Formation Of Starch-lipid Complexes Research Articles

Effect of electron beam irradiation pretreatment and different fatty acid types on the formation, structural characteristics and functional properties of starch-lipid complexes

The effects of different electron beam irradiation doses (2, 4, 8 KGy) and various types of fatty acids (lauric acid, stearic acid, and oleic acid) on the formation, structure, physicochemical properties, and digestibility of starch-lipid complex were investigated. The complexing index of the complexes was higher than 85 %, indicating that the three fatty acids could easily form complexes with starch. With the increase of electron beam irradiation dose, the complexing index increased first and then decreased. The highest complexing index was lauric acid (97.12 %), stearic acid (96.80 %), and oleic acid (97.51 %) at 2 KGy radiation dose, respectively. Moreover, the microstructure, crystal structure, thermal stability, rheological properties, and starch solubility were analyzed. In vitro digestibility tests showed that adding fatty acids could reduce the content of hydrolyzed starch, among which the resistant starch content of the starch-oleic acid complex was the highest (54.26 %). The lower dose of electron beam irradiation could decrease the digestibility of starch and increase the content of resistant starch.

Effect of pre-treatments and frying conditions on the formation of starch-lipid complex in potato starch chips during deep-frying process

This study examined the influence of various pretreatment methods, frying durations, and temperatures, as well as the type of frying oil, on the formation and structure of starch-lipid complexes in fried potato chips. Potato starch was processed into dough, sliced, and subjected to deep frying following various pretreatments. Structural analysis showed that steaming as a pretreatment facilitated the generation of V-type starch-lipid complexes, whereas resistant starch type III (RS3) materialized in the desiccated samples instead of the anticipated complexes. The rate of starch-lipid complex formation initially surged but subsequently declined as treatment time increased. A reduction in treatment temperature from 190 °C to 170 °C was conducive to complex formation. Moreover, the maximum relative crystallinity (19.74 %) and ΔH value (7.76 J/g) were recorded for potato starch slices pretreated by steaming and frying in palm oil. Rapeseed oil, which is rich in unsaturated fatty acids (89.98 %), inhibits complex formation. The study concludes that pretreatment methods exert a substantial effect on the formation of starch-lipid complexes and that extended frying duration and elevated temperature may reduce this formation. Oils with longer-chain fatty acids and a lower degree of unsaturation were favorable for complex formation.

Starch spectra of Ampelopteris prolifera (Retz.) Copel, a new addition to the existing lexicon and its comparison with a local potato cultivar (Solanum tuberosum L. cv. Kufri Jyoti)

Novel kinds of starch spectra were generated from a lesser-known plant, making this investigation unique. The recent trend of starch characterization shows the establishment of novel bioresources from nonconventional unexplored databases. The present endeavor was made to obtain the starch fingerprint of Ampelopteris prolifera (rhizome) belonging to seedless vascular plants. For comparison, a commercial local cultivar of potato (Kufri Jyoti) was taken. The starch particle of A. prolifera shows much uniqueness depicting its novelty viz., crystallinity index of 60.04 %, powder diffractogram at (2θ scale)17.57° to 39.78°; this diffractogram pattern is reported from this study as newer one i.e. R type(whereas potato starch is CB type); characteristic peak at 2θ = 20.07° suggests starch-lipid complex formation and V type crystallinity (i.e. RS 5 type); FTIR spectra showing the presence of more short chain branching; high gelatinization temperature(84.62 ± 0.10), particle size and zeta value of A. prolifera is 4.00 ± 0.81 μm and − 18.91 ± 3.58 mV respectively. Bragg's peak from the single crystal X-ray diffraction has been generated for the first time of A. prolifera. Extraction of the starch particle was performed in chilled water. Therefore, the present study suggests wide-spectrum commercial utility and cost-effective production.

New Insight into the Effects of Endogenous Protein and Lipids on the Enzymatic Digestion of Starch in Sorghum Flour.

The effects of endogenous lipids and protein in sorghum flour on starch digestion were studied following the depletion of lipids and/or protein and after the reconstitution of separated fractions. The removal of protein or lipids moderately increases the digestibility of starch in raw (uncooked) sorghum flour to values close to those for purified starch. Rapid Visco Analyzer data (as a model for the cooking process) show that cooked sorghum flours with lipids have a lower starch digestibility than those without lipids after RVA processing, due to the formation of starch-lipid complexes as evidenced by their higher final viscosity and larger enthalpy changes. Additionally, the formation of a starch-lipid-protein ternary complex was identified in cooked sorghum flour, rather than in a reconstituted ternary mixture, according to the unique cooling stage viscosity peak and a greater enthalpy of lipid complexes. After heating, the sorghum flour showed a lower digestibility than the depleted flours and the reconstituted flours. The results indicate that the natural organization of components in sorghum flour is an important factor in facilitating the interactions between starch, lipids, and protein during RVA processing and, in turn, reducing the starch digestion.

The influence of short-range molecular order in gelatinized starch on the formation of starch-lauric acid complexes

A model system of gelatinized wheat starch (GWS) and lauric acid (LA) was used to examine the effect of residual short-range molecular order in GWS on the formation of starch-lipid complexes. The extent of residual short-range molecular order, as determined by Raman spectroscopy, decreased with increasing water content or heating duration of gelatinization. The enthalpy changes, crystallinity, short-range molecular order and the in vitro enzymic digestion of GWS-LA complexes increased initially to a maximum and then declined as the short-range molecular order in GWS decreased, showing that there was an optimal amount of residual short-range molecular order in GWS for maximizing GWS-LA complexes formation. Below this optimum amount, the limited disruption of short-range molecular order may constrain the mobility of amylose chains for complexation with LA, whereas with excessive disruption above this amount the amylose chains may be too disorganized or entangled to form complexes with LA. The susceptibility of GWS-LA complexes to enzymatic hydrolysis was influenced by both long- and short-range structural order, and to a lesser extent the amounts of complexes. This study showed clearly the role of short-range molecular order in gelatinized starch in influencing the formation of GWS-LA complexes.

Structural modification of starch and protein: From the perspective of gelatinization degree of oat flour

To clarify the relationship between gelatinization degree and structure characteristics, oat kernels were roasted to different gelatinization degree of 15 %–90 % based on tempering water content of 22.5 %–35 %, and the structure characteristics of starch and protein were evaluated. The results showed that the increased gelatinization degree dependent on tempering water content promoted protein aggregation on the surface of starch particles, forming larger aggregates with molecular weight >100 kDa. Oat kernels presented a dense starch gel network structure induced by gelatinized starch. Partial gelatinization of starch led to a decrease in pasting viscosities (setback viscosity, 3.91 Pa·s–1.59 Pa·s) and enthalpy (5.12 J/g–0.11 J/g). With the increase of gelatinization degree, the starch crystal structure conversed from A + V type to V type, accompanied by the formation of starch-lipid complexes and a decrease of relative crystallinity (22.28 %–8.72 %). Moreover, 50 % gelatinized oat flour possessed the highest β-sheet structure (38.04 %), but a decrease in surface hydrophobicity and an increase in endogenous fluorescence intensity were found in oat flour of gelatinization degree >50 %. This study provided a theoretical reference for the application of oat flour with different gelatinization degrees to match suitable products.

Impact of lipids on the functional, rheological, pasting and thermal properties of ultrasound-processed canary seed flours

Canary seed, a gluten-free cereal, is renowned for its high content of fats, starch, and proteins. The extraction of oil is often necessary to extend flour shelf life or obtain purified starch and protein fractions. Similar to many gluten-free flours, it may require additional thermal treatments to enhance its suitability to formulate several food products. Thus, this study investigated the impact of ultrasound (US) treatment on the techno-functional and physicochemical properties of both whole (WCS) and defatted (DWCS) canary seed flours. The US treatment slightly increased water and oil absorption capacities in WCS. Lipids in the flour and treatment temperature affected the surfactant properties. Untreated and treated defatted DWCS flours exhibited higher emulsifying activity (up to +36%) and foaming capacity (up to +340%) than WCS. The presence of lipids and US treatment influenced protein extraction, with changes in albumins (WCS and DWCS), globulins (DWCS) and prolamins (WCS) recovery. US treatment altered pasting and rheological properties of all studied flours, impacting viscosity and starch-lipid complex formation. Rheological properties were lipid-dependent, and defatted samples formed stronger gels. US treatment decreased gelatinization enthalpy in WCS (up to −9.5%) and increased it in DWCS (up to +11.3%) flours. Moreover, lipids significantly influenced retrogradation, which was absent in untreated and treated WCS flours. US-treated flours displayed similar diffraction patterns to untreated samples, but with reduced intensities as temperature increased. The untreated defatted sample exhibited a 9% lower crystallinity. These findings highlight the benefits of US treatment and defatting for improving gluten-free food products formulated with canary seed flour.

Effect of plasma-activated water on the formation of endogenous wheat starch-lipid complexes during extrusion

The aim of this study was to investigate the effect of plasma-activated water (PAW) during extrusion on the formation of endogenous starch complexes with wheat starch (WS) as a model material. Using PAW during the extrusion process resulted in an increase in amylose content from 27.87 % to 30.07 %. Results from Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry indicated that the PAW facilitated the formation of endogenous starch-lipid complexes during extrusion. PAW120 (distilled water treated by plasma for 120 s) showed a better promotion effect than PAW60 (distilled water treated by plasma for 60 s). EWS120 (WS extruded using PAW120) exhibited lower peak viscosity and swelling power, but higher solubility, particle size, and resistant starch content compared with EWS0 (WS extruded using distilled water) and EWS60 (WS extruded using PAW60). In a word, the acidic substances in PAW may lead to hydrolysis of starch and generate more amylose, thus improving the amount of endogenous starch-lipid complexes. The present study provides a novel extrusion method to obtain modified starch with higher RS content than common extrusion, which has potential application in the industrial production of functional foods with low glycemic index.

Insights into ball milling treatment promotes the formation of starch-lipid complexes and the relation between multi-scale structure and in vitro digestibility based on intermolecular interactions

This study aimed to investigate the changes in the physicochemical properties, multiscale structure and in vitro digestibility of the corn starch (CS)- lauric acid (LA) complexes under ball milling treatment to elucidate the correlation between structure and digestibility based on intermolecular interactions. The findings showed that the apparent viscosity of CS decreased significantly with the increasing of ball milling time from 0 min to 60 min, and the average molecular weight decreased from 561.96 kDa to 274.66 kDa, which laid the foundation for the subsequent experiments. Scanning electron microscopy (SEM) results indicated with increasing ball milling time, the surface morphology of the CS-LA complexes became more and more rough and agglomerated. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) findings indicated that the CS-LA complexes prepared by ball milling exhibited higher thermal stability, better short-range ordering and a compact V-shaped crystal structure. In terms of digestibility, the rapidly digested starch (RDS) content of the CS-LA complexes decreased by 15.93% and the resistant starch (RS) increased by 14.96%, reducing the digestibility of the starch. Density functional theory (DFT) calculations showed that the ordered structure and intermolecular interactions between LA and CS were mainly composed of hydrogen bonds and hydrophobic interactions. We tentatively established the interconnection between multi-scale structure and digestibility through correlation analysis, which provided technical support for further exploitation of starch resources.

Effects of rice protein on the formation and structural properties of starch-lipid complexes in instant rice noodles incorporated with different fatty acids

Herein, the influence of rice protein (10%, w/w) on the formation of indica rice starch-lipid complexes in pure indica rice starch (IRS) system, and the influence of rice starch-lipid complexes formed in instant rice noodles (IRN) after the incorporation of fatty acids (FAs) on in vitro starch digestion were systemly evaluated. The viscoelastic properties of IRS samples increased after the incorporation of protein and lipids. The V-type diffraction intensity in IRS-lipid samples compounded with protein was greater than that of IRS-lipid samples supplemented without protein. In comparison to natural IRN samples, IRN fortified with FAs (especially for LOA) displayed significantly higher relative crystallinity (35.76%) and resistant starch content (14.42%). As shown by SEM, the microstructure of IRN incorporated with SA and LOA presented more denser and regular lamellar structures than those supplemented with shorter-chain FAs; confirmed by the significantly increased short-range order structure and better thermal stability. Collectively, this research may provide a deep understanding on how these three macronutrients (starch, protein, and lipids) interactions taken place during food processing, which might be helpful to develop novel stable foods with desirable digestive and functional properties in an innovative pathway.

Impact of okara on quality and in vitro starch digestibility of noodles: The view based on physicochemical and structural properties

The development of cereal foods with slow starch digestibility is important for the general improvement of human health. In this study, the quality properties of noodles with added okara, in vitro starch digestibility, and the underlying mechanisms of the influence of okara on noodles were studied. Low concentrations (5 and 10 %) of okara improved the texture, cooking, and sensory properties of the noodles. Okara decreased the rapidly digestible starch (RDS) content, increased the resistant starch (RS) content, and reduced the predicted glycaemic index (pGI) of noodles. The pasting viscosity, thermal stability, and dynamic rheological results indicated that okara improved the starch crystallite stability of wheat flour and viscoelasticity of dough. Moreover, Fourier transform infrared (FTIR) spectroscopy showed that okara promoted the formation of starch-lipid complexes and improved the short-range structural order of starch. Additionally, microstructure imaging and protein network analysis (PNA) indicated that low addition of okara promoted the compactness of the okara-gluten-starch matrix, thus reducing the contact between starch and hydrolytic enzymes. These results reveal the effect of okara on the quality properties and starch digestibility in a starch-gluten complex system.

Formation of Starch-Lipid Complexes during the Deep-Frying Process and Its Effects on Lipid Oxidation.

In the present study, maize starch (MS), potato starch (PS), high-amylose maize starch (HAMS), and wheat starch (WS) were deep-fried in soybean oil that was continuously heated for 40 h under 180 °C. The thermodynamic and pasting properties of deep-fried starch samples were determined. The results suggested that starch–lipid complexes formed with the extension of frying oils’ usage; however, their number was not dependent on the frying oils’ life cycle. Importantly, the results of pasting properties revealed the following strength of intermolecular force in deep-fried starch samples: PS > MS > HAMS > WS. The results of XRD and FTIR analysis confirmed the formation of starch–lipid complexes during the deep-frying process. Furthermore, the results of the in vitro digestibility of deep-fried starch revealed that the formation of starch–lipid complexes inhibited the swelling of starch granules and prevented the entrance of amylase into the interior. Additionally, the results of the oxidation stability of deep-frying oil indicated that the formation of starch–lipid complexes did not alter the trend of lipid oxidation as an effect of the limited number of starch–lipid complexes. These results could have critical implications for the development of healthier deep-fried foods.

The formation of starch-lipid complexes in instant rice noodles incorporated with different fatty acids: Effect on the structure, in vitro enzymatic digestibility and retrogradation properties during storage

The formation of starch-lipid complexes in instant rice noodles (IRN) free from and incorporated with fatty acids (FAs) and their impacts on textural, in vitro digestive and retrogradation properties were investigated. The gelatinization enthalpy values of IRN samples (1.24–4.93 J/g) were noticeably decreased (P < 0.05) compared to rice starch samples (2.54–6.89 J/g) fortified with FAs. Additionally, long-chain saturated FAs (stearic acid (SA, C18:0)) complexes produced higher ordered structures than the shorter-chain FAs (C12:0-C16:0), for 18-carbon FAs, the unsaturated FAs (linoleic acid (LOA, C18:2)) exhibited the strongest intermolecular interactions with rice starch. The relative crystallinity of IRN (27.01%–38.47%) was lower than the rice starch-FAs complexes (38.36%–56.80%). FAs delayed the retrogradation degree of IRN storaged at 4 °C for 21 days ascribed to the formation of V-type complexes. Higher enzymatic resistance was observed in IRN added FAs with resistant starch content increased from 5.13% to 14.42% (LOA), and the sample fortified with SA exhibited the highest slowly digestible starch content (35.92%). SEM revealed that the IRN compounded with palmitic acid, SA and LOA displayed more compact and regular structures. Overall, the formation of starch-FAs complexes probably is a novel strategy in improving the textural, digestive, and retrogradation properties of IRN.

Impact of starch-lipid complexes on oil absorption of starch and its mechanism.

Worldwide, fried food has a huge demand and good development prospects. Low oil in foods is the standard that everyone is now pursuing for a healthy diet. The oil absorption behavior of rice starch during frying was investigated in the presence or absence of fatty acids or fatty acid esters with different carbon chain lengths. The complex formed between starch and fatty acids or fatty acid esters was dependent on lipid chain length, which was confirmed by X-ray diffraction and complexing index. The formation of starch-lipid complexes could significantly reduce the oil absorption of starch, and the complexes with higher complexing index had lower oil absorption. The starch-palmitic acid complex showed the lowest oil absorption after frying, which was 14.06 g per 100 g lower than that of gelatinized starch. This was attributed to the ability of the palmitic acid to increase the density of starch crystalline polymorphs as well as their ability to complex with the amylose spiral cavity. These results may be useful for development of healthier fried starch-based foods with reduced oil contents. © 2022 Society of Chemical Industry.

Influence of different kinds of fatty acids on the behavior, structure and digestibility of high amylose maize starch-fatty acid complexes.

The formation of starch-lipid complexes is of interest to food processing and human nutrition. Fatty acid (FA) structure is important for the formation and structure of starch-FA complexes. However, there is limited research regarding the complexing behavior between amylose and different kinds of FAs, as well as the relationship between fine structures and digestibility of the formed complexes. This study aimed to investigate the behavior, fine structure, and digestibility of complexes formed between high amylose maize starch (HMS) and FA having various chain lengths and unsaturation degrees. Complexes containing different FA structures showed V6III -type crystals. Complexes containing 18-carbon unsaturated FAs displayed significantly higher complexing index (P < 0.05) than other complexes. Complexes containing 12-carbon FAs and 18-carbon FAs with one unsaturation degree showed a higher degree of structural order and resistant starch (RS) content than other complexes. The 12-carbon FAs exhibited a higher binding degree with helical cavity of amylose than other FAs. Additionally, 10-carbon and 18-carbon saturated FAs tended to combine with HMS outside amylose helices more than other FAs. Laser confocal micro-Raman imaging revealed that the physically embedded 10-carbon and 18-carbon saturated FAs showed heterogeneous distribution in complexes, and that the complexed 18-carbon FAs with one unsaturation degree exhibited homogeneous distribution. The behavior, structural order and digestibility of complexes could be regulated by FA structure. The 12-carbon FAs and 18-carbon FAs with one unsaturation degree were more suitable for the production of HMS-FA complexes with higher structural order and RS content than other FAs. © 2022 Society of Chemical Industry.

Production of buckwheat starch-myristic acid complexes and effect of reaction conditions on the physicochemical properties, X-ray pattern and FT-IR spectra

In this study, the effect of reaction parameters on complex index (CI%) value of complexes formed between buckwheat starch (BS) and myristic acid (MA) was investigated. The temperature (60–90 °C) and MA to BS ratio (0.1–0.8 mmoL/g) were determined as the most effective parameters and their effect on CI% was evaluated using response surface methodology. The MA to BS ratio, temperature, and interaction between them had an influence on CI%. The CI% of BS-MA complexes increased with increasing MA ratio until a certain level of MA. Principal component analysis (PCA) was used for correlation analysis between parameters. Swelling power and paste clarity of BS decreased with complex formation while syneresis increased. Peak and final viscosity values of the BS-MA complexes were significantly lower than those of BS. FT-IR revealed the complex formation led to change in starch structure. The XRD confirmed the BS-MA complex formation but the BS-MA produced using 0.1 mmoL/g at 60 °C was not detected by XRD due to having low crystallinity, and expectedly, the lowest relative crystallinity value was achieved with this sample among complex samples. All results showed that the buckwheat might be an alternative starch source for starch-lipid complex formation.

The formation of starch-lipid complexes by microwave heating

This study investigated the impact of microwave treatment on the formation of starch-lipid complexes, and physicochemical properties of wheat starch (WS) fortified with lipids, such as lauric acid (LA), glycerol monolaurate (GML), and stearic acid (SA). Specimens were prepared using a conventional water bath and microwave heating and evaluated using macrostructural and microstructural analyses. Iodine staining and scanning electron microscopy revealed interplay between WS and LA. Diffraction peaks around 7.5°, 13°, and 20° and the absence of the absorption band in the 2850 cm−1 were observed in microwave treated WS-lipid samples than conventional water bath samples. Further, more type I complexes were formed in WS-LA microwave-assisted samples, as demonstrated by differential scanning calorimetry. Additionally, more resistant starch was formed in specimens treated by microwave than water bath treated counterparts, the finding that was proved by in vitro enzymatic hydrolysis. In short, the current study may suggest the applications of microwave treatment in foods for hypoglycemia.

Effects of Rice Protein on the Formation and Structural Properties of Starch-Lipid Complexes in Instant Rice Noodles Incorporated with Different Fatty Acids

Effects of Rice Protein on the Formation and Structural Properties of Starch-Lipid Complexes in Instant Rice Noodles Incorporated with Different Fatty Acids

Octenyl Succinate Modification of Starch Enhances the Formation of Starch-Lipid Complexes.

The present study investigated the effect of octenyl succinic anhydride (OSA) modification of starch on the formation of starch-lipid complexes. The complexing index (CI) showed that native maize starch (NMS) formed more complexes with monopalmityl glycerol (MPG) than with palmitic acid (PA), whereas dipalmityl glycerol (DPG) was not effective in forming complexes with NMS. After OSA modification, the complexation between OSA-starch and lipids was greatly enhanced, especially for PA and DPG, and the CI values increased from 79.6 to 93.3% for OSA-starch-PA and from 80.3 to 93.2% for OSA-starch-DPG complexes with increasing DS of OSA-starch. Structural analyses showed that OSA-starch-lipid complexes had higher degrees of long- and short-range molecular orders than the corresponding NMS-lipid complexes. This study showed for the first time that DPG can form complexes with OSA-starch, which was attributed to the increased dispersion of DPG in water by the emulsifying ability of OSA-starch. The finding is of great significance for a better understanding of the formation of starch-lipid complexes.

The impact of gliadin and glutenin on the formation and structure of starch-lipid complexes

This study evaluated the influence of the main gluten fractions (gliadin and glutenin) on the physicochemical properties of binary wheat starch-Lauric acid (WS-LA) complexes during heat processing to explore the complex structure and digestion of WS-LA in the presence of gluten. Ternary WS-LA-glutenin complexes were prepared at different pH (5.2 and 7), whereas WS-LA-gliadin was prepared using ethanol, and their physicochemical properties were analyzed. We found that the addition of glutenin displayed a sharper and higher diffraction peak than samples without protein, which increased short-range order structure (low full width at half-maximum (FWHM) of the band at 480 cm−1) and good thermal stability (melting peak appeared at a higher temperature); the opposite was shown for gliadin. Even though glutenin increased the resistant starch (RS) content than WS-LA, all samples prepared in 65% ethanol showed higher RS content than WS-LA-glutenin samples. These findings might improve our understanding of the relationship between gliadin/glutenin and binary complexes and provide a theoretical basis for preparing starch-based foods with a low glycemic index.