Tiger Nut Oil Research Articles

Thermal, structural, and sensory properties of tiger nut oil (Cyperus esculentus L.) – beeswax oleogels flavoured with butter and honey

AbstractThe aims of this study were to prepare butter and honey flavoured tiger nut oil oleogels with beeswax oleogelator and to compare them with the unflavoured control sample. The oleogels prepared with 10 wt% beeswax and 0.5 wt% of each flavour addition were analysed for main physicochemical, thermal, and structural properties. In addition, a trained panel described the samples with 11 sensory descriptive (hardness, spreadability, roasted, liquefaction, rancid, waxy, nutty, butter, honey, cooling, and mouth coating) terms. It was found that the oleogels melt around 52 °C and included β′ type polymorphs. The sensory data proved that the samples were quite well spreadable and had enough hardness to stay as solid-fat samples at room temperature. Further, addition of butter and honey flavours masked the waxy attribute. In conclusion, flavoured tiger nut oil-beeswax oleogels were new and successful products, and future studies with food applications are suggested.

Enzymatic synthesis of novel structured lipids with tiger nut oil: optimized by response surface methodology

Enzymatic synthesis of novel structured lipids with tiger nut oil: optimized by response surface methodology

Effect of hot-air drying on drying characteristics and quality of tiger nut.

The delayed drying of newly harvested tiger nuts can lead to mold and rancidity. Timely drying is therefore important. However, few studies have analyzed the impact of hot-air drying on the quality of tiger-nut oil and starch, making it essential to establish optimal drying conditions. The results showed that the drying temperature was the most important factor affecting the drying speed, followed by drying airflow rate and loading capacity. A logarithmic model can describe the hot-air drying process of tiger nuts. The oil yield of tiger nut was highest after drying at 60 °C, reaching 22.40%. Meanwhile, the starch extracted from after drying at 60 °C had the highest solubility and expansion rate, 4.77% and 9.74%, respectively. Starch has the highest viscosity after drying at 70 °C, and it forms gel easily after aging. High-quality tiger nuts should be produced under optimal conditions: a hot-air drying temperature of 60 °C, an airflow rate of 1.0 m s-1, and a loading capacity of 100 g. The results of this study have practical implications for the effective drying of tiger nuts. © 2024 Society of Chemical Industry.

Effect of freeze-thaw treatment on the yield and quality of tiger nut oil

To investigate the effect of freeze-thaw (FT) process on the yield and quality of tiger nut oil, tiger nuts were subjected to 0–12 cycles of FT treatment. Results indicated that FT treatment ruptured the cell structure of tiger nut, resulting in an increase in oil yield. Acid value (2.09–2.42 mg KOH/g) and peroxide value (0.40–0.42 mmol/kg) increased with the number of FT cycles, but the increments were small. Likewise, slight differences in fatty acid composition and thermal properties between control and FT-treated samples were observed. FT treatment remarkably increased the bioactive components (e.g., vitamin E, sterols, chlorophyll and carotenoids) in the oil and extended the oxidation induction time from 1.2 to 5.57 h. FT treatment altered the volatile composition of tiger nut oil, increasing the relative content of heterocycles and pyrazines such as 2-methoxy-4-vinylphenol, trimethylpyrazine and tetramethylpyrazine. It was suggested that FT treatment prior to oil extraction was beneficial to improve the oil yield and quality.

Insights on tiger nut (Cyperus Esculentus L.) oil-loaded microcapsules: characterization and oxidation stability analysis

In this paper, tiger nut oil-loaded microcapsules (TNOMs) were prepared by complexation soybean protein isolate (SPI) and maltodextrin (MD) as wall materials using the spray drying method with tiger nut oil (TNO) as the core material, and its physicochemical properties and stabilities were characterized and analyzed. Under the optimum conditions, the encapsulation efficiency (EE) of TNOMs could reach up to 91.23%. Of note, after 60 days of storage at 60 °C, the peroxide value (PV) of TNO was almost 21.8 times as much as that of TNO encapsulated. Furthermore, TNOMs had good thermal stability below 200 °C and are sufficient for the general food processing needs. By fitting Arrhenius oxidation kinetics model, it was predicted that the shelf life of the product stored at 25 °C was 352.48 d. Therefore, it is promised to be applied to the development of high oleic acid food in the future. This study offered a theoretical framework for utilization and broadening the range of applications of TNO in the food industry.

Effects of different isolation methods on the structure and functional properties of starch from tiger nut (Cyperus esculentus L.) meal

Tiger nut (Cyperus esculentus L.) tuber meal as the major by-product of tiger nut oil production is a promising starch source. Starches obtained from tiger nut meal using different isolation methods were compared: distilled water (DWS), citric acid (CAS), enzyme (ESS), 0.5 g/L NaOH (LNS-0.5), 2 g/L NaOH (MNS-2), and 5 g/L NaOH (HNS-5). The highest yield (36.2% of tiger nut meal) was observed in HNS-5. Moreover, HNS-5 demonstrated the smallest particle size (7.69 μm), the highest amylose ratio (13.7%), and strongest freeze-thaw stability. ESS showed the highest relative crystallinity (20.0%), pasting temperature (79.1 °C), and its gel demonstrated higher hardness and adhesiveness compared to others. The average chain length of amylopectin (degrees of polymerization: 20.0−20.6), and the proportion of the amorphous phase (7.67%–8.66%) in starches were slightly affected by different isolation methods. Nevertheless, the crystalline pattern (C-type) of all starches was not changed, and all starch gels exhibited a similar single rate constant (0.037 min−1) during the simulated digestion process. Therefore, different isolation methods could be used to achieve different processing objectives, such as high yield or obtaining starch with enhanced properties.

Effect of different degumming methods on the chemical composition and physicochemical properties of tiger nut (Cyperus esculentus L.) oil

Abstract Objectives Tiger nut (Cyperus esculentus L.) oil is a promising edible oil that is rich in oleic acid. This study aimed to clarify the impact of different degumming methods on the chemical composition and physicochemical properties of crude tiger nut oil (CTO). Materials and Methods Five degummed tiger nut oils were prepared by high-temperature water (HWDO), medium-temperature water (MWDO), sodium chloride solution (SDO), acidic solution (ADO), and enzymatic method (EDO), respectively. Results Compared to that of CTO, the phospholipid contents of HWDO, MWDO, SDO, ADO, and EDO were reduced by 99.39%, 97.18%, 69.95%, 63.77%, and 65.60%, respectively. For CTO and all degummed oils, the fatty acid and endogenous antioxidant (i.e. tocopherols, sterols, flavonoids, total phenolics, and carotenoids) contents showed only small differences, but showed significant differences in quality parameters. Both the oxidative stability index and ferric ion-reducing antioxidant power decreased significantly after degumming; the former decreased from 52.26 to 15.55–19.80 h, and the latter decreased from 5818.91 to 4348.73–4524.34 μmol Trolox (TE)/kg. Conclusions These changes are highly related to the removal of hydratable phospholipids. In short, EDO exhibited the lowest turbidity, whereas MWDO showed the best oxidative stability (19.80 h) and highest smoke point (230.0 °C). This information can be utilized to improve the industrial production of tiger nut oil.

Impact of high temperature on microstructural changes and oil absorption of tigernut (Cyperus esculentus L.) starch: Investigations in the starch-oil model system

This study was to explore the internal reasons for the changes in oil absorption performance of tigernut starch (TS) by revealing the high-temperature induced variations of structural and functional properties of TS. The results showed that as the temperature increased from 80 °C to 140 °C, the degree of starch gelatinization increased, while the proportion of double helix structures, the total proportion of B1 and B2 chains, the relative crystallinity and the molecular weight decreased, accompanied by the fragmentation and swelling of TS granules. The oxidation of tigernut oil (TNO) led to a decrease in oil density and an increase in total polar component content. These phenomena could result in an increase of oil absorption capacity of TS and starch-lipid complex index. With further increase in temperature from 170 °C to 200 °C, the disruption of the crystalline structure and chain structure increased, resulting in the melting and disintegration of TS granules. This caused a decrease in the starch-oil contact area and capillary absorption of TNO by the TS granules. The results will contribute to revealing the effect of high-temperature induced changes in the structural and functional properties of TS on its oil absorption properties.

Tiger Nut Oil-Based Oil Gel: Preparation, Characterization, and Storage Stability.

In this study, Tiger nut (Cyperus esculentus L.) oil-based oleogels were prepared using the emulsion template method with whey protein (WPI; 0.5-2.5% (w/v) and Xanthan gum (XG; 0.1-0.5% (w/v). The microstructure of the oleogels obtained from the high internal phase emulsion (HIPE) and an emulsion after further shearing were observed using an optical microscope and laser confocal microscopy. A series of rheological tests were conducted to evaluate the effect of WPI and XG concentrations on the strength of the emulsion and oleogel. The texture, oil holding capacity, and oxidative stability of oleogels were characterized. The results showed that XG alone could not form oleogel, while the concentration of WPI had more effect than XG. When WPI was at a fixed concentration, the viscoelasticity of HIPE increased with the addition of XG. This was due to the complexation of WPI and XG, forming a stable gel network between the tight emulsion droplets and thus giving it a higher viscoelasticity. With an increase in WPI concentration, the stability and viscoelasticity of the emulsion were increased, and the oil-holding capacity and gel strength of the oleogels were enhanced. Moreover, the addition of XG could significantly enhance the stability and viscoelasticity of the emulsion (p < 0.05), and an increase in the concentration had a positive effect on it. The oleogels showed high gel strength (G' > 15,000 Pa) and good thixotropic recovery when the XG concentration was higher than 0.3% (w/v). WPI (2.0%) and XG (>0.3%) could be used to obtain HIPE with good physicochemical and viscoelastic properties, which in turn lead to oleogels with minimal oil loss, viscoelastic and thixotropic recovery, and temperature stability. Compared with tiger nut oil-based oleogel, tiger nut oil contained more polyunsaturated fatty acids, which were more easily decomposed through oxidation during storage and had lower oxidation stability. This study provides a reference for the preparation of oleogels from food-approved polymers and provides additional theoretical support for their potential application as solid fat substitutes.

Preparation of a novel healthy tiger nut oil-based margarine fat with low trans and saturated fatty acids.

The present study sought to develop a novel healthy margarine fat with low levels of trans and saturated fatty acids in order to promote healthier alternatives. In this work, tiger nut oil was first used as a raw material to prepare margarine fat. The effects of mass ratio, reaction temperature, catalyst dosage, and time on the interesterification reaction were investigated and optimized. The results showed that, the margarine fat with≤40% saturated fatty acids was achieved using a 6:4 mass ratio of tiger nut oil to palm stearin. The ideal interesterification parameters were 80°C, 0.36% (w/w) catalyst dosage, and 32min. Compared with physical blends, the interesterified oil had lower solid fat content (3.71% at 35°C), lower slip melting point (33.5°C), and lower levels of tri-saturated triacylglycerols (1.27%). This investigation provides important information for the utilization of tiger nut oil in healthy margarine formulation.

Tiger nut (Cyperus esculentus L.) oil: A review of bioactive compounds, extraction technologies, potential hazards and applications.

Tiger nut is a tuber of a plant native in the Mediterranean coastal countries, which is of great interest in food industry due to its richness in carbohydrates, lipids, starches, minerals, etc. Recent studies have focused on the analysis of the phytochemical composition of tiger nut, including six essential nutrients, polyphenols, and the extraction of proteins, starches, and phenolic compounds from the by-products of tiger nut milk 'horchata'. Few works were focused on the possibility of using tiger nut oil, a nutritious oil comparable to olive oil, as an edible oil. Therefore, this review discussed some extraction technologies of tiger nut oil, and their effects on the properties of oil, such as bioactive compounds, oxidative stability and potential hazards. The information on the emerging applications of tiger nut oil was summarized and an outlook on the utilization of tiger nut oil by-products were also reviewed.

The effect of roasting process on tiger nut oil properties and enhancing the oxidative stability of sunflower oil by blending with it

The effect of roasting process on tiger nut oil properties and enhancing the oxidative stability of sunflower oil by blending with it

Effect of steam pretreatment on the microstructure of tiger nuts (Cyperus esculents L.) and quality properties of its oil

Effect of steam pretreatment on the microstructure of tiger nut as well as the yield and quality properties of tiger nut oil (TNO) were investigated. Confocal laser scanning microscopy was used to demonstrate that steam pretreatment caused the cell structure of tiger nut to rupture and starch granules to aggregate, which resulted in 8.72%–18.85% increase in oil yield. Furthermore, steam pretreatment at 120 °C for 60 min was found to significantly (P < 0.05) increase the induction time (3.47 vs. 1.10 h), total phenolic (88.85 vs. 48.58 mg/kg) and vitamin E (237.94 vs. 166.47 mg/kg), and decrease the levels of acid value (1.14 vs. 2.00 mg KOH/g) and carotenoids (5.12 vs. 6.09 mg/kg) in comparison to untreated TNO. The gas chromatography analysis indicated that steam pretreatment had no significant (P > 0.05) effect on the fatty acid composition of TNO. A total of 60 volatile compounds were detected in TNO samples, with aldehydes being the most abundant compounds in all samples, followed by esters and phenols. Steam pretreatment had a marked influence on the profiles of volatile compounds in TNO. In conclusion, steam pretreatment may be a feasible approach to enhance the oil yield and quality of TNO.

Investigating the Effectiveness of Tiger-Nut Oil (Cyperus esculentus L.) as Base Fluid in Synthetic-Based Mud

Due to the environmental effects and following the stringent regulations on drilling operations and the associated drilled cutting disposal, drilling fluid with less environmental impact are highly desirable over the conventional diesel based mud. This study seeks to determine the effect of ester derived from the oil of tiger nut using alkali catalyzed transesterification as base fluid for the formulation of a synthetic base mud. A total of four mud samples were formulated, three samples of 10ppg synthetic based muds were formulated using the ester at 70:30, 75:25, and 80:20 Oil-water ratio. The last mud sample was formulated using diesel as base fluid but at 75:25 Oil-water ratio. The fresh oil and its ester were characterized. The tiger nut ester was purified and the compositional analysis of the ester was carried out using the Fourier transform infrared spectrometry. The API recommended procedure was used to determine the mud samples density, rheological, filtration and emulsion properties. The result of the FTIR shows an absorption band at 1743.56 cm-1 indicates the presence of C=O of an ester. The result of the density of the fresh Tiger Nut Oil (TNO) and the ester are 0.98 and 0.87respectively, the viscosities are 25.7cp and 3.25cp respectively, the flash point and pour point are 173oC and -25oC, and 160oC and -15oC respectively. The plastic viscosity and yield point of the synthetic based mud ranges between 7.0cp to 16.0cp and 9.0lb/100sqft to 46.0lb/100sqft, while 9.0cp to 14.0cp and 20lb/100sqft to 27lb/l00sqft was measured for diesel oil-based mud. The filtrate volume and mud cake thickness for the synthetic based mud at 70:30, 75:25, and 80:20 oil-water ratio are 2.6ml and 1.2mm, 3.8ml and 1.1mm, 4.1ml and 1,0mm respectively, while 15.6 and 5mm were recorded for diesel oil based mud. The gel strength at 10sec and 10min of the synthetic based mud ranges between 6.0 and 11.0, while 7.0 and 8.0 were recorded for the oil based mud. These result shows that the ester based synthetic oil compared favorably with diesel in the formulation of drilling mud. From the result, it is observed that esterified TNO can as a base fluid for a synthetic base mud, but further research on the most cost effective way of producing the oil from tiger nut.

Tiger Nut (Cyperus esculentus L.) oil quality evaluation as affected by variety and processing conditions

Tiger Nut (Cyperus esculentus L.) oil quality evaluation as affected by variety and processing conditions

Effects of different extraction methods on the physicochemical properties and storage stability of tiger nut (Cyperus esculentus L.) oil

Tiger nut (Cyperus esculentus L.) tubers are promising resources in the oil industry due to their high yield and oil content. In this study, five tiger nut oils, namely, cold pressing oil (CPO), roasted-pressing oil (RPO), solvent leaching oil (LPO), aqueous enzymatic extraction oil (AEO), and subcritical fluid extraction oil (SEO) were obtained, with yields of 14.00%, 9.80%, 20.80%, 14.60%, and 23.50%, respectively. After accelerated storage, their unsaturated fatty acid contents and tocopherol contents decreased significantly by 2.20–3.59% and 8.66–23.07 mg/100 g, respectively. Aldehydes formed by oil oxidation were the main volatiles in CPO (58.478%), RPO (34.471%), and AEO (47.780%), while the main volatiles in LPO and SEO were still alkanes (38.488–40.210%). Oxidative deterioration of oils was also characterized by nuclear magnetic resonance, differential scanning calorimetry, and physicochemical properties (e.g., peroxide value, acid values, p-anisidine values, iodine values, 2-thiobarbituric acid levels, conjugated diene/triene values, refractive indices, and color). The above results all demonstrated the superior storage stability of LPO and SEO, which was also consistent with the high oxidative stability indices of LPO (125.0 h) and SEO (61.5 h) than other oils (4.8–11.8 h). This study will benefit to the development of tiger nut oil in the edible oil field.

Application of Cyperus esculentus oil in the development of sustained release diclofenac sodium-loaded nanostructured lipid carrier

The aim of the work was to develop sustained release diclofenac sodium nanostructured lipid carrier (NLC) using tigernut oil (TNO), solid lipids and polyethylene glycol 4000 (PEG 4000) and to evaluate the properties of the formulations. Structured lipids containing tiger nut oil, Softisan®154 and Phospholipon® 90H at varying ratios were prepared by fusion and used as the lipid carrier in formulating the NLC. PEGylated lipid carriers were also employed and the physicochemical properties of these formulations were studied using standard methods including particle size and polydispersity index, encapsulation efficiency, loading capacity and drug release. The results revealed some monodispersed nano-sized formulations that were stable over time. Particle size ranged from 75.22 ± 22.72 nm to 78.11 ± 32.73 nm. High encapsulation efficiency of about 92 % was obtained confirming the suitability of the TNO based carrier. In vitro drug release in simulated intestinal fluid (pH 7.2) revealed that PEGylated diclofenac sodium-loaded NLC exhibited significantly higher sustained release properties than the non-PEGylated formulations (p &lt;0.05). The results of the drug release kinetics models revealed that the NLC followed a mixed order release kinetic. Hence, the findings in this work showed that TNO could be used as a lipid carrier matrix in combination with other solid lipids for the development of sustained release diclofenac sodium-loaded nanostructured lipid carrier.

Optimization and Kinetics Modeling of Microwave-Assisted Subcritical n-Butane Extraction of Tigernut Oil.

In this study, tigernut oil was extracted from tigernut meal by subcritical n-butane extraction with the assistance of microwave pretreatment. Effects of microwave pulse duration, particle size of tigernut meal, and subcritical extraction variables (temperature, time, solid-liquid ratio, number of extraction cycles) on extraction efficiency were examined by single-factor experiments and Response Surface Methodology (RSM) modeling. The results indicate that microwaving (560 W, 6 min) significantly increased the subcritical extraction efficiency. The variation of extraction yield could be interpreted as a nonlinear function of extraction time, temperature and liquid-solid ratio. Changing the independent variables could affect the oil extraction efficiency. The subcritical extraction of tigernut oil with a liquid-solid ratio of 3.62 kg/(kg of tigernut meal) at a temperature of 52°C for 32 min after three extraction cycles produced the most oil, and a maximum yield (24.736%) of tigernut oil was achieved. The ratio of unsaturated to saturated fatty acids (4.68 UFA/SFA), low acid value (3.30 mg KOH/g oil), low peroxide value (0.28 meq.kg-1), and preponderance of oleic acid indicate a high-quality oil. To describe the extraction kinetics, a modified Brunner's mathematical model was used. The model fit the experimental data well over the entire operating range, and the explanation coefficient exceeds 96%. Our results can be used to develop an optimized method for subcritical fluid extraction of tigernut oil and can move industry further toward implementing microwave-assisted subcritical extraction in oil processing.

Effects of cold‐pressing conditions on physicochemical and functional properties of cold‐pressed tigernut oil and starch isolated from press‐cake

SummaryTigernut tuber is a peculiar source of oil because it has high amounts of starch. To collect tigernut oil and obtain high‐quality starch from pressed cake, a comprehensive validation of the cold‐pressing method was conducted. At 40–60 MPa, from one pressing, 67.18–73.97% of total oil content can be obtained; with three pressings, 77.38–82.34% of total oil can be obtained. Starch yields from solvent extraction of cold‐pressed press‐cake are significantly higher (P &lt; 0.05) compared with native tigernut flour. For oils from different pressings, the fatty acid and total tocopherol contents had no obvious difference. Structural and functional analysis of the starch showed that cold‐press pretreatment had little effect on the particle size and molecular chains of the starch, while the syneresis and storage modulus (G′) of starch gel increased slightly. Overall, cold‐pressing is a potential processing method for effectively developing tigernut oil and starch as industrial resources.

Effects of various roasting temperatures on the structural and functional properties of starches isolated from tigernut tuber

Roasting pretreatment enhances the commercial qualities of tigernut oil. Oil extraction leaves behind meal, which is a potential source of starch. For industry to use this starch, its physicochemical characteristics of starch in meals after oil extraction with different roasting temperatures must be known, but have not been reported. In this investigation, the physicochemical properties of starches extracted from tigernut tubers before and after roasting at four different temperatures were investigated. Roasting increased the number of double helices and the ratios of A chains while decreasing crystallinity. There were differences in starch structure among samples roasted at different temperatures, which induced functional differences. The increase in A chains led to a decrease of peak viscosity, and improvement in freeze-thaw stability; the destruction of molecular interactions caused a decrease in pasting temperature; damage to the crystalline structure caused the decrease in gelatinization enthalpy and transition temperatures. As for differences in rheological properties, the interference of non-starch components and molecular interactions appear to be major factors. This study provides scientific information for the complete utilization of tigernut tubers.