Fine structure and gelatinization and pasting properties relationships among starches from pigmented potatoes

Insight to starch retrogradation through fine structure models: A review

The retrogradation of starch is crucial for the texture and nutritional value of starchy foods products. There is mounting evidence highlighting the significant impact of starch's fine structures on starch retrogradation. Because of the complexity of starch fine structure, it is a formidable challenge to study the structure-property relationship of starch retrogradation. Several models have been proposed over the years to facilitate understanding of starch structure. In this review, from the perspective of starch models, the intricate structure-property relationship is sorted into the correlation between different types of structural parameters and starch retrogradation performance. Amylopectin B chains with DP 24-36 and DP ≥36 exhibit a higher tendency to form ordered crystalline structures, which promotes starch retrogradation. The chains with DP 6-12 mainly inhibit starch retrogradation. Based on the building block backbone model, a longer inter-block chain length (IB-CL) enhances the realignment and reordering of starch. The mathematical parameterization model reveals a positive correlation between amylopectin medium chains, amylose short chains, and amylose long chains with starch retrogradation. The review is structured according to starch models; this contributes to a clear and comprehensive elucidation of the structure-property relationship, thereby providing valuable references for the selection and utilization of starch.

Starch from Unripe Apples (Malus domestica Borkh) as an Alternative for Application in the Food Industry

This study investigated the properties of starch isolated from the unripe fruit of two apple cultivars (Malus domestica Borkh) grown in southern Poland (Central Europe). The chemical composition of both starches, molecular mass, their granulation, thermal characteristics, swelling characteristics, and rheological characteristics were studied. The starches differed significantly in ash, phosphorus, and protein content. The water-binding capacity at temperatures of 25-65 °C was similar, while differences of 20% appeared at higher temperatures. In contrast, a significant difference was found in the solubility of the two starches in the temperature range of 25-75 °C. The study showed that apple starches have a relatively low tendency to retrograde, with the enthalpy of gelatinization for starch from the Oliwka variety being 40% higher than that from the Pyros variety. However, the starches differed in the hardness of the gels formed, i.e., one variety formed soft gels with an internal structure resistant to external forces, while the other formed hard gels.

Investigating the evolution of the fine structure in cassava starch during growth and its correlation with gelatinization performance

The evolution of the starch fine structure during growth and its impact on the gelatinization behavior of cassava starch (CS) was investigated by isolating starch from South China 6068 (SC6068) cassava harvested from the 4th to 9th growth period. During growth, the short-range ordered structure, crystallinity as well as particle size distribution of starch were increased. Meanwhile, the starch molecular size and amylopectin (AP) proportion increased, while the proportion of amylose (AM) exhibited a decreasing tendency. The chains of short-AM (X ~ 100-1000) were mainly significantly reduced, whereas the short and medium-AP chains (X ~ 6-24) had the most increment in AP. The solubility, thermal stability, shear resistance, and retrogradation resistance of starch were enhanced after gelatinized under the influence of the results mentioned above. This study presented a deeper insight into the variation of starch fine structure during growth and its influence on gelatinization behavior, which would provide a theoretical basis for starch industrial applications.

Colorimetric pH indicators based on well-defined amylose and amylopectin matrices enriched with anthocyanins from red cabbage

This study aimed to prepare a novel colorimetric indicator film from virtually pure (99 %) amylose (AM) and anthocyanins extracted from red cabbage (RCA). The AM used was a unique engineered bulk material extracted from transgenic barley grains. Films produced by solution casting were compared to normal barely starch (NB) and pure barley amylopectin (AP), with amylose contents of 30 % and 0 %, respectively. The pH-indicator films were produced by incorporation of RCA into the different starch support matrices with different amylose contents. Barrier, thermal, and mechanical properties, photo degradation stability, and release behavior data revealed that RCA interact differently through the glucan matrices. Microstructural observations showed that RCA were evenly dispersed in the glucan matrix, and AM+RCA indicator films showed high UV-barrier and mechanical performance over normal starch. FTIR revealed that RCA was properly affected by the AM matrix. Moreover, the AM+RCA films showed sensitive color changes in the pH range (2-11) and a predominant Fickian diffusion release mechanism for RCA. This study provides for the first time data regarding AM films with RCA and their promising potential for application as support matrices in responsive food and other industrial biodegradable packaging materials.

Comparison of the fine structure and physicochemical properties of proso millet (Panicum miliaceum L.) starch from different ecological regions

Field experiments were conducted to evaluate the morphology, granule size, fine structure, thermal properties, and pasting properties of starch from a waxy (139) and a non-waxy (297) varieties of proso millet grown in Yulin (YY) and Yangling (YL). Compared with the starches from the two varieties grown in YY, the starches from the two varieties grown in YL exhibited higher relative crystallinities, 1045/1022 cm-1 ratio, and amounts of amylopectin long branch chains (APL) but lower 1022/995 cm -1 ratio, amounts of amylopectin short branch chains (APs), and APs/APL ratios. Starches from YL also synthesized long branch-chain amylopectin to enhance intermolecular interactions and form a stable granular structure, which resulted in increased starch gelatinization temperature, enhanced shear resistance, and reduced setback viscosity. Starch from the waxy (139) variety has good application prospects in the food industry because of its high gelatinization temperature and light transmittance and low setback value, which can be ascribed to its extremely low amylose content, polydispersity index, high molecular weight, and dispersed molecular density. It may serve as a reference for applying proso millet starches in the food industry and developing breeding programs to improve starch quality.

Multi-Scale Comparison of Physicochemical Properties, Refined Structures, and Gel Characteristics of a Novel Native Wild Pea Starch with Commercial Pea and Mung Bean Starch

In the present study, the morphology, refined structure, thermal properties, and dynamic rheological, texture, and digestive properties of common vetch starch, a potential new type of legume starch, were systematically investigated, and compared with commercially available pea and mung bean starch. The results showed that the composition and chemical structure of common vetch starch were similar to the pea and mung bean starch. However, the amylose content (35.69), A-chain proportion (37.62), and relative crystallinity (34.16) of common vetch starch were higher, and the particle size and molecular weight (44,042 kDa) were larger. The value of pasting properties and enthalpy change (ΔH) of gelatinization of common vetch starch was lower and higher than mung bean and pea starch, respectively, and a lower swelling power and pasting index indicate that common vetch starch had higher hot-paste and cold-paste stability. In addition, common vetch starch gel exhibited good rheology, cohesiveness, and anti-digestive properties. These results provide new insights into the broader application of common vetch starch.

Effects of different altitudes on the structure and properties of potato starch

The main element influencing the quality of potato starch is the environment. To investigate the effects of different altitude cultivation locations on the molecular structure and physicochemical properties of starch, two potato varieties, Jiusen No.1 B1 and Qingshu No.9 B2, were planted in three different altitude zones: A1 at low altitude (Chongzhou 450 m), A2 at middle altitude (Xichang 2800 m), and A3 at high altitude (Litang 3650 m). The results showed that the average volume, number, surface area diameter, average branched polymerization degree, crystallinity, and gelatinization temperature of two potato granules in high altitude areas were significantly lower than those in middle and low altitude areas were, and the gelatinization performance of potato starch was affected according to the correlation of starch structure characteristics. Potato starch with more short-branched chains and less long branched chains resulted in a lower gelatinization temperature in high altitude areas. The results showed that Jiusen No. 1 and Qingshu No. 9 were mainly affected by accumulated radiation and accumulated rainfall in Litang, a high altitude area, and by effective accumulated temperature in Xichang, a middle altitude area. This study quantified the influence of meteorological factors on the main starch quality of potato tubers. The results can be used as a theoretical basis for the scientific planting of high-quality potatoes.

High-amylose starch: Structure, functionality and applications

Starch with a high amylose (AM) content (high AM starch, HAS) has attracted increasing research attention due to its industrial application potential, such as functional foods and biodegradable packaging. In the past two decades, HAS structure, functionality, and applications have been the research hotspots. However, a review that comprehensively summarizes these areas is lacking, making it difficult for interested readers to keep track of past and recent advances. In this review, we highlight studies that benefited from rapidly developing techniques, and systematically review the structure, functionality, and applications of HAS. We particularly emphasize the relationships between HAS molecular structure and physicochemical properties.

Infrared heating under optimized conditions enhanced the pasting and swelling behaviour of cowpea starch

Native starches are not suitable for industrial use and must be modified for improved functionality. In this study, the effect of moisture preconditioning and infrared heating time on physicochemical properties of cowpea starch was investigated using a two-factor central composite rotatable design. Factors (moisture levels:10-40 g/100 g starch and infrared heating time:10-60 min) with their corresponding α mid-point values resulted in 13 experimental runs. Selected functional and pasting properties were determined as response variables. Starch samples produced under optimized conditions were compared with corn starch and their physicochemical properties determined. Except for pasting temperature, cowpea starch prepared using the optimal conditions (moisture: 46.21 g/100 g starch, dry basis and heating time of 32.88 min) had higher functional and pasting properties compared with the native cowpea starch. Infrared heating significantly reduced the gelatinization temperatures of cowpea starch but did not significantly change that of the corn starch. The crystallinity and double-helical order structure of moisture conditioned cowpea starch also reduced after modification. Cowpea starch showed a bigger granule size, higher swelling power but lower water absorption capacities and pasting properties compared with the control. The infrared heating process is a novel and promising modification method for improving the swelling properties of starch.

The relationship between amylopectin fine structure and the physicochemical properties of starch during potato growth

The aim of this study was to explore the relationship between the structural and functional properties of starch isolated from Atlantic potatoes at different stages of growth without the effect of varieties and growth environment. The molecular size and chain-length distribution of amylopectin significantly varied with growth. The M_w and M_n of amylopectin ranged from 2.976 × 10⁷ to 4.512 × 10⁷ g/mol and 1.275 × 10⁷ to 2.295 × 10⁷ g/mol, respectively, suggested that the polydispersity varied with growth. The average chain length of amylopectin during potato growth showed small but significant changes and ranged from DP 23.59 to 24.73. Overall, A_fp chains, A_crystal chains, and B1 chains increased with growth, and B2 and B3 chains decreased with growth. There was wide variation in starch pasting, gelatinization, retrogradation, in vitro starch digestibility, swelling power, solubility, and gel stability properties. Specifically, potato starch harvested at the earliest time had the highest resistant starch content. The variation trend of swelling power and solubility was similar, reached highest value at 42 days, were 20.38 g/g and 8.83%, respectively. Correlation analysis revealed that the physicochemical properties were significantly affected by amylopectin fine structure. The results of this study enhance our understanding of the structure-function relationship of potato starch.

Insights into the structure and conformation of potato resistant starch (type 2) using asymmetrical flow field-flow fractionation coupled with multiple detectors

Insight into the structure and conformation characteristics of starch that influence its enzyme susceptibility is import for its potential application. In this study, the capacity of asymmetrical flow field-flow fractionation (AF4) coupled online with multi-angle light scatting (MALS) and differential refractive index (dRI) detectors (AF4-MALS-dRI) for monitoring of change in structure and conformation of potato starch during enzymatic hydrolysis was evaluated. The dissolution behavior of potato resistant starch (type 2) (PRS) was investigated. The effect of incubation time and amyloglucosidase concentration on the structure and conformation of potato starch was studied. The apparent density and the ratio of R_g (radius of gyration) to R_h (hydrodynamic radius) obtained from AF4-MALS-dRI were proven to be important parameters as they offer an insight into conformation of PRS at molecular level. Results suggested that gelatinization process made potato amylose molecules have a loose and random coil conformation which could contribute to an acceleration of enzymatic hydrolysis of potato starch. Furthermore, an intermediate with an elongated branched conformation was found between amylose and amylopectin populations, which may play a role in digestion property of potato starch. The results demonstrated that AF4-MALS-dRI is a powerful tool for better understanding of conformation of PRS.

Development and evaluation of a novel oleogel system based on starch-water-wax-oil

A novel oleogel system was developed, and its characteristics and properties were investigated. The results indicate that a low-cost, low-fat and low hardness oleogel product was formed by potato starch, candelilla wax, oil, and distilled water. Specifically, the content of potato starch and candelilla wax in the oleogel system was 5 wt%. A potato starch/candelilla wax ratio from 1.22 to 5.67 led to the formation of a type II starch-lipid oleogel system, and the content of distilled water was 45 times the starch content. All the above-mentioned information demonstrated that starch/wax-based oleogels are a typical lipid system. They can reduce the content of wax and oil in oleogel systems, form oleogel products with low hardness values and exhibit great potential in the field of low-fat food and low-cost food industrial applications.

Relationship between structure and physicochemical properties of ginkgo starches from seven cultivars

The structures and physicochemical properties of ginkgo starches from seven cultivars were investigated and their relationships analyzed. The ginkgo starches had oval or irregular shapes, size distributions with a unimodal peak, and an A-type crystal pattern. The fine structures, crystalline structures, and physicochemical properties varied significantly among these ginkgo starches. Pearson correlation analysis and a PCA loading plot indicated that amylopectin A-chains and amylose had negative effects on the IR ratio, I_max, and D, while amylopectin B-chains had a clear positive effect on the relative crystallinity. Furthermore, the amylopectin short B1-chains and long B-chains contributed amorphous and single-helix structures, respectively. The thermal properties of the ginkgo starches were mainly influenced by the amylopectin B-chains and I_max, while the pasting properties were mainly influenced by amylopectin B-chains and helical structures. These results indicated that the starch fine structures and crystalline structures had significant effects on the physicochemical properties.

Gelatinization, pasting and retrogradation properties and molecular fine structure of starches from seven cassava cultivars

Genetic diversity in the physicochemical properties and fine structures of seven cassava starches samples was studied. The apparent amylose content ranged from 24.8 to 27.6%. The whole branched starches showed significant differences in average hydrodynamic radius, ranging from 53.35 to 58.45 nm, while debranched starch exhibited differences in degrees of polymerization and height of both amylose and amylopectin peaks. The molecular size of amylose and amylopectin was positively correlated. The amount of short chains fa (6 ≤ X ≤ 12) and fb1 (13 ≤ X ≤ 24) had significant differences among the cultivars. Structure-function relation analysis indicated that the CPV and SB were mainly determined by amylopectin fine structures, BD, PTi and Tp and retrogradation properties were mainly determined by the amylose fine structure, while PTe and To were mainly affected by both amylose and amylopectin fine structures. The current findings will be helpful to improve the understanding cassava starch quality for use in industrial starch applications.

Characterization of Starches Isolated from Colombian Native Potatoes and Their Application as Novel Edible Coatings for Wild Andean Blueberries (Vaccinium meridionale Swartz)

Andean blueberry is a promissory fruit native to South America. The current work aimed to characterize starches isolated from Colombian native potatoes and to evaluate the effect of the application of starch edible coatings on the changes in the physicochemical quality parameters of the Andean blueberry during storage. Starches were isolated from three different potatoes varieties (pacha negra, mora, and alcarrosa) and characterized. Then, starch-based coatings were applied to Andean blueberries, and the changes in their quality parameters were monitored during 12 days of storage. Despite the phenotypical differences in the starch sources used, starches were similar in terms of their granule morphology, amylose content (~19%), crystallinity degree (~46%), and thermal properties. Coatings were able to reduce the gaseous exchange of the fruit, and, thus, the respiration rate of all coated blueberries was ~27% lower compared to the uncoated fruits (p < 0.05) at the end of the storage. While the application of starch coatings did not prevent water loss, all samples reached water loss of up 20%. Besides, the coated fruits showed soluble solids contents ~14% higher compared to the control one, as well as better bright and firmness. The new edible coatings can help add value to the Andean blueberry.

Genetic diversity and stability in starch physicochemical property traits of potato breeding lines

Cross breeding may create wider genetic variation than two parents used in hybridization, but breeding efforts towards starch quality improvement are less reported in potato. A cross was made between Zhongshu-3 and Favorita to select desired starch properties in progenies. Among 206 F₁ clones with potential high yield, starch qualities such as apparent amylose content (AAC), pasting viscosity, and thermal properties were further evaluated. A wide variation was observed in different starch physicochemical indices for 206 potato accessions. Twenty clones with high/low AAC, peak viscosity and peak gelatinization temperature were selected and then grown at another location to evaluate the stability of the traits. Similar wide range of variation in the starch properties was observed. Cluster analysis based on starch properties of the 20 selected clones indicating relative stability of the starch property traits across different locations. New breeding lines identified have potential for application in food and other industries.

Molecular structure-property relations controlling mashing performance of amylases as a function of barley grain size

In brewing, amylases are key enzymes in hydrolyzing barley starch to sugars, which are utilized in fermentation to produce ethanol. Starch fermentation depends on sugars produced by amylases and starch molecular structure, both of which vary with barley grain size. Grain size is a major industrial specification for selecting barley for brewing. An in-depth study is given of how enzyme activity and starch structure vary with grain size, the impact of these factors on fermentable sugar production, and the underlying mechanisms. Micro-malting and mashing experiments were based on commercial methodologies. Starch molecular structural parameters were obtained using size-exclusion chromatography, and fitted using biosynthesis-based models. Correlation analysis using the resulting parameters showed larger grain sizes contained fewer long amylopectin chains, higher amylase activities and soluble protein level. Medium grain sizes released most sugars during mashing, because of higher starch utilization from the action of amylases, and shorter amylose chains. As starch is the substrate for amylase-driven fermentable sugars production, measuring its structure should be a prime indication for mashing performance, and should be used as an industry specification when selecting barley grains for brewing.