Yam Starch Research Articles

Enhancing resistant starch fraction in modified elephant foot yam starch: optimizing preparation conditions and exploring tribological properties

IntroductionElephant foot yam starch is highly susceptible to enzymatic digestion. To address this, heat-moisture treatment (HMT) has been used to modify its digestive properties and functionalities. However, when using modified starch in various food compositions, it is ultimately necessary to cook it in water-rich environments. The present work thus offers a systematic understanding of the heating and cooking procedures for modified starch, with a view to maintaining its structural and digestive properties.MethodsExperimental investigations employing X-ray diffraction, scanning electron microscopy, and enzymatic digestion have been utilized to gain insights into the characteristics of cooked starches. The interactions between amylose and amylopectin in native starch are more susceptible to disruption during cooking, which results in changes in texture and a reduction in resistant starch (RS) retention. Additionally, these preparations have been investigated by tribology to test structure and and friction.Results and discussionThe application of HMT has been observed to induce changes that stabilize the interactions between amylose and amylopectin, thereby ensuring better maintenance of granular integrity and higher RS retention under specific cooking conditions. The findings indicate that following a 2-min cooking period at 100°C, the modified elephant foot yam starch (EFYS) demonstrated enhanced granular stability, which was subsequently compromised after 10 min of cooking. Additionally, when modified elephant foot yam starch (EFYS) was heated at a temperature of 86°C for 2 and 6 min, it demonstrated superior preservation of resistant starch (RS) in comparison to a cooking time of 10 min. Moreover, the HMT starch exhibited the highest RS retention when cooked at 100°C for 2 and 6 min at approximately 39.12% and 20.23%, respectively. However, this retention decreased significantly to 1.08% after 10 min of cooking. Furthermore, the insights from tribology, when combined with the proposed naive models, enhance the understanding of how preparation conditions affect the functionalities of starches, which is crucial for designing food products with desired textural and nutritional qualities, especially in water-rich environments, where maintaining structural integrity and RS content is important.

The structural properties of “Huilou” yam starch fermented with five microbial species

In this study, we employed two lactic acid bacterial species, two yeast species, and Bacillus amyloliquefaciens to ferment “Huilou” yam starch. The aim was to explore the effects of fermentation time and microbial species on the structural properties of yam starch. The results showed that fermentation caused an increase in relative crystallinity (29.23 %–37.98 %) compared with native starch (25.69 %). The fermentation process altered the thermal properties of yam starch, leading to higher enthalpy of gelatinization values compared with unfermented starch. Notably, an absorption peak of native starch shifted from 992 cm−1 to 1015 cm−1 upon 2-day fermentation by Bacillus amyloliquefaciens and 5-day fermentation by Lactobacillus plantarum or Pediococcus pentococcus, associated with an increase in the presence of amorphous structures in yam starch. “Huilou” yam starch obtained through lactic acid bacterial fermentation exhibited a significant presence of organic acids, whereas samples derived from Bacillus amyloliquefaciens fermentation were primarily affected by amylase activity. Following yeast fermentation, organic acids and amylase were observed, albeit with relatively low influence. This research reveals that microbial fermentation can potentially alter the structural characteristics of yam starch, which can improve the quality of yam starch-based foods.

Pyro-dextrinization, acid hydrolysis, and cross-linking impacts on functional, pasting and structural properties of elephant foot yam starch

Underutilized plants represent valuable reservoirs of starch, urging the need for prominent exploration of these botanical resources. The effects of pyrodextrinization, acid hydrolysis and cross linking modification on the physico-chemical, functional, structural and pasting properties of elephant foot yam (Amorphophallus paeoniifolius) starches were studied. Yam starch was cross-linked using boric acid, which is for the preparation of cross-linked yam starch. The results suggested that cross linking modification significantly decreased moisture content (10.46–1.91 %), swelling power (3.71–1.69 %) and solubility (3.58–1.51 %) of yam starch. At the same time it significantly (P < 0.05) improved amylose content (13.89–18.04 %) of starch. Increase in degree of crystallinity of all modified starches was depicted from X-ray diffractogram. Decrease in viscosity profile of modified starches was observed using Rapid Visco Analyzer. The morphology of the starch granules presented surface fissures in case of acid, whereas smooth surface of native, pyrodextrinized and cross-linked starches were observed. This research has demonstrated that chemical alterations induce notable transformations in the inherently flexible starch polymer, thereby influencing its functional characteristics and structural features. The treatment which resulted in the most thermostable starch obtained in this study was cross-linked yam starch. The ultimate goal is to offer yam starch suitable for a wide range of applications across various industries, including both food and non-food sectors positively revealing its utmost applicability for food packaging industry to be utilized as a film or coating material (cross-linked starch), fat replacers/mimickers in low-fat starch based healthy foods (acid-hydrolyzed starch).

Development of Edible Coatings Based on Pineapple Peel (Ananas Comosus L.) and Yam Starch (Dioscorea alata) for Application in Acerola (Malpighia emarginata DC).

Acerola fruit has great nutritional and economic relevance; however, its rapid degradation hinders commercialization. The use of coatings reduces post-harvest biochemical modifications and provides physical and biological protection for vegetables such as acerola. This study developed and characterized an edible coating made from pearl pineapple peel flour (PPPF) and yam starch (YS) to preserve the quality standards of acerola fruits during storage at room temperature and under refrigeration. The edible coating, composed of 4 g of PPPF, 3 g of starch, and 10% glycerol, presented excellent moisture content (11%), light tone (L* 83.68), and opacity (45%), resistance to traction of 27.77 Mpa, elastic modulus of 1.38 Mpa, and elongation percentage of 20%. The total phenolic content of the coating was 278.68 ± 0.45 mg GAE/g and the antioxidant activity by DPPH was 28.85 ± 0.27%. The quality parameters of acerolas were evaluated with three treatments: T1-uncoated fruits; T2-fruits coated with 1% glycerol; and T3-fruits coated with PPPF-YS. The T3 treatment reduced the weight loss of stored acerolas, maintaining the light and bright color of the fruits, and delayed the decrease in soluble solids, especially in refrigerated fruits. Therefore, edible coatings based on pineapple flour and yam starch are effective technologies for controlling the physical and physicochemical parameters of acerolas during storage, benefiting the post-harvest quality of this fruit.

Development and characterization of antimicrobial film based on yam starch and basil leaf extracts for active food packaging applications

Development and characterization of antimicrobial film based on yam starch and basil leaf extracts for active food packaging applications

Yam protein ameliorates cyclophosphamide-induced intestinal immunosuppression by regulating gut microbiota and its metabolites

Yam is a dual-purpose crop used in both medicine and food that is commonly used as a dietary supplement in food processing. Since yam proteins are often lost during the production of yam starch, elucidating the functionally active value of yam proteins is an important guideline for fully utilizing yam in industrial production processes. This study aimed to explore the potential protective effect of yam protein (YP) on cyclophosphamide (CTX)-induced immunosuppression in mice. The results showed that YP can reduce immune damage caused by CTX by reversing immunoglobulins (IgA, IgG and IgM), cytokines (TNF-α, IL-6, etc.) in the intestines of mice. Moreover, YPs were found to prevent CTX-induced microbiota dysbiosis by enhancing the levels of beneficial bacteria within the microbiome, such as Lactobacillus, and lowering those of Desulfovibrio_R and Helicobacter_A. Metabolomics analyses showed that YP significantly altered differential metabolites (tryptophan, etc.) and metabolic pathways (ABC transporter protein, etc.) associated with immune responses in the gut. Furthermore, important connections were noted between particular microbiomes and metabolites, shedding light on the immunoprotective effects of YPs by regulating gut flora and metabolism. These findings deepen our understanding of the functional properties of YPs and lay a solid foundation for the utilization of yam.

Zearalenone removal using inactivated yeast embedded in porous modified yam starch aerogels and its application in corn silk tea

Zearalenone contaminates food and poses a threat to human health. It is vital to develop cost-effective and environmentally-friendly adsorbents for its removal. By screening Sporobolomyces pararoseus (SZ4) and modified yam starch (adsorption capacity (qe) of 1.33 and 0.94 mg/g, respectively), this study prepared a novel composite aerogel adsorbent (P-YSA@SZ410). The compressive strength of P-YSA@SZ410 was 1.35-fold higher than unloaded yeast. It contained several functional groups and three-dimensional interconnected channels, achieving a 0° contact angle within 0.18 s, thereby demonstrating excellent water-absorbent properties. With a qe of 2.96 mg/g at 308 K, the adsorption process of P-YSA@SZ410 was spontaneous, endothermic, and matched pseudo-second-order and Langmuir models. The composite adsorbed zearalenone via electrostatic attraction and hydrogen bonding, maintaining a qe of 2.24 mg/g after five cycles. P-YSA@SZ410 was found to remove zearalenone effectively under various conditions and could be applied to corn silk tea, indicating its great potential as an adsorbent material.

Functional and pasting properties of aerial yam starch at different harvesting periods

The impact of the harvesting period (sixth, seventh and eighth month) on functional and pasting properties of starches from Tob2857 and Tob3059 cultivars of aerial yam was investigated. Matured yam bulbils were further classified into two; matured ripe bulbils (MRB) and matured unripe bulbils (MUB) based on their peel colours at harvest. Starch content, amylose, resistant starch (RS), pasting and morphological characteristics of starches were evaluated using standard methods. RS (5.11-12.37%), amylose (14.88-20.15%) and solubility (1.16-3.98%) were higher in MUB than MRB starches and varied with the harvesting period. Pasting profiles revealed that peak, hot, break down, cold paste and set back viscosities, respectively ranged thus; (261.50-528.92 RVU), (269.00-458.38 RVU), (16.95-70.54 RVU), (304.14-576.79 RVU) and (71.42-118.41 RVU). Pasting time and temperature ranged from 4.68-5.92 min and 84.18-88.26 oC, respectively. The swelling power (0.53-9.85%) varied significantly between the cultivars and ripeness of the bulbils. The starch granules showed similar shapes (ovo-triangular-oblong) and granule size (16.80-32.34 µm) varied significantly with the harvesting period. The variation in functionality of aerial yam starch cultivars at different harvesting periods in this study could be exploited for the postharvest valorization of aerial yam starches.

Effects of cold plasma pretreatment before different drying process on the structural and functional properties of starch in Chinese yam

This article compared the effects of hot air drying (HAD), infrared drying (IRD), and cold plasma (CP) as a pretreatment on the structure, quality, and digestive characteristics of starch extracted from yam. As the most commonly used drying method, HAD was used as a control. SEM and CLSM images showed that all treatments preserve the integrity of the yam starch. CP caused some cracks and breaks in the starch granules. IRD did not destroy the crystal structure of starch molecules, but made the spiral structure tighter and increased short-range orderliness. However, CP led to the depolymerization and dispersion of starch molecular chains, resulting in a decrease in average molecular weight and relative crystallinity. These molecular conformation changes caused by different processes led to differences in solubility, swelling power, pasting parameters, digestion characteristics, and functional characteristics. This study provided an important basis for the reasonable drying preparation and utilization of yam starch.

Evaluación de las propiedades proximales, estructurales, morfológicas fisicoquímicas y de digestibilidad in vitro en mezclas de harinas de ñame y batata

Yam (Dioscorea spp.) and sweet potato (Ipomeas batata) flours must be treated through modification processes because they have limitations in their physicochemical and structural properties for use in agri-food matrices. This study aimed to evaluate the effect of different proportions of flours on the proximate, structural, morphological, physicochemical, pasting, and in vitro digestibility properties of yam and sweet potato flour blends. Flours were obtained by drying the tubers with hot air at 55 °C, and mixtures were prepared at 25:75, 50:50, and 75:25 w/w sweet potato and yam flour proportions, respectively. The yam starch granules were spherical, oval, irregular, and larger than those of sweet potatoes, which are ovoid and flared. Furthermore, yam and sweet potato granules presented with type-B and type-A diffraction patterns, respectively, which, together with the starch content, amylose, non-starch components, and their molecular interactions, influenced the decrease in the molecular order and degree of crystallinity of the flour blends, without altering the morphological characteristics of the simple flours. Additive and non-additive effects were observed on flour blends’ swelling power and water absorption capacity. Likewise, breakdown and setback viscosity increased, which decreased thermal stability, increased the tendency to retrogradation, and elevated the fractions of rapidly digestible starch and resistant starch. These results suggest the high potential of flour blends in preparing baked products from the Caribbean Region, such as white bread, cookies, and cakes.

Physicochemical properties of tablet dosage form based on pre-gelatinized- and phosphorylated-modified starches from white-water yam (Dioscorea alata L.)

Abstract Background White-water yam (Dioscorea alata L.) is one of the potential sources of starch; however, it is not yet available for commercial purposes. Besides, native white-water yam starch (WS) presents limited functionality due to poor flowability, mechanical properties and instability at high temperature and acidic conditions. Therefore, this study aims to modify the starch to improve its characteristics and make it useful as an excipient for the preparation of the tablets. Materials and methods The modification of WS was achieved by physical and chemical treatments, specifically pre-gelatinization and phosphorylation, respectively. Pre-gelatinization WS involves heating, meanwhile phosphorylation WS is obtained by treating WS with sodium tripolyphosphate. Results The results showed that the powder of the modified WS has good characteristics which improved the flowability of the powder mixture as a granule based on density, porosity, compressibility index and swelling power determination. The WS granules were found to display the oval or irregular (polygonal) shape with the amylose content 11.92±0.61% for unmodified WS, 10.41±0.90% for pre-gelatinized WS and 12.61±1.75% for phosphorylated WS. Furthermore, the granule was formulated as an excipient in tablet preparations, and the formulas were compressed after wet granulation. The mechanical properties of the tablets were assessed using uniformity of mass and size, hardness, friability and disintegration time. WS modification affects the hardness of tablets when used as a binder. Phosphorylated WS is recommended to be used as a binder in wet granulation formulations because it produces tablets with a longer disintegration time, which means better binding ability. However, the utilization of modified WS with both pre-gelatinization and phosphorylation leads to tablets with low brittleness compared to others with unmodified binder with the disintegration time still met the requirement of fast disintegrating tablet (&lt;15 minutes). Conclusion All the physical properties studied indicated that the modified WS is a promising pharmaceutical excipient in tablets.

Molecular mechanism for the influence of yam starch multiscale structure on the sensory texture of cooked yam

Yam is a dual-purpose crop as both medicine and food. However, the mechanism controlling the eating quality of yam remains to be elucidated. This study explored the influence of starch multiscale structure on the texture of yam. The results indicated that FS and RC yam have higher hardness and chewiness, while BZ, XM, and PL yam possess waxiness, Fineness, and Stickiness. Statistically, high amylose (AM) can increase hardness, chewiness, and compactness; and average molecular size (Rh) is positively correlated with stickiness, fineness, and waxiness. Specifically, medium- and long-chain amylose (1000 < X ≤ 10,000) and amylopectin (24 < X ≤ 100), particularly medium-chain amylose (1000 < X ≤ 5000) and long-chain amylopectin (24 < X ≤ 36), primarily affect sensory and rheological stickiness. The long chains of amylose form a straight chain interspersed in the crystalline and amorphous regions to support the entire lamellar structure. Higher proportion of amylose long chains, promoting the starch's structural rigidity, which in turn enhanced its hardness-related attributes. Moreover, a higher ratio of long chains within amylopectin results in tightly intertwined adjacent outer chains, forming double helix crystalline zones. This consequently augmenting the texture quality linked to stickiness-related attributes.

Effects of cooking methods on the physical properties and in vitro digestibility of starch isolated from Chinese yam

The objective of this study was to compare the structural and functional attributes of Chinese yam starches obtained via different domestic cooking methods. Cooking changed the crystalline type from the C type to the CB type, and disrupted the short- and long-range molecular order of Chinese yam starch. The average chain length of amylopectin in BOS (boiling starch) was the smallest at 22.78, while RWS had the longest average chain length, reaching 24.24. These alterations in molecular structure resulted in variations in functional properties such as solubility, swelling power (SP), pasting characteristics, and rheological properties. Among these alterations, boiling was the most effective method for increasing the water-binding capacity and SP of starch. Specifically, its water holding capacity was 2.12 times that of RWS. In vitro digestion experiments indicated that BOS has a higher digestion rate (k = 0.0272 min−1) and lower RDS (rapidly digestible starch), which may be related to its amylopectin chain length distribution. This study can guide us to utilize yam starch through suitable cooking methods, which is relevant for the processing and application of Chinese yam starch.

Effect of Heat Moisture Treatment, Annealing, and Gelatinization‐Retrogradation Modifications on Physico‐Chemical, Functional, and Structural Properties of Starch from Elephant Foot Yam (Amorphophallus paeoniifolius)

AbstractRoots and tuberous plants are vital food crops used as food supplements in many parts of the tropics. Being a major food item, starch is used in food products as thickeners, adsorbent, film forming agent. Starch, naturally, possess certain limitations &amp; starch modifications can overcome the limitations, thereby increasing its versatility and meeting the needs of consumer. Current study focuses on comparative analysis between modified Elephant Foot Yam (Amorphophallus paeoniifolius) starch using physical methods (heat treatment method, annealing and gelatinization‐retrogradation) and to study the effect of modification on physico‐chemical, functional, structural and thermal properties. Results reveal that all physically modified starches positively altered the functional and physiological characteristics of native yam starch. However, maximum restriction in swelling power (2.54 %), solubility (2.47 %), moisture content (1.96 %), water absorption capacity (1.41 g/mL) is observed in heat moisture treated (HMT) starch. These HMT modified starches can be used in the manufacturing of baked and dairy products having reduced glycemic index, can be used as a packaging material for coating of fruits and vegetables. Henceforth, suitable and relevant application of modified starches of desired physical and functional features may be produced for industrial utilisation, or as additives fulfilling specific purposes in foods.

Characterization of Polylactic Acid Biocomposites Filled with Native Starch Granules from Dioscorea remotiflora Tubers.

Biocomposites were fabricated utilizing polylactic acid (PLA) combined with native starch sourced from mountain's yam (Dioscorea remotiflora Knuth), an underexplored tuber variety. Different starch compositions (7.5, 15.0, 22.5, and 30.0 wt.%) were blended with PLA in a batch mixer at 160 °C to produce PLA/starch biocomposites. The biocomposites were characterized by analyzing their morphology, particle size distribution, thermal, X-ray diffraction (XDR), mechanical, and dynamic mechanical (DMA) properties, water absorption behavior, and color. The results showed that the amylose content of Dioscorea remotiflora starch was 48.43 ± 1.4%, which corresponds to a high-amylose starch (>30% of amylose). Particle size analysis showed large z-average particle diameters (Dz0) of the starch granules (30.59 ± 3.44 μm). Scanning electron microscopy (SEM) images showed oval-shaped granules evenly distributed throughout the structure of the biocomposite, without observable agglomeration or damage to its structure. XDR and DMA analyses revealed an increase in the crystallinity of the biocomposites as the proportion of the starch increased. The tensile modulus (E) underwent a reduction, whereas the flexural modulus (Eflex) increased with the amount of starch incorporated. The biocomposites with the highest Eflex were those with a starch content of 22.5 wt.%, which increased by 8.7% compared to the neat PLA. The water absorption of the biocomposites demonstrated a higher uptake capacity as the starch content increased. The rate of water absorption in the biocomposites followed the principles of Fick's Law. The novelty of this work lies in its offering an alternative for the use of high-amylose mountain's yam starch to produce low-cost bioplastics for different applications.

Effect of Konjac Glucomannan on Structure, Physicochemical Properties, and In Vitro Digestibility of Yam Starch during Extrusion

In this study, the effect of konjac glucomannan (KGM, 0–5%) on the structure, physicochemical properties, and in vitro digestibility of extruded yam starch (EYS) was investigated. The EYS became rougher on the surface and the particle size increased as observed using scanning electron microscopy and particle size analysis. X-ray diffraction and Raman results revealed that the relative crystallinity (18.30% to 22.30%) of EYS increased, and the full width at half maxima at 480 cm−1 decreased with increasing KGM content, indicating the increment of long-range and short-range ordered structure. Differential scanning calorimetry and rheological results demonstrated that KGM enhanced thermal stability and the gel strength of EYS due to enhanced interaction between KGM and YS molecules. Additionally, a decrease in the swelling power and viscosity of EYS was observed with increased KGM content. The inclusion of KGM in the EYS increased the resistant starch content from 11.89% to 43.51%. This study provides a dual-modified method using extrusion and KGM for modified YS with high thermal stability, gel strength, and resistance to digestion.

Thermal Properties and Dynamic Rheological Characterization of Dioscorea Starch Gels.

Yam (Dioscorea. sp.) is an edible starchy tuber with potential for being a commercial source of starch for industrial purposes, but yam starch is underutilized. The dynamic oscillatory and thermal properties of yam starches from sixteen varieties each of Dioscorea. rotundata, Dioscora. alata, Dioscorea. bulbifera and one variety of Dioscorea. dumetorum from Nigeria were studied to determine their potential for industrial utilization. The storage modulus, loss modulus, damping factor and complex viscosity as a function of frequency (ω) of the dioscorea gels, as well as the onset temperature (To), peak gelatinization temperature (Tp), end of gelatinization (TC), and gelatinization enthalpy of the starches were determined by standard procedures. Results showed that all the dioscorea starches showed a typical elastic behavior with the magnitude of G' greater than G″ while tan δ < 1 in all varieties. Thus, the starch gels were more elastic than viscous. All the starch gels exhibited shear thinning characteristics and showed frequency (ω) independence characteristics of weak gels. D. rotundata varieties had the lowest ∆Hgel, while D. bulbifera varieties had the highest. The diversity of the visco-elastic and thermal properties of the yam starch gels from different varieties and species can be an advantage in their utilization in both food and non-food industries.

The Effect of Starch Concentration on the Characteristics of Modified Purple Yam Starch Using the Precipitation Method

Purple yam starch-based edible film experienced high water vapor transmission rate. The use of composite starch using addition of modified starch of smaller size particles may decrease the rate. This study aimed to obtain starch concentrations that produced smallest size of modified starch, to produce composite starch for edible films and to determine the characteristics of edible films made out of native starch and edible films from composite starch (mixture of native starch and modified starch with the smallest size). This research was conducted in 2 stages: modification of purple yam starch by precipitation method and production of edible films from native starch and composite starch. This study was designed to produce modified starch using 5 levels of starch concentration (0,2%, 0,4%, 0,6%, 0,8%, and 1%) and 2 repetitions. The results showed that the treatment of 0,8% starch concentration produced the smallest particle size of starch (3,211 x 10,340 µm) up to (20,876 x 25,437 µm) with starch yield of 76,25%. Edible films made out composite starch have different characteristics than native starch alone. Edible films from composite starch produced higher thickness values ​​of 0.161 ± 0.007 mm, lower solubility 32,080 ± 4,671%, lower transparency of 10.644 ± 0.357% / mm and lower water vapor transmission rate (WVTR) of 24,701 ± 7,05 g / m2. hour and higher compressive strength 356,87 ± 7,38 gF than native starch edible films.

Characteristics of Edible Film Elephant Foot Yam Starch with Calcium Carbonate as Cross–Linking Agent

Characteristics of Edible Film Elephant Foot Yam Starch with Calcium Carbonate as Cross–Linking Agent

Structural, physicochemical, and pasting properties of native cassava (Manihot esculenta) and yam (Dioscorea alata) starch blends

Starch blends are a technological alternative aimed at the development of starchy matrices that exhibit improvements in some physicochemical properties from interactions between their individual components. Native cassava and yam starches were mixed in different proportions and the effect of the blend on the structural, physicochemical, and pasting properties was evaluated. The viscosity behavior as a function of temperature revealed a significant non-additive effect on the pasting parameters of all the blends with respect to the individual native starches. Similarly, non-additive variations were evident in the crystallinity index of some mix ratios (NSB-2: 40.11%). Likewise, the difference in the amylose content of each native starch (20.88-25.66%) possibly exerted an effect on the resulting semicrystalline characteristics of the blends and the gelatinization behavior. Hence, the botanical origin and the proportion of starch blends play an important role in the behavior of the resulting physicochemical properties and in vitro digestibility. Polymeric blends were obtained with a low tendency to retrogradation and lower crystallinity index values compared to their native counterparts and a regulated water absorption capacity, all potentially desirable characteristics in the food industry.