, and rujak mi (Figure 7). Tekwan ( Figure 7A) is created by boiling fish dough along with jicama (Pachyrizus erosus) tu ber and wood ear mushroom (Auricularia auricularjudae) in shrimp or fish broth (50). Model is pretty similar to tekwan in the sense that the broth used is either clear shrimp or fish broth, with the difference being the Pempek in model is a combination of fish dough and tofu (beancurd) sticked together (51). Laksan ( Figure 7B) and celimpungan ( Figure 7C) are the creamier variants due to the addition of coconut milk to the broth (50). Celimpungan generally has a yellowish opaque colored broth due to the addition of turmeric, while laksan has a reddish broth due to the addition of red chili pepper (50). Rujak mi ( Figure 7D) is a famous salad dish in South Sumatra made of chunks of Pempek (mostly Pempek lenjer), tofu, yellow egg noodles, cellophane noodles, cucumber, and beansprouts immersed in kuah cuko (52).

Philosophy of Pempek
Food is regarded as a symbol of civilization since eating is a part of human daily activities. Traditional Indonesian foods harbor noble philosophical values that have been passed down through generations as the source and guide for Indonesian people's lives. Some of these values include solidarity, mutual cooperation, respect for fellow humans and diversity, and gratitude towards nature and the gods (53).
Philosophically, Pempek contains four humanistic values that reflect the way of life of South Sumatrans (54). Firstly, the chewy texture of Pempek reminds that life should be dynamic and flexible, particularly when we face changes and adapt with them. Secondly, the complex flavor of Pempek symbolizes life balance. Pempek is indeed rich in flavor, from the salty and umami taste of the fish to the sweet, spicy, and sour taste of kuah cuko. All these flavors exist in harmony and do not overpower one another. Thus, this aspect reflects a life balance that would lead to a harmonious way of living. Thirdly, the quality of Pempek represents credibility. It appears primordial to opt for fish of high quality to be used as the main ingredient for Pempek. Pempek sellers should be consistent in producing Pempeks of good quality to gain consumers' trust and maintain their credibility. This aspect contains the philosophy of always doing one's best and respecting integrity in life. Lastly, the local story of Pempek being invented by a Chinese old man noticing wasted unsold fish teaches us to be creative and courageous. Such a story also inspires to always look out for opportunities in life.

A local saying in South Sumatran traditional language describes Pempek as follows :
Pempek ; when it is served in a clear soup, it becomes tekwan ; when it is served in a yellow coconut milk soup, it becomes celimpungan ; when it is served in a red coconut milk soup, it becomes laksan ; when it is wrapped in beaten eggs and grilled, it becomes lenggang ; when it is served in kuah cuko with noodles and fried tofu, it becomes rujak mi ; therefore, the value that we can learn from Pempek is that wherever we live, we need to adapt with the environment and be useful to other people (55). Moreover, a local expression "ngirup cuko Pempek" (literally translated to sipping the cuko of Pempek) reflects the love and pride of South Sumatrans towards Pempek (56). Such an expression is popular among South Sumatrans working and living in other cities or islands who often say "kangen ngirup cuko Pempek" or longing to sip the cuko of Pempek to describe their genuine feelings of missing their home town and eat delicious and authentic Pempek amidst their families and friends. Therefore, for South Sumatrans, Pempek is also a symbol of togetherness and kinship (56).

Nutritional Aspects of Pempek
The nutritional profile of narrow-barred Spanish mackerel filet and Pempek is presented in Table 1 (57,58). Both narrow-barred Spanish mackerel and Pempek can be considered as good sources of protein due to their high protein content (19.3% and 12.6% respectively). Protein is essential to a plethora of body functions, including building tissues and muscles, producing hormones and enzymes, providing energy, and supporting immunity (59). Among the essential amino acids, lysine and leucine are found in a relatively high amount in narrowbarred Spanish mackerel (60). Therefore, it is suggested to be a complementary ingredient to cereals (including rice, the staple food in Indonesia) that are usually poor in lysine (59). Narrow-barred Spanish mackerel and Pempek are also sources of unsaturated fatty acids, mostly oleic acid (C18:1, n-9) and docosahexaenoic acid (C22:6, n-3; DHA) 60. High consumption of unsaturated fatty acids is linked to lower incidence of cardiovascular diseases and improvement of cognitive functions in children (61). Selenium (Se) is a micromineral found in a relatively high amount in narrow-barred Spanish mackerel (36.5 mcg Se/100 g filet fulfilling 52% of daily requirement for Se) (57). Indeed, Se is an essential component of various proteins called selenoproteins that help protect the cells against cell damage and infections (62). The caveat related to consuming narrow-barred Spanish mackerel and Pempek would be their relatively high concentration of cholesterol. High consumption of foods rich in cholesterol has been demonstrated to promote cardiovascular diseases (63).
Since Pempek is produced through deep frying and is often served with kuah cuko made from palm sugar, it can be considered to be high in fat, sugar, and calorie. A chunk of fried Pempek weighs approximately 30-50 g, depending of its type and size (58). Compared to Pempek adaan, Pempek kapal selam would provide a higher amount of energy due to its larger size and the presence of a whole chicken egg as its stuffing. A portion of Pempek adaan dish would generally consist of 4-5 chunks of Pempek. These Pempeks are also served with approximately 150-200 mL of kuah cuko containing 10-20% palm sugar (45). Therefore, a portion of Pempek adaan in kuah cuko may contain 300-500 kcal (58). Moreover, if the dish is consumed with noodles, the energy it provides would increase. Thus, it is advised not to eat Pempek in an excessive manner. Since Pempek is poor in dietary fiber and vitamins, consuming vegetables and fruits in addition to Pempek would help reach a more balanced diet. Furthermore, consumption of soluble dietary fiber would help the body eliminate cholesterol that is found in a relatively high concentration in Pempek (64).

Current Development of Pempek
Since being invented, Indonesian communities have adopted Pempek in numerous ways and this has led to the development of different types of Pempek served widely across the archipelago. While Pempek has become a popular dish in the neighboring provinces such as Jambi, Bengkulu, and Lampung, the popularity of Pempek has also expanded to big cities across Indonesia and some other neighboring countries including Malaysia, Singapore, and Australia (65). However, the taste of Pempek in other regions usually differs from the original South Sumatran variant since the main ingredients such as fish and flour may be difficult to find in other regions outside South Sumatra. Today, Pempek has become the identity of South Sumatra and is known as one of the most popular Indonesian dishes (8,9).
Currently, Pempek can be easily found in many Indonesian cities ( Figure 8A-E), from food courts in shopping centers, traditional markets, to ambulant Pempek vendors on motorcycles or carts. There are also small traditional restaurants and eateries specialized in serving Pempek, most of which are usually run by South Sumatran owners. Some Pempek establishments are very popular nationally and have opened franchised branches in many cities (65). In South Sumatra, Pempek is sold mainly as foodstuff gifts or souvenirs for visitors from other Indonesian cities (66). In this case, Pempek is commonly sold as frozen ready-tocook dumplings in vacuum packagings along with concentrated kuah cuko that needs further diluting upon consumption ( Figure 8F). Palembang Pempek is also delivered to neighboring provinces and islands (mostly Java) on daily basis for restaurant supplies or individual consumption. During the first 10 days of the Ramadan in 2016, the Indonesian Postal Service (PT Pos Indonesia) handled the deliveries of 11 tons of Pempek from Palembang to other big cities in Indonesia, mainly Jakarta, Bandung, Semarang, and Surabaya in Java (67). In addition, since there are many domestic tourist visiting South Sumatra to eat authentic Pempek dishes, Pempek can also be considered as a potential gastronomic tourist attraction (65,68). The preservation technique for Pempek has also developed across the years as it grew in popularity as souvenirs. Freezing is the most common preservation method for Pempek to allow longer shelf life and further transportation range (69). In addition to this, food preservatives (antimicrobial agents) are also added by some Pempek producers to inhibit the growth of microorganisms in Pempek and thus, prolonging its shelf life (70). Modern innovations on Pempek (Figure 9) are also sprouting, especially in big cities in Java such as Jakarta, Bandung (West Java), and Surabaya (East Java) where interest in fusion food tends to be higher, particularly among young people. This includes the addition of melted mozzarella cheese as topping on Pempek lenggang and stuffing different varieties of filling inside Pempek, such as sausage, cheese, salmon, beef salami, or spicy chili peppers (71,72). Other innovations include making a large-sized Pempek stuffed with eggs and smaller Pempeks (Pempek beranak or Pempek giving birth), filling Pempek with condensed kuah cuko (Pempek klepon), creating Pempek in the form of a donut (Pempek donat), and adding fruit and vegetable extracts as dyes in Pempek dough to make colorful Pempek (Pempek pelangi or rainbow Pempek) (72). Up to this point, most of the Pempek production is dominated by home industries and there is no industrialization that allows mass production with consistent quality (73). Further development for Pempek production is still required, particularly in terms of production hygiene and innovative preservation method to ensure the safety of Pempek when consumed, since Pempek is categorized as a perishable food prone to putrefactive and pathogenic microorganisms. Pempek mozzarella using melting mozzarella cheese as filling, (B) Pempek klepon whose appearance resembles the popular Javanese green klepon cake with condensed kuah cuko as filling, (C) Pempek beranak or Pempek giving birth stuffed with eggs and smaller Pempeks, and (D) colorful Pempek pelangi or rainbow Pempek made using extracts of different fruits and vegetables.

Conclusions
Pempek is a traditional fishcake dish from Palembang, South Sumatra that has gained popularity across Indonesia and some neighboring countries, such as Malaysia, Singapore, and Australia. There is a plethora of Pempek varieties as the result of years of acculturation between the Chinese and South Sumatran culture. Composition, shape, filling, cooking method, and serving style are the determinants of Pempek varieties. From the nutritional point of view, Pempek is a good source of protein and unsaturated fatty acids, despite containing a relatively high amount of cholesterol. More than just a traditional food, Pempek is also a symbol of identity and pride which embodies a wide range of philosophical values upheld by the people of South Sumatra. The authors hope that this review would provide a thorough understanding with regard to Pempek and open the possibility for further studies on Pempek.
For condiments: 100 g of yellow egg noodles, 1 tbsp of dried shrimp flakes (ebi), and 1 cucumber (diced). Instructions: For Pempek: In a container, the ground fish fillet is mixed with the beaten egg, shallots, leek, garlic, salt, sugar, pepper, coconut milk, and sago starch until they are mixed thoroughly and form a homogenous Pempek dough. Afterwards, a portion of the dough is taken and then rolled to form a certain shape (ball, cylinder, etc) using one's hands. The steps are repeated until all the dough has been used and transformed into Pempeks. The Pempeks are then cooked in boiling water until they are thoroughly cooked and float. During this step, the noodles can also be cooked together with the Pempeks in the boiling water. The cooked Pempeks are then drained and can be stored in the freezer or deep fried directly in cooking oil. Once the Pempeks turn slightly brownish, they are ready to serve. For kuah cuko: In boiling water, all the ingredients are put and stirred constantly. Some unwanted particles can be removed by using a fine mesh strainer or other types of filter. The kuah cuko is cooked until it reaches the desired level of thickness. Serving: The Pempeks are placed on a plate with the pre-cooked noodles and diced cucumber as condiments. Some types of Pempek might need cutting into smaller pieces of bite size to facilitate eating. The kuah cuko is then poured into the plate. Some dried shrimp flakes (ebi) can be sprinkled on the top of the Pempek dish to improve its flavor.