(g/g)
The content of amylose and amylopectin was determined by colorimetric method based on amylase–iodine complex formation. The respective protein content in table was determined using the Kjeldahl method (Nitrogen content to protein conversion factor was 6.25).
The relative proportion of amylose and amylopectin is largely responsible for the functional and physicochemical properties of starches, such as gelatinization, paste viscosity, gel stability and solubility. Among them, the starch extracted by the water extraction has a slightly higher amylose content, which enhances the film-forming ability. The starch obtained by sodium metabisulfite extraction has a higher amylopectin content, which exhibits a pasting property. Compared with potato, cassava and other native starches (15–30%), tiger nut starch has a lower amylose content but higher amylopectin content, indicative of stronger associative forces suitable to be applied as a binder.
The physicochemical properties of tiger nut starch are closely dependent on the seed varieties (black and yellow) and the pretreatment of the nut for oil. The study showed wide variations in some physicochemical properties of starches isolated from the two types of tubers (black and yellow) [ 54 ]. Both starches largely consist of spherical granules with smooth surfaces, but the black nut starch contained smaller granules [ 54 ]. Starch gels from the yellow variety were clearer, softer and more adhesive, cohesive and stable after freeze-thaws. The black nut starch showed higher peak viscosity and setback viscosity and lower breakdown, which made it suitable to be used as food packaging materials and drug transport films. The structural and functional properties of tiger nut starches were different with nut meals after hexane extraction, hot pressing, cold pressing and subcritical fluid extraction. The ordered structure of starch granules was caused by the various oil extraction processes, which led to higher solubility and swelling power, lower freeze-thawing stability of starch compared to untreated nuts [ 58 ].
No matter which method is used, the tiger nut starch obtained has common properties. Tiger nut starch is a brilliant white, odorless powder with a warm bland taste and smooth texture. It consists of elliptical to spherical and small- to medium-sized granules with particle sizes ranging from 2 to 17μm [ 53 ]. It has a relatively high content of amylopectin with good thickening and bonding effects.
Tiger nut starch has similar viscosity characteristics to native starch, but its gel texture properties (hardness, elasticity, cohesion and chewiness) are higher than those of traditional corn and sweet potato starch. In addition, its freeze-thaw stability is better than that of corn starch, which can be used in cold drinks and frozen foods and has a wide range of application values. Therefore, it has potential commercial value and has been used in the food and pharmaceutical industry.
The tiger nut starch gels are clear, soft, adhesive and cohesive, which is a good choice for use as a thickener, binder and humectant in food products, such as soups and dessert powders [ 54 ]. In addition, it has a high gel strength and thawing stability in the hydrated state, which is suitable for the production of jelly, cold drinks and candies [ 50 ]. Starch is one of the most frequently used excipients in pharmaceutical formulations and is included in the GRAS (Generally Recognized as Safe) list of the World Health Organization. The tiger nut starch shows high compatibility and binding ability, has good swelling power, density water absorption and good binding efficiency with medicines, which conforms to the pharmaceutical standard [ 48 ]. So, the nut starch can be used as an excipient, binder, filler and lubricant for the production of pharmaceutical preparations [ 53 ]. Indeed, this starch showed excellent binder activity, mechanical strength, fluidity and release properties when it was used as glidant and binder in the production of metronidazole and ascorbic acid tablets [ 52 , 59 ]. The native tiger nut starch showed flow properties comparable to maize and potato starch, as well as excellent binder activity when metronidazole tablets’ hardness and friability were evaluated [ 48 ].
Modified starch overcomes limitations of natural starch, thereby improving its practicality in industrial applications. A low digestible and viscous starch was obtained by modifying tiger nut starch used the pullulans hydrolysis, which is highly valued as a component in functional foods such as improving lipid and cholesterol metabolism and strengthening intestinal function [ 50 ]. Furthermore, modified starch was used in the productions of ascorbic acid granules and ibuprofen tablets in the pharmaceutical industry to improve the tablet’s mechanical strength, swelling capacity, adhesion and release properties [ 48 , 60 ].
After oil extraction, the meals as the by-product of oil extraction are currently used for animal feed or directly discarded, causing a lot of waste and environmental pollution. The tiger nut protein is suitable for patients with diabetes or digestion-dysfunction diseases and plays an important role in the prevention of heart disease [ 3 ]. Therefore, isolated protein from the meals after the oil extraction of tiger nuts can be further processed into health products.
Nowadays, shown in Table 4 , the main extraction methods of tiger nut protein are the alkali extraction–acid precipitation [ 55 ], ammonium precipitation [ 56 ] and reverse micelle extraction [ 57 ].
For tiger nut protein extraction, traditional alkaline extraction–acid precipitation was widely used with the advantages of simple operation and low cost. However, the protein biological activity was compromised during processing, and the discharged acid and alkali may impact on the environment. Compared with the alkaline solution and acid precipitation method, the protein obtained by ammonium precipitation has higher purity (83.4%) and quality, as the structural properties of protein are mildly affected. However, this method is time-consuming and complicated to operate and not suitable for industrial production. The reverse micelle technology is a new effective separation technology. It uses surfactants to dissolve in a non-polar solution to form a polar core, which can solubilize the protein, thereby isolating the protein from the solvent and reducing the denaturation of the protein by the solvent [ 61 ]. At present, the molecular mechanism of reverse micelle extraction of proteins is not yet clear, and the use of organic solvents will bring safety hazards which is not suitable for large-scale industrial production.
The molecular weight of the tiger nut protein is 5.5–88 kDa. The composition of tiger nut protein is 47.5% gluten, 31.8% albumin, 4.7% globulin and 3.8% prolamin [ 59 ]. Furthermore, other research has shown different composition results with the highest gluten content (about 82–91%) in tiger nut protein [ 62 ]. The reason for this difference was possibly because that the proximate composition of tiger nut was mainly dependable on their geographical origin [ 12 ]. The various components of tiger nut protein have different effects on their functional properties, and it is meaningful to find protein components suitable for the production of different products for the comprehensive utilization of tiger nut protein.
Plant proteins can now be regarded as functional ingredients or as biologically active components more than as essential nutrients. Because functional properties of protein often have a tight relationship with its amino acid profile, so the amino acid composition represents the potential quality of a plant protein. Researchers evaluated the nutritional value of tiger nut protein by considering both the essential amino acid profile and protein digestibility. Tiger nut protein contains 18 kinds of amino acid, of which the essential amino acids accounts for 46.03%, largely exceeding the value specified in the WHO/FAO model (36%), higher than soy protein (41.3%) and close to egg protein (48.8%). According to the literature, lysine is the first limiting amino acid of some nuts (Brazil nuts, macadamia nuts and almonds and some cereal grains (rice, white flour, corn, etc.)). However, the amounts of lysine in tiger nut are much greater, accounting for 15.4% of essential amino acids, which is higher than 13.3% of soybean [ 63 ]. Therefore, with respect to lysine amino acid contents, cereal and tiger nut proteins are nutritionally complementary. The first limiting amino acids of the tiger nut protein is methionine. Taking the score of the first limiting amino acid as the protein amino acid score, the amino acid score of tiger nut protein is 78.9, which is higher than soy protein (51.4) and lower than egg protein (97.2). The digestibility of the tiger nut protein was also evaluated. The results showed that tiger nut protein has 76% of in vitro digestibility, slightly lower than soy protein (86%) [ 63 ]. In conclusion, the protein derived from tiger nut is considered high quality and commercial value based on amino acid profile and bioavailability. On the other hand, the protein of tiger nut is limited in methionine. We recommend the tiger nut as the sources of complementary protein.
The tiger nut protein extracted by alkali extraction–acid precipitation with the solubility of approximately 41.29%, emulsifying activity index of 42% and emulsion stability index of 12.6% [ 58 ], which are lower than soybean, peanut and corn proteins. The functional properties of natural tiger nut protein cannot meet the requirements for food processing and production; therefore, it is necessary to improve the physical and chemical properties of the protein by biochemical modification.
The effective modification methods such as ultrasound technology and pH shift have been used in the modification of tiger nut protein obtained by alkali extraction–acid precipitation extraction. The increase in ultrasound power and pH value induced the increase in the solubility and emulsifying properties, respectively. Ultrasound treatment can cause a cavitation effect, which destroys the insoluble protein aggregates, reduces the particle size and enhances the expansion of the hydrophobic groups of the protein molecules [ 58 ]. These treatments directly lead to an increase in the solubility and emulsifying properties of the nut protein. With the increasing pH, the surface hydrophobicity and emulsification ability of the protein firstly decreased and then increased. In the proper pH range, the compact protein structure unfolds, the hydrophobic group wrapped in the protein molecule is exposed and, thus, the surface activity is enhanced, leading to an increase in emulsification [ 64 ]. Consequently, the ultrasound and pH treatment could be applied to make the tiger nut protein suitable for different food processing conditions in the actual production.
Natural antioxidant peptides have the characteristics of low toxicity, high efficiency and easy absorption, which are becoming more and more popular for their use as an antioxidant. Yin et al. analyzed the antioxidant capacity of Tiger nut antioxidant peptide prepared from Tiger nut protein extracted by alkali extraction–acid precipitation. The studies showed that using alkaline protease to prepare antioxidant peptides with the ACE inhibition rate of 74.16% [ 65 ].
There are relatively few studies and applications on tiger nut protein, the future development should focus on the following technologies: functional and nutritional properties of each component, application more than peptide in the food industry.
In addition to the macromolecular nutrients such as oil, starch and protein, studies have shown that there are small molecules or secondary metabolites that are mainly responsible for biological activity, including flavonoids, minerals, vitamins and Stigmasterol [ 17 ]. Among all of the secondary metabolites, the flavonoids quercetin and myricetin show a wide range of biological activities that include strong anti-oxidant, anticarcinogenic, anti-inflammatory and antidiabetic effects. Due to the presence of quercetin, this tuber has aphrodisiac activity, enhancing male sexual libido and performance [ 17 ]. The minerals in the tiger nut are sodium, potassium, calcium, iron, magnesium, zinc, copper and phosphorus. The high potassium (110.70–21.95 mg/100 g) to low sodium ration (99.95–105.6 mg/100 g) of tiger nuts may be imperative in diet formulations for patients with high blood pressure and edema [ 5 ]. Moreover, the presence of vitamin C and E gives the tuber the function of preventing scurvy and promoting liver detoxification [ 17 ]. The cholesterol-lowering activity and the protective effect against cardiovascular disease of the tuber may be due to the stigmasterol. However, the isolation, identification and quantification of these active ingredients, which have not been adequately studied, are necessary for the development of functional properties of tiger nut.
The tubers are rich in nutrients and have a wide range of applications. They can be made into snacks, beverages [ 2 ] and gluten-free [ 66 ] bread due to the flavor of sweet and nutty, dietary fiber and fermentable sugars. In addition, it has certain medical properties. The main product application of tiger nut has been shown in Figure 3 , and the industrial products have been shown in Figure 4 .
Applications of the whole tuber of the tiger nut in the food industry.
Tiger nut tuber and its products (( a ) tuber; ( b ) edible oil; ( c ) liquor; ( d ) crunchy bio toast; ( e ) solid powder drink; ( f ) meal replacement powder).
“Horchata de chufa” is a plant milk produced by tiger nut and is still popularly consumed in Spain. Compared with animal milk, plant milk has many positive health effects on the human body, especially for people with milk allergies and lactose intolerance. The tiger nut milk is produced by the steps of wet milling, filtration, addition of ingredients, sterilization, homogenization, aseptic packaging and refrigeration. It contains phenolic compounds, unsaturated fatty acids and biologically active substances [ 62 ].
In spite of the advantages of “Horchata de chufa”, it has not been widely distributed worldwide due to the high microbiological loads of harvested tubers and short shelf life. Moreover, conventional thermal treatments such as pasteurization and sterilization result in an undesirable loss of the most appreciated sensory characteristics of “Horchata de chufa”. Owing to this, the food industry looks for alternative technologies that can improve the microbiological quality of “Horchata de chufa” while preserving the sensory characteristics.
Tiger nut contains a high amount of starch that is easy to gelatinize during the pasteurization process, leading to the coagulation of the milk and limits the output. Exogenous amylase can be used to increase the yield through the in situ hydrolysis of starch, which is a process that increases the sweetness of milk and is suitable for the industrial production of tiger nut milk [ 67 ]. In addition, heat treatment could cause the loss of nutrients such as the total protein, phenols and vitamins of the tiger nut milk. Compared with thermal processing, non-thermal processing retains the nutritional quality and is more suitable for the production of tiger nut milk [ 68 ]. In non-thermal processing, ultra-high-pressure homogenization [ 69 ], short-wave ultraviolet treatments [ 70 ] and pulsed electric field [ 71 ] can effectively inhibit the growth of microorganisms and extend the shelf life. On the other hand, studies have shown that the microencapsulation of tiger nut milk by a blend of inulin and modified tiger nut starch can make a product with good characteristics and shelf life [ 72 ].
The by-products during tiger nut milk production account for about 60% of the harvested material and can be used as sources of polysaccharides, fibers, oil and antioxidants (vitamin E and polyphenols) [ 6 ]. The by-products are divided into two parts by pressing and filtering (shown in Table 5 ): the liquid phase contains biologically active substances such as phenols [ 73 ] and the solid phase include dietary fibers [ 74 ].
Application of tiger nut milk by-products in the food industry.
Tiger Nut By-Products | Source | Food Product |
---|---|---|
liquid phase | phenolic compounds | natural antioxidants |
replacing water | cooked pork liver meat product | |
carbon source for growth of probiotic bacteria | fermentable substrates | |
solid phase | Tiger nut fiber | cereal foods (such as chips, breakfast cereal or dry pasta) |
pork pies, pork burgers and dry-cured sausages |
The liquid phase of milk by-products is an important source of natural antioxidants, which have antioxidant properties and can inhibit lipid peroxidation. Elena et al. [ 75 ] extracted phenolic compounds from the by-products, and the results showed that 222.6 mg of gallic acid equivalents was obtained from 100 g of matter. Therefore, it can be regarded as a valuable source of phenolic compounds with potential applications in food industry, nutraceuticals and cosmetics. The liquid by-products can be used as an ingredient replacing water in a cooked pork liver meat product. The pig liver paste produced with 50 and 100% of water replacement had a higher content of heme and a low degree of formation of myoglobin, which had good sensory properties [ 76 ]. Sanchez et al. proposed the liquid by-products of the tiger nut milk as carbon source for growth of probiotic bacteria ( Lactobacillus acidophilus and Bifidobacterium ) and metabolic activity. The results indicated that it has a high potential for probiotic microorganisms’ growth and stability as fermentable substrates [ 77 ], but more studies are required to establish the doses, the stability and its compatibility with other probiotic microorganisms.
The solid by-products of tiger nut milk are the main source of fiber. Compared with other sources of dietary fibers (oat bran, rice bran, sugarcane waste), tiger nut fiber has higher water holding capacity, oil holding capacity and emulsification stability and low water absorption [ 78 ]. Studies have shown that foods rich in dietary fiber are essential for preventing colon cancer, constipation, obesity and cardiovascular disease [ 9 ]. Adding solid co-products to cereal foods (such as chips, breakfast cereal or dry pasta) would reduce the capacity of generic vitreous wheat-based matrix to interact with solvents from the 10% substitution level, with diminished surface tension, wettability and water–oil diffusion properties [ 79 ]. Tiger nut fibers have the ability to lower cholesterol, which can be used in pork pies [ 80 ], pork burgers and dry-cured pork sausages [ 81 ] with higher nutritional quality (lesser percentage of fat and more total dietary fiber content) and cooking characteristics. Furthermore, the solid by-products of tiger nut milk can also be used as a carrier of unsaturated fatty acids oil rich in dry-cured sausages for avoiding the problems related with its incorporation in the meat matrix and for controlling lipid oxidation [ 82 ].
Demand for gluten-free products is increasing as a result of the increase in the prevalence of celiac disease, but high-quality gluten-free bread production is a big challenge [ 83 ]. To improve the organoleptic properties and shelf life, cereal flours, starches, proteins, hydrocolloids and emulsifiers are usually mixed in the production of gluten-free bread. The tiger nut was evaluated as a new ingredient in gluten-free products [ 83 ]. In gluten-free bread, tuber flour can be used as emulsifier and shortening when combined with chickpea flour; as a result, the bread products have good baking characteristics in color, hardness and volume [ 84 ]. Moreover, tiger nut flour can be added as a functional ingredient to promote a reduction in diameter, expansion ratio, true density and total pore volume in the extrudates and the ash, protein and total phenol content of extruded snacks [ 85 ]. In a subsequent study, compared with biscuits containing only corn flour, biscuits made with tiger nut powder have better shape, cross-sectional area, hardness and surface appearance [ 86 ].
Due to the good sensory properties such as sweet taste, it has a wide range of applications in beverage. Badejo et al. [ 87 ] used tiger nut as a synergistic vehicle in combining leafy vegetable ( Momordica charantia and Vernonia amygdalina ) of functional beverages. The addition of tiger nut reduced bitter taste and increased antioxidant and anti-diabetic potentials of the beverage. Furthermore, carbonated tiger nut beverages mixed with apple, pineapple and coconut showed good qualities in chemical composition, physiochemical properties, microbiological evaluation, vitamins, mineral content and shelf life, which are all in compliance with standard specifications [ 88 ].
There has been a trend of using non-durum wheat ingredients to enhance the nutritional and functional characteristics of pasta. Tiger nut was mixed with wheat flour to produce composite fresh pasta. The addition of tiger nut powder significantly improved the fiber, fat and mineral qualities of the product. The substitution of 30% tiger nut powder can ensure the fiber content of products exceeds 3%. However, the gluten protein structure needs to be strengthened in order to reduce cooking loss and increase the firmness of the pasta [ 89 ]. The powder (20 and 40%) and xanthan gum (1%) incorporation into fresh egg pasta compensates for the problem displaying a good gluten network. It has shown that the rheological and structure properties of pasta were modified significantly with the optimum cooking time for 2 min [ 90 ]. Uncooked pasta has good water absorption and swelling index, less cooking loss. The cooked pasta has good hardness, elasticity, color and sensory attributes [ 91 ].
Tiger nut has been shown to be a good source of bioactive substances. It contains polyphenols, flavones, minerals, essential fatty acids and vitamins C, D and E, etc. Therefore, it might possess medicinal properties. Ademosun & Oboh sought to investigate the radical scavenging ability and in vitro inhibition of lipid peroxidation, α-amylase and α-glucosidase activities of tiger nut extracts. The assessed antioxidants of aqueous extracts of the tiger nut as typified by 1,1-diphenyl-2 picrylhydrazyl (DPPH) and hydroxyl (OH) radicals showed scavenging abilities and the inhibition of Fe 2+ -induced malondialdehyde (MDA) production in rat pancreas in vitro. The results showed that the EC50 of DPPH· and OH· scavenging abilities, Fe 2+ -chelating ability, inhibition of Fe 2+ -induced MDA production and inhibition of α-amylase and α-glucosidase activities by aqueous extracts of the tiger nut are 9.63 ± 0.7 mg/mL, 3.01 ± 0.12 mg/mL, 0.72 ± 0.07 mg/mL, 2.09 ± 0.10 mg/mL and 0.76 ± 0.06 mg/mL, respectively [ 92 ]. The findings support the hypothesis that tiger nut maybe beneficial in the management of type 2 diabetes. In other studies, the tiger nut powder was administered to the rats daily showed anti-inflammatory and anti-apoptotic effects to prevent testicular dysfunction [ 93 ], ameliorated male arousal [ 94 ], reduced diarrheal symptoms in albino rats [ 95 ] and reduced oxidative stress in liver and inflammatory with atherosclerosis [ 96 ]. The above results are most likely related to the presence of alkaloids, quercetin, vitamins, steroids and zinc, etc., in tiger nuts. Therefore, in addition to be the food and industrial materials, tiger nuts may also be developed into functional foods. Nevertheless, future investigations are warranted to confirm these effects of tiger nut in humans and to identify the specific ingredients that play the medicinal role.
Tiger nut is a valuable source for diverse nutrients, such as oil, starch, fiber, protein, phenolic compounds, etc. Several conventional (Soxhlet extraction and mechanical expressing) and alternative innovative methods (gas, enzyme, microwave and ultrasonic assistance, SC-CO 2 and SBE) have been developed for the efficient recovery of tiger nut oil. GAME has a high oil yield, similar to SE. ME has the advantages of low free fatty acid and acid value, while having a lower yield. Tiger nut starches obtained by alkaline, sodium metabisulfite and water extractions have relatively high contents of amylopectin with good thickening and bonding effects. The recovery of protein from tiger nut is performed using the alkali extraction–acid precipitation, ammonium precipitation and reverse micelle extraction methods. The protein obtained by ammonium precipitation has higher purity and quality, but the process is more time-consuming. The combination of multiple techniques is the direction of the future development of tiger nut. In addition, it can be used in production of edible oil, jelly, candy, pharmaceutical standard, antioxidant peptide, etc., owing to diverse nutrients. On the other hand, it could be developed with whole tuber in the production of milk, gluten-free bakery, beverages and pasta. Innovative methods are still needed to fully utilize the whole tiger nut for more healthy products.
Tiger nut is an excellent and healthy crop from both a nutritional and commercial point of view. Green production and comprehensive utilization are the future development direction. In the process of the full utilization of tiger nut, the first step is to extract oil, and the extraction method of oil has a certain influence on the yield and physiochemical properties of subsequent starch, protein and fiber. Therefore, the use of innovative combination methods to fractionate and extract the nutrients oil, starch, protein and fiber in a tuber is worth thinking about in the future. It is meaningful to make modifications to the natural tiger nut starch and develop new varieties of starch, making it adaptable to different processing conditions and use it in biological preservative films. In addition, investigating the functional properties of protein and using it in baking and nutritional meal replacement foods is crucial to the study of tiger nut protein. Due to its high fiber content, it can be used in the development of food for improving gut health and weight loss.
We are grateful to Changhui Zhao for editing of English language.
SE | Soxhlet extraction |
ME | mechanical expressing |
GAME | gas assisted mechanical expression |
MEEA | mechanical compressing with enzyme assistance |
MAE | microwave-assisted extraction |
MUAAEE | microwave-ultrasonic-assisted aqueous enzymatic extraction |
SC-CO2 | supercritical carbon dioxide fluid extraction |
SBE | subcritical n-butane extraction |
MUFA | monounsaturated fatty acids |
PUFA | polyunsaturated fatty acids |
SFA | saturated fatty acid |
Y.Y.: investigation, supervision, validation, writing—review and editing; X.L.: investigation, formal analysis, writing—original draft; T.Z.: formal analysis, project administration, visualization; C.Z.: Language; S.G.: data curation; Y.P.: resources; F.G.: conceptualization, validation, writing—review and editing. All authors have read and agreed to the published version of the manuscript.
This research was funded by Jilin Scientific and Technological Development Program, grant number 20200502002NC.
Informed consent statement, data availability statement, conflicts of interest.
The authors declare no conflict of interest.
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Tiger nut ( cyperus esculentus l.): nutrition, processing, function and applications.
Graphical Abstract
2. tiger nut oil, 2.1. extraction methods of tiger nut oil, 2.2. physiochemical and functional characteristics of tiger nut oils, 2.2.1. fatty acid profile of nut oil produced by different extraction methods, 2.2.2. chemical characteristics of tiger nut oil by different extraction methods, 2.2.3. functional properties of tiger nut oil, 2.3. applications of tiger nut oil, 3. tiger nut starch, 3.1. extraction and physicochemical properties of tiger nut starch, 3.2. applications of tiger nut starch, 4. tiger nut protein, 4.1. extraction of tiger nut protein, 4.2. composition and nutritional evaluation of tiger nut protein, 4.3. physiochemical characteristics of tiger nut protein, 4.4. applications of tiger nut protein, 5. tiger nut-based food products, 5.1. tiger nut milk, 5.2. comprehensive utilization of tiger nut milk by-products, 5.3. gluten-free bakery products, 5.4. tiger nut beverage, 5.5. tiger nut pasta, 6. medicinal properties of tiger nut, 7. conclusions, author contributions, institutional review board statement, informed consent statement, data availability statement, acknowledgments, conflicts of interest, abbreviations.
SE | Soxhlet extraction |
ME | mechanical expressing |
GAME | gas assisted mechanical expression |
MEEA | mechanical compressing with enzyme assistance |
MAE | microwave-assisted extraction |
MUAAEE | microwave-ultrasonic-assisted aqueous enzymatic extraction |
SC-CO2 | supercritical carbon dioxide fluid extraction |
SBE | subcritical n-butane extraction |
MUFA | monounsaturated fatty acids |
PUFA | polyunsaturated fatty acids |
SFA | saturated fatty acid |
Click here to enlarge figure
Method | Condition | Oil Yield | Reference |
---|---|---|---|
SE | Powder: n-hexane = 1:10(w/v), extraction temperature 80 °C, 6 h | 29.85 g/100 g | [ ] |
MAE | petroleum ether and acetone (2:1, v/v), microwave power 420 W, liquid to solid ratio 7.0 mL/g, 75 °C and 55 min | 24.12 g/100 g | [ ] |
ME | Pressing temperature 40 °C, 120 min, 30 MPa, speed 0.1 mm/s | 19.94 g/100 g | [ ] |
GAME | Temperature 40 °C, CO pressure 20 MPa, CO flow 8.5 kg/h, pump pressure 30 MPa, 120 min | 28.48 g/100 g | [ ] |
MEEA | Protease, α-amylase and Viscozyme L(1/1/1, w/w/w), mixed enzyme addition 1%, pH 8, 40 °C | 20.79 g/100 g | [ ] |
MUAAEE | Cellulase, pectinase and hemicellulase (1/1/1, w/w/w), 40 °C, pH 3.5, ultrasonic power 300 w, microwave power 300 w, radiation time 30 min, enzyme concentration 2%, liquid to solid ratio 10 mL/g and enzymolysis time 180 min | 25.44 g/100 g | [ ] |
SC-CO | Extraction temperature 60 °C, pressure 28 MPa, 90 min | 27.79 g/100 g | [ ] |
SBE | Extraction temperature 40 °C, extraction time 50 min | 26.03 g/100 g | [ ] |
Fatty Acid | SE | ME | MAE | MUAAEE | SC-CO | SBE |
---|---|---|---|---|---|---|
Palmitic acid (C16:0) | 11.65 ± 0.28 | 11.98 ± 0.00 | 12.08 ± 0.16 | 11.86 ± 0.23 | 12.36 ± 0.01 | 12.14 ± 0.01 |
Palmitoletic Acid (C16:1) | 0.26 ± 0.00 | - * | 0.22 ± 0.00 | 0.25 ± 0.00 | - * | - * |
Cydonic acid (C17:0) | 0.07 ± 0.00 | - * | 0.06 ± 0.00 | 0.07 ± 0.00 | - * | - * |
Stearic acid (C18:0) | 2.43 ± 0.05 | 4.92 ± 0.00 | 2.24 ± 0.04 | 2.37 ± 0.07 | 4.76 ± 0.00 | 4.84 ± 0.00 |
Oleic acid (C18:1) | 74.52 ± 0.51 | 73.97 ± 0.01 | 75.60 ± 0.58 | 74.73 ± 0.46 | 73.83 ± 0.01 | 74.10 ± 0.01 |
Linoleic acid (C18:2) | 9.63 ± 0.12 | 8.75 ± 0.00 | 8.85 ± 0.13 | 9.46 ± 0.18 | 8.86 ± 0.00 | 8.75 ± 0.00 |
α-linolenic acid (C18:3) | 0.21 ± 0.00 | 0.38 ± 0.00 | 0.91 ± 0.00 | 0.2 ± 0.00 | 0.19 ± 0.00 | 0.17 ± 0.00 |
Arachidic acid (C20:0) | 0.45 ± 0.00 | - * | 0.41 ± 0.00 | 0.42 ± 0.00 | - * | - * |
Eicosenoic acid (C20:1) | 0.28 ± 0.00 | - * | 0.28 ± 0.00 | 0.29 ± 0.00 | - * | - * |
Saturated fatty acids | 14.25 ± 0.05 | 16.90 ± 0.01 | 14.69 ± 0.05 | 14.65 ± 0.07 | 17.12 ± 0.01 | 16.98 ± 0.01 |
Monounsaturated fatty acids | 75.06 ± 0.12 | 73.97 ± 0.01 | 76.16 ± 0.12 | 75.24 ± 0.13 | 73.83 ± 0.01 | 74.10 ± 0.01 |
Polyunsaturated fatty acids | 9.84 ± 0.07 | 9.14 ± 0.00 | 9.04 ± 0.07 | 9.72 ± 0.09 | 9.05 ± 0.00 | 8.92 ± 0.00 |
Reference | [ ] | [ ] | [ ] | [ ] | [ ] | [ ] |
Method | Refractive Index (25 °C) | Acid Value (mg/g) | Peroxide Value (meqO /kg) | Saponification (mg/g) | Iodine Value (g/100 g) | Reference |
---|---|---|---|---|---|---|
SE | 1.46 ± 0.00 | 4.15 ± 0.32 | 16.26 ± 0.53 | 187.25 ± 1.42 | 84.78 ± 1.13 | [ ] |
ME | 1.48 ± 0.00 | 1.90 ± 0.01 | 15.76 ± 0.00 | 174.53 ± 0.62 | 67.35 ± 0.49 | [ ] |
MAE | 1.46 ± 0.00 | 2.26 ± 0.17 | 8.78 ± 0.42 | 185.67 ± 1.37 | 85.41 ± 1.06 | [ ] |
MUAAEE | 1.46 ± 0.00 | 2.35 ± 0.13 | 7.63 ± 0.35 | 187.52 ± 1.23 | 83.67 ± 0.85 | [ ] |
SC-CO | 1.46 ± 0.00 | 3.39 ± 0.16 | 15.76 ± 0.00 | 175.33 ± 1.61 | 65.60 ± 0.14 | [ ] |
SBE | 1.46 ±0.00 | 2.86 ± 0.02 | 23.64 ± 0.00 | 176.71 ± 0.81 | 66.15 ± 0.64 | [ ] |
Method | Condition | Amylose (g/g) | Amylopectin (g/g) | Protein Content | Reference |
---|---|---|---|---|---|
Alkaline method | solid–liquid ratio of 1:15, 0.15% sodium hydroxide, soak 30–40 min, 45 °C drying 24 h | 16.18 | 83.82 | - | [ ] |
Sodium metabisulfite extraction | sodium metabisulfite solution (0.075% w/v) dispersing, 150 µm muslin cloth filtering, air dried for 10 h, further dried for 5 h at 50 °C | 11.5 | 88.5 | - | [ ] |
Water extraction | milled with water, Gauze filter, 150 μ mesh filter, 40 °C drying 18 h | 19.1 | 80.9 | - | [ ] |
Alkali extraction-acid precipitation | alkali extraction pH 8.5, extraction time 1.5 h, acid precipitation pH 4.5, incubated at 4 °C for 2 h | - | - | 72% | [ ] |
Ammonium precipitation | pressing of the pre-soaked mush, filter through a 13-µm pore-size membrane, 50% w/v ammonium sulphate, 16 h, 6- to 8- kDa cut-off membrane tube dialyzing | - | - | 83.5% | [ ] |
Docusate sodium/isooctane reverse micelle extraction | The pre-extraction condition are as follows: 0.05 g/mL feed volume, 40 °C, 86 min, pH 7, the docusate sodium mass concentration is 0.12 g/mL, the water content is 16, the KCl concentration is 0.02 mol/L. The back-extraction conditions were as follows: stripping time was 5 min, the pH of the aqueous phase was 11, and the KCl concentration was 1.2 mol/L. | - | - | - | [ ] |
Tiger Nut By-Products | Source | Food Product |
---|---|---|
liquid phase | phenolic compounds | natural antioxidants |
replacing water | cooked pork liver meat product | |
carbon source for growth of probiotic bacteria | fermentable substrates | |
solid phase | Tiger nut fiber | cereal foods (such as chips, breakfast cereal or dry pasta) |
pork pies, pork burgers and dry-cured sausages |
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Yu, Y.; Lu, X.; Zhang, T.; Zhao, C.; Guan, S.; Pu, Y.; Gao, F. Tiger Nut ( Cyperus esculentus L.): Nutrition, Processing, Function and Applications. Foods 2022 , 11 , 601. https://doi.org/10.3390/foods11040601
Yu Y, Lu X, Zhang T, Zhao C, Guan S, Pu Y, Gao F. Tiger Nut ( Cyperus esculentus L.): Nutrition, Processing, Function and Applications. Foods . 2022; 11(4):601. https://doi.org/10.3390/foods11040601
Yu, Yali, Xiaoyu Lu, Tiehua Zhang, Changhui Zhao, Shiyao Guan, Yiling Pu, and Feng Gao. 2022. "Tiger Nut ( Cyperus esculentus L.): Nutrition, Processing, Function and Applications" Foods 11, no. 4: 601. https://doi.org/10.3390/foods11040601
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2014, European Journal of Lipid Science and Technology
Onyinye Ezeh
Ken-Bossman Awuni Jnr
Tiger nut (Cyperus esculentus var. sativa) as a plant, its derivatives/uses and benefits are mainly discussed. The hunt for lesser known and un-exploited crops, many of which are potentially valuable as human and animal foods has been on the high side now to retain the equilibrium between population growth and agricultural productivity, particularly in the tropical and subtropical areas of the world. Tiger nut is an underutilized crop of the family Cyperaceae, which produces rhizomes from the base and tubers that are somewhat spherical. Pollination is by wind. Young tubers are white, while older tubers are covered by a yellow outer membrane; they are usually found within six inches of the ground surface. Vegetative colonies of its plants are often produced from the tubers and their rhizomes. They are usually preserved by sun drying for about three months before storage. It can be eaten raw, dried, roasted, or grated and can be subjected to further processing. Its uses in cooking and as fuel, baking flour, fish baits; milk in lieu of cow's milk are outlined. Regarding the plant high percentage of carbohydrates (mono-and di-), fibre, and oil (especially oleic acid) and its moderately high level of protein, minerals (calcium, magnesium, iron and phosphorous), and vitamins C and E makes it a good source of food for humans and animals. It is a cheap source of nutrition for both the rich and the poor. The health benefits reflect reduction of low density lipoprotein-cholesterol, which is good for sports' men and women and those intending to lose weight; it is also said to serve as a cure for flatulence and diarrhea, and as control against heart attacks, thrombosis and colon cancer, among others. The presence of anti-nutrients like polyphenols and tannins can be eliminated by boiling in water. The tiger nut, though under-utilized, is still a good food snack for all. There is a need for awareness creation on tiger nut's inherent nutritional properties.
Ahmad Gambo
RICHARD OMOREGIE
Anne Mette Lykke , Souleymane Bado
Journal of The American Oil Chemists Society
The deodoriser distillate (DOD) of Indian soybean oil obtained from two industries processing soybean oil was investigated for its physicochemical characteristics, its composition of tocopherols, phytosterols, fatty acids and recovery of phytosterols for use in nutraceutical products. It was found that the two DOD samples studied were dark in color and had higher amounts of free fatty acids (22.7 and 49.9%), unsaponifiable matter (11.8 and 21.9%) (5–10 times found in soybean oil), total tocopherols (1957–2256 mg/100 g) (20 times the amount in soybean oil), and 6–10% of phytosterols (12–20 times the soybean oil). The fatty acids found were palmitic (23.2–25.5%), stearic (1.4–2.4%), oleic (23.8–26.1%), linoleic (40.4–41.1%) and linolenic (2.7–3.2%) acids. The unsaponifiable matter (21.9%) and phytosterols (8.7%) content of DOD-2 were higher than in DOD-1 and hence was more suited for isolation of phytosterols. Using hexane and water for crystallisation, the DOD-2 yielded a phytosterol fraction with lower recovery of 13.2–17.8% while treatment with alkali to remove FFA and the glycerides followed by organic solvent extraction yielded unsaponifiable matter containing phytosterols with a recovery of 74.6%. Later the unsaponifiable matter was purified by double crystallisation into a mixture of phytosterols of 87% purity containing β-sitosterol (34.3%), stigmasterol (3.1%) and campesterol (50.1%). The product may find use in foods, pharmaceuticals, cosmetics and allied industries probably as a nutraceutical.
Industrial Crops and Products
Domingo Carlos Salazar-García
Oduro Ibok , William Ellis
Two varieties of tiger nuts obtained from eight different sites and two harvesting periods in Ghana were evaluated for their chemical composition. The effect of site on sensory quality of milk extracted was also evaluated. The ranges (g kg-1) for fat, ash, carbohydrate and fiber of the black and brown varieties were 155.4 respectively. The mean energy and free fatty acid values for black and brown tubers for all sites and both planting periods were 4707.7 kcal kg-1 , 4585.4 kcal kg-1 and 0.59% and 0.75% respectively. The ranges for mineral compositions (mg kg-1) for the black and brown varieties included sodium 521.19-924.07, 484.51-1075.80; potassium 6750.0-12780, 8052.0-14241; magnesium 535.0-747.0, 551.0-740.0; phosphorus 279.33-477.41, 258.65-478.37 and zinc 23.08-60.58, 33.57-55.84. With the exception of milk from Tanoso tubers, milk from all other sites was acceptable to the sensory panel. The fat and milk obtained from tiger nuts tubers could be exploited for industrial and commercial applications.
IJAERS Journal
The appropriate concentrations of inulin and modified tiger nut starch were evauated in a sequential experimental design to improve the microencapsulation process of tiger nut milk. The stability emulsification index was the response variable studied to evaluate the effectiveness of the microencapsulation process. The concentrations observed through the central composite design (CCD) that most improved the stability emulsification index corresponded to 9.40% inulin and 0.40% modified tiger nut starch. The preservation capacity of the microencapsulated tiger nut milk was evaluated by determining the solubility in water (76%) and oxidative stability (46 h) of the microspheres. The chemical composition indicated important concentrations of protein (5.40%), calcium (191.65 mg / 100 g), carbohydrate (65.10%) and vitamin C (3.17%).
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Cleiton DCA
European Journal of …
Anders Carlsson
Frantisek Kreps
IJAR Indexing
Badiru Dolapo
European Journal of Lipid Science and Technology
George Boskou
Food Research International
samuel yeboah
Susana Casal
Maria Dolores Savarese , Cristina Parisini
Ahmed Rebai
Mohammed Tawfeek
International Journal of Food Studies
Amparo Chiralt
Tijjani Imam
Nutritive Mineral Content of Dichrostachy cinerea (Sickle bush) Seeds and Fruits
Iliya Yerima
yerima iliya
American Journal of Immunology
Prof. Mohamed Labib Salem
Food and Bioproducts Processing
Ana Paula Gomes
Frédéric Fine
African Journal of Pharmacy and Pharmacology
Uwakwe Onoja , John Ihedioha
Mohsen Zommara
Plant biotechnology journal
Rosemary White
Mohamed Edbeib
ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT
IOSR Journals
Mohammad Hossein Tavassoli Kafrani
European Journal of Lipid Science …
Erica R Baümler
Ana Maria Beltran
Mertxe de Renobales
Olivera Koprivnjak
Nalda Romero
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Download full-text PDF Read full-text. ... Through the review of related literature, this study demonstrates that indigenous foods contribute to improving household health, food, and nutritional ...
The tiger nut is the tuber of Cyperus esculentus L., which is a high-quality wholesome crop that contains lipids, protein, starch, fiber, vitamins, minerals and bioactive factors.
The tiger nut is the tuber of Cyperus esculentus L., which is a high-quality wholesome crop that contains lipids, protein, starch, fiber, vitamins, minerals and bioactive factors. This article systematically reviewed the nutritional composition of tiger nuts; the processing methods for extracting oil, starch and other edible components; the physiochemical and functional characteristics; as ...
Download full-text PDF Read full-text. ... Considering all these enormous benefits and applications of tiger nut, it is the intention of this review, to add to the scope of available information ...
This paper is a review on little history and the composition of Tigernut ranging from proximate, mineral and amino acid content. ... Tiger Nut ( Cyperus Esculentus ): Composition, Products, Uses and Health Benefits - A Review ... Semantic Scholar is a free, AI-powered research tool for scientific literature, based at the Allen Institute for AI.
Download Free PDF. Tigernut: A Nutrient-Rich Underutilized Crop with Many Potentials. Tigernut: A Nutrient-Rich Underutilized Crop with Many Potentials. Alkasim kabiru Yunusa ...
A similar study on the effect of tiger nut oil from Xinjiang China, on female experimental mice indicated that the oil displayed significant free Annals of Science and Technology 2020 Vol. 5(1) 31-38 |33 Adenowo and Kazeem, 2020 A mini review on Tiger nut radical scavenging as well as antioxidant activity (Jing et al., 2013).
Download Free PDF. Download Free PDF. TIGER NUT ( C Y P E R U S E S C U L E N T U S ): COMPOSITION, PRODUCTS, USES AND HEALTH BENEFITS - A REVIEW ... This review was intended to provide an overview on the nutritional and nutraceutical properties of various tigernut products. Also to provide information on the effects of various processing ...
Download full-text PDF Download full-text PDF Read full-text. ... Maduka and Ire new review 2018.pdf. ... wrote the first draft of the manuscript and managed the literature searches. Author
1. Introduction. Tiger nut (Cyperus esculentus L.) also called chufa sedge, is a tuber known under various names such as: nut grass, earth or ground almond, yellow nut and edible galingale [1]. It is commonly used as a healthy food for humans and animals in some parts of the world like Africa, Europe and America [1].
Literature Review on Tiger Nut - Free download as PDF File (.pdf), Text File (.txt) or read online for free. The document discusses the challenges of writing a literature review on the niche topic of Tiger Nut. It notes that locating relevant sources can be difficult given the limited research on Tiger Nut. Additionally, critically analyzing and synthesizing disparate studies into a cohesive ...
The tiger nut is the tuber of Cyperus esculentus L., which is a high-quality wholesome crop that contains lipids, protein, starch, fiber, vitamins, minerals and bioactive factors. This article systematically reviewed the nutritional composition of tiger nuts; the processing methods for extracting oil, starch and other edible components; the physiochemical and functional characteristics; as ...
However, tiger-nut milk (kunun-aya) must be consumed within 2-4 hours at 40°C-100°C due to its poor shelf life Rowland et.al,(2017). Some researchers have reported the ability of pasteurization and addition of citric acid, ginger and garlic to extend the shelf-life of tiger-nut milk by minimum of 2-3 days Nwobosi et. al, (2013). The shelf ...
The composition of tiger nut is extensively reviewed in many literature (Aremo et al., 2015; Bado et al., 2015; Codina-Torrella et al., 2015), but little is known about the nutrient transfer from tiger nuts to the tiger nut milk after the extraction procedure. Due to inadequate data on
This review article summarizes the current knowledge about the major nutrients of the tiger nut, the processing methods, their physicochemical properties, functional characteristics and the applications in the industry. 2. Tiger Nut Oil. The tiger nut contains a substantial amount of lipids (22.14-44.92%).
The medicinal properties of Tiger nut are seldom discussed, although its medicinal use is well known in folklore activities. To explore the medicinal properties of Tiger nut, This review tries to investigate the potential anticancer properties of components issued from Tiger nut by reviewing the existing literature in the field.
Download full-text PDF Download ... sensory profile of gluten‐free tiger nut ... Considering all these enormous benefits and applications of tiger nut, it is the intention of this review, to add ...
tiger nut, the processing methods, their phys icochemical properties, functional character-istics and the applications in the industry. 2. Tiger Nut Oil The tiger nut contains a substantial amount of lipids (22.14-44.92%). The lipid profil-ing is similar to olive oil that is considered to be the most suitable fat for human consump-tion [14].
Download full-text PDF Read full-text. Download full-text PDF. ... dried, roasted, and prepared as tiger nut milk or oil, as well as used as a composite in the production of confectioneries [18 ...
III Physical, chemical and functional properties of tiger nuts selected from Ghana, Cameroon and UK (market (Spain) Abstract The tiger nut (Cyperus esculentus) has attracted a lot of unsubstantiated health claims, yet there is a dearth of research investigation within Ghana specifically in the area of
3. Magnesium Research has shown that tiger nuts have the perfect content of magnesium to help promote normal nerve and muscle function, regulate sugar and blood pressure levels, strengthen bones, process protein and keep you healthy. 4. Protein Tiger nuts are one of the best, non-meat source of protein that there is.
Tiger nut (Cyperus esculentus var. sativa) as a plant, its derivatives/uses and benefits are mainly discussed. The hunt for lesser known and un-exploited crops, many of which are potentially valuable as human and animal foods has been on the high side now to retain the equilibrium between population growth and agricultural productivity, particularly in the tropical and subtropical areas of the ...
Download full-text PDF Read full-text. Download full-text PDF. ... Tiger-nut (Cyperus esculentus) is a tuber with high health benefits and nutritive value, found in the tropical and Mediterranean ...