Starch Damage Research Articles

Stone Milling versus Roller Milling in Soft Wheat (Part 2): Influence on Nutritional and Technological Quality of Products.

Wholegrain soft wheat flours can be obtained by either roller milling or stone milling. In this paper, we report on the continuation of a study aimed at analysing compositional and technological differences between differently milled wholegrain flours. Eight mixes of soft wheat grains were stone milled and roller milled and the milling products analysed for their phytic acid, lipids composition to determine the presence of trans-fatty acids and damaged starch. A wholegrain flour milled with a laboratory disk mill was also analysed as comparison, as well as seven wholegrain flours purchased on the market. For phytic acid we found that that there is no compositional difference between a stone milled or a roller milled flour if the milling streams are all recombined: the milling streams instead have different amounts of phytic acid which is mainly present in the fine bran and coarse bran. It was not possible to highlight differences in the milling technology due to the presence of trans-fatty acids in the stone milled wholegrain flour whereas it was possible to find that starch damage depended on the milling method with stone milled wholegrain flours having in all cases significantly higher values than the roller milled ones.

Holistic View of Starch Chemistry, Structure and Functionality in Dry Heat-Treated Whole Wheat Kernels and Flour

Heat treatment is used as a pre-processing step to beneficially change the starch properties of wheat flour to enhance its utilisation in the food industry. Heat-treated wheat flour may provide improved eating qualities in final wheat-based products since flour properties predominantly determine the texture and mouthfeel. Dry heat treatment of wheat kernels or milled wheat products involves heat transfer through means of air, a fluidising medium, or radiation—often resulting in moisture loss. Heat treatment leads to changes in the chemical, structural and functional properties of starch in wheat flour by inducing starch damage, altering its molecular order (which influences its crystallinity), pasting properties as well as its retrogradation and staling behaviour. Heat treatment also induces changes in gluten proteins, which may alter the rheological properties of wheat flour. Understanding the relationship between heat transfer, the thermal properties of wheat and the functionality of the resultant flour is of critical importance to obtain the desired extent of alteration of wheat starch properties and enhanced utilisation of the flour. This review paper introduces dry heat treatment methods followed by a critical review of the latest published research on heat-induced changes observed in wheat flour starch chemistry, structure and functionality.

Comparative study on chemical and functional properties of flours produced from selected clones of low and high postharvest physiological deterioration cassava (Manihot esculenta Crantz)

The industrial usage to which flour could be put to is essentially determined by its physical, chemical and functional characteristics. This study compared the chemical and functional properties of high quality cassava flours (HQCFs) produced from low and high postharvest physiological deterioration (PPD) cassava. Wholesome four varieties of Low PPD cassava and one variety of high PPD cassava were processed into HQCFs. The flours were analyzed for chemical and functional properties. Pertinent data generated were analyzed using SPSS 25.0, Duncan multiple range tests was applied to separate significant means. Sugar, starch, amylose, cyanogenic potential, total titratable acidity and total carotenoid ranged from 4.23±0.04-5.10±0.04%, 80.54±0.57-82.30±0.15%, 31.50±0.11-33.62±0.11%, 0.02±0.00-0.51±0.01 mg/kg, 0.04±0.00-0.06±0.01% and 0.34±0.01-3.14±0.06 μg/g. Water absorption, swelling power, solubility, starch damage, oil absorption, least gelation capacity and bulk density ranged from 416.01±2.70-547.56±2.15%, 9.03±0.04-14.02±1.23, 32.63±1.21-53.62±3.31%, 3.08±0.04-3.40±0.07%, 105.19±0.55-120.56±2.06%, 7.00±1.41-13.00±1.41% and 0.53±0.01-0.66±0.01 g/cm3. Low PPD cassava flours studied had relatively higher water absorption, swelling power, starch solubility and high gel strength than flours from high PPD, and could find application in food industry as thickeners and pharmaceutical industry for drug delivery systems.

Data Mining and Application of Decision Tree Modelling on Electrochemical Data Used for Damaged Starch Detection

In this study, unsupervised and supervised machine learning techniques, principal component analysis and classification tree modelling which could be improved with additional input variables were applied on iodine oxidation voltammetric data in order to determine routes and extract information about the electrochemical conditions leading to different damaged starch ratios in flour. For this purpose a database of 3542 observations which was normalized and filtered from outliers was used. It was seen that although it was almost impossible to generalize information or determine correlations from voltammetric data at different conditions, principal component analysis indicate that on platinum electrode UCD values of 16.5 mostly seen at high potentials, optimized decision tree indicate that the impact of variables on UCD values can be ordered as current density > potential > electrode type > KI concentration and give routes to UCD values with high class membership leaf nodes. Therefore machine learning with decision tree modelling could open perspectives for practical and fast prediction of damaged starch ratio which would help food industry to speed up and economize costs for analysis in flour.

Effects of non‐thermal plasma treating wheat kernel on the physicochemical properties of wheat flour and the quality of fresh wet noodles

AbstractThe effects of non‐thermal plasma (NTP) on the physicochemical properties of wheat flour and the quality of fresh wet noodles (FWN) were investigated. The results showed that NTP effectively decreased the total plate count (TPC), yeast and mould count (YMC) and Bacillus spp. in wheat flour. Wet gluten contents and the stability time reached the maximum when treated for 20 s. The viscosity of starch increased significantly after treatment due to the increased of damaged starch. The contents of secondary structure were altered to some extent, which was because that the ordered network structure of gluten protein broken. Furthermore, compared with the control, texture properties of FWN were enhanced significantly at 20 s, and the darkening rate of FWN was greatly inhibited due to the low polyphenol oxidase (PPO) activity. Consequently, the most suitable treatment was 500 W for 20 s, providing a basis for the application of NTP in flour products.

Physicochemical and rheological properties of Australian and Russian wheat flour mill streams

AbstractBackground and objectivesThe physicochemical and rheological properties of flour mill streams obtained from the normal milling process of two wheat types were studied. Flour mill streams from consecutive milling processes (breaking, dividing, and reduction stages) differed in their overall technological functionality.FindingsFor both Australian and Russian wheat types, break streams had higher moisture and ash contents than did reduction streams. Ash content increased with progressively increasing break and reduction streams. Likewise, protein and fat contents increased with successive break streams (B1–B5) and reduction streams (C5 and C6). The results for both wheat types indicate that the progressive milling of break and reduction mill streams led to a marked decrease in flour gluten index. For both wheat types, the reduction flour streams had higher levels of damaged starch than did the break section flour streams. The break section flour streams had a higher α‐amylase activity than did the reduction flour streams.ConclusionsRheological properties illustrated a wide range of dough properties between the different break and reduction streams of Australian and Russian wheat types.Significance and noveltyThe present study was applied on flour mill streams at large‐scale milling. Also, fat content of the investigated mill streams is somewhat novel.

Impact of milling on the functional and physicochemical properties of green lentil and yellow pea flours

AbstractBackground and objectivesPulse flours with different particle sizes are available for food production. The effect of varying milling techniques on the quality characteristics of green lentil (GL) and yellow pea (YP) flours was investigated.FindingsUsing a Ferkar mill (one‐step vertical knife mill) caused wider distribution and bigger particle size in all flours than milling with a roller mill. The highest starch damage (3%), starch content (57%), but lowest protein content (22%) were found in YP break flours produced by roller milling. Foaming stability of pulse flours decreased to 51%–71% after 120 min. Lowest viscosities were determined in Ferkar milled flours during pasting. There was no difference in protein strength of GL flours; however, starch gelatinization was found the highest in Ferkar milled flours. In vitro starch digestibility and in vitro protein digestibility‐corrected amino acid score were not affected from milling type within each pulse type.ConclusionDifferent flour streams and different milling technologies caused changes in various flour characteristics. However, the particle size of roller mill flours was similar in each pulse type.Significance and noveltyThe obtained results are a crucial step in better understanding the functional properties and possible food applications of pulse flours according to different milling streams and particle sizes.

Development of gluten‐free bread using low‐pressure homogenized rice flour supplemented with faba bean flour

AbstractBackground and objectivesLow‐pressure homogenization (30 MPa‐3 passes) applied to long (LRF) and medium (MRF) rice grain flours was tested as physical method for improving gluten‐free breads (GFB) without additives. Rice flours were blended with faba bean flour (FBF) in the ratio 2:1 (w:w).FindingsLow‐pressure homogenization increased damaged starch content of rice flours and decreased the particle size distribution of blends, leading to higher volumes during batters' fermentation. Homogenization treatment improved the GFB texture profile, decreasing hardness and increasing cohesiveness and resilience. The crumb structure, particularly that of GFB from LRF:FBF blends, was greatly improved by the treatment, and better shape (lower width/height ratio) was obtained. No significant differences were found on the hardening rate of stored GFB, when using homogenized rice flours.ConclusionsIn general, long rice homogenized flour revealed the greatest capacity to improve the GFB quality. Low‐pressure homogenization of long or medium rice flour can be an adequate physical treatment to improve breadmaking properties of rice flours.Significance and noveltyThe study confirms the suitability of low‐pressure homogenized LRF and MRF blended with FBF as raw ingredient in GF breadmaking without additives.

Effect of roasted barley flour on lipid metabolism and gut fermentation in mice fed high-fat diets

We investigated the compositional changes in β-glucan and other nutrients in roasted barley flour by comparing them to untreated barley flour. We also examined whether the intake of roasted barley flour improved lipid metabolism and gut fermentation of barley β-glucan using obese mice fed high-fat diets supplemented with cellulose, untreated barley flour, and roasted barley flour. The molecular weight (MW) of β-glucan in roasted barley flour was reduced by approximately 16%–49% when compared to the untreated barley flour, but the content of β-glucan was not changed. Resistant starch and damage starch were increased in the roasted barley flour. Lipid metabolism was improved in C57BL/6J mice fed roasted barley flour when compared to cellulose. Short-chain fatty acids (SCFAs) were also increased in the cecum of mice fed roasted barley flour compared with untreated barley flour. These results indicated that the roasting process of barley grain caused a reduction in the MW of β-glucan, but the improving effects on lipid metabolism was enhanced through a prebiotic action promoted by SCFAs.

PSV-11 The effects of pelleting and extrusion on nutrient composition and protein quality measurements in a variety Canadian pulses

Abstract Alternative forms of protein are an important focus in nutrition. This study sought to compare the effects of pelleting and extrusion on nutrient composition and protein quality measurements of Canadian pulses. Pulses used for the study included: 2 pea variety (Amarillo and dunn), lentils, chickpeas, and faba bean. Ingredients were ground through a 10/64” or a 2/64” screen to create a coarse and fine ground product, respectively. Both coarse and fine ground ingredients were pelleted at 60–65, 70–75, and 80–85 C0. Fine ground ingredients were extruded at three different temperatures (110, 130, 150 C0) and two moisture levels (18 and 22%). Samples were collected for all runs at the beginning, middle, and end of each run for both pelleted and extruded samples. Samples were analyzed for proximate analysis, amino acids including lysinoalanine, total and damaged starch, and total dietary fibre (including insoluble and soluble). Data were analyzed using a mixed model via proc glimmix in SAS, where ingredient, process, grind, temperature, and extrusion moisture were treated as fixed effects with different interactions selected based on model investigated. Crude protein content of whole pulses was highest in faba bean and lowest in the Amarillo pea, with faba bean protein content significantly higher than all other pulses, and lentil protein content significantly higher than Amarillo peas (P < 0.05). All pelleting temperatures, nested within grind, significantly increased crude protein content of all pulses compared to whole pulses (P < 0.05). All extrusion moistures significantly increased crude protein content of all pulses compared to whole pulses (P < 0.05) and moisture/temperature interactions were significantly higher for all pulses compared to whole pulses (P < 0.05). Amino acid comparisons produced similar significant results. This suggests that pelleting and extrusion processing can have a positive impact on protein content of pulses and protein quality measurements in pulses.

Relationships between grain, flour, and dough quality characteristics and solvent retention capacity tests of twelve triticale cultivars and parental species

Relationships amongst solvent retention capacity (SRC) profiles and quality characteristics of triticale cultivars were investigated. Superior triticale grains resulted into flours with preferable quality attributes for baking bread. Standard and supplementary SRC-values exhibited significant correlation with grain, flour, and dough quality. Positive correlations among sucrose-SRC with ash, pentosan, and ferulic acid (FA) contents were significant. The standard SRC-profiles along with metabisulfite-SRC (MBS-SRC) and ethanol-SRC exhibited significant correlation with damaged starch (DS) content. The ethanol-SRC demonstrated strong correlations with water absorption capacity, FA, and Dmax-value alveolab parameter. Triticale flours containing a higher amount of anti-parallel β-sheets and tyrosine exhibited higher lactic acid-SRC (LA-SRC) and gluten-performance-index (GPI). Positive correlations between sodium dodecylsulphate-SRC (SDS-SRC) and anti-parallel β-sheets percentages were noticed. The LA-SRC, GPI, MBS-SRC, SDS-SRC, and SDS+MBS-SRC were positively correlated with SDS-sedimentation, gluten index and negatively to sulfhydryl-groups content. Triticales having higher LA-SRC and MBS-SRC resulted in dough with higher strength and tenacity.

Dental calculus in the industrial age: Human dental calculus in the Post-Medieval period, a case study from industrial Manchester

The analysis of dental calculus (mineralised dental plaque) has become an increasingly important facet of bioarchaeological research. Although microscopic analysis of microdebris entrapped within dental calculus has revealed important insights into the diet, health, and environment of multiple prehistoric populations, relatively few studies have examined the contributions of this approach to more recent historical periods. In this study, we analyze dental calculus from an English Post-Medieval, middle-class urban skeletal assemblage from Manchester, England using light microscopy. We characterize all types of microremains, observing heavily damaged starch and plant material, high quantities of fungal and yeast spores, the presence of wood particles, plant (cotton) and animal (wool) fibres, as well as limited quantities of microcharcoal and burnt debris. We observe the presence of non-native, imported plant products, including New World maize and potentially tapioca starch. We compare our results to similar studies from earlier time periods to reveal the impacts of the significant economic, social and environmental changes occurring during the Industrial period in England, including changes in food processing, food access, food storage, and air quality. We conclude by outlining important methodological considerations for the future study of Post-Medieval dental calculus and propose potential areas of future research.

Assessment of the quality of fresh nixtamalized maize doughs with different degrees of cooking and milling: A comparison of Mixolab and RVA analyses

Fresh nixtamalized maize dough (NMD) is commonly preferred by producers as raw material for the manufacture of a diversity of nixtamalized products. Based on the application, NMD may have different particle size distributions that may limit their analysis by common methods such as RVA. In the present study, we used the Mixolab to analyze fresh NMD produced with three degrees of cooking (undercooked, adequate cooked and overcooked) and milled to produce coarse, intermediate and fine doughs. Results were correlated with starch and tortilla features in order to evaluate the prediction of pregelatinization and starch damage occurring during processing, and with the quality of the final product. RVA was used for comparison purposes. Unlike RVA curves, Mixolab showed defined peak viscosities during heating independently of the milling degree of samples. Moreover, the Mixolab parameters showed strong correlations with the starch thermal properties, crystallinity, starch damage and lixiviated amylose. More correlations were obtained among Mixolab and RVA parameters in relationship with the attributes of tortillas. Results validated that the Mixolab is an efficient and rapid strategy to discern among different cooking degrees of fresh NMD independently of the particle size distribution, and may be useful to predict the quality of tortillas.

The physicochemical and pasting properties of purple corn flour ground by a novel low temperature impact mill

Purple corn flour (PCF) was prepared by a low temperature impact mill (LTIM) with various air classifier speeds (300, 600, 1200 and 1800 rpm). The effects of processing speed on physicochemical and pasting properties of PCF were investigated. Particle size (D[4,3]) of PCF decreased from 442 μm to 35 μm. The color of PCF became redder supported by increased a* values (from 2.12 to 6.90). As compared with untreated sample, the bioactive component content and antioxidant properties of LTIM-treated PCF increased at low speed (300–600 rpm), then kept constant with further increasing speed. Furthermore, LTIM distinctly changed the pasting properties of PCF, which was demonstrated by lower viscosities, pasting temperature, retrogradation tendency. This change was related to decreased particle size, increased damage starch content, improved hydration properties and promoted destruction of crystal and microstructure. The information obtained may enhance the high-value utilization of functionally superfine ingredient in food applications. Industrial relevancePoor palatability and processing characteristics of whole cereal flour limited its utilities in food industries. Superfine grinding is regarded as one of the effective ways to reduce these problems. However, some superfine grinding technology have some problems such as temperature rise and large dust. A low temperature impact mill (LTIM) recently designed overcame the drawbacks. The present research provided information that LTIM was a good method to pulverize cereals and could be used for the manufacture of functionally superfine ingredient.

Effect of Single and Dual Hydrothermal Treatments on the Resistant Starch Content and Physicochemical Properties of Lotus Rhizome Starches.

Heat-moisture treatment (HMT) changed the morphology and the degree of molecular ordering in lotus rhizome (Nelumbo nucifera Gaertn.) starch granules slightly, leading to some detectable cavities or holes near hilum, weaker birefringence and granule agglomeration, accompanied with modified XRD pattern from C- to A-type starch and lower relative crystallinity, particularly for high moisture HMT modification. In contrast, annealing (ANN) showed less impact on granule morphology, XRD pattern and relative crystallinity. All hydrothermal treatment decreased the resistant starch (from about 27.7–35.4% to 2.7–20%), increased the damage starch (from about 0.5–1.6% to 2.4–23.6%) and modified the functional and pasting properties of lotus rhizome starch pronouncedly. An increase in gelatinization temperature but a decrease in transition enthalpy occurred after hydrothermal modification, particularly for hydrothermal modification involved with HMT. HMT-modified starch also showed higher pasting temperature, less pronounced peak viscosity, leading to less significant thixotropic behavior and retrogradation during pasting-gelation process. However, single ANN treatment imparts a higher tendency of retrogradation as compared to native starch. For dual hydrothermally modified samples, the functional properties generally resembled to the behavior of single HMT-modified samples, indicating the pre- or post-ANN modification had less impact on the properties HMT modified lotus rhizome starch.

Ohmic Baking of Gluten-Free Bread: Role of Starch and Flour on Batter Properties

The viscosity of gluten-free (GF) batter significantly influences GF bread quality. This study attempts to understand how the rheological properties of GF batter are affected by the type of starch and the amount of water and how they influence GF bread properties when baked with two methods (conventional oven, ohmic heating). For this purpose, the physical and chemical properties of different starches (corn, wheat, potato, cassava) and GF flours (rice, buckwheat) were evaluated. Rheological behavior of GF batter was not only influenced by the starch:water ratio, but also greatly by the starch source and structure, which influenced its physical properties (e.g., water holding capacity, swelling power, solubility, starch damage, and pasting properties). All batters consistently exhibited shear-thinning and dominant viscous behavior. Between viscosity and ohmic-heated bread properties, a non-linear relationship was observed. Two categories of required water content or viscosity ranges were defined for estimating final GF bread properties: low water content with a viscosity range of 47.12–56.20 Pa·s for B-type starches, and medium water content with a low to medium viscosity range of 2.29–15.86 Pa·s for A-type starches. This finding could be useful for further research to design GF batter viscosities for tailored bread quality.

Effects of wheat flour particle size on flour physicochemical properties and steamed bread quality.

In this study, differently sized particles of wheat flour (from 52.36 μm to 108.89 μm) were obtained by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1 mm) of a heart mill. Results showed that reducing the particle size significantly increased the damaged starch (DS) content. Uniaxial tensile measurement of dough showed that reducing the particle size of wheat flour can effectively increase the maximum tensile resistance, but the extensibility reaches the maximum in samples at medium particle diameter (78 and 66 μm). Additionally, the ratio of dynamic moduli (G″/G′) decreased with a reducing particle size. The results of disulfide bond content, gluten microstructure, showed that finer flour granulation can strengthen the gluten network. The steamed bread (SB) making test showed that SB made from wheat flour of a smaller particle size had a significantly smaller specific volume than that made from a larger particle size. The texture profile analysis showed that with a decrease of wheat flour particle size, the hardness, chewiness of SB increased, the resilience decreased, and there was no significant difference in adhesiveness. Overall, the quality of SB made flour of medium particles (78 μm) is better.

Influence of damaged starch on the properties of rice flour and quality attributes of gluten-free rice bread

The effect of damaged starch (DS) content on rice flour properties and rice bread quality was investigated. Five samples containing different amounts of DS (4%, 6%, 8%, 10% and 12%) were employed without changing particle size. With the DS content increased, the fragments stripped from the surface of starch granules increased, the hydrated starch structure became loose, and the crystallinity of rice flour decreased greatly from 26.24% to 22.11%, concurrent with a decrease in the enthalpy (ΔH). Moreover, the increment of DS content caused a gradual increase in hydration properties of rice flour in cold water, an increase in viscoelastic modulus of rice batter and overall decrease in pasting viscosity. Rice bread of good appearance in terms of higher specific volume, stronger network structure, relatively soft bread texture and porous cell structure was obtained in rice flour with less DS content. Finally, it could be concluded that rice flour with 4% and 6% DS content had good flour characteristics and was suitable for gluten-free bread making.

Effect of Starch Damage Degree of Rice Flour on Bread-making Properties and Temporal Changes of Wheat Flour and Rice Flour Blended Bread

Effect of Starch Damage Degree of Rice Flour on Bread-making Properties and Temporal Changes of Wheat Flour and Rice Flour Blended Bread

Physicochemical Properties of Starches from Four Local Varieties of Millet in Nigeria.

Purpose: The study was carried out to evaluate the physico-chemical properties of starches from four local varieties of millet in salad cream production.
 Methodology: Starches were extracted from four varieties of millet, two varieties of pearl millet were used namely Gero and Maiwa (Pennisetum glaucum), Tamba-Finger millet (Eluesine coracona) and Acha-Fonio millet (Digitaria exillis) using dry and wet milling processes for characterization and salad cream production. Standard analytical methods were used in determining the physicochemical properties of the starches.
 Findings: The various starches physical properties, including colour, Amylose, Amylopectin, Starch Damage and Total Starch of millet cultivars were determined, and significant (p < 0.05) differences were observed among them. Values obtained for Amylose and amylopectin ranged from 24.47 to 26.91% and 73.09 to 74.51% respectively. The amount of starch damage varied from 0.08 to 0.10 % while total starch contained in the various samples ranged from 89.74 to 98.42 %. Proximate composition showed no significant difference among the starches in terms of moisture except in the wet milled Acha with 10 %. Ash content of the starches ranged between 0.79 and 9.22 %. Fat was higher in the control sample 10.22 % and lowest in the wet milled Tamba 1.69 %. Significant differences P<0.005 were found in the protein content amongst the various starches extracted, with Wmg having the highest value of 9.26 %. Crude fibre was in the range of 2.37 and 4.50 %. The Resistant starch was highest in Wmt (79.44%) and lowest in Dma (16.90%). Carbohydrate content was less in the control sample Wmc (62.40%) and highest in Wma (75.29%). Functional properties of various starches such as Bulk density ranged from 0.59% to 0.77%. Water absorption capacity of the starches were between 0.35% and 4.80% with Dmm starch having the lowest and Wmg the highest. Oil absorption capacity of starches varied between 2.10g/ml and 2.80g/ml. while swelling power were 0.43 to 0.91% with Dmc starch recording the lowest and Dmg starch the highest. Solubility values ranged from 9.50 to 24.00% with Dmm and Dmg having lowest and highest respectively. Least gelation capacity varied from 6% to 10%. The pasting characteristics of the four different starches were significantly (p < .05) different. Peak viscosity ranged from 2145.5 to 4379.0 RVU while Trough viscosity ranged from 1311.0 to 3190.0 RVU. Breakdown viscosity ranged from 625.5 RVU to 2401.5 RVU. The Final viscosity varied between 2704.5 and 5495.0 RVU. Increase may be attributed to high carbohydrate content in the different starches. Setback viscosity in this study ranged from 1393.5 to 2633.0 RVU. Peak time measured the peak viscosities in minutes of the cooking time of the starches and it ranged from 4.93 min to 6.30 min. Pasting temperature varied between 75.85°C and 88.40°C. Starches produced from the four local Millet varieties can be utilized for making diverse food products to meet the growing demand for starches in the food industries.