Cornstarch Powder Research Articles

INVESTIGATION OF THE RHEOLOGICAL, NUTRITIONAL, AND SENSORY PROPERTIES OF THE GLUTEN-FREE BREAD PRODUCED FROM RICE, BEAN, AND CHICKPEA FLOUR

In recent years, the demand for gluten-free products has been constantly increasing due to the increase in the number of people suffering from celiac disease. Bread is the main product consumed in our country; therefore, gluten-free bread for celiac patients on the market is mostly of poor quality and low nutritional value, while gluten-free flour has a very high price. The purpose of this work was to investigate the rheological properties of dough, the nutritional value of bread, as well as the sensory properties of gluten-free bread produced from mixtures of raw materials such as rice, chickpea, and bean flour, corn starch, and egg powder. The results showed that the gluten-free bread had different rheological properties, and only mixes M5 and M6 had similar rheological properties, such as dough development, stability, and degree of softening, to the control bread M1. Gluten-free bread from mixtures M2 and M3 had higher contents of protein, fat, cellulose, and minerals, while bread from mixtures M5 and M6 had medium contents. Bread M2 and M3 had acidity levels above the allowed limits which made them unusable or had a short shelf life. Sensory analyses showed that bread M5 had similar sensory properties to the control bread M1 and fell into the same quality category; also, bread from the M5 mixture has a much better taste and aroma. For consumption, we recommend using gluten-free bread from the M5 mixture, which in its composition has 80% rice flour, 7.5% chickpea flour, 5% bean flour, and 7.5% egg powder.

Starch powder in short air contact time: Material moisture change, stickiness and deposition at different air relative humidity and temperature

Starch powder can get sticky and cause deposition in process, resulting in downtime and performance deterioration. Glass transition temperature (Tg) is a key aspect of semi-crystalline material stickiness, being function of material water content, and the surpass of material temperature above Tg is related to its stickiness. During pneumatic transport and process, in short air contact time, powders can exchange heat and water, which might change stickiness. Dairy powders were already assessed on stickiness tests replicating these conditions, but not starches. Potato and corn starch powders are investigated and stickiness, deposition and water content change are measured. Water content changed linearly with relative humidity. Deposition occurred on a plate at high and low air flow velocities and the deposition patterns correlate with the flow velocity profile. Corn starch presented higher stickiness and more deposition. Stickiness can be achieved by the combination of different air temperatures and relative humidities.

Construction of borate-ester-based COFs with high specific surface area for the detection of H2O content in the food field

Excessive H2O content in food will cause the hydrolysis of nutrients and provide a favorable environment for the growth of mycotoxins, thus, developing fast response, low detection limit, and high detection capacity sensors is urgently needed for food quality and safety. In this work, we developed two borate-ester-based covalent organic frameworks (COF-5 and COF-10) with high specific surface areas (1189.0 m2·g−1 and 1105.1 m2·g−1), which exhibited rapid response (COF-5 about 40 s and COF-10 about 35 s), good linearity (COF-5:R2=0.9981 and COF-10:R2=0.9993), and low detection limits (LODCOF-5=0.044 v/v% and LODCOF-10=0.016 v/v%). DFT theoretical calculation demonstrated that H2O participated in the partial hydrolysis of the B-O bond, resulting in the enhancement of fluorescence. Based on the good fluorescence properties, these two probes had been successfully used to quantificationally detect H2O content in honey, corn starch, and milk powder with satisfactory results, indicating an excellent application potential in the food field.

Harnessing fluorescent carbon quantum dots from natural resource for advancing sweat latent fingerprint recognition with machine learning algorithms for enhanced human identification.

Nowadays, it is fascinating to engineer waste biomass into functional valuable nanomaterials. We investigate the production of hetero-atom doped carbon quantum dots (N-S@MCDs) to address the adaptability constraint in green precursors concerning the contents of the green precursors i.e., Tagetes erecta (marigold extract). The successful formation of N-S@MCDs as described has been validated by distinct analytical characterizations. As synthesized N-S@MCDs successfully incorporated on corn-starch powder, providing a nano-carbogenic fingerprint powder composition (N-S@MCDs/corn-starch phosphors). N-S@MCDs imparts astounding color-tunability which enables highly fluorescent fingerprint pattern developed on different non-porous surfaces along with immediate visual enhancement under UV-light, revealing a bright sharp fingerprint, along with long-time preservation of developed fingerprints. The creation and comparison of latent fingerprints (LFPs) are two key research in the recognition and detection of LFPs, respectively. In this work, developed fingerprints are regulated with an artificial intelligence program. The optimum sample has a very high degree of similarity with the standard control, as shown by the program's good matching score (86.94%) for the optimal sample. Hence, our results far outperform the benchmark attained using the conventional method, making the N-S@MCDs/corn-starch phosphors and the digital processing program suitable for use in real-world scenarios.

Insight into the ignition characteristics of dust layers by mechanical friction sparks

Frictional sparks resulting from malfunctions pose a potential hazard for the accidental ignition of combustible materials in the processing industry. Ignition experiments revealed that mechanical friction sparks generated by TC4 titanium alloy, Q235 steel or 304 stainless steel were unable to ignite corn starch, PMMA, or wood powders. However, friction sparks generated by those materials at a pressure of 3.75 N/mm2 and a disc speed of 12 m/s could ignite a cotton fibrous dust layer. The release of frictional sparks is accompanied by energy dissipation. As friction pressure and rotational speed increase, the initial energy of the friction spark increases. Thus, the possibility of igniting the cotton fibrous dust layer increases, while the ignition time decreases. In terms of the ability to ignite the fibrous dust layer under identical friction conditions, the ranking is as follows: TC4 titanium alloy > Q235 steel >304 stainless steel. Moreover, TC4 friction sparks demonstrate weak ignition capability for dust layers with humidity levels of 2% and 10%. The susceptibility of the cotton fibre dust layer to ignition diminishes with increasing humidity. The distinctive flocculation structure of fibrous dust makes it more prone to ignition by mechanical friction sparks compared to traditional spherical dust. These findings imply that when employing metal alloys as mechanical equipment or tools in fibrous processing, the possibility of mechanically generated sparks serving as an ignition source should be taken into account.

Development and Characterization of Bio-Based Composite Films for Food Packing Applications Using Boiled Rice Water and Pistacia vera Shells.

Customer demand for natural packaging materials in the food industry has increased. Biocomposite films developed using boiled rice water could be an eco-friendly and cost-effective packaging product in the future. This study reports the development of bio-based films using waste materials, such as boiled rice water (matrix) and Pistacia vera shells (reinforcement material), using an adapted solution casting method. Several film combinations were developed using various concentrations of plasticizing agent (sorbitol), thickening agent (oil and agar), and stabilizing agents (Arabic gum, corn starch, and Pistacia vera shell powder). Various packaging properties of the film were analyzed and examined to select the best bio-based film for food packaging applications. The film fabricated with Pistacia vera shell powder in the biocomposite film exhibited a reduced water solubility, swelling index, and moisture content, as compared to polyethene packaging material, whereas the biocomposite film exhibited poor antimicrobial properties, high vapor transmission rate, and high biodegradability rate. The packaging properties and characterization of the film indicated that the boiled rice water film with Pistacia vera shell powder was suitable for packaging material applications.

Fracture toughness of hybrid natural fiber/nanoclay reinforced starch biocomposite material

In this paper, fracture toughness of banana fiber reinforced thermoplastic starch (BF_TPS) material was studied. Fiber weight percent (30, 40, and 50 wt.%) to starch polymer was fabricated using hot press at a pressure of 5 MPa of 160°C for 30 min. Experimental result shows that 40 wt.% BF_TPS biocomposite gave optimum tensile strength. Furthermore, nanoclay with varying weight percentage (1–5 wt.%) of dry cornstarch (CS) powder was added to enhance the property of the optimum 40 wt.% BF_TPS biocomposite, hence, forming hybrid clay/BF_TPS biocomposite. Tensile, impact, and fracture mechanics (Mode I fracture test) through Single End Notched Bending (SENB) Test were studied concurrently. Thermal properties and degradations were equally studied through Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). Results show that tensile strength and impact resistance increased to the maximum of 65% and 15.6%, respectively, at 3 wt.% clay addition. Critical stress intensity factor ( K IC) was approximately higher by 276% when compared to neat BF_TPS material. Strain energy release rates ( G IC) values were minimal. Delamination and catastrophic failures occurred with less fiber crack propagation along the crack initiation notches. In TGA, less weight reduction was observed at 3 wt.% clay/BF_TPS material, while a positive shift occurred in DMA tan delta (Tan δ) T g by 30°C. The micrography of the clay-enhanced biocomposites resulted in better bonding interaction between the polymer and fiber.

Evaluating the effect of cow's milk fortified with albumin powder on malnutrition and anthropometric indices in primary-school children with mild-to-moderate underweight: A randomized double-blinded clinical trial.

A proper diet plan is one of the necessary conditions for maintaining the children's health. The aim of this study was to evaluate the effect of consumption of pasteurized cow's milk fortified with albumin protein in primary-school children, in Yasuj, Iran. In this double-blind randomized clinical trial with 12 weeks of duration, 60 children aged 7-13 years, mild to moderate underweight (-1≥ weight-for-age z-score ≥-3), were randomly assigned to control and albumin groups. The albumin group and the control group received 200 cc of milk with 10 g of albumin powder and 200 cc of milk with 10 g of cornstarch powder, respectively. At the beginning and end of the study, food intake and anthropometric indices were measured. After 12 weeks of intervention, none of the anthropometric indices (weight, weight-for-age z-score, body mass index (BMI), BMI-for-age z-score, and waist circumference) showed significant changes as compared to baseline in the control group, but weight-for-age z-score and BMI-for-age z-score showed significant increase as compared to baseline in the albumin group (before: -2.25 ± 0.40, after: -1.98 ± 0.35, P = 0.001 and before: -3.48 ± 0.86, after: -3.06 ± 0.71, P = 0.009, respectively). The comparison of the mean changes between the two groups showed significant difference regarding weight-for-age z-score (control group: -1.70 ± 0.31 in comparison with albumin group: -1.98 ± 0.35, P = 0.002), BMI (control group: 12.08 ± 1.96 in comparison with albumin group: 12.13 ± 1.49, P = 0.03), and BMI-for-age z-score (control group: -3.11 ± 0.91 in comparison with albumin group: -3.06 ± 0.71, P = 0.02). The consumption of albumin powder with milk can improve weight-for-age z-score and BMI-for-age z-score indices in children with mild-to-moderate underweight. Larger controlled interventional studies with longer duration are recommended.

Modulatory Effects of NBF1, an Algal Fiber-Rich Bioformula, on Adiponectin and C-Reactive Protein Levels, and Its Therapeutic Prospects for Metabolic Syndrome and Type-2 Diabetes Patients.

An unhealthy diet can lead to the development of metabolic disorders. C-reactive protein (CRP) has been reported to be an inflammatory component of metabolic disorders. Additionally, reduced adiponectin (APN) levels is known as a predictor of metabolic disorders. We report on the beneficial effects of NBF1, an algal fiber-rich formula, on CRP, APN, and diabetes markers. Additionally, associations between dietary nutrients, CRP, and APN were investigated. A dietary survey that used a brief self-administered diet history questionnaire, a validated 58-item fixed-portion-type questionnaire, and a 4-week placebo-controlled dietary intervention were carried out. The latter consisted of a twice daily intake of 3 g of sujiaonori alga-based powder as a supplement (NBF1, n = 16), whereas the placebo group received the same amount of corn starch powder (n = 15). CRP and APN levels were assayed by ELISA. Clinical cases comprising three subjects with metabolic disorders treated with NBF1, including two type 2 diabetes mellitus patients and one subject with hypercholesterolemia, are also reported. They received 2.1g NBF1 once daily for 12 weeks. Intakes of algal fiber and n-3 PUFA were positively associated with the increase of APN, and n-3PUFA intake was inversely associated with CRP. All cases had improved metabolic health profile.

Starch-based sustainable hydrogel loaded with Crocus sativus petals extract: A new product for wound care

The aim of the present study was to valorize Crocus sativus petals, the main waste deriving from saffron stigma harvesting, as source of bioactive molecules to be used in health field. Three different dry extracts were prepared by eco-friendly methods (maceration and ultrasound bath assisted maceration) using saffron petals as raw material and ethanol 70 % either ethanol 96 % as extraction solvents. A preliminary evaluation of the antioxidant activity (measured by ABTS*+, DPPH* and FRAP) highlighted that the most suitable extraction solvent is represented by ethanol 70 %. By in vitro studies on keratinocytes emerged that the extract obtained by maceration (rich in gallic and chlorogenic acids) stimulates their growth in a safe concentration range (0.02–0.4 mg/mL) suggesting a potential application in skin diseases such as superficial wounds.Due to the low manageability, the extract was firstly supported on corn starch powder particles and then formulated as starch gel. The obtained formulation showed both suitable rheological properties and spreadability necessary for an easy and pain free application on damaged skin. Moreover, in vitro microbiological studies of starch gel demonstrated antimicrobial activity toward S. epidermidis and self-preserving capacity.

Suitability of electrostatic ignition to determine the explosive characteristics of different types of dust in the 5-L explosion vessel

To reveal the effect of electrostatic ignition on the measurement of different types of dust explosion characteristics. In this study, the explosion characteristics of corn starch, aluminum powder, and hexogen (RDX) were studied in the 5-L explosion vessel using electrostatic and pyrotechnical igniter respectively. The energy release characteristics of these two ignition methods were studied using the schlieren technique. The results showed that the explosion pressures of the three dust clouds measured by electrostatic and pyrotechnical igniter under the same conditions were basically the same. The rate of explosion pressure rise for corn starch and aluminum powder measured by electrostatic ignition was less than that measured by the pyrotechnical igniter. Whereas the opposite was true for RDX. Different ignition methods affect the rate of explosion pressure rise by influencing the time it takes for the flame to propagate from the center of the explosion vessel to its walls.

No Effect of Oral Mecobalamin on Skin Numbness at 3 Months After Total Knee Arthroplasty: A Randomized, Double-Blinded, Placebo-Controlled Superiority Trial.

Background:An area of skin numbness (AON) around an incision commonly occurs following total knee arthroplasty (TKA). Mecobalamin has been shown to facilitate peripheral nerve recovery in various conditions; accordingly, the present study aimed to investigate the ameliorative effect of mecobalamin on AON following TKA, as compared with a placebo.Methods:This superiority study was a double-blinded, randomized controlled trial. All patients undergoing primary TKA were assessed for eligibility. Included patients were randomized to receive either mecobalamin (500 µg, twice daily) or placebo (corn starch powder; 500 µg, twice daily) for 3 months. The primary outcome was the change in the AON around the surgical site from 2 weeks to 3 months after TKA. Secondary outcomes included the rates of different adverse events, functional outcomes, and visual analogue scale patient satisfaction scores.Results:A total of 154 patients were enrolled, with 77 patients each in the mecobalamin and placebo groups. The mean AON among patients in the mecobalamin group was 61.6 cm2 at baseline (2 weeks) and 29.1 cm2 at 3 months, compared with 55.9 cm2 and 33.2 cm2 among patients in the placebo group, respectively. Intention-to-treat analysis showed no significant difference in the change in AON around the surgical site between the 2 groups (mean difference, 7.5; 95% confidence interval, −4.2 to 25.3; p = 0.159). The rates of adverse events, functional outcomes, and visual analogue scale patient satisfaction score were also not significantly different between groups.Conclusions:Mecobalamin did not demonstrate superiority over a placebo in reducing the AON around the surgical site at 3 months after primary TKA.Level of Evidence:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Corn starch biofilm reinforced with orange peel powder: Characterization of physicochemical and mechanical properties

The bio-plastics has been attracted by many countries for the benefit of environment. Starch is a very common polymer that is used as bio-degradable plastic because of its abundance availability and less cost. The aim of this work is to incorporate dry orange peel powder (OPP) with corn starch powder (CSP) in order to enhance properties of biofilms (BFS) prepared interms of mechanical and solubility. Main source of starch used in the current study is corn starch (CS). Five films were prepared by varying the weight % of OPP like 20% (CSOPP20), 30% (CSOPP30), 40% (CSOPP40) and 50% (CSOPP50) and 0% CS (CSO). The physiochemical properties like moisture content, solubility in water and alcohol, absorption of water, biodegradability and mechanical properties like tensile strength and % elongation at break of the prepared film were characterized. The Fourier transform infrared spectroscopy (FTIR) results confirm the interaction between OPP and CS. FTIR peaks at 3200–4000 cm−1, 2925 cm−1, 1210–1320 cm−1, 900–1033 cm−1 and 1075–1155 cm−1 proves the presence of starch, cellulose, OPP, glycerol, vinegar and water, respectively, used for the film preparation. Of all the films, CSOPP40 resulted with highest tensile strength and lowest % elongation at break which corresponded to 1.41 MPa and 11.12% respectively. It was confirmed that the biodegradability was accelerated with the incorporation of OPP in the starch film. The water absorption value, solubility in alcohol, and water was found to be the highest for CSOPP50 film which were 145%, 33.5% and 37%, respectively.

The effects of hot air-dried white button mushroom powder on glycemic indices, lipid profile, inflammatory biomarkers and total antioxidant capacity in patients with type-2 diabetes mellitus: A randomized controlled trial.

Background:The inflammatory and metabolic responses to mushroom in type 2 diabetes mellitus (T2DM) are unknown. The study aimed to evaluate the effect of Hot Air-dried White Button Mushroom (HAD-WBM) powder on glycemic status, lipid profile, inflammatory markers, and total antioxidant capacity (TAC) in T2DM patients.Materials and Methods:This randomized controlled trial was conducted at Golestan Hospital, Ahvaz, Iran. Eligible patients were adults aged 20–50 with Type 2 diabetes. Patients were assigned to each group using a randomized block design with block randomization (n = 22, in each group). Randomization was performed by an assistant and group allocation was blinded for the investigator and participants. The intervention and control groups received 16 g/day HAD-WBM or cornstarch powder for 8 weeks. The primary outcomes of interest were fructosamine, fasting blood sugar (FBS), insulin, homeostatic model assessment for insulin resistance, and secondary outcomes were triglyceride, low-density lipoprotein (LDL), high-density lipoprotein, very-LDL, cholesterol, high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and TAC.Results:After 8 weeks, a significant decrease was observed in fructosamine (−0.228 ± 0.36 vs. 0.03 ± 0.38; P = 0.02) and LDL (−13.05 ± 20.67 vs. 0.81 ± 21.79; P = 0.04) in the HAD-WBM group compared to the control group. No significant changes were observed in fasting insulin and FBS between the two groups. However, a significant within-group reduction (−28.00 ± 42.46; P = 0.006) was observed for FBS in the HAD-WBM group. In the HAD-WBM group, insulin resistance reduced significantly at the end of the study (From 4.92 to 3.81; P = 0.016), but it was not significantly different between the two groups. There was no significant difference in TAC, hs-CRP, and IL-6 between the two groups.Conclusion:Considering the results of this study about the beneficial effects of HAD-WBM on the improvement of glycemic indices and LDL in T2DM patients, it is recommended that HAD-WBM could be used to control T2DM.

Application of SeDeM Expert System in the development of novel directly compressible co-processed excipients via co-processing

BackgroundComputer-aided formulation design is gaining fantastic attention in chemical engineering of high functionality pharmaceutical materials for dosage form manufacture. To accelerate development of novel formulations in a quality-by-design perspective, SeDeM Expert System preformulation algorithm was developed as a tool for the design of solid drug delivery systems and for prediction of direct compression manufacturability of solid formulations. This research aims to integrate SeDeM Expert System into particle engineering design space of co-processing of solid excipients to develop novel composites with optimum direct compression propensity, using corn starch and microcrystalline cellulose powders as model primary excipients.ResultThe data and information generated from the expert system have elucidated the bulk-level characteristics of the primary excipients, enabled computation of the optimum co-processing ratio of the ingredients, and validated the impact of co-processing on material functionality. The experimental flowability (7.78±0.17), compressibility functions (5.16±0.14), parameter profile (0.92), and parametric profile index (6.72±0.27) of the engineered composites, were within the acceptable thresholds. With a reliability constant of 0.961, the net direct compression propensity of the composites expressed as Good Compression Index (6.46±0.26) was superior to that of the primary excipients, but comparable to reference co-processed materials, StarLac® (6.44±0.14) and MicroceLac®100 (6.58±0.03).ConclusionApplication of SeDeM Expert System in particle engineering via co-processing has provided an accelerated upstream proactive mechanism for designing directly compressible co-processed excipients in a quality-by-design fashion. A four-stage systematic methodology of co-processing of solid excipients was postulated. Stage I entails the characterization of CMAs of both defective and corrective excipients, and elucidation of their physicomechanical limitations using SeDeM diagrams. Stage II involves computation of loading capacity of the corrective excipient using dilution potential equation. Stage III entails the selection of co-processing technique based on desired Critical Material Attributes as revealed by the information obtained from Stage I. Stage IV evaluates the impact of co-processing by monitoring the critical behavior of the engineered composites with a decision on either to accept or reject the product.

Development of low-cost biodegradable films from corn starch and date palm pits (Phoenix dactylifera)

This study was conducted to produce a new biodegradable film from easily available and low-cost raw materials by casting method. Corn starch and date pits powder (DPP) in the proportions of 100:0, 90:10, 80:20, 70:30, and 60:40% (w/w) were used. Physical, mechanical, barrier, morphological and antioxidant properties of the developed films were evaluated. The incorporation of DPP increased the thickness, tensile strength, Young's modulus, phenolic compounds, and antioxidant activity of the films, but decreased their swelling index, water solubility, water vapor permeability and elongation capacity. An increase in DPP content decreased the L* values and increased the a*, b*, and ΔE values of the films. SEM images showed that the addition of DPP up to 30% improved the morphological properties of the films. All the developed films were totally biodegradable. This study revealed the potential use of DPP with corn starch for composite biodegradable films formulation.

Chitin increases drying survival of encapsulated Metarhizium pemphigi blastospores for Ixodes ricinus control

Ticks, like Ixodes ricinus, have negative impacts on human and animal health in Germany and worldwide, with almost no specific scientifically proven biological control agent commercially available. Biological control agents containing entomopathogenic fungi present many advantages over chemical acaricides but usually high doses of aerial conidia (1013-1014 conidia/ha) are required to control arthropod pests in the field. A suitable formulation containing nutrients not only makes sensitive blastospores applicable but also functions as a microfermenter to multiply the biomass and thus significantly reduce the required application dosage. For this approach, Metarhizium pemphigi X1c blastospores were encapsulated in calcium alginate beads with granular corn starch or chitin powder as nutrients to ensure formation of aerial conidia on the surface and were then dried. The highest concentration was obtained with moist beads containing chitin (4.68 ± 0.71∙107 conidia∙bead-1). The highest drying survival was also obtained with chitin as the additive (14.7 ± 2.18%). Newly formed aerial conidia of all formulations showed high virulence and caused 100% mortality of I. ricinus nymphs. Altogether, this study paves the way for a lower dose and cost-effective application of blastospores for the control of above ground arthropod pests.

The benefits of latex-free gloves in the operating room environment

Sterile protective gloves are used to reduce the risk of infection for patients and clinicians in all healthcare settings. This is particularly important in operating theatres, where surgical site infection is a common and serious complication for perioperative patients. These gloves have traditionally been made from natural rubber latex and dusted with cornstarch powder. However, frequent use of latex gloves can lead to a hypersensitivity or allergy to latex. A latex allergy causes discomfort and inconvenience, and it may reduce productivity, impose significant financial burdens and even be life threatening. There has not been sufficient evidence to ban the clinical use of latex; however, in cases of suspected latex allergy, guidelines recommend the use of either latex-free gloves or powder-free, low-protein latex gloves. The use of these alternative gloves has typically been limited to cases of allergy, because they have previously been associated with reduced dexterity and durability compared with latex gloves. This article presents four case studies, in which health professionals in a perioperative setting compare the advantages and disadvantages of using traditional latex surgical gloves with those of latex-free gloves manufactured by Cardinal Health. The findings of these case studies suggest that these latex-free gloves are equal to latex gloves in terms of establishing asepsis and providing comfort and dexterity to the wearer, without presenting the risk of developing latex sensitivity and/or allergy.

Low-energy short-term cold atmospheric plasma: Controlling the inactivation efficacy of bacterial spores in powders.

The present research work aims to elucidate kinetics and mechanisms of the inactivation of Bacillus subtilis spores by a surface micro-discharge (SMD) - cold atmospheric pressure plasma (CAPP). Regarding industrial applications, the inactivation of spores was also studied for a static layer of a biopolymer powder or film, with an air plasma and at ambient pressure. Close to 4 log10 cycles of inactivation of Bacillus subtilis spores were achieved when exposing spores on flat glass to the SMD-CAPP. This effect can be reached at a very low plasma power density of 5mW/cm2 in 7min exposure time. The maximum inactivation level of spores drops when treating corn-starch powder to 2.6 log10 cycles at 7mW/cm2 plasma power density for 5min and with a polymer load of 5mg/cm2. Similar is true for films produced with hydroxymethyl cellulose (HMC). The inactivation efficacy can be tuned and is a function of applied surface energy (product of the plasma power density and the exposure time) and the polymer load. Plasma diagnostics reveal the fundamental importance of reactive nitrogen species (RNS) in the inactivation. Etching of spore hull is supposed to be triggered by the plasma density, while UV-C and UV-B radiation do not contribute directly and significantly to the inactivation effect at least in a biopolymer matrix. Fluidization of a fixed powder layer is supposed to overcome limitations of the inactivation efficacy by reducing the diffusion distance of active plasma species between the source and the sample. The combination of low plasma power density with short treatment time is supposed to reduce the risk of the formation of side-products from the matrix.

Quantifying the influence of surface chemical composition on surface energy during powder flow

In this study, the dominant intermolecular interactions at powder surfaces were investigated using inverse gas chromatography. Silica beads coated with molasses, corn starch, butter, or wheat gluten were used as model powders to emulate the interactions of surface components present in common food powders. The flow properties of the powders were analyzed using a rotational shear cell device at ambient conditions (25 °C and 40% relative humidity). A positive correlation (r = 0.72, p < 0.05) between the acid-base ratio (accounting for the ratio between the number of electron acceptor to electron donor surface sites) and the flow factor (flowability indicator, ffc at 1 kPa pre-shear stress) was observed for all the size ranges of surface-modified silica beads and industry-grade powders (modified corn starch and palm oil powders). The results depict the importance of acid-base surface components in understanding the mechanistic influence of pre-load molecular dynamics on the bulk flowability.