Tempeh
Soybeans, Fermentation starter (Rhizopus spp.) | |
Tempeh or tempe (
It is especially popular on the
Etymology
The term tempe is thought to be derived from the Old Javanese tumpi, a whitish food made of fried batter made from sago or rice flour which resembles rempeyek.[5] The historian Denys Lombard also suggests that it could be linked to a later term tape or tapai which means 'fermentation'.[6]
In the western world, tempeh is the most common spelling. This is done to prevent readers from incorrectly pronouncing the word as "temp". The first known usage of this spelling is in an 1896 German article. Other spellings, such as témpé, were also used, but tempeh has become the standard spelling in English since the 1960s.[7]
History
Tempeh originated in Indonesia, almost certainly in central or east Java[1] with an estimated discovery between a few centuries ago to a thousand years or more.[8]: 145
The invention of tempeh cannot be separated from the origin of the fungus, which is the important part of the fermentation. This fungus consists of a
The type of soybean first used to make tempeh was the black soybean, which was a native plant.[10] This later changed with the importation of white/yellow soybeans and the rise of the tofu industry on the island.[11]
Debate over origins
Murdijati Gardjito, a food historian at Gadjah Mada University, argued that tempeh was made by native Javanese people, and that its preparation predates the introduction of Chinese-style tofu products.[12] Some ancient texts mention tempe dhele, old Javanese for 'native soybean tempeh'; dhele was used to refer to the native soybean variety. White soybeans that are used to make most tempe dhele today used to be called dhele putih ('white soybeans'), and were only available in Java centuries later. Mary Astuti, a food historian at Gadjah Mada University specializing in tempeh, argued that the native variety of soybean had been grown before the Chinese arrived in the region.[6]
Sri Tandjung noted that Javanese had been eating cooked (native black) soybeans since the 12th century. By the 16th or the 19th century, depending on which period of time the writer of Serat Centhini referred to, Javanese people had mastered the art of cooking with tempeh, when it was not only eaten as is, but converted into different types of dishes, showing a full understanding and mastery of the food product.[12]
Gardjito noted that Javanese noble families rarely wrote about tempeh in ancient texts because it had never been a part of royal cuisine, but rather a staple food of the lower classes.[12]
Indonesian historian
However, tahu was (and is still) made of white soybeans (
Tahu (tofu) made its way to
Tempeh later began to be made with white soybeans, leading to the decreased use of its native black variety. Black soybeans have been replaced by other commodity plants since. The original version of tempe dhele has been forgotten as tahu has since become the common people's food, and dependence on imported white soybeans grows.[13]
Production
Tempeh begins with whole soybeans, which are softened by soaking, and
The principal step in making tempeh is the fermentation of soybeans which undergo inoculation with Rhizopus spp. molds, a type of filamentous fungus most widely used for the production of tempeh. A fermentation starter containing the spores of fungus Rhizopus oligosporus or Rhizopus oryzae is mixed in.[16] The beans are spread into a thin layer and are allowed to ferment for 24 to 36 hours at a temperature around 30°C (86°F). The soybeans have to cool down to allow spore germination and abundant growth of mycelium. Later, the temperature of the beans will naturally rise and rapid mold growth happens for around 4 hours. As mold growth declines, the soybeans should be bound into a solid mass by the mycelium. In good tempeh, the beans are knitted together by a mat of white mycelium. Typically, tempeh is harvested after 48 hours of fermentation with its distinguishable whitish color, firm texture, and nutty flavor. Extended fermentation time results in an increase in pH and undesirable color darkening in the tempeh.[17]
During the fermentation process, optimal time of fermentation, temperature, oxygen, humidity, and pH levels are required to encourage the growth of the Rhizopus mold, while discouraging the growth of undesired microorganisms.[18] The pH level should be kept around 3-5 by adding a mild acidulant such as vinegar, lactic acid, or acetic acid, thereby favoring mold growth and restricting the growth of spoilage microorganisms.[19] Oxygen is required for Rhizopus spp. growth, but should be maintained at low levels to prevent the production of undesired microorganisms. Under conditions of lower temperature, or higher ventilation, gray or black patches of spores may form on the surface—this is not harmful, and should not affect the flavor or quality of the tempeh.[20] This sporulation is normal on fully mature tempeh. A mild ammonia smell may accompany good tempeh as it ferments, but it should not be overpowering.
Traditional tempeh is often produced in Indonesia using Hibiscus tiliaceus leaves. The undersides of the leaves are covered in downy hairs (known technically as trichomes) to which the mold Rhizopus oligosporus can be found adhering in the wild. Soybeans are pressed into the leaf, and stored. Fermentation occurs resulting in tempeh.[14] In particular, the tempeh undergoes salt-free aerobic fermentation.[21]
Tempeh made with traditional inoculation methods are also more likely to include molds of other species including Rhizopus arrhizus and Rhizopus delemar which may outcompete Rhizopus oligosporus as the dominant mold. This results in white woolly appearance and more pleasant aroma compared with tempeh made with commercial starter containing only Rhizopus oligosporus. Famously these variant tempeh are found in Malang and Purwokerto in the 1960s, because Malang is located in a cool plateau, and tempeh made with Rhizopus oligosporus resulted in less compact and more alcoholic-smelling tempeh, while Rhizopus arrhizus required lower optimum temperature which made it more ideal. However the widespread use of commercial starter resulted in most tempeh in Java only contains Rhizopus oligosporus, with few traditionally made tempeh outside Java still contains Rhizopus arrhizus and Rhizopus delemar.[22]
Dry matter losses and yield
During the processing of soybeans to make tempeh there are inevitable losses of material due to the removal of the hulls and the leaching of soluble compounds during the soaking, washing and cooking stages. Hulls constitute about 8% of the dry beans and losses due to the leaching of soluble compounds equate to 12 - 17% of the dry beans. The
Determining quality
Once tempeh is produced, it is divided into three categories based on its quality: good, unfinished, and inedible. Good tempeh includes
Packaging
Food grade wrapping paper and perforated
Nutrition
Nutritional value per 100 g (3.5 oz) | |
---|---|
Energy | 803 kJ (192 kcal) |
7.64 g | |
10.80 g | |
20.29 g | |
Niacin (B3) | 17% 2.640 mg |
Vitamin B6 | 13% 0.215 mg |
Folate (B9) | 6% 24 μg |
Vitamin B12 | 3% 0.08 μg |
Minerals | Quantity %DV† |
Calcium | 9% 111 mg |
Iron | 15% 2.7 mg |
Magnesium | 19% 81 mg |
Manganese | 57% 1.3 mg |
Phosphorus | 21% 266 mg |
Potassium | 14% 412 mg |
Sodium | 0% 9 mg |
Zinc | 10% 1.14 mg |
Other constituents | Quantity |
Water | 60 g |
†Percentages estimated using US recommendations for adults,[27] except for potassium, which is estimated based on expert recommendation from the National Academies.[28] |
Tempeh is 60% water, 20%
Effects of fermentation
The soy carbohydrates in tempeh become more digestible as a result of the fermentation process. In particular, the
In western countries, it is more common to use a pure culture containing only Rhizopus oligosporus, which makes little B12 and could be missing Citrobacter freundii and Klebsiella pneumoniae, which have been shown to produce significant levels of B12 analogs in tempeh when present.[32]
Studies of fortifying tempeh with vitamin B12 through fermentation using microorganisms indicate that lactic acid bacteria and propionic acid bacteria produce vitamin B12.[33]
Preparation
In the kitchen, tempeh is often simply prepared by cutting it into pieces, soaking in brine or a salty sauce, and then fried. In Java, tempeh is often traditionally prepared by cutting it into pieces, marinated in a mixture of ground garlic, coriander and turmeric, salt and water; then deep fried,[34] and often served with sambal ulek chili paste. Cooked tempeh can be eaten alone, or used in chili, stir fries, soups, salads, sandwiches, and stews. Tempeh's complex flavor has been described as nutty, meaty, and mushroom-like. It freezes well, and is now commonly available in many western supermarkets, as well as in ethnic markets and health food stores. Tempeh can be steamed, marinated, thinly sliced, blackened, or crumbled into sauces and stews.[35]
Tempeh performs well in a
Types
The most common and widely known tempeh is made from fermented soybeans, called tempeh kedele or tempeh dele, made from controlled fermentation of
Tempeh can also be differentiated according to its degrees of maturity (i.e. the mycelium's growth/age). Tempe mondhol is a tempeh that is not fully fermented, that is, the mycelium has not fully covered the surface. The taste of the beans is more solid and profound. Sometimes tempeh is left to ferment further, creating more pungently varieties: tempe wayu (day-old tempeh), i.e. when the tempeh starts to age; tempe semangit (a few-days old tempeh), i.e. when the tempeh becomes yellowish, a bit slimy, and the smell becomes more potent;[37] and tempe bosok (lit. 'rotten tempeh'), when the mycelium has acquired a blackened coloration and the product has a putrid smell.
Some types of tempeh are made of ingredients that would be otherwise wasted if not used. According to traditional Javanese customs, wasting food is deemed as a sign of disrespect to Nature and other beings, and encourages efforts to use every part of an ingredient.
The wrappings used in tempeh making can contribute to its flavor and aroma. Though some prefer the traditional banana, waru or teak leaf, readily available plastic sheet wrappings have been increasingly widely used.
Tempe gembus
Soft and fluffy tempeh made from
Tempe semangit
In Indonesia, ripe tempeh (two or more days old) is considered a delicacy. Names include tempe semangit ('stinky tempeh') in Java, hampir busuk ('almost rotten') tempeh or tempe kemarin ('yesterday tempeh'). Having a slightly pungent aroma, small amounts are used as a flavoring agent in traditional Javanese sayur lodeh vegetable stew and sambal tumpang.[37]
Tempe gódhóng
In Javanese, the term gódhóng means 'leaf'.[40] Traditionally tempeh is wrapped in organic banana leaf, gódhóng waru (Hibiscus tiliaceus leaf) or gódhóng jati (teak leaf).[41]
Tempe murni
Pure soybean cake, tempeh made in plastic wrap without any fillings or additives such as grated raw papaya. This was meant to create a more "hygienic and pure" tempeh free from any impurities or unwanted microbes.[citation needed]
Tempe menjes kacang
A specialty of Malang, the rough-textured tempeh menjes kacang is made from black soybeans mixed with other ingredients, such as peanut dregs, cassava fiber, and soybean meal. The process of making menjes kacang is quite similar to black oncom.[42]
Tempe bongkrèk
Tempe bongkrèk is a variety of tempeh from
Fatalities from contaminated tempe bongkrèk were once common in the area where it was produced.
Oat tempeh
A form of tempeh based on barley and oats instead of soy was developed by scientists at the Swedish Department of Food Science in 2008. It can be produced in climatic regions where it is not possible to grow soybeans.[49]
Cooking methods and recipes
The simplest way to cook tempeh is by frying. It is both deep-fried and stir-fried. However, there are several cooking methods and recipe variations. Among others are:
Tempe goreng
Perhaps the simplest and most popular way to prepare tempeh in
prior to frying, or directly fried without any batter.Tempe bacem
Tempe bacem is a traditional Javanese dish originating in Central Java. Bacem is a Javanese cooking method of braising in spices and palm sugar and boiling the food in a closed place until the water runs out.[51] The tempeh is first braised in a mixture of coconut water, palm sugar, and spices including coriander seeds, shallots, galangal, and bay leaves, and then briefly deep-fried. The result is a moist, sweet and spicy, dark-colored tempeh. Tofu may also be used, yielding tahu bacem.[52]
Tempe mendoan
This variation is often found in
Tempe kering
Also known as kering tempe (lit: 'dry tempeh'), or sambal goreng tempe if mixed with plenty of hot and spicy sambal chili pepper sauce. It is a crispy, sweet and spicy, fried tempeh.[53] The raw tempeh is cut into small sticks and thoroughly deep-fried until no longer moist, and then mixed with palm sugar, chili pepper or other spices, or with sweet soy sauce. Often it is mixed with separately fried peanuts and anchovies (ikan teri). This dry tempeh will keep for up to a month if cooked and stored properly.
Tempe orek or orak-arik tempe
This variation is almost identical to tempe kering, but is more soft and moist.
Tumis tempe or oseng tempe
Stir-fried tempeh with vegetables such as green bean, basil, or onion, with spices.[56] Other recipes might add coconut milk for a milky-colored, and rather moist, stir-fried tempeh.
Tempe penyet
Fried tempeh mixed with sambal chili paste in a mortar and pestle. Usually served in addition to other penyet dishes, such as ayam penyet (chicken) or iga penyet (ribs).
Tempe satay
Tempeh skewered and grilled as satay.
Sate kere (Javanese for 'poor man's satay') from Solo in Central Java is made from fluffy tempe gembus.[57] Ground tempeh can also be made into a thick sauce, such as in sate ambal, a chicken satay from Kebumen, Central Java where tempeh flavored with chili and spices replaces the more common peanut sauce.[58]
Kripik tempe
Tempeh sandwich or tempeh burger
Fried, grilled or otherwise cooked tempeh patties, sandwiched between slices of bread or hamburger buns with salad, sauces or seasonings.[60]
-
The common tempeh goreng (un-battered) in Indonesia
-
Fried tempeh (battered) sold at a food court in Singapore
-
Tempe bacem
-
Tempe mendoan
-
Kering tempe or sambal goreng tempe
-
Tempe orek or orak-arik tempe
-
Tempe penyet
-
Crispy kripik tempeh as a snack
-
Fried menjes kacang
-
Grilled tempeh
-
Tempeh sandwich
Preservation
Freshly made, raw tempeh remains edible for a few days at room temperature. It is neither acidic nor does it contain significant amounts of alcohol. It, however, does possess stronger resistance to lipid peroxidation than unfermented soybeans due to its antioxidant contents.[61]
Cooked as tempe kering, the deep-fried and seasoned bits of tempeh can last for a month or more and still be good to consume, if cooked correctly and stored properly in an air-tight jar. The deep-frying process removes the moisture, preventing further fermentation and deterioration, thus prolonging its shelf life.
Antimicrobial agents
Rhizopus cultures responsible for the fermentation of tempeh from soybean produce natural, heat-stable antimicrobial agents against spoilage and disease-causing microorganisms, extending the shelf life of the fermented product through microbial antagonism. The mold is capable of inhibiting the growth of other fungi such as Aspergiluus flavus and Aspergillus parasiticus by interfering with the accumulation of aflatoxin (especially aflatoxin B1), the mycotoxin of greatest concern. R. oligosporus has also been reported to produce four to five antibacterial substances during fermentation process. It produces phenolic compounds against pathogenic bacteria such as Helicobacter pylori and an antibacterial protein has been identified with activities against Bacillus species (especially against Bacillus subtilis and Bacillus cereus[62]), Staphylococcus aureus, and Streptococcus cremoris.
Non-refrigerated fresh tempeh
Tempeh can be sold and consumed fresh within 48 hours once removed from its incubator. It is commonly transported to the market in its incubation container (e.g. polyethylene bag, banana leaf wrapper, etc.) and placed in the shade. In areas with warmer climates, tempeh can be kept at room temperature for one to three days before it becomes overripe. In locations with more temperate temperatures, it can keep for one to four days but will usually need to be refrigerated to prevent spoilage.[19]
Refrigeration
Fresh refrigerated tempeh should be sealed in a labeled polyethylene bag and kept in temperatures below 4 °C (40 °F). It can be kept at this temperature for three to five days and sometimes, even as long as a week. Storage life could be extended to two or three weeks if the tempeh is blanched or steamed prior to refrigeration due to the inactivation of enzymes and destruction of bacteria.[19]
Freezing
Freezing is the preferred way to preserve tempeh due to its capability for wide distribution. Tempeh can be frozen whole or in slices, depending on preference. During the freezing process, whole tempeh is placed in its perforated wrapper whereas sliced tempeh is packaged in a labelled polyethylene bag prior to being sealed in an outer bag and then frozen immediately. This method will keep for months with only a small loss of texture and flavor.[19]
Blanching
Blanching tempeh by steaming or parboiling helps to extend the storage life by preventing bacterial growth, stopping mold growth and inactivating enzymes. Steaming appears to have a less negative effect than parboiling in terms of texture, flavor and nutritional value. Blanching is a great method for preserving tempeh prior to refrigeration, though not as beneficial for tempeh that is to be frozen.[19]
Dehydration
Air tray drying
Tempeh can be dried via the air tray drying method. Cubes of tempeh placed on steel, mesh bottom trays are dried by the circulating hot air dryer. After the product is finished, they can be cut into 2.5-centimetre (1-inch) squares at 90 °C (200 °F) for 90 to 120 minutes in order to reduce moisture content to 2–4%. When placed in moisture proof Pliofilm bags, the tempeh has a shelf life of several months at room temperature. Although this is a convenient method that produces a shelf stable product without requirement of refrigeration, the process of hot air drying can cause a significant loss of nutritional content such as the soluble solids and nitrogen protein content.[19]
Sun drying
This preservation method is most economical out of all methods. The tempeh can be blanched prior to dehydration to preserve flavor and prolong shelf life. Tempeh is exposed to internal solar dryer temperature of 80–90 °C (180–200 °F) in this method. A disadvantage of this method is that sunlight can destroy some of the vitamin B12 of tempeh.[19]
Freeze-drying
This method is the most expensive out of all dehydration methods but provides the advantage of long stable shelf life at room temperature and an excellent retention of soluble nutrients (nitrogen protein and other solids). The product undergoes quick freeze at 10 °C (50 °F) and is then dried at a moderate temperature inside a strong vacuum. Due to the expensive nature of the equipment, the final product price is higher than tempeh preserved through other methods.[19]
Spray-drying
As this method is traditionally used for small particles, it is used to produce tempeh powder for products such as soups, breads, tortillas, etc. However, this method can be expensive due to the bulky nature of the equipment.[19]
Deep-frying
This method produces ready to eat tempeh products. A culinary oil with a high smoke point, such as rapeseed, soy, safflower, peanut, or coconut oil, is heated to 180 °C (350 °F) in the deep fryer. The tempeh is deep-fried until golden brown and crisp, and then cooled quickly in a sterile environment to be sealed in Pliofilm bags and stored in a cool, dry place. The shelf life of this product lasts around a week but can be extended if the tempeh is sun dried or oven dried prior to deep frying.[19]
See also
- List of fermented soy products
- List of meat substitutes
- List of soy-based foods
- Miso
- Nattō
- Oncom
- Tapai
- Food portal
- Veganism
References
- ^ a b c Shurtleff, William; Aoyagi, Akiko. "History of Tempeh". www.soyinfocenter.com. p. 1. Retrieved 2018-09-16.
- ^ "Tempeh". Dictionary.com.
- ISBN 9781592577705. Retrieved 6 May 2011.
- ISBN 9781563057113. Retrieved 6 May 2011.
- ^ "Resep Peyek/tumpi teri medan oleh Siti bundae arfa shaka". Cookpad (in Indonesian). 26 June 2018. Retrieved 2018-08-03.
- ^ a b c d Hendri F. Isnaeni (9 July 2014). "Sejarah Tempe" (in Indonesian). Historia. Retrieved 30 May 2015.
- ^ "History of Tempeh - page 1". www.soyinfocenter.com. Retrieved 2020-10-25.
- ISBN 9780060140090.
- ^ Tamam, Mh Badrut (2017-06-13). "Jenis dan Mekanisme Fermentasi Mikroorganisme". Generasi Biologi. Retrieved 2021-02-23.
- ^ a b "Sejarah Kedelai, Manfaat Kedelai, Dan Serat Dalam Kedelai | Distributor bahan pakan ternak hijauan, bungkil kedelai, meat bone meal, DDGS, kedelai import". Retrieved 2021-02-23.
- ^ a b "Sejarah Tahu, Tahu Sejarah". Historia - Majalah Sejarah Populer Pertama di Indonesia (in Indonesian). 2014-01-10. Retrieved 2021-02-23.
- ^ a b c Media, Kompas Cyber (12 September 2020). "Sejarah Tempe, Makanan Asli Indonesia yang Mendunia". KOMPAS.com (in Indonesian). Retrieved 2021-02-23.
- ^ "Agricultural Commodities: Indonesia Highly Dependent on Soybean Imports | Indonesia Investments". www.indonesia-investments.com. Retrieved 2021-02-23.
- ^ ISBN 9780060140090. Archived from the original(PDF) on 2013-08-19.
- PMID 35050152.
- ^ "What is tempeh starter?". Tempeh.info.
- .
- S2CID 19259459.
- ^ OCLC 13002817.
- ^ "How to Make and Cook Tempeh". Mother Earth News. September–October 1977. Retrieved 3 January 2013.
- S2CID 45727148.
- PMID 34907227.
- ^ ISBN 0-8247-9352-8.
- ^ ISBN 978-1-4398-4480-9.
- PMID 10552819.
- ^ ISSN 0146-9428.
- ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". Retrieved 2024-03-28.
- )
- PMID 563702.
- doi:10.1111/j.1365-2621.1987.tb06650.x. Archived from the originalon 2013-01-05.
- PMID 11285348.
- PMID 8017933.
- S2CID 256712324.
- ^ Najam, Pawon Mommy (12 October 2019). "Resep Tempe Goreng Garit oleh pawon mommy najam". Cookpad (in Indonesian). Retrieved 2019-10-17.
- ^ "Five Ways to Prepare Tempeh". Kitchn. Retrieved 2018-01-19.
- ISBN 9789790822061.
- ^ a b Penulis Wahyu Adityo Prodjo (23 July 2016). "Olahan Tempe Busuk Murah Meriah nan Menggugah Selera". KOMPAS.com (in Indonesian). Retrieved 2019-10-17.
- ^ a b Safira, Maya. "Tempe Gembus yang Empuk Menthul-menthul Kayak Kasur". detikfood (in Indonesian). Retrieved 2018-01-19.
- ^ a b Mustinda, Lusiana. "Apa Benar Tempe Gembus dan Tempe Bongkrek Nutrisinya Rendah?". detikfood (in Indonesian). Retrieved 2018-01-18.
- ^ "Arti kata godhong (godhong) dalam kamus Jawa-Indonesia. Terjemahan dari bahasa Jawa ke bahasa Indonesia - Kamus lengkap online semua bahasa". kamuslengkap.com (in Indonesian). Retrieved 2018-01-19.
- ^ "Mikrobiologi Tempe Daun Waru". Scribd (in Indonesian). Retrieved 2018-01-19.
- ^ Maharrani, Anindhita (2016-08-26). "Menjes, tempe khas dari Malang". Beritagar (in Indonesian). Retrieved 2018-01-19.
- ISBN 9781928914303.
- ^ Liputan6.com (25 September 2003). "Bahaya Tempe Bongkrek Kurang Sosialisasi". liputan6.com (in Indonesian). Retrieved 2018-01-18.
{{cite news}}
: CS1 maint: numeric names: authors list (link) - ^ . Retrieved 29 April 2023.
- ^ "A Short Review of Bongkrekic Acid In Food Safety Perspective. [Abstract]" (PDF).
- ^ PMID 28105575.
- ^ Setiarto, Raden Haryo Bimo. "Waspadai Toksoflavin dan Asam Bongkrek Yang Dihasilkan Bakteri Pseudomonas" (in Indonesian). Retrieved 2018-01-18.
- ^ "New Vegetarian Food With Several Health Benefits". ScienceDaily. May 30, 2008. Retrieved 20 January 2018.
- ^ "Fried Tempeh & Tofu | Tahu Tempe Goreng". www.lestariweb.com. Archived from the original on 2018-01-20. Retrieved 2018-01-19.
- ^ Indonesia, Aplikasi. "arti bacem adalah dalam Kamus Besar Bahasa Indonesia KBBI Online". aplikasi-indonesia.com (in Indonesian). Retrieved 2020-12-05.
- ^ "Tahu dan Tempe Bacem (Braised Spiced Tofu and Temphe)". What To Cook Today. 2017-07-21. Retrieved 2018-01-19.
- ^ "Crispy And Spicy Fried Tempe (Kering Tempe)". Indonesian Recipe. 2013-08-07. Retrieved 2018-01-19.
- ^ "Tempe Orek Recipe | Another Classical of Cooking Tempeh". indonesianfoods-recipes.blogspot.co.id. Archived from the original on 2018-01-20. Retrieved 2018-01-19.
- ^ "Orek Tempe". Retrieved 2018-01-19.
- ^ "4.971 resep oseng tempe enak dan sederhana". Cookpad (in Indonesian). Retrieved 2018-01-19.
- ^ "11 resep sate tempe gembus enak dan sederhana". Cookpad (in Indonesian). Retrieved 2018-01-19.
- ^ "Recipe for Sate Ambal". chickensatay.org. Retrieved 2018-01-19.
- ^ "Kampung Sanan, Sentra Industri Tempe yang Hasilkan Rp 1 M per Hari". kumparan (in Indonesian). Retrieved 2022-10-28.
- ^ "Tempeh Vegan Club Sandwiches Recipe - Love and Lemons". Love and Lemons. 2017-04-06. Retrieved 2018-01-20.
- ^ Umm al-Qura University, Mecca, Saudi Arabia Handbook of Fermented Functional Foods Archived 2015-07-14 at the Wayback Machine
- S2CID 44995408.