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LF is a bioactive protein, derived from colostrum and milk that has been found to possess various immunomodulatory, iron chelating, and antimicrobial properties, especially in its apo-form. Recent studies have demonstrated the functionality of LF in attaching to the S proteins of SARS-CoV-2, thereby preventing it from interacting with the ACE-2 receptor. However, the molecular mechanism mediating the process is poorly understood. In this study, molecular docking and MD simulations coupled with free energy calculations were applied to elucidate the key interaction of apo-LF and its N-lobe and C-lobe derivative forms with the RBD of coronavirus S proteins. This has also been extended into evaluating the L452R mutant, which is associated with the delta variant of SARS-CoV-2. The results demonstrate the efficacy of the apo-LF C-lobe in binding to the RBD of both variants, primarily through electrostatic attractions between the acidic residues of the former and the basic residues of each RBD. Furthermore, due to the additional arginine in the L452R variant, the interaction between the C-lobe and the latter is stronger, resulting in a more favourable binding and tightly bound structure. The simulations highlight that the C-lobe, followed by full-length apo-LF can form a multimeric complex with the RBD of SARS-CoV-2, indicating their potential use as novel therapeutics, particularly the cleaved C-lobe of apo-LF to disrupt the S proteins from binding to the host ACE-2 receptor. Communicated by Ramaswamy H. Sarma.

Lactoferrin is a protein, primarily found in milk that has attracted the interest of the food industries due to its health properties. Nevertheless, the instability of lactoferrin has limited its commercial application. Recent studies have focused on encapsulation to enhance the stability of lactoferrin. However, the molecular insights underlying the changes of structural properties of lactoferrin and the interaction with protectants remain poorly understood. Computational approaches have proven useful in understanding the structural properties of molecules and the key binding with other constituents. In this review, comprehensive information on the structure and function of lactoferrin and the binding with various molecules for food purposes are reviewed, with a special emphasis on the use of molecular dynamics simulations. The results demonstrate the application of modeling and simulations to determine key residues of lactoferrin responsible for its stability and interactions with other biomolecular components under various conditions, which are also associated with its functional benefits. These have also been extended into the potential creation of enhanced lactoferrin for commercial purposes. This review provides valuable strategies in designing novel nutraceuticals for food science practitioners and those who have interests in acquiring familiarity with the application of computational modeling for food and health purposes.

Lactoferrin is a protein, primarily found in milk that has attracted the interest of the food industries due to its health properties. Nevertheless, the instability of lactoferrin has limited its commercial application. Recent studies have focused on encapsulation to enhance the stability of lactoferrin. However, the molecular insights underlying the changes of structural properties of lactoferrin and the interaction with protectants remain poorly understood. Computational approaches have proven useful in understanding the structural properties of molecules and the key binding with other constituents. In this review, comprehensive information on the structure and function of lactoferrin and the binding with various molecules for food purposes are reviewed, with a special emphasis on the use of molecular dynamics simulations. The results demonstrate the application of modeling and simulations to determine key residues of lactoferrin responsible for its stability and interactions with other biomolecular components under various conditions, which are also associated with its functional benefits. These have also been extended into the potential creation of enhanced lactoferrin for commercial purposes. This review provides valuable strategies in designing novel nutraceuticals for food science practitioners and those who have interests in acquiring familiarity with the application of computational modeling for food and health purposes.

A fundamental study was carried out to evaluate patterns of vitamin B6 release from genipin crosslinked gelatin in aqueous media at ambient temperature. Up to ninety percent crosslinking was achieved, with FTIR and WAXD data arguing for partial replacement of the triple helix with a covalent pattern of bonding between protein and crosslinker. Formation of a “composite network” yielded increasing compressive stress-at-failure values followed by a decrease as a function of genipin addition, with the yield strain decreasing continuously. Electron microscopy images showed a reduction in the size of the hydrogel pores with a higher degree of crosslinking. Experimental evidence was supported by the Flory-Rehner theory that predicted a lower swelling ratio and reduced molecular weight between adjacent crosslinks with genipin addition. Furthermore, Peppas-Sahlin equation was used to rationalise the interplay between network morphology and diffusion of bioactive compound over prolonged timeframes of release testing.

Background There is increased interest in the food, pharmaceutical and cosmetic industries in using ascorbic acid as an important component in the human diet for health support and disease prevention. However, its use as an ingredient is limited by its high instability and sensitivity to environmental conditions. Microencapsulation technology has been proposed to increase the stability of ascorbic acid. The aim this work was to evaluate the effect of ascorbic acid loading rate on the physicochemical properties of encapsulated ascorbic acid. Loading contents of ascorbic acid of 6%, 9%, 18%, 36%, 54% and 72% were trialled using spray drying in conjunction with starch-based encapsulating agents. Results The results showed that the loading content has a significant effect on ascorbic acid retention, yield, moisture content, water activity, colour change, particle size and distribution of microcapsules. Morphology of microcapsules also was assessed using environmental scanning electron microscopy, showing that the microcapsules had good structure and integrity for a loading content of 18% and even as high as 54%. At levels beyond this, capsules showed a lack of coherence and integrity of the outer shell. Conclusions The results indicated that ascorbic acid microparticles at various loading rates have a substantial impact on physical and chemical properties of microcapsules. Loading content can be selected to ensure colour uniformity and minimal effects on colour during food fortification processes. © 2020 Society of Chemical Industry.

In order to further characterise sorghum starch as a potential ingredient in food formulations, starch granules have been extracted from sorghum flour and characterised. The lamellar structure of granules and the uptake of water under ambient conditions have been investigated using small-angle X-ray scattering (SAXS). The lamellar structure was affected by the uptake of water and crystallinity was disrupted as water was absorbed. The diameter of sorghum granules had a bimodal distribution and the lamellar patterns were similar to those of other cereal starches. Moisture uptake occurred within the first four hours of exposure to water and SAXS provides a valuable technique for further studies of granular starch, including changes during the uptake of water.

The minor protein in milk, lactoferrin (Lf), is known for a variety of biological functions, and has been investigated as a protective encapsulant for probiotic bacteria in health-promoting food products. Lf is likely to be exposed to extreme pH conditions which are known to have disruptive influences on its functionality. The molecular mechanisms underlying these pH-dependent changes are not well-understood. To explore the potential of Lf as an encapsulant, molecular dynamics (MD) simulations were applied to study its conformational changes under extreme acidic (pH 1.0) or basic (pH 14.0) conditions, relative to neutral pH. Simulations indicate that the structure of apo-Lf is relatively stable at neutral pH, while acidic and basic pH result in substantially greater flexibility, partly induced by the loss of contacts between the N- and C-terminal lobes, causing them to undergo extensive relative bending and twisting motions. Basic pH causes greater structural disruption compared to acidic exposure. The latter has greater influence on the N-terminus, with increased fluctuations and disruptions of inter-residue contacts compared to those at neutral pH; while basic pH was found to more prominently disrupt contacts at the C-terminus. These results help elucidate possible functional consequences on Lf of exposure to extreme pH conditions.

Lactoferrin (LF) is a multi-functional protein that is primarily found in milk. The apo form of LF (apo-LF) is devoid of iron, and as a result, may serve as an iron scavenger with attendant anti-pathogenic properties, thereby, endowing apo-LF with promising health benefits. Despite these advantages, the structural stability of apo-LF may be perturbed by various processing conditions. One of the strategies employed to stabilise the activity of apo-LF is to encapsulate it as part of an oligomeric complex, composed of apo-LF, α-lactalbumin (α-La) and β-lactoglobulin (β-Lg). Accordingly, the aim of this study is to investigate the structural changes of apo-LF and its interactions with α-La and β-Lg under the temperature conditions of freeze-drying (−30, 0, and 20 °C). Using in silico approaches, molecular dynamics simulations showed apo-LF had limited structural perturbation when processed at these temperatures. Both α-La and β-Lg stabilise apo-LF by enhancing and maintaining the structural integrity and cohesion of the tertiary structure of apo-LF. These stabilities are the result of electrostatic interactions, binding apo-LF and the protective proteins into a multimeric complex. The secondary structure and the anti-bacterial derivatives in apo-LF were also sustained under these simulated conditions. Furthermore, inter-residue contact maps in apo-LF predict an increase in intramolecular contacts at simulated freeze-drying conditions, resulting in agglomeration and, therefore potential proteins dispersibility during subsequent rehydration. Overall, this work demonstrates the advantages of computational approaches to understand the macromolecular conformations, interactions, and functional implications of a multimeric complex composed of apo-LF, α-La, and β-Lg at low temperatures.

There has been considerable research into ascorbic acid (AA) as a food component in the human diet and disease prevention. Microencapsulation technology has a promising strategy for enhancing the stability of AA towards the carrier food. The effects of varying hydrocolloid proportions on encapsulation of AA by spray drying have been evaluated. Spray drying pilot plant scale was used to produce the microcapsules, and capillary electrophoresis has been applied to analyse the retention of AA during bread making process. To investigate the characteristics of microstructure of encapsulated AA after processing, the environmental scanning electron microscope was used to investigate the structure of microcapsules. In addition to that to measure the particle size and distribution of microcapsules, the laser beam scattering was used. The impact of varying hydrocolloids proportion on encapsulation of AA by spray drying was studied.

Increasingly, lactic acid bacteria have been encapsulated into food formulations because of their health advantages, including modulation of the gut microflora. However, the molecular mechanism on how these bacteria interact with the encapsulating agent, which is typically composed of milk proteins is not fully comprehended. Accordingly, molecular dynamics simulations were employed to investigate the interaction between the cell wall component of these bacteria, specifically the peptidoglycan layer and a protein complex, comprising apo-lactoferrin, β-lactoglobulin, and α-lactalbumin at spray drying temperatures (68 and 110 °C). The results demonstrate that the peptidoglycan model interacts with the posterior N-lobe of apo-lactoferrin and the three-turn α-helix of β-lactoglobulin via van der Waals, electrostatic, and non-polar solvation interactions. Free energy calculations also show higher binding affinity at 110 °C than 68 °C, indicating that elevated temperatures are essential to facilitate hydrophobic interactions between the peptidoglycan component and the N-lobe of apo-lactoferrin. Furthermore, the secondary structure and the antibacterial regions in apo-lactoferrin are maintained following thermal simulations. The simulations not only highlight the formation of a stable complex, involving the peptidoglycan component, apo-lactoferrin, β-lactoglobulin, and α-lactalbumin, but also the preservation of the functionalities of apo-lactoferrin, which may provide valuable insights into the development of novel nutraceuticals.

This study employs computational techniques to investigate whether the inclusion of β-lactoglobulin and α-lactalbumin can enhance the molecular stability of apo-lactoferrin in conditions of gastric pH. Atomistic molecular dynamics simulations reveal that acidic pH results in weakened interactions between lactoferrin and the other proteins compared to those under neutral pH. Nevertheless, protein-protein dissociation free energy calculations using the umbrella sampling calculations confirm that some contacts are maintained between apo-lactoferrin and the other whey proteins, specifically the β-lactoglobulin units. This is manifested as a broad energy minimum at the intermediate inter-molecular distance of the inter-protein free energy profiles; thereby, demonstrating the formation of a nano-scale flocculant, followed by a potential gel, composed of protein particles. Practically, this property could be exploited to entrap further bioactive components within the protein matrix for novel engineered food materials. Furthermore, it was found that the anti-bacterial peptide regions of apo-lactoferrin are unaffected by the acidic pH, indicating the potential capability of apo-lactoferrin to act against harmful bacteria. Overall, this work unveils an understanding at a molecular level regarding the structural changes of the aforementioned proteins that maybe beneficial for future advancement of nutraceuticals.

This study optimises a protocol for the estimation of α-amylase activity in a condensed starch matrix in the vicinity of the glass transition region. Enzymatic activity on the vitrified starch system was compared with that of a reference substrate, maltodextrin. The activity was assayed as the rate of release of reducing sugar using a dinitrosalicylic acid procedure. The condensed carbohydrate matrices served the dual purpose of acting as a substrate as well as producing a pronounced effect on the ability to enzymatic hydrolysis. Activation energies were estimated throughout the glass transition region of condensed carbohydrate preparations based on the concept of the spectroscopic shift factor. Results were used to demonstrate a considerable moderation by the mechanical glass transition temperature, beyond the expected linear effect of the temperature dependence, on the reaction rate of starch hydrolysis by α-amylase in comparison with the low-molecular weight chain of maltodextrin.

Preharvest sprouting of grains causes significant losses to growers and buyers. The problem occurs throughout the world, and economic losses can be millions of dollars. Visual assessment of germination is ineffective because even grains showing no external signs (e.g., having a visible shoot) may still have germinated sufficiently so that it is no longer possible for high-quality products to be made from them. Current procedures to determine whether a grain has germinated are based around measuring enzyme or starch levels. However, despite protracted efforts to develop enhanced ways to measure germination over the last 50 years, there are currently no sufficiently accurate or reliable approaches available. The present work assesses the potential for infrared spectroscopy-based metabolomic profiling to assess the germination of barley and wheat. The results indicate that mid- and near-infrared spectroscopy are able to determine if the grain has germinated and give an indication of how long the germination ...

Lactobacillus plantarum A17 was encapsulated in a series of matrices of whey protein isolate (WPI) formulated with varying degrees of denaturation induced either by acid or heat treatment prior. Zeta potential measurements were used to study the complexation of WPI and the bacteria at different pH values. Whey protein capsules obtained at pH 7 (native) and 4 as well as those at pH 7 but with heat treatment at 75 °C for 1 min or 78 °C for 10 min showed survival rates during spray drying of 69.0, 39.3, 40.3 and 25.0% respectively. Significantly higher survival of cells was observed in the matrix of native WPI where the protein structure was more compact and globular. After exposure to acid at pH 4, the survival of A17 was reduced to ∼39%. It appears that a lower degree of protein denaturation before spray drying as characterized by Micro-DSC benefits the survival of A17 during encapsulation. In addition, spray drying conditions (outlet temperature of ∼70 °C) did not contribute significantly to further denaturation of the WPI matrix. A unique layer-by-layer electrostatic mechanism involved in encapsulation of A17 at pH 7 was found responsible for higher survival of these cells.

There has been increasing interest in lactoferrin as a bioactive compound from milk, as it functions as an antimicrobial and also in delivering iron. Despite the potential as a food ingredient, the low bioavailability of lactoferrin has limited opportunities for commercialisation. Therefore, protective encapsulation of lactoferrin has been explored as a means of enhancing its bioavailability. In this study, a novel in silico approach was adopted to explore the possibility of employing whey protein components to encapsulate lactoferrin. The most unstable form of the protein, apo-lactoferrin has been studied, particularly interactions with the whey proteins β-lactoglobulin and α-lactalbumin. Temperature conditions that might be encountered during spray drying (95 and 180 °C) have been modelled in order to provide an in-depth understanding of the interactions at the molecular level. The findings indicate that β-lactoglobulin and α-lactalbumin are able to preserve the two antibacterial regions within the apo-lactoferrin structure (lactoferricin and lactoferampin). Intra-molecular residue contact analyses within apo-lactoferrin illustrate the tendency for agglomeration under these temperature conditions, indicating that it is most likely to be readily dispersible during subsequent rehydration. Furthermore, free energy calculations found electrostatic attractions to be the primary mode of interaction between apo-lactoferrin, β-lactoglobulin, and α-lactalbumin. This data is confirmed by a network analysis that demonstrates how interactions amongst apo-lactoferrin, β-lactoglobulin, and α-lactalbumin are predominantly a result of the acidic and basic amino acid residues of the proteins. Overall, this study provides molecular insights in understanding the interactions between lactoferrin with β-lactoglobulin and α-lactalbumin for potential encapsulation strategies via spray drying.

Resistant starch (RS) refers to the portion of starch not digested by human digestive enzymes and not enzymatically degraded into glucose in either the mouth or the small intestine, but is subject to bacterial fermentation within the large intestine. A wide variety of health benefits have been associated with the consumption of RS, including weight management, anticancer properties, and improved kidney function. Currently, there are a number of methods available to measure RS in foods, reflecting a focus on development during the 1990s as more and more health benefits have been discovered. As a result, significant research has been conducted in the past decade dedicated to enhancing RS concentrations in various foods, with efforts to minimize effects on the sensory properties of the food. Being a common staple globally, bread therefore provides a potential medium for RS intake, with studies already showing possible approaches, including fruit and flour supplementation, as well as altering bread-making procedures.

The relative mobility of ascorbic acid incorporated in a condensed matrix of high-methoxy pectin (HMP) and polydextrose is reported. Physicochemical and structural characterisation of the high-solid systems utilised modulated differential scanning calorimetry, small deformation dynamic oscillation in shear, scanning electron microscopy, Fourier transform infrared spectroscopy and wide angle X-ray diffraction. Theoretical modeling of the thermomechanical measurements demonstrated that the mechanism of free volume governs stress relaxation phenomena of the polymeric system through the process of vitrification yielding the mechanical glass transition temperature. Combination of UV-vis spectrophotometry and a vitamin-dye binding method was employed to follow for 60 min the diffusion process of ascorbic acid from the concentrated HMP/polydextrose matrix to the absolute ethanol phase throughout the temperature range of −30 to 20 °C. A relatively low estimate of activation energy for the diffusion of vitamin C reflects its freedom of mobility and high free volume, as compared to the relaxation of the polymeric system that exhibits strong temperature dependence in the glass transition region. Utilisation of the concept of diffusion coefficient sheds further light into the relationship between free volume of the polymeric system and diffusional mobility of the micronutrient.

Diffusion patterns of nicotinic acid were evaluated following its microencapsulation into a whey protein matrix through spray drying. Micro-differential scanning calorimetry, small-deformation rheological techniques, wide-angle X-ray scattering, Fourier transform infrared spectroscopy, particle size analysis and scanning electron microscopy were utilised to characterize encapsulant and bioactive compound in the composite material. UV–vis spectroscopy, the newly introduced concept of spectroscopic shift factor and the Konig reaction were also employed to elucidate the rate of vitamin transport throughout the polymeric matrix as a function of a broad time and temperature spectrum. Mechanical properties of the condensed matrix followed a progression that was described with the combined Williams-Landel-Ferry/free volume theory leading to the prediction of the mechanical glass transition temperature. Modified Arrhenius equation demonstrated that the kinetics of nicotinic-acid mobility were distinct from the structural relaxation of the polymeric segments. The former was further examined using the second law of Fickian diffusion. A direct relationship between fractional free volume of the whey protein network and diffusion coefficient of the nicotinic acid was established within the experimental temperature range.

Resistant starch has potential health benefits but the factors affecting its formation in bread and baked products are not well studied. Here, the formation of resistant starch in wholemeal bread products was evaluated in relation to the processing conditions including fermentation time, temperature and the inclusion of palm oil as a vitamin source. The effects of each the factor were assessed using a full factorial design. The impact on final starch content of traditional sourdough fermentation of wholemeal rye bread, as well as the bulk fermentation process of wheat and wheat/oat blends of wholemeal bread, was also assessed by enzyme assay. Palm oil content was found to have a significant effect on the formation of resistant starch in all of the breads while fermentation time and temperature had no significant impact. Sourdough fermentation of rye bread was found to have a greater impact on resistant starch formation than bulk fermentation of wheat and wheat blend breads, most likely due the increased organic acid content of the sourdough process.

All forms of baking and processing cause a loss of nutrients, including vitamin E, but little is known about these occurrences or if they could be avoided. The objective of this research was to study the incorporation of palm oil and the stability of vitamin E in palm oil during breadmaking. Wheat meal and rye breads were baked with and without the addition of 0, 2, 5, or 8% palm oil. The eight E group vitamers (tocopherols and tocotrienols) were extracted by using accelerated solvent extraction, freeze dried, and then analyzed with normal-phase HPLC. Compared with the controls, the inclusion of palm oil was found to increase the quantity of all forms of vitamin E in the final baked products. It is concluded that palm oil is effective in increasing the vitamin E content of whole grain bread.

Increasingly the number of individuals being diagnosed with some form of sensitivity to the proteins in wheat grains represents a cause for concern. Currently, the treatment is dietary withdrawal of gluten, but commercial gluten-free bread presents some undesirable properties. The objective of this study has been to assess the ability of the enzyme caricain (from papaya latex) to detoxify gliadin in whole wheat flour and develop bread suitable for coeliacs and gluten intolerant individuals. Ion exchange chromatography was used to enrich the caricain in papaya latex and an enzyme-linked immunosorbent assay test kit was used for the analysis of gliadin residues in the baked bread. The partially purified enzyme was found to be more effective in reducing gliadin content than the crude papain and the resultant loaves had acceptable crumb and crust characteristics. Caricain appears to be capable of detoxifying gliadin and has the potential to mitigate the problems confronting coeliacs.

The work dealt with the diffusional mobility of thiamin embedded in a high-solid matrix of κ-carrageenan with glucose syrup. It utilized thermomechanical analysis in the form of modulated differential scanning calorimetry and small-deformation dynamic oscillation in shear, Fourier transform infrared spectroscopy, wide angle X-ray diffraction, scanning electron microscopy and UV-vis spectrophotometry. The structural properties of the matrix were assessed in a temperature induced rubber-to-glass transformation. A thiamin-dye binding assay was employed to monitor the diffusion process of the vitamin from the high-solid preparation to ethylene glycol. The relationship between mechanical properties of the carbohydrate matrix and vitamin mobility was assessed via the application of the combined framework of the free volume theory and the predictions of the reaction rate theory. Results argue that the transport of the micronutrient is governed by the structural relaxation of the high-solid matrix. These were further treated with the concept of Fickian diffusion coefficient to provide the rate of the bioactive compound mobility within the present experimental settings.

The current study evaluates the effect of temperature on α-glucosidase activity, following incorporation of the enzyme into a whey protein matrix through spray drying. Thermomechanical characterization of the matrix was achieved using the techniques of modulated temperature differential scanning calorimetry and small-deformation dynamic mechanical analysis. As the concentration was raised from 75 to 94% (w/w), denaturation of the protein occurred at increasing temperatures. In contrast, denaturation was not observed in calorimetric scans after spray drying. The glass transition temperature (Tg) measured in the dried particles using dynamic mechanical analysis was approximately 40°C. An optimized procedure was developed whereby α-glucosidase and its substrate p-nitrophenyl α-d-glucopyranoside were incorporated into the whey matrix. The effect of temperature on enzymatic catalysis was investigated and, below 40°C, activity was low and relatively independent of temperature. However, the rates of product formation markedly accelerated as temperatures were increased beyond Tg. These novel observations strongly emphasize the pronounced effect of mechanical Tg of the protein matrix on enzymatic activity.

Gluten samples were obtained from two wheat flours with different levels of total protein in the presence or absence of sodium chloride (2% flour base). The dynamic oscillation rheology, large extensional deformation, confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM) and chemical analysis of disulfide bond linkages and the ratio of polymeric glutenins and monomeric gliadins were used to investigate the effect of salt on the structure and rheological properties of gluten. CLSM and TEM images showed that NaCl caused the gluten to form fibrous structure. The presence of NaCl increased non-covalent interactions and β-sheet structure, measured by FTIR, in gluten proteins. The gluten matrix formed with salt resulted in higher tan δ values corresponding to a less elastic network when measured using oscillatory rheometry. Large deformation extensional measurements showed that the maximum force to fracture were lower for the gluten samples prepared in the presence of NaCl. The results from this study indicate that changes in the solvent quality due to the presence of NaCl during dough mixing result in different molecular conformation and network structure of gluten proteins which contributed to the differences in the rheological properties.

Wholegrain bread is generally thought of as being more healthy than white bread due to it having a higher content of dietary fibre, vitamins (especially vitamin B and E) and many important minerals. However, wholegrain bread also contains high levels of phytate (myo-inositolhexakisphosphate, InsP-6) which may bind desirable nutrients, preventing their absorption in the gut and thereby reducing the nutritional value of the end product. In order to evaluate factors influencing phytate levels, the effects of fermentation and selected wholemeal flours from rye, oats and wheat were investigated. Phytate levels were assessed using a spectrophotometric assay based on the measurement of iron with 2,2′-bipyridine. Phytate decreased in freshly ground wholegrain flour dough during the fermentation process with time of fermentation being the most important factor. Fermentation temperature was found to make only a small difference to the process of phytate reduction. Since the potential benefits of wholemeal breads incorporating various grains (e.g. oats and rye) are increasingly evident, this research has important implications for human health.

The objective of this study was to investigate the feasibility of incorporating common buckwheat (Fagopyrum esculentum Moench) into instant noodle formulations. Australian Soft (AS) and Baker's flours were used to evaluate the effects of varying buckwheat contents (0–40%) on noodle quality. The results of texture analysis indicate that noodles made using AS flour produced softer texture whereas there was minimal effect for Baker's flour when buckwheat was incorporated. The colour, measured by L* values, decreased with increased addition of buckwheat for both flours. Fat uptake for noodle samples made from AS flour was only marginally affected, but increased for Baker's flour, when higher levels of buckwheat flour were added. The antioxidant rutin was detected in noodles made from both wheat flours, generally increasing with % buckwheat flour added. These findings indicate that the incorporation of 20% buckwheat into the formulation can be used to enhance the quality of instant noodles.

The effect of varying concentrations of co-solute (polydextrose) on thermomechanical and physicochemical properties of deacylated gellan matrices is presented. Modulated differential scanning calorimetry, micro differential scanning calorimetry, small deformation dynamic oscillation in shear, Fourier transform infrared spectroscopy, wide angle X-ray diffraction and environmental scanning electron microscopy have been used to investigate the structural transformations in aqueous, low-solid and condensed systems. There was a rise in values of storage modulus as the level of co-solute was increased, followed by a significant decline at intermediate concentrations, with high modulus values being regained as more of the co-solute was incorporated. These results confirm the hypothesis of a structural transformation from a highly enthalpic aggregated assembly in the aqueous/low-solid environment to a lightly cross linked polysaccharide network in the high solids regime. Time-temperature superposition (TTS) phenomena observed for amorphous synthetic polymers have been utilised to generate master curves of viscoelasticity, which afforded rationalisation of results on the basis of the free volume theory.

Resistant starch (RS) can form during storage of foods, thereby bestowing a variety of potential health benefits. The purpose of the current study has been to determine the influence of storage temperature and time on the crystallinity and RS content of bread. Loaves of white bread were baked and stored at refrigeration, frozen and room temperatures with analysis over a period of zero to seven days. RS determination and X-ray diffraction (XRD) were used to evaluate the influence of storage temperature and time on total crystallinity and RS content. The rate of starch recrystallisation was affected by storage temperature and time, where refrigeration temperatures accelerated RS formation and total crystallinity more than storage time at both frozen and room temperature. A strong statistical model has been established between RS formation in bread and XRD patterns, having a 96.7% fit indicating the potential of XRD to measure RS concentrations.

The impact of ingredients, pH and cooking on fortification of Asian noodles with vitamin B6 has been investigated. Fortification for three styles of noodle, using pyridoxine hydrochloride, resulted in enhanced levels in the final cooked products. For each, the overall retentions were similar and the varying formulations and processes for each style had relatively little impact on stability of the fortificant. Losses occurred at most stages during processing, including the initial mixing of the doughs. Product pH was not a primary determinant, and the greatest losses were found for steps involving elevated temperatures, particularly deep-frying of instant noodles, as well as boiling of the each of the three styles. Allowance for the total losses of 57–66% would require the incorporation of substantial overages during formulation of Asian noodles.

The objective of this study has been to investigate the effects of two ingredients i) acetylated potato starch (APS) and ii) sodium carboxymethyl cellulose (CMC) on the textural attributes and eating quality of instant noodles. Using low-protein soft wheat flour (Australian Soft) as the base material, samples of noodles incorporating varying proportions of APS and CMC were evaluated for product texture, colour and fat uptake. The variables were studied using a central composite design and textural characteristics were assessed using the TA-XT2, colour by the Minolta Chroma Meter. The results were analyzed by response surface methodology and showed that the two variables enhance the hardness and reduce adhesive values of cooked instant noodles. Electron microscopy also demonstrated the development of a more continuous network structure within the noodles. The addition of CMC had weakened the noodle inner structure and reduced the cohesiveness values of the cooked instant noodles. In contrast, APS provides hardness but does not affect cohesiveness. Marginal observable difference was found in product colour for the various treatment combinations, with a slightly dull appearance, viz less white and less yellow compared with the control. Trials to produce the lowest fat uptake rating indicated that 10% APS was optimal. The results may provide a basis for modifying formulations for use with low-protein soft wheat flours to provide eating quality and colour attributes to meet the preferences of specific customer groups. The conclusion of this study is that the combined use of APS and CMC primarily affects the textural attributes of hardness and adhesiveness rather than the other quality parameters of instant noodle that have been assessed. In addition, APS has the potential to enhance the performance of low-protein soft wheat flours for instant noodle manufacture.

Soy protein isolate (SPI) was modified with glucose (G-) through the amino-carbonyl reaction (Maillard reaction). Solubility and emulsifying properties of the modified proteins were investigated. G-SPI conjugate was highly soluble at a wide range of pH values, while untreated SPI showed limited solubility especially at pH 4-6. Solubility of modified SPI showed the resistance to heat treatment and high ionic strength. Emulsifying activity and emulsion stability of G-SPI conjugate were much higher than those of native SPI. Comparing with some commercial emulsifiers, G-SPI conjugate showed excellent emulsifying properties in high salt concentration and neutral pH. Sodium dodecylsulfate-polyacrylamide gel electrophoresis was also used to confirm the formation of G-SPI conjugate.

Instant fried noodles are typically made from flour of medium protein content. In order to examine the potential application of microbial transglutaminase (MTGase), a low-protein soft wheat flour (Australian Soft) has been used. Trials were carried out to evaluate the effects of varying proportions of three ingredients (MTGase, sodium stearoyl lactylate (SSL) and water) on product texture and colour of instant noodles. The variables were studied using a central composite design. Textural characteristics were assessed using the TA-TX2, colour by the Minolta Chroma meter and the results analysed by response surface methodology. MTGase and SSL enhanced the textural properties of noodles prepared with the low-protein flour and electron microscopy confirmed the enhanced development of structure within the noodles. No significant observable difference was found in noodle colour between the various treatment combinations. MTGase and water had an impact on fat uptake with an inverse relationship between water incorporation and uptake.

Proteins from Brassica sp. were prepared by alkaline extraction followed by acid precipitation. A double-enzyme (As1.398 and Flavourzyme) two-stage hydrolysis was used to hydrolyse Brassica sp. proteins, and the hydrolysates were used to generate meat-like flavourings. The effect of processing conditions on the volatile products generated from the thermal reaction between the protein hydrolysates and other additives was studied. The results indicated that temperature and pH influenced not only the number but also the amount of products. Those with the most favourite flavour and the highest volatile amount were generated at 160 °C, pH 4.0, whereas a burnt odour was produced at 180 °C, pH 8.0. Analysis using response surface methodology showed that the interaction of pH and temperature had a significant influence on the total amount of volatile products (P < 0.01). GC-MS analysis demonstrated that most of the components in the reaction products occur in food flavourings which had been identified in model systems.

In this study, a new system for analysis using a dual comprehensive two-dimensional gas chromatography/targeted multidimensional gas chromatography (switchable GC × GC/targeted MDGC) analysis was developed. The configuration of this system not only permits the independent operation of GC, GC × GC and targeted MDGC analyses in separate analyses, but also allows the mode to be switched from GC × GC to targeted MDGC any number of times through a single analysis. By incorporating a Deans switch microfluidics transfer module prior to a cryotrapping device, the flow stream from the first dimension column can be directed to either one of two second dimension columns in a classical heart-cutting operation. Both second columns pass through the cryotrap to allow solute bands to be focused and then rapidly remobilized to the respective second columns. A short second column enables GC × GC operation, whilst a longer column is used for targeted MDGC. Validation of the system was performed using a standard mixture of compounds relevant to essential oil analysis, and then using compounds present at different abundances in lavender essential oil. Reproducibility of retention times and peak area responses demonstrated that there was negligible variation in the system over the course of multiple heart-cuts, and proved the reliable operation of the system. An application of the system to lavender oil, as a more complex sample, was carried out to affirm system feasibility, and demonstrate the ability of the system to target multiple components in the oil. The system was proposed to be useful for study of aroma-impact compounds where GC × GC can be incorporated with MDGC to permit precise identification of aroma-active compounds, where heart-cut multidimensional GC-olfactometry detection (MDGC-O) is a more appropriate technology for odour assessment.

Protein-lipid interactions in dough have an important impact on the quality of bakery products. Understanding of protein-lipid interactions in gluten can enhance the development of technological solutions to improve the breadmaking quality of flour as well as the functional properties of gluten. In this study, acetic acid at two different concentrations was used for treating and fractionating gluten. The impact of these procedures on the distribution of lipid components was measured. Acetic acid was able to dissociate non-polar lipids from the gluten protein matrix. Upon fractionation monomeric proteins (predominantly gliadins) and phospholipids were high in the 0.01 M acetic acid soluble fraction. The subsequent fractionation step using 0.1 M acetic acid resulted in an increased amount of high-molecular-weight glutenin subunits (HMW-GS) in the soluble fraction, along with more non-polar lipids and glycolipids in both the free and bound lipid extracts. The distribution of lipid classes demonstrates that non-polar lipids are either associated with the glutenin polymeric network through hydrophobic interactions or entrapped within the gluten matrix. The results also indicate that in gluten, glycolipids are likely to be associated with glutenins through both hydrophobic interactions and hydrogen bonds whilst phospholipids preferentially interact with gliadins and lipid binding proteins.

Asian noodle products are a staple food in many countries, representing the end-use of approximately one eighth of all wheat produced globally. Relatively little has been published on the contribution of Asian noodles to dietary intakes of essential nutrients including the B group vitamins. Therefore, the aim of this study has been to investigate the factors influencing the retention of riboflavin in these products. The three most common styles of Asian noodles (white salted, yellow alkaline and instant) have been prepared under controlled laboratory conditions and riboflavin contents measured at each stage of processing. The stability varied markedly between the different styles with losses occurring at each step. Declines ranging from 27% to 38% of the initial riboflavin levels were found in fortified noodles prior to cooking. During boiling at the optimum temperature, further decreases occurred resulting in overall losses of 52-74% of the amounts incorporated into the various formulations. The presence of alkaline salts as ingredients appeared to be the primary factor influencing the extent of losses in the three styles. White salted and instant Asian noodles are effective vehicles for enhancing dietary intakes of riboflavin.

A simple, rapid procedure, using capillary zone electrophoresis (CZE), that can efficiently measure added folic acid in fortified instant fried noodles has been developed and validated. Optimum separation of folic acid was obtained on a 72 cm × 75 μm capillary using 8 mM phosphate-12 mM borate run buffer with 5% MeOH at pH 9.5, temperature of 30 °C and voltage of 28 kV. The extracts were introduced into the capillary via electrokinetic injection and the folic acid monitored at 214 nm. For quantification purposes, nicotinic acid was added as internal standard to all samples. Under these conditions the analysis required approximately 12 min. Good results were obtained for different analytical parameters including linearity, accuracy and precision. The limit of detection was calculated to be 5.3 mg/L. Prior to CZE determination, noodle samples were homogenized in the buffer solution for 1 h followed by treatment with α-amylase solution for 1 h at 65 °C or protease solution for 4 h at 37 °C. The enzyme solution was added at a concentration of 25 mg/L and then adjusted to pH 7.0. Using standard addition to eliminate the effect of sample matrix interference, results showed that a higher and more efficient recovery of added folic acid could be obtained when using α-amylase. During the four main stages of instant fried noodle manufacturing (dough crumbs, cut sheets, steaming and frying) folic acid was found to be stable with recoveries of 96–103%.

The effect of inulin addition on rheology and texture of nonfat yogurt (NFY) was studied by the large (texture analyzer) and small (dynamic oscillatory rheometry) deformation tests. Skim milks (12% solids) were supplemented with three commercial chicory inulins with different chain lengths at 4% level and inoculated with mixed cultures of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. Textural and rheological tests were conducted after an overnight storage at 4C and during a shelf life of 28 days. A good correlation was observed between the two tests. During storage, all inulin-containing yogurts in comparison with the control NFY were characterized by lower values of firmness, apparent viscosity, yield stress, complex viscosity, storage modulus and loss modulus. NFYs supplemented with long-chain inulin demonstrated a rheological behavior closer to that of control full-fat yogurt. PRACTICAL APPLICATIONS The use of inulin and oligofructose in the food industry has grown recently because of their interesting nutritional and technological properties. In the work presented here, three commercial inulin products with different chemical composition and functions were added to yogurt milk, and changes in rheological properties of yogurt were investigated in comparison with nonsupplemented control yogurts. According to the manufacturer's specifications, Raftiline HP and Raftiline GR are suitable for fat replacement because of the presence of long-chain inulins, while Raftilose P95, being rich in mono- and disaccharides, is highly recommended for sugar replacement. The knowledge obtained from this study may be applied for the development of nonfat yogurts to satisfy the nutritional expectations of ever-increasing health conscious consumers and at the same time to match the sensory and textural characteristics of full-fat yogurt.

A single enzyme treatment with alpha-amylase, prior to the quantification of added folic acid (FA) in fortified instant fried Asian noodles with analysis performed by capillary zone electrophoresis (CZE) and reversed-phase high performance liquid chromatography (RP-HPLC) with UV detection, is described. The method was validated and optimized for capillary electrophoresis (CE) with separation achieved using a 8 mM phosphate-12 mM borate run buffer with 5% MeOH at pH 9.5. FA was well separated from matrix components with nicotinic acid (NA) employed as an internal standard. In a comparative study, separation of FA was performed using HPLC with a mobile phase consisting of 27% MeOH (v/v) in aqueous potassium phosphate buffer (3.5 mM KH(2)PO(4) and 3.2 mM K(2)HPO(4)), pH 8.5, and containing 5 mM tetrabutylammonium dihydrogen phosphate as an ion-pairing agent. For both methods, excellent results were obtained for various analytical parameters including linearity, accuracy and precision. The limit of detection was calculated to be 2.2 mg/L for CE without sample stacking and 0.10 mg/L with high performance liquid chromatography (HPLC). Sample extraction involved homogenization and enzymatic extraction with alpha-amylase. Results indicated that FA was stable during four main stages of instant fried noodle manufacturing (dough crumbs, cut sheets, steaming and frying).

Different anion salts from the Hofmeister series were used to investigate their effects on gluten network formation. The effects of these anion salts on the mixing properties of the dough and the rheological and chemical properties of gluten samples extracted from the dough with these respective salts were compared. The aim of this work was to determine how different anion salts influence the formation of the gluten structure during dough mixing. It was found that the Hofmeister anion salts affected the gluten network formation by interacting directly with specific amino acid residues that resulted in changes in gluten protein composition, specifically the percentage of the unextractable polymeric protein fractions (%UPP). These changes consequently led to remarkable differences in the mixing profiles and microstructural features of the dough, small deformation rheological properties of the gluten and a strain hardening behaviour of both dough and gluten samples.

Cereal based foods, including Asian noodles which represent the end use of at least one-eighth of global wheat production, are potentially good sources of thiamine. However, there is a lack of data on the stability of thiamine during processing. The aim of this study was to investigate the thiamine contents of three styles of Asian noodle products: white salted, yellow alkaline and instant. A standard method of analysis (Association of Official Analytical Chemists (AOAC), method number 953.17) was used to determine the thiamine content of noodles before and after cooking. Factors influencing thiamine stability were also investigated. The results showed that Asian noodles include products which vary significantly in formulation and are manufactured by distinct processes. pH levels were highest in yellow alkaline and lowest in white salted style. White salted noodles have higher thiamine levels although there is clearly variation between individual samples for each style of product. For most samples, thiamine levels were relatively low and considerable losses occurred during cooking. Thiamine values were particularly low for samples where alkaline salts were incorporated during manufacture. It is concluded that greater losses occur where higher pH values were observed and there is considerable variation in the thiamine content of Asian noodles.

This article reviews the applications of CE that are relevant to the analysis of small molecules in foods. CE has been applied to a wide range of important areas of food analysis and is rapidly being established as an alternative technique to chromatographic methods including HPLC and GC within analytical food and research laboratories. In recent years the analysis of food by CE has become more frequent and important and as such a variety of compounds have been separated and quantified. Although many other analytes have been detected by CE, this review will highlight areas relating primarily to the rather broad chemical classes of free amino acids, carbohydrates, organic acids, vitamins and a variety of antioxidants. In addition, information relating to the analyte, sample matrix, mode of CE employed, scope of the methodology and the detection and derivatization of the small molecules are considered and discussed.

Asian noodles, a widely consumed staple food, were evaluated as potential vehicles for fortification with folic acid. Samples of white salted, yellow alkaline, and instant noodles, prepared under controlled laboratory conditions, were fortified and folates were measured at each stage of processing using a microbiological assay. Although the 3 styles showed differing patterns of retention, overall losses were slightly more than 40% and were similar for all styles. White salted and yellow alkaline noodles showed no significant decrease in total folate content during production. In contrast, significant losses occurred for instant noodles during steaming and deep-frying of the noodle strands. In all cases, substantial losses occurred during subsequent cooking of the dried noodles. Fortification at a rate of 50% of the reference value per serving resulted in retention of folate at levels corresponding to 30% following cooking, whereas unfortified noodles contributed less than 4% per serving. It is concluded that fortifying Asian noodles provides an effective means for enhancing folate intake.

Optimal conditions for fructan precipitation from Jerusalem artichoke concentrate by adding ethanol were established by response surface methodology. The combination of the starting syrup concentration (9.9-40°B), ethanol-to-syrup (E/S) ratio (2.3:1-15.7:1) and precipitation temperature (3.1-62 °C) was varied at design points of a central composite rotatable design. Significant regression models describing the changes of average chain length, fructan precipitation yield and purity value of fructans were developed with the coefficient of determination greater than 0.8. The results suggested that higher syrup concentration resulted in an increased fructan yield, but further increase in concentration had a reverse effect on average chain length and purity values. The optimum conditions for fractionating fructan composition by ethanol were estimated to be 32 °B initial syrup concentration, E/S ratio of 13 and temperature of 42 °C.

Asian styles of noodle products represent the end-use of at least one eighth of all wheat produced globally and are potentially a good dietary source of essential nutrients. In order to investigate the factors influencing thiamin content, three styles of noodles were made under controlled laboratory conditions. The losses during preparation of dried white salted noodles were low. Boiling of these noodles resulted in a 43% decline in total thiamin level. In contrast, the relative losses of thiamin were high for yellow alkaline noodles and these occurred at each step in the process including dough mixing and drying. For instant noodles decreases also occurred at each step and these were smaller than for yellow alkaline but greater than for white salted noodles. The variation in ingredients and processing accounts at least partially for differences in thiamin levels of different noodle styles.

Enriched caricain was able to detoxify a major proportion of the gliadin in wholemeal wheat dough by allowing it to react for 5h at 37 °C during the fermentation stage. A reduction of 82% in toxicity, as determined by the rat-liver lysosome assay, was achieved using 0.03% enzyme on weight of dough. Without enzyme, only 26% reduction occurred. The difference in reduction of toxicity achieved is statistically significant (p < 0.01). The results are very similar to those obtained in our previous work using an immuno assay and the same enzyme preparation. They confirm the value of caricain as a means of reducing the toxicity of gliadin and open the way for enzyme therapy as an adjunct to the gluten free diet. This approach should lead to better control over the elimination of dietary gluten intake in conditions such as coeliac disease and dermatitis herpetiformis.

The consumer acceptance of white salted Asian noodles depends on starch characteristics, and the purpose of this study has been to investigate the potential of exogenous α-amylases to enhance textural characteristics of this product. Noodles were prepared from commercial flours with low α-amylase activity, and the endogenous enzyme remained relatively stable during various processing and storage treatments. α-Amylase preparations of bacterial origin and from barley malt were incorporated, and the products were assessed by texture analysis and electron microscopy, as well as for color characteristics. On addition of the amylase preparations, noodles were softer when texture was assessed using either a flat cylinder probe or an axial blade. Some discoloration occurred in treated noodle sheets, although this was minimal in final products that had been cooked immediately after preparation or following drying. Scanning electron microscopy confirmed that the α-amylase of bacterial origin had greater im...

The enzyme lipoxygenase has a number of functions in breadmaking. Although white salted noodles are a staple food in various countries, the significance and potential of lipoxygenase in noodlemaking are less well understood. In these products a bright, uniform appearance is particularly important and so the aim of the present research has been to study the effect of endogenous and exogenous lipoxygenase upon discolouration of white salted noodles as well as on the textural and structural attributes. Similar lipoxygenase levels were recorded in the flours studied and no significant losses of activity were found during noodle manufacture and subsequent storage. Less discolouration occurred in treated noodle sheets compared with control samples. Discolouration happened to a lesser extent when samples were cooked immediately after preparation or drying for both treated and control noodles. Whiter noodle sheets were obtained when a soybean lipoxygenase was added to the formulation. Textural and structural properties of white salted noodles were not adversely affected by enzyme addition, giving firm, elastic and non-sticky products. It is concluded that the incorporation of the lipoxygenase preparation offers prospects for colour enhancement of white salted noodles.