Tiger Nuts

The importance of archaeobotany has been widely recognized in recent years, and more research is being conducted to study botanical remains. Only a very few of the cultivated vegetables grown in fields and in gardens were indigenous to Egypt, but one was the tiger nut (Cyperus esculentus L.) which was known and consumed since the Predynastic Period. Remains of dry tiger nuts tubers were found in large quantities in tombs from Neolithic times onwards. Some were found inside the stomachs of bodies as early as the Predynastic Period. Tiger nuts are attested in funerary offering lists, festival offerings, in medicine and in diet. This paper sheds light on the importance of tiger nuts and its different uses. It also urges their use in modern Egypt.

Drying Kinetics and Quality of Whole, Halved, and Pulverized Tiger Nut Tubers (Cyperus esculentus)

The objective of this study was to provide the optimum drying conditions to produce high-quality dried tiger nuts using hot-air drying. For this, we evaluated the effect of the whole, halved, and pulverized tiger nuts and air temperature (50 to 70°C) on the drying kinetics and quality of tiger nuts. The drying process generally followed a constant rate in the first 3 hours and a falling regime. We found the optimum drying conditions for tiger nuts to be crushed before convective hot-air drying at a temperature of 70°C. At this optimum condition, the predicted drying time, vitamin C content, reducing sugars, browning, brightness, redness, and yellowness was 780 min, 22.9 mg/100 mg dry weight, 157.01 mg/100 g dry weight, 0.21 Abs unit, 56.97, 1.6, and 17.0, respectively. The tiger nut’s reducing sugars increased from the 130.8 mg/100 dry weight in the raw tiger nuts to between 133.11 and 158.18 mg/100 dry weight after drying. The vitamin C degradation rate was highest in the uncut tiger nuts (32-35%) while in the halved and the pulverized samples, it was between 12 and 17%. The crushed samples’ effective moisture removal increased between 5.6- and 6.75-fold at the different air temperatures than that of the intact tiger nuts. The activation energy was 18.17 kJ/mol for the unbroken, 14.78 kJ/mol for the halved, and 26.61 kJ/mol for the pulverized tiger nut samples. The model MR = 0.997 exp − 0.02 t 1.266 + 0.0000056 t was the most suitable thin-layer drying model among the models examined for convective hot-air drying of tiger nuts. It is advisable to crush tiger nut before hot-air drying to produce better-quality flour for making milk beverages, cakes, biscuits, bread, porridge, and tiger nut-based breakfast cereals.

Nutritional composition, microbial load and consumer acceptability of tiger nut (Cyperus esculentus), date (Phoenix dactylifera l.) and ginger (Zingiber officinale Roscoe) blended beverage

Beverage consumption is increasing but rarely used to promote micronutrient intakes in Nigeria. Diversifying the crops in local beverage production could improve dietary diversification and increase nutrients intake. This study determined the nutritional composition, microbial load and consumer acceptability of tiger nut, date and ginger blended beverage. Fresh tiger nuts, date and ginger were processed to formulate four beverage blends in these ratios 100:0:0; 85:10:5; 70:20:10; and 55:30:15. Samples were analysed for proximate, vitamins, minerals, anti-nutrients content and microbiological attributes using standard procedures. Consumer acceptability was determined using a 9-point hedonic scale by 30 untrained panelists. Data were analysed using descriptive statistics, independent t-test and ANOVA at p ≤ 0.05. Moisture, protein, fat, fibre, ash, carbohydrate (mg 100 g–1) and metabolizable energy composition (kCal 100 ml–1) ranged from 80.33-84.78, 0.71-0.8, 2.96-4.94, 0.20-1.63, 0.34-0.44, 9.10-13.63 and 78.2-101.5, respectively. Thiamin, niacin, ascorbic acid and tocopherol composition (mg 100 g–1) ranged from 0.30-0.68, 0.08-0.17, 4.73-8.40, and 7.20-15.31, respectively. Calcium, potassium, phosphorus, and iron contents (mg 100 g–1) ranged from 1.07-6.79, 164.8-259.3, 43.86-47.1, and 6.88-9.26, respectively. Saponin ranged from 0.01-0.05 mg 100 g–1. Number of colonies were negligible after refrigeration for 10 days. Sensory properties ranged from 6.40-6.63, 4.93-6.40, 4.70-7.20, 5.93-6.90, and 5.27-7.17 for appearance, aroma, taste, consistency and general acceptability, respectively. Date and ginger substitution enhance fibre, ash, carbohydrate, and calcium composition, the shelf life and sensory properties of tiger nut beverage, the blends are generally acceptable to consumers and considered safe up to day 10 when refrigerated.

Evaluation of changes in food properties and mineral composition of tiger nuts at variable drying temperatures

Effective storage conditions can resolve the challenge of food scarcity and extinction of certain foodspecies. Therefore, this study investigated the changes in the food properties and mineral composition of tiger nuts attemperatures of 23, 40, 55, 80 and 100°C. Results show that while the temperature of 55°C influenced water, crude proteinand carbohydrate contents retention in the tiger nuts, fats were better retained at 80°C. This indicates that food nutrientsand properties of tiger nuts should be better retained at temperatures ≥ 50°C

Comparative Analysis of Nutrients Content and Characterization of Oil from Two Varieties of Tiger Nut (Cyperus esculentus)

Background: Tiger nut (Cyperus esculentus) belong to the family of Cyperaceae and the order of Commelinalis. It has been existing for more than 4,000 years ago. Objective: To determine the nutritional composition (protein, fat, fiber, ash, moisture and carbohydrate) of nut, to extract and characterize oil from varieties of tiger nuts, to determine the mineral elements presence in the nut. Study Design: A descriptive research design was adopted by this study to determine the nutritional composition (protein, fat, fiber, ash, moisture and carbohydrate) of nut, to extract and characterize oil from varieties of tiger nuts and to determine the mineral elements presence in the nut. Place and Duration of the Study: The study was conducted at Biochemistry Department, Bayero University Kano, between April, 2019 to September, 2019. Methods: The Proximate compositions were determined using the method describe by Association of official analytical chemist’s, while Carbohydrate were determined by difference. The physicochemical properties were determined using the method describe by American oil Chemist’s society and Mineral composition were determined. Results: The proximate composition of the yellow variety was moisture (9.48%), ash (2.07%), fat (33.5%), protein (6.11%), crude fibre (17.5%) and carbohydrate (31.2%). Corresponding values of the brown variety was moisture (9.62%), ash (2.76%), fat (34.2%), protein (6.93%), crude fibre (15.3%) and carbohydrate (30.9%) respectively. The extracted oil has a golden colour and a nutty taste. The saponification, acid, peroxide, iodine and free fatty acid values of the yellow variety were found to be 210.8±4.28, 3.17±0.64, 1.00±0.52, 78.7±13.1 and 0.40±0.21 and the saponification, acid, peroxide, iodine and free fatty acid values of the yellow variety were also found to be 212.2±4.92, 3.36±0.56, 1.06±0.75, 76.5±14.6 and 0.42±0.04 and was not significantly (P> 0.05) different between th yellow and brown varieties respectively. The mineral element (mg/100g) of the brown variety is Mg 133.67, P 527.33, K 957.67, Ca 394, Cu 2.0 and Fe 1.86. Corresponding values for the yellow variety are Mg 118.13, P 159.61, K 384.33, Ca 152, Cu 2.0 and Fe 1.04. Lead and Cadmium were not detected in both varieties. Conclusion: These results indicate that tiger nut tuber oil could be a good source of edible oil, highly nutritive and can provide a lot of energy like some starchy food.

Cyperus esculentus L. Tubers (Tiger Nuts) Protect Epithelial Barrier Function in Caco-2 Cells Infected by Salmonella Enteritidis and Promote Lactobacillus plantarum Growth

Cyperus esculentus L. tubers (tiger nuts) contain different compounds with several intestinal health-promoting properties. Here, we studied the capacity of tiger nuts from Valencia, Spain, to prevent epithelial barrier function disruption induced by Salmonella enteritidis in Caco-2 cell cultures. Paracellular permeability was assessed by transepithelial electrical resistance (TER) and tight junction protein immunolocalization. Moreover, the effect of tiger nuts on S. enteritidis agglutination, oxidative stress, and Lactobacillus plantarum growth was tested. Compared to controls, tiger nuts partially restored TER in S. enteritidis-infected cultures, an effect confirmed by immunolocalization of tight junction proteins ZO-1 and occludin. The results also revealed that this protective effect may be associated with the capacity to agglutinate the pathogen, restore TER in TNFα-stimulated cultures, and reduce reactive oxygen species in H2O2-stimulated cultures. Moreover, they favor L. plantarum growth. In conclusion, this study demonstrates that the tiger nut protects epithelial barrier function by reducing bacterial invasion, along with counteracting TNFα and H2O2 effects, thus giving an additional value to this tuber as a potential functional food.

Integrative Analysis of Lipidomics and Transcriptomics Revealed Dynamic Details of Lipids Metabolism and Accumulation in Developing Tiger Nut (Cyperus Esculentus) Tubers

Background: Oil crop varieties are currently subjected to an increasing worldwile demand and the tiger nut (Cyperus esculentus L.) attracts significant attention because of its huge capacity of lipids production. In eukaryotic cells, the balance between the accumulation of lipids and the distribution of certain pivotal molecules is fundamental for the regulation of many complex transcriptional regulatory networks. However, many studies have struggled to understand the dynamic of lipids and the transcriptomic mechanisms governing their biosynthesis and accumulation process during plant development. Results: Our results displayed dynamic patterns for key lipids like glycolipid, phospholipid, and glyceride during the development of tiger nut tubers. Lipidomic analysis showed molecular species distribution of lipid class during developing stages. Here, we also characterrized transcription profiles of key transcripts that determined biosynthesis and distribution of natural lipids in tiger nuts tuber. The expression of FAD2 exhibited a significant influence on the molecular composition of phosphatidylcholines (PC) and phosphatidyl ethanolamine (PE) in tiger nuts. Moreover, during lipids accumulation, the expression pattern of three candidate transcripts of oleosin genes (OLE9, OLE10 and OLE11) also displayed significant leverage on the size of lipid drops. Conclusion: We described the significant alterations in the composition of lipids class during developing stages of tiger nut tuber, we also revealed transcriptional profiles of genes invloed in lipid biosynthesis and accumulation. These results provided new landscapes for research on lipid composition, synthesis and accumulation during different developmental stages of plant tubers.