Effect of tiger-nut (Cyperus esculentus) milk co-product on the surface and diffusional properties of a wheat-based matrix

Cellulose synthesis from germinated tiger nut residue and its application in the production of a functional cookie

In this study, cellulose was synthesized from the residue obtained after germinating tiger nuts for 0, 48, 72 or 96 h. The influence of the synthesized cellulose (0%, 2%, or 5%) on the quality of clove extract laden-cookies was evaluated. The optimum structure, morphology, and thermal properties of cellulose were obtained after geminating tiger nuts for 72 h. Adding cellulose to the dough stabilized the total phenolic, flavonoid, and protein contents and radical scavenging activity during the baking operation. The addition of 2% cellulose generally enhanced the hydration, pasting, and viscoelastic properties of the dough. However, 5% cellulose negatively affected the highlighted properties, culminating in poorer textural and sensory properties of the cookies produced therefrom. Germination could be effective in modifying the properties of cellulose from tiger nuts; thus, enhancing its application in the production of a functional cookie.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05972-8.

Physicochemical properties of tiger nut (Cyperus esculentus L) polysaccharides and their interaction with proteins in beverages

This study aimed to extract tiger nut polysaccharides (TNPs) by the cellulase method which were graded using the DEAE-cellulose ion exchange method to obtain neutral (TNP-N) and acidic (TNP-A) polysaccharide classes. Analysis of the physical structures and monosaccharide compositions of TNP-A (3.458 KDa) and TNP-N (10.640 KDa) revealed lamellar and dense flocculent structures, with both primarily containing the monosaccharides glucose, galactose, and arabinose (Glc, Gal, and Ara). Single-factor and orthogonal tests were used to select three hydrocolloids, and the optimal ratio of the composite hydrocolloids was determined. Peanut protein drinks with a centrifugal sedimentation rate of 9.71% and a stability factor of 69.28% were obtained by adding 2.78% polysaccharide extract, 0.1% monoglyceride, and peanut pulp at a ratio of 1:15.5 g/mL. Polysaccharide protein drinks are more stable than commercially available protein drinks, with nutritional parameters either comparable to or better than those of the non-polysaccharide protein drinks.

Beyond Insoluble Dietary Fiber: Bioactive Compounds in Plant Foods

Consumption of plant foods, including whole grains, vegetables, fruits, pulses, nuts, and seeds, is linked to improved health outcomes. Dietary fiber is a nutrient in plant foods that is associated with improved health outcomes, including a lower risk of chronic diseases such as cardiovascular disease, type 2 diabetes, and certain cancers. Different fibers deliver different health benefits based on their physiochemical properties (solubility, viscosity) and physiological effects (fermentability). Additionally, plant foods contain more than dietary fiber and are rich sources of bioactives, which also provide health benefits. The concept of the solubility of fiber was introduced in the 1970s as a method to explain physiological effects, an idea that is no longer accepted. Dividing total dietary fiber (TDF) into insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) is an analytical distinction, and recent work finds that IDF intake is linked to a wide range of health benefits beyond increased stool weight. We have focused on the IDF content of plant foods and linked the concept of IDF to the bioactives in plant foods. Ancestral humans might have consumed as much as 100 g of dietary fiber daily, which also delivered bioactives that may be more important protective compounds in disease prevention. Isolating fibers to add to human diets may be of limited usefulness unless bioactives are included in the isolated fiber supplement.

Influence of Partially Substituting Wheat Flour with Tiger Nut Flour on the Physical Properties, Sensory Quality, and Consumer Acceptance of Tea, Sugar, and Butter Bread

Tiger nut is a valuable source of fiber, lipids, minerals, and carbohydrates. However, avenues for incorporating tiger nuts into food remain underexplored, especially in several tropical countries where the plant grows well. The current study investigated the effects of partially substituting wheat flour (WF) with tiger nut flour (TNF) on the physical and sensory properties of different bread types to evaluate the more amenable system for tiger nut incorporation. The substitution was done at WF:TNF ratio of 100 : 0, 90 : 10, 85 : 15, 80 : 20, 75 : 25, and 70 : 30 for butter bread (B_b), tea bread (T_b), and sugar bread (S_b). The results show that WF substitution with TNF increased bread brownness and color saturation and decreased lightness, showing the highest impact on S_b, followed by T_b and B_b. Additionally, bread-specific volume decreased significantly after 20% (B_b), 25% (T_b), and 30% (S_b) TNF substitution. Furthermore, substituting WF with 30% TNF increased crumb hardness from approx. 1.87 N to 3.64 N (B_b), 3.46 N to 8.14 N (T_b), and 6.71 N to 11.39 N (S_b) and caused significant increases to 17.80 N (T_b) and 21.08 N (S_b) after 3 d storage. Only a marginal effect on storage hardness (4.32 N) was observed for B_b. Substituting WF with 10% TNF for B_b or 25% TNF for T_b led to significantly higher consumer (N = 56) scores for all attributes and overall acceptability. However, no significant effect on the overall acceptability of S_b was observed. Flash profiling showed frequently used descriptors for B_b as firm, moist, buttery, smooth, and astringent. After 10% TNF substitution, descriptors were chewy, firm, sweet, porous, dry, and caramel, and that of 30% TNF were grainy, chocolate, brown, nutty, and flaky. Substituting WF with TNF increased the lipids, fiber, and minerals content but decreased the protein and carbohydrate contents of bread. TNF substitution led to different physical and sensory effects depending on bread type, showing that B_b with 10% or T_b with 25% TNF is more comparable with the overall acceptance quality of 100% WF. The study is relevant for utilizing tiger nuts as an ingredient in bread products.

Chemical Composition and Bioactive Antioxidants Obtained by Microwave-Assisted Extraction of Cyperus esculentus L. By-products: A Valorization Approach

Tiger nut is highly appreciated in the Mediterranean basin by the large number of nutritional advantages offered by a beverage, called "horchata," which is directly obtained from the tuber of Cyperus esculentus L. However, the current tiger nut harvesting and processing practices generate a large number of residues, mainly a solid by-product after processing and the plant that remains spread out in the fields. In this work the plant residues have been fully characterized to get a clear picture of the possibilities for its valorization to generate products with high added value. Several analytical techniques have been applied to obtain data to assess the real possibilities of these residues in advanced applications in the food, packaging and nutrition sectors. Results on the compositional and elemental analysis, monosaccharide composition, phenolic concentration, and antioxidant capacity were obtained from the dry powder (DP). The high content of α-cellulose (47.2 ± 1.8%) in DP could open new possibilities for these residues as raw material in the production of cellulose nanoentities. Many essential minerals with nutritional interest (Na, Mg, Ca, Mn, Fe, Cu, and Zn) and free sugars (xylose, arabinose, glucose, and galacturonic acid) were identified in the DP making it an interesting source of valuable nutrients. The total carbohydrate content was 171 ± 31 mg gdm -1. In addition, microwave-assisted extraction (MAE) was used to obtain extracts rich in polyphenolic compounds. A Box-Behnken design (BBD) was used, and the optimal extraction conditions predicted by the model were 80°C, 18 min, ethanol concentration 40% (v/v), and solvent volume 77 mL, showing an extraction yield of 2.27 ± 0.09%, TPC value was 136 ± 3 mg GAE 100 gdm -1 and antioxidant capacity by the ABTS method was 8.41 ± 0.09 μmol trolox gdm -1. Other assays (FRAP and DPPH) were also tested, confirming the high antioxidant capacity of DP extracts. Some polyphenols were identified and quantified: p-coumaric (7.67 ± 0.16 mg 100 gdm -1), ferulic (4.07 ± 0.01 mg 100 gdm -1), sinapinic (0.50 ± 0.01 mg 100 gdm -1) and cinnamic acids (1.10 ± 0.03 mg 100 gdm -1), 4-hydroxybenzaldehyde (1.28 ± 0.06 mg 100 gdm -1), luteolin (1.03 ± 0.01 mg 100 gdm -1), and naringenin (0.60 ± 0.01 mg 100 gdm -1). It can be concluded that C. esculentus L. residues obtained from the tiger nut harvesting and horchata processing could be an important source of high value compounds with potential uses in different industrial sectors, while limiting the environmental hazards associated with the current agricultural practices.

Tiger Nut (Cyperus esculentus L.): Nutrition, Processing, Function and Applications

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 well as their applications in food industry. Different extraction methods can affect functional and nutritional properties to a certain extent. At present, mechanical compression, alkaline methods and alkali extraction-acid precipitation are the most suitable methods for the production of its oil, starch and protein in the food industry, respectively. Based on traditional extraction methods, combination of innovative techniques aimed at yield and physiochemical characteristics is essential for the comprehensive utilization of nutrients. In addition, tiger nut has the radical scavenging ability, in vitro inhibition of lipid peroxidation, anti-inflammatory and anti-apoptotic effects and displays medical properties. It has been made to milk, snacks, beverages and gluten-free bread. Despite their ancient use for food and feed and the many years of intense research, tiger nuts and their components still deserve further exploitation on the functional properties, modifications and intensive processing to make them suitable for industrial production.