Starch-lipid Complexes Research Articles

Molecular mechanisms underlying the formation of starch-lipid complexes during simulated food processing: A dynamic structural analysis

The aim of the present study was to investigate the mechanism of formation of maize starch (MS)-lipid complexes during pasting in the Rapid Visco Analyser. MS-lauric acid (LA) and MS-monomyristyl glycerol (MMG) samples with lipid concentrations of 0–5% were prepared and characterized. Complexing index (CI) and rheological analyses showed that the viscosity and gel strength of starch was highly correlated to the amount of starch-lipid complex that formed. An increase followed by a decrease in CI values, enthalpy change and structural order during pasting of MS-2% LA mixture indicated that starch-lipid complexes were mostly formed during the setback stage, and that the disruption of some complexes formed at higher lipid concentration occurred with ongoing cooling. This study revealed the mechanisms of formation of starch-lipid complexes during simulated food processing, and how such complexes affect the viscoelastic properties of starch pastes, which is of relevance to the texture of starchy foods.

Effect of microwave heating and vacuum oven drying of potato strips on oil uptake during deep-fat frying

The properties of moisture and starch in potatoes affect the quality and oil absorption of final fried products. In this study, changes in moisture state, starch properties, and micromorphology of potato strips pretreated by microwave heating (MH) and vacuum oven drying (VOD) were investigated using low-field nuclear magnetic resonance, magnetic resonance imaging (MRI), differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy (SEM) analyses. The influence of changes in these properties on the oil content and distribution of fried potato strips was analyzed. Results showed that the decreased moisture content and changed moisture state in the pretreated samples had a positive effect on reducing the oil content. The pregelatinized starch facilitated the formation of V-type starch–lipid complexes, which formed a protective layer to prevent oil absorption. Analysis of MRI and confocal laser scanning microscopy images confirmed this finding. SEM observation showed microstructural changes might have an effect on oil absorption and its results exhibited crusts of the MH-pretreated samples thickened after frying, and the internal pores and structures of the VOD-pretreated samples became small and dense, respectively; both changes negatively affected oil absorption. Results could help understand the oil absorption behavior of starch-based food during frying and provide a basis for improving the quality and controlling the final oil content of the product.

Physicochemical properties of pea starch-lauric acid complex modified by maltogenic amylase and pullulanase

An enzymatic method was investigated to initiate a strategy of increasing the branch density of pea starch, thus facilitating the formation of a starch-lipid complex after debranching. When the starch was modified by exposure to maltogenic amylase (MAL) and pullulanase (PUL), lower molecular weight values and higher amylose content resulted compared to the untreated sample. High-performance anion-exchange chromatography results suggested that the average chain length decreased and the branch density increased after the starch received MAL treatment. The diffraction intensities and the total melting enthalpies of the dual-enzyme treated complex were greater than those for other samples when the level of MAL between 4–12 U/g. Fourier transform infrared spectroscopy revealed that more ordered structure was formed in MAL (4/8/12)-PUL-starch-lauric acid (Lau) complexes. Digestive performance analysis indicated that the enzyme resistance of the starch-Lau complex was reinforced by applying the MAL-PUL modification to the starch.

Fabrication and characterization of hollow starch nanoparticles by heterogeneous crystallization of debranched starch in a nanoemulsion system

The development of hollow nanoparticles has attracted widespread interest due to their potential commercial applications. This work aimed to prepare a novel hollow starch nanoparticles (HSNPs) from debranched waxy corn starch (DBS) via an oil-in-water (O/W) emulsion templating method. The effects of different concentrations of DBS on the formation of HSNPs at 4 °C and 25 °C were investigated. The monodispersed HSNPs obtained with 0.5% concentrations of DBS at 25 °C had spherical shapes, ranging between 200 and 800 nm. HSNPs with relative crystallinities of 16.9%–29.7% exhibited V-type or B + V-type structures, which indicated that DBS at low concentrations (0.5%–2.0%) could recrystallize and concomitantly form starch–lipid complexes around emulsion droplets. This novel approach of preparing HSNPs is viable and simple. The developed HSNPs could have great potential for delivering drugs or active ingredients.

Physicochemical properties and in vitro digestibility of lotus seed starch-lecithin complexes prepared by dynamic high pressure homogenization

The objective of this study was to investigate the physicochemical properties and in vitro digestibility of lotus seed starch-lecithin inclusion complexes (ICs), prepared by dynamic high pressure homogenization. Raman spectrometry indicated that the IC formed between starch and lecithin, compared with the control mixture, could modify the helix rearrangement between different amylose conformations, to promote the formation of an ordered and stable V-type conformation. The content of amylose single helix appeared to be an important factor in the formation of starch-lipid complexes. Dispersion stability and solubility determinations indicated that the effect of mixing lecithin with starch mainly focused on the dispersion stability and not the solubility of starch emulsions. ICs with a V-type conformation, formed by homogenization of lecithin and amylose, achieved the same, or better emulsion stability as mixed lecithin, and the formation of ICs reduced the affinity of starch chains for water molecules, lowering their solubility. Digestion analysis suggested that the higher proportion of microcrystalline region in V6I complexes, resulted in a lower digestion rate and a higher resistant starch (RS) content.

Starch-lipid and starch-lipid-protein complexes: A comprehensive review.

Physical interactions often occur between major food components during food processing. These interactions may involve starch, lipids, and proteins forming V-type starch-lipid complexes or ternary starch-lipid-protein complexes of larger molecular size and greater structural order. Complexes between starch and lipids have been the subject of intensive research for over half a century, whereas the study of starch-lipid-protein complexes is a relatively new field with only a limited amount of knowledge being gained so far. The formation of these complexes can significantly affect the functional and nutritional properties of finished food products in terms of flavor, texture, shelf life, and digestibility. This article provides a comprehensive review of starch-lipid and starch-lipid-protein complexes, including their classification, factors affecting their formation and structure, and preparative and analytical methods. The review also considers how complexes affect the physicochemical and functional properties of starch, including digestibility, and potential applications in the food industry.

Supernatant starch fraction of corn starch and its emulsifying ability: Effect of the amylose content

Corn starches with different amylose contents (2.0%, 27.5%, and 49.1%) were gelatinized and centrifuged to obtain the supernatants. It was found that the starch fractions in the three supernatants might be amylose and have similar molecular weight. However, the solid content in the supernatants was in the order of normal corn starch > high-amylose corn starch > waxy corn starch. Contact angle analysis indicated that these supernatant starch fractions had affinity for both water and oil, thus displaying emulsifying ability. Subsequently, the supernatants were used to prepare oil-in-water emulsions. All emulsions had good ionic, pH and thermal stability, while their storage stability was in the order of normal corn starch emulsion > high-amylose corn starch emulsion > waxy corn starch emulsion. In addition, no starch-lipid complex was detected in the emulsion by DSC and XRD analysis. These results suggested that the supernatant starch fractions had emulsifying ability and the stability of obtained emulsions depended on the solid content of the supernatants.

Functional and pasting properties of a starch–lipid complex formed with gaseous ozone and palm oil

ABSTRACT Arrowroot starch repeatedly ozonated for 10 and 30 cycles was mixed with 5 and 10 g palm oil/100 g starch to form a complex. The complex index increased as oil concentration or ozonation cycles increased. The increased complex due to ozonation could be linked to depolymerization or ring opening but not to the increase in the number of polar carboxyl groups, so more entry points to the amylose cavity became available for lipid inclusion. The properties of the ozonated starch mixed with palm oil were affected by the interplay between the effect of lipid–starch complex and carboxyl content. The effect of the lipid–starch complex prevailed over that of the carboxyl group at a palm oil concentration of 10 g palm oil/100 g starch.

Efecto de la temperatura de extrusión, humedad y contenido del aceite de girasol sobre las propiedades funcionales y digestibilidad de alimentos para ganado bovino

Preparation of extruded products with high oil content, presents a technological challenge, due oil decreases specific mechanic force but also acts as a lubricant, and forms starch-lipid complexes; thus, decreasing starch gelatinization. This research aimed to evaluate the effect of temperature, moisture, and sunflower oil content, on the extrusion process of bovine cattle feed. Two main ingredients were used for each diet: alfalfa (Medicago sativa L.), and bean (Phaseolus vulgaris L.). The obtained results showed that high temperature, moisture, and oil content, decreased bulk density, and hardness (P < 0.05). Oil content-temperature interaction increased both bulk density and hardness, while moisture-oil content interaction increased (P < 0.05) hardness. Optimization was performed based on the physicochemical characteristics of commercial feeds, showing that the best bean diets were obtained at 121oC, 14% moisture content with 0% sunflower oil; 120oC and 16% moisture content with 3.5% sunflower oil; and, 142oC and 15% moisture content with 7% sunflower oil. Effective degradability ranged from 87.4 - 90.4% for all extruded diets; and none of them showed significant differences between bean and alfalfa (P < 0.05), which opens a high potential opportunity of producing high concentrations of CLA from sunflower oil at a ruminal level.

Effects of pullulanase debranching on the properties of potato starch-lauric acid complex and potato starch-based film

The effects of different debranching time on the properties of potato starch and its films were evaluated. Potato starch granules were debranched with pullulanase for 0, 0.5, 1.0, 1.5 or 2.0 h. The effects of pullulanase debranching treatment on the chain-length distributions of amylopectin were analysed by high performance anion exchange chromatography (HPAEC), which proved that the shorter debranching treatment generated more linear chains with favourable lengths to facilitate the formation of potato starch-lauric acid complexes. The debranched starch-lipid complexes showed higher lauric acid content than that of the untreated sample. X-ray diffraction showed that the diffraction intensity of the debranched sample was stronger than that of the undebranched sample, and when the debranching time was >1.5 h, the diffraction intensity and relative crystallinity of the complexes decreased. The sample exhibited a high melting enthalpy (ΔH) under the pullulanase debranching treatment for 1.5 h. Scanning electron microscope data indicated that the surface of the composite film was flatter after the debranching treatment and that the films exhibited the lowest water vapour permeability and highest tensile strength after the treatment time for 1.5 h.

Preparation of starch-lipid complex by ultrasonication and its film forming capacity

Ultrasonication was used to promote the complexation between amylose and fatty acids with different states. The physicochemical properties of amylose-lipid inclusion complexes and their film-forming capacities were investigated. The fatty acids in the liquid state showed a greater complex-forming ability with amylose molecules than those in the solid state. The formation of V-amylose complex was revealed by XRD. The diffraction intensities of the corn starch-fatty acid complexes followed the order: capric acid > octanoic acid > lauric acid > myristic acid. The starch-lipid inclusion complexes with ultrasonic treatment showed higher melting enthalpies (△H) than those of untreated ones. The surface of the corn starch-fatty acid composite films became smooth after the starch underwent ultrasonic treatment. The ultrasonically-treated films exhibited lower water vapor permeability and elongation at break and higher tensile strength than those of the untreated samples.

Sensory, Tribological, and Rheological Profiling of “Clean Label” Starch–Lipid Complexes as Fat Replacers

Dietary fat is highlighted as one of the critical risk factors that contribute to a number of chronic diseases. In this study, the sensory profile, tribological, and rheological properties of starch–lipid complexes, as a potential fat replacer, is investigated. Starch–lipid complexes are formulated by incorporating food friendly chemicals (stearic acid and monoglyceride) into maize starch by wet‐heat processing and compared with a commercial fat replacer. The starch–lipid complexes have good lubricating properties and are described by the panelists as being glossy, smooth, creamy, and easy‐to‐swallow. All the complexes exhibited a shear thinning behavior and had lower firmness, due to their non‐gelling ability compared to the commercial fat replacer. The properties of starch–lipid complexes for non‐gelling, good lubricating, smooth, and creamy can be related to the formation of amylose–lipid complexes and other properties. The complexes have the potential to produce non‐gelling emulsions having a creamy and smooth texture with no adverse effect on the overall aroma and flavor.

The effect of NaCl on the formation of starch-lipid complexes

The aim of this study was to investigate the effect of NaCl on the formation, structure and property of samples formed from wheat starch (WS) and the fatty acids (lauric acid (LA), myristic acid (MA), palmitic acid (PA) and stearic acid (SA)). Results from RVA, DSC, XRD and Raman analyses showed that LA, and to a lesser extent MA, formed complexes with WS. Under the experimental conditions used, only minor amounts of WS-PA and WS-SA complexes formed. The low solubility of PA and SA, and to some extent MA, in water caused these fatty acids to mostly self-aggregate. The presence of NaCl promoted the formation of WS-LA complexes and, to a lesser extent complexes with MA, but had little effect on the formation of WS-PA and WS-SA complexes. Solubility of fatty acids in aqueous medium was proposed to be a major factor for the formation of starch-fatty acid complexes.

Complexation of Amylosucrase-Modified Waxy Corn Starch with Fatty Acids: Determination of Their Physicochemical Properties and Digestibilities.

In this study, starch-lipid complexes were prepared using normal corn starch (NC) and amylosucrase-modified waxy corn starch (ASWC) with myristic acid (C14:0) and palmitic acid (C16:0). The amylosucrase modification elongated branch chains in waxy corn starch leading to an increase of apparent amylose content (29.7%) similar to that of NC (29.0%). The X-ray diffraction of starch-lipid complexes revealed a V-type pattern, a clear indication of complex formation. The ability of the ASWC to complex with fatty acids was greater than that of NC. Interestingly, the changes in relative crystallinity, thermal parameters, and digestion properties according to the complexation showed opposite patterns in NC and ASWC. This study found that the structure of ASWC contributes to the formation of starch-fatty acid complexes and suggested that the ASWC can be preferred over NC in a delivery system. PRACTICAL APPLICATION: Amylopectin has been considered to be incapable of forming complexes with fatty acids due to its short chain length and steric hindrance. Through this study, an appropriate enzymatic modification of the molecular structures of waxy starches could make a complexation of waxy starches with fatty acids possible. The findings of this study suggest a promising perspective for utilization of waxy starch as a carrier material of lipophilic molecules.

Status of polymorphism, physicochemical properties and in vitro digestibility of dual retrogradation-annealing modified rice starches.

In this research, for the first time, dual retrogradation-annealing modification was applied to three rice starches with 22.7%, 9.8% and 0.3% apparent amylose content (AAC). Amylose partially inhibited the effect of gelatinization on amylopectin crystallinity. Polymorphism in retrograded starches was feeble and unstable. Annealing principally caused amylopectin crystal growth by lamellar rearrangement and simultaneous degeneration of weaker lamellae. Reappearance of physical growth rings occurred. Altered crystalline arrangement had direct effect on cooked paste viscosity, gel texture, swelling power, suspension turbidity, and freeze-thaw stability of the samples. A new prominent X-ray diffraction peak (2θ = 29.1) confirmed development of novel polymorphic form other than characteristic A-, B- and V-types. Crystallite melting enthalpy (ΔH) was higher in dual modified starches (9.9 J/g, 12.9 J/g, 19.0 J/g) than native samples (ΔH = 7.4 J/g, 9.1 J/g, 12.1 J/g). Starch-lipid complexes formed the major portion of the crystalline phase within the modified starch matrices. Amylopectin played the major role in crystalline reformation and formed prominent amylopectin-lipid complexes. Simultaneous conversion of slowly digestible starch to resistant starch occurred. Enhanced thermostability, enzyme resistance and functional properties may be suitably targeted for food and non-food applications of the dual modified rice starches.

Investigation the molecular degradation, starch-lipid complexes formation and pasting properties of wheat starch in instant noodles during deep-frying treatment

The effects of frying temperature and time on the amylose content, thermodynamic properties, crystalline properties, and pasting properties of starch in wheat-flour based noodles were investigated. The amylose content increased when the frying temperature increased or the frying time extended. Differential scanning calorimetry confirmed the formation of starch-lipid complexes. ΔH of the complexes increased sharply from 0.91 to 1.40 J/g with increased frying temperature, while it initially increased from 1.01 to 1.40 J/g and then decreased rapidly to 1.17 J/g with prolonged frying time. These observations were consistent with the results of relative crystallinity. Rapid viscosity analysis showed that the viscosities decreased by the increasing frying temperature or the prolonging frying time. The results showed that the deep-frying process destroyed the starch structure and led to the formation of starch-lipid complexes.

Structural Changes of Starch-Lipid Complexes during Postprocessing and Their Effect on In Vitro Enzymatic Digestibility.

The effects of cooking and storage on the structure and in vitro enzymatic digestibility of complexes formed between fatty acids and debranched high-amylose starch (DHA7-FA) were investigated for the first time. Cooking greatly decreased the crystallinities of DHA7-lauric acid (LA) and DHA7-myristic acid (MA) complexes but had little effect on the crystallinities of DHA7-palmitic acid (PA) and DHA7-stearic acid (SA) complexes. Cooking increased the enthalpy-change (Δ H) values and short-range molecular orders of DHA7-FA complexes. Cooking decreased the in vitro enzymatic digestibility of DHA7-FA complexes, with the extent of the effect decreasing with increasing fatty acid chain length. Holding the samples at 4 °C for 24 h after cooking did not greatly affect the long- and short-range molecular orders nor the in vitro enzymatic digestibility of DHA7-FA complexes. From this study, we conclude that cooking disrupted the long-range crystalline structures of DHA7-LA and DHA7-MA complexes but enhanced the short-range molecular orders of all of the DHA7-FA complexes. The latter effect accounted mainly for the reduced in vitro enzymatic digestibility of DHA7-FA complexes.

Proximate composition andin vitro protein digestibility of extruded aquafeeds containingAcheta domesticus andHermetia illucens fractions

Major protein sources for feed manufacture have become costly, and this has led to increased cost of products such as aquafeeds. This has dampening effect on fish production especially in developing countries, and has necessitated a search for alternative protein sources in processed feeds. The effects of extrusion on aquafeed blends containing fractions of adult cricket (Acheta domesticus) meal (ACM) or black soldier fly (Hermetia illucens) pre-pupae meal (BSFM) on proximate composition andin vitro protein digestibility were investigated. Extrusion resulted in higher contents of protein and nitrogen free extract, and lower contents of ether extract and crude fibre as compared to the non-extruded feed. These observations were mainly associated with denaturation of proteins leading to increase in solubility, solubilisation of fibre due to the shearing forces at high temperature resulting in higher nitrogen free extract, and formation of starch-lipid complexes leading to lower ether extract. Our findings indicate that ACM or BSFM can be used to substitute fresh water shrimp meal up to 75 g/100 g level and still achieve highly nutritious processed fish feed.

Insights of the ability of gelatinized fractions from non-chemical modified corn, rice, wheat, and waxy corn starches to stabilize O/W emulsions

Non-chemical modified native corn (NCS), rice (NRS), wheat (NWS), and waxy corn (WCS) starch dispersions (5.0 g/100 g water) were heated (90 °C, 20 min) for producing gelatinized starch dispersions (GSD). GSD were centrifuged and the supernatant starch fraction (SF) was used for preparation of O/W emulsions (dispersed phase mass fraction of 0.15). The interfacial activity of the different SFs was assessed by dynamic interfacial tension measurements. The SF from NCS, NRS and NWS showed significantly higher and faster interfacial tension decaying rates than the WCS SF. All the SFs were able to form O/W emulsions. The volume-weighted mean droplet diameter (d4,3) of the fresh emulsions were significantly different ranging from ∼1.4 to 19 μm. The emulsions made with SFs from NCS, NRS and NWS showed larger d4,3 and faster creaming rates than that made with SF of WCS. The latter produced an emulsion with practically unchanged d4,3 and slowest creaming rate with storage time. FTIR, XRD, zeta-potential measurements, and adsorption time relaxation constants allowed postulating that emulsion stability was related to the formation of inclusion starch-lipid complexes at the oil-water interface. This study provides insights about the phenomena occurring on O/W emulsions interface due to interactions between cooked starch fractions from different botanical origin and lipids, and which might occur during food processing.

Effect of water content of high-amylose corn starch and glutinous rice starch combined with lipids on formation of starch-lipid complexes during deep-fat frying.

Moisture affects the combination of starch granules and fatty acids in deep-fat frying. In this study, high-amylose corn starch (HACS) and glutinous rice starch (GRS) with various water contents were fried in rapeseed oil at 170 °C for 7 min. The complex index (CI) of the GRS-lipid and HACS-lipid complexes improved as the moisture content increased from 6% to 40%; however, further increasing the water content from 40% to 60% led to a decrease in the CI. At a moisture content of 40%, the CI of the HACS-lipid complexes was higher than that of the GRS-lipid complexes. Fatty acid content analysis revealed that the total fatty acid content at different moisture contents in the HACS-lipid complexes was higher than that in the GRS-lipid complexes both before gelatinization and after enzyme hydrolysis. In addition, the total fatty acid content in the HACS-lipid complexes and GRS-lipid complexes at 40% moisture content was the highest among all the measured moisture contents. Scanning electron microscopy revealed that both the HACS and GRS granules lost their integrity after deep-fat frying, and no free lipid droplets were noted among the starch granules after defatting. Both Fourier-transform infrared spectroscopy and fluorescence microscopy verified that HACS combined with lipids yielded a stronger lipid-binding capacity than that of GRS at a moisture content of 40%. The study results may be potentially useful in the deep-fat frying of starchy food to produce foods with lower fatty acid content.